AD664KPZ [ADI]

Monolithic 12-Bit Quad DAC; 单片12位四路DAC
AD664KPZ
型号: AD664KPZ
厂家: ADI    ADI
描述:

Monolithic 12-Bit Quad DAC
单片12位四路DAC

文件: 总23页 (文件大小:671K)
中文:  中文翻译
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Monolithic  
12-Bit Quad DAC  
a
AD664  
PIN CONFIGURATIONS  
FEATURES  
Four Complete Voltage Output DACs  
Data Register Readback Feature  
“Reset to Zero” Override  
44-Pin Package  
Multiplying Operation  
Double-Buffered Latches  
Surface Mount and DIP Packages  
MIL-STD-883 Compliant Versions Available  
APPLICATIONS  
Automatic Test Equipment  
Robotics  
Process Control  
Disk Drives  
Instrumentation  
Avionics  
PRODUCT DESCRIPTION  
The AD664 is four complete 12-bit, voltage-output DACs on  
one monolithic IC chip. Each DAC has a double-buffered input  
latch structure and a data readback function. All DAC read and  
write operations occur through a single microprocessor-compatible  
I/O port.  
28-Pin DIP Package  
The I/O port accommodates 4-, 8- or 12-bit parallel words al-  
lowing simple interfacing with a wide variety of microprocessors.  
A reset to zero control pin is provided to allow a user to simulta-  
neously reset all DAC outputs to zero, regardless of the contents  
of the input latch. Any one or all of the DACs may be placed in  
a transparent mode allowing immediate response by the outputs  
to the input data.  
The analog portion of the AD664 consists of four DAC cells,  
four output amplifiers, a control amplifier and switches. Each  
DAC cell is an inverting R-2R type. The output current from  
each DAC is switched to the on-board application resistors and  
output amplifier. The output range of each DAC cell is pro-  
grammed through the digital I/O port and may be set to unipo-  
lar or bipolar range, with a gain of one or two times the reference  
voltage. All DACs are operated from a single external reference.  
4. The asynchronous RESET control returns all D/A outputs  
to zero volts.  
5. DAC-to-DAC matching performance is specified and tested.  
The functional completeness of the AD664 results from the  
combination of Analog Devices’ BiMOS II process, laser-trimmed  
thin-film resistors and double-level metal interconnects.  
6. Linearity error is specified to be 1/2 LSB at room tempera-  
ture and 3/4 LSB maximum for the K, B and T grades.  
7. DAC performance is guaranteed to be monotonic over the  
full operating temperature range.  
PRODUCT HIGHLIGHTS  
1. The AD664 provides four voltage-output DACs on one chip  
offering the highest density 12-bit D/A function available.  
8. Readback buffers have tristate outputs.  
9. Multiplying-mode operation allows use with fixed or vari-  
able, positive or negative external references.  
2. The output range of each DAC is fully and independently  
programmable.  
10. The AD664 is available in versions compliant with MIL-  
STD-883. Refer to the Analog Devices Military Products  
Databook or current AD664/883B data sheet for detailed  
specifications.  
3. Readback capability allows verification of contents of the in-  
ternal data registers.  
D
REV.  
Information furnished by Analog Devices is believed to be accurate and  
reliable. However, no responsibility is assumed by Analog Devices for its  
use, nor for any infringements of patents or other rights of third parties  
which may result from its use. No license is granted by implication or  
otherwise under any patent or patent rights of Analog Devices.  
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.  
781/329-4700  
781/461-3113  
Fax:  
Tel:  
(VLL = +5 V, VCC = +15 V, VEE = –15 V, VREF = +10 V, TA = +25؇C  
unless otherwise noted)  
AD664–SPECIFICATIONS  
Model  
JN/JP/AD/AJ/SD  
KN/KP/BD/BJ/BE/TD/TE  
Min  
Typ  
Max  
Min  
Typ  
Max  
Units  
RESOLUTION  
12  
12  
*
*
Bits  
ANALOG OUTPUT  
Voltage Range1  
UNI Versions  
BIP Versions  
Output Current  
Load Resistance  
Load Capacitance  
Short-Circuit Current  
0
VCC – 2.02  
VCC – 2.02  
*
*
*
*
*
Volts  
Volts  
mA  
kΩ  
pF  
mA  
VEE + 2.02  
5
2
*
*
500  
40  
*
*
25  
ACCURACY  
Gain Error  
–7  
–2  
–3  
–3/4  
–1  
±3  
7
2
3
3/4  
1
–5  
–1  
–2  
–1/2  
–3/4  
–1/2  
±2  
5
1
2
1/2  
3/4  
1/2  
LSB  
LSB  
LSB  
LSB  
LSB  
LSB  
Unipolar Offset  
±1/2  
±3/4  
±1/2  
±3/4  
±1/4  
±1/2  
±1/4  
±1/2  
Bipolar Zero3  
Linearity Error4  
Linearity TMIN to TMAX  
Differential Linearity  
Differential Linearity TMIN to TMAX  
Gain Error Drift  
–3/4  
3/4  
Monotonic @ All Temperatures  
Monotonic @ All Temperatures  
Unipolar 0 V to +10 V Mode  
Bipolar –5 V to +5 V Mode  
Bipolar –10 V to +10 V Mode  
Unipolar Offset Drift  
Unipolar 0 V to +10 V Mode  
Bipolar Zero Drift  
–12  
–12  
–12  
±7  
±7  
±7  
12  
12  
12  
–10  
–10  
–10  
±5  
±5  
±5  
10  
10  
10  
ppm of FSR5/°C  
ppm of FSR/°C  
ppm of FSR/°C  
–3  
±l.5  
3
–2  
±l  
2
ppm of FSR/°C  
Bipolar –5 V to +5 V Mode  
Bipolar –10 V to +10 V Mode  
–12  
–12  
±7  
±7  
12  
12  
–10  
–10  
±5  
±5  
10  
10  
ppm of FSR/°C  
ppm of FSR/°C  
REFERENCE INPUT  
Input Resistance  
1.3  
2. 6  
*
*
*
*
kΩ  
Volts  
Voltage Range6  
VEE + 2.02  
VCC – 2.02  
POWER REOUIREMENTS  
VLL  
ILL  
4.5  
5.0  
5.5  
*
*
*
*
Volts  
@ VIH, VIL = 5 V, 0 V  
@ VIH, VIL = 2.4 V, 0.4 V  
VCC /VEE  
ICC  
IEE  
0.1  
3
1
6
*
*
*
*
*
*
*
*
mA  
mA  
Volts  
mA  
mA  
؎11.4  
؎16.5  
15  
19  
12  
15  
400  
*
*
*
Total Power  
525  
mW  
ANALOG GROUND CURRENT7  
–600  
±400  
+600  
*
*
*
µA  
MATCHING PERFORMANCE  
Gain8  
–6  
–2  
–3  
–1.5  
±3  
±1/2  
±1  
6
2
3
1.5  
–4  
–1  
–2  
–1  
±2  
±1/4  
±1  
4
1
2
1
LSB  
LSB  
LSB  
LSB  
Offset9  
Bipolar Zero10  
Linearity11  
±1/2  
±1/2  
CROSSTALK  
Analog  
Digital  
–90  
–60  
*
*
dB  
dB  
DYNAMIC PERFORMANCE (RL = 2 k, CL = 500 pF)  
Settling Time to ±1/2 LSB  
OffBitsOn, GAIN = 1, VREF = 10  
Settling Time to ±1/2 LSB  
–10VREF 10 V, GAIN = 1, Bits On  
Glitch Impulse  
8
10  
*
*
*
*
µs  
10  
µs  
nV-sec  
500  
MULTIPLYING MODE PERFORMANCE  
Reference Feedthrough @ 1 kHz  
Reference –3 dB Bandwidth  
–75  
70  
*
*
dB  
kHz  
POWER SUPPLY GAIN SENSITIVITY  
11.4 VVCC16.5 V  
–16.5 VVEE–11.4 V  
±2  
±2  
±2  
؎5  
؎5  
؎5  
*
*
*
*
*
*
ppm/%  
ppm/%  
ppm/%  
4.5 VVLL5.5 V  
D
–2–  
REV.  
AD664  
Model  
JN/JP/AD/AJ/SD  
KN/KP/BD/BJ/BE/TD/TE  
Min  
Typ  
Max  
Min  
Typ  
Max  
Units  
DIGITAL INPUTS  
VIH  
VIL  
2.0  
0
*
*
Volts  
Volts  
0.8  
*
Data Inputs  
IIH @ VIN = VLL  
IIL @ VIN = DGND  
CS/DS0/DS1/RST/RD/LS  
IIH @ VIN = VLL  
IIL @ VIN = VLL  
MS/TR12  
–10  
–10  
±1  
±1  
10  
10  
*
*
*
*
*
*
µA  
µA  
–10  
–10  
±1  
±1  
10  
10  
*
*
*
*
*
*
µA  
µA  
IIH @ VIN = VLL  
IIL @ VIN = DGND  
QS0/QSl/QS2 l2  
IIH @ VIN = VLL  
IIL @ VIN = DGND  
–10  
–10  
5
–5  
10  
0
*
*
*
*
*
*
µA  
µA  
–10  
–10  
5
±1  
10  
10  
*
*
*
*
*
*
µA  
µA  
DIGITAL OUTPUTS  
VOL @ 1.6 mA Sink  
VOH @ 0.5 mA Source  
0.4  
*
Volts  
Volts  
2.4  
*
TEMPERATURE RANGE  
JN/JP/KN/KP  
AD/AJ/BD/BJ/BE  
SD/TD/TE  
0
40  
–55  
+70  
+85  
+125  
*
*
*
*
*
*
°C  
°C  
°C  
NOTES  
1A minimum power supply of ±12.0 V is required for 0 V to +10 V and ±10 V operation. A minimum power supply of ±11.4 V is required for –5 V to +5 V operation.  
2For VCC < +12 V and VEE > –12 V. Voltage not to exeeed 10 V maximum.  
3Bipolar zero error is the difference from the ideal output (0 volts) and the actual output voltage with code 100 000 000 000 applied to the inputs.  
4Linearity error is defined as the maximum deviation of the actual DAC output from the ideal output (a straight line drawn from 0 to F.S. – 1 LSB).  
5FSR means Full-Scale Range and is 20 V for ±10 V range and 10 V for ±5 V range.  
6A minimum power supply of ±12.0 V is required for a 10 V reference voltage.  
7Analog Ground Current is input code dependent.  
8Gain error matching is the largest difference in gain error between any two DACs in one package.  
9Offset error matching is the largest difference in offset error between any two DACs in one package.  
10Bipolar zero error matching is the largest difference in bipolar zero error between any two DACs in one package.  
11Linearity error matching is the difference in the worst ease linearity error between any two DACs in one package.  
1244-pin versions only.  
*Specifications same as JN/JP/AD/AJ/SD.  
Specifications subject to change without notice.  
Specifications shown in boldface are tested on all production units at final electrical test. Results from those tests are used to calculate outgoing quality levels. All min  
and max specifications are guaranteed, although only those shown in boldface are tested on all production units.  
ABSOLUTE MAXIMUM RATINGS*  
VLL to DGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 V to +7 V  
Digital Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +7 V  
Analog Outputs . . . . . . . . . . . . . . . . . . . . . Indefinite Shorts to  
V
V
CC to DGND . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 V to +18 V  
EE to DGND . . . . . . . . . . . . . . . . . . . . . . . . . . . –18 V to 0 V  
VCC, VLL, VEE and GND  
*Stresses above those listed under “Absolute Maximum Ratings” may cause  
permanent damage to the device. This is a stress rating only and functional  
operation of the device at these or any other conditions above those indicated in the  
operational section of this specification is not implied. Exposure to absolute  
maximum rating conditions for extended periods may affect device reliability.  
Soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +300°C, 10 sec  
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . 1000 mW  
AGND to DGND . . . . . . . . . . . . . . . . . . . . . . . . –1 V to +1 V  
Reference Input . . . . . . . . . . . . . . . . . . VREF ±10 V and VREF  
(VCC – 2 V, VEE + 2 V)  
V
CC to VEE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to +36 V  
CAUTION  
ESD (electrostatic discharge) sensitive device. Unused devices must be stored in conductive foam  
or shunts. The protective foam should be discharged to the destination socket before devices are  
removed.  
WARNING!  
ESD SENSITIVE DEVICE  
D
REV.  
–3–  
AD664  
Figure 1a. 44-Pin Block Diagram  
FUNCTIONAL DESCRIPTION  
tions. This register may also be read back to check its contents.  
A RESET-TO-ZERO feature allows all DACs to be reset to 0  
volts out by strobing a single pin.  
The AD664 combines four complete 12-bit voltage output D/A  
converters with a fast, flexible digital input/output port on one  
monolithic chip. It is available in two forms, a 44-pin version  
shown in Figure 1a and a 28-pin version shown in Figure 1b.  
44-Pin Versions  
Each DAC offers flexibility, accuracy and good dynamic perfor-  
mance. The R-2R structure is fabricated from thin-film resistors  
which are laser-trimmed to achieve 1/2 LSB linearity and guar-  
anteed monotonicity. The output amplifier combines the best  
features of the bipolar and MOS devices to achieve good dy-  
namic performance and low offset. Settling time is under 10 µs  
and each output can drive a 5 mA, 500 pF load. Short-circuit  
protection allows indefinite shorts to VLL, VCC, VEE and GND.  
The output and span resistor pins are available separately. This  
feature allows a user to insert current-boosting elements to in-  
crease the drive capability of the system, as well as to overcome  
parasitics.  
Digital circuitry is implemented in CMOS logic. The fast, low  
power, digital interface allows the AD664 to be interfaced with  
most microprocessors. Through this interface, the wide variety  
of features on each chip may be accessed. For example, the in-  
put data for each DAC is programmed by way of 4-, 8-, 12- or  
16-bit words. The double-buffered input structure of this latch  
allows all four DACs to be updated simultaneously. A readback  
feature allows the internal registers to be read back through the  
same digital port, as either 4-, 8- or 12-bit words. When dis-  
abled, the readback drivers are placed in a high impedance  
(tristate) mode. A TRANSPARENT mode allows the input data  
to pass straight through both ranks of input registers and appear  
at the DAC with a minimum of delay. One D/A may be placed  
in the transparent mode at a time, or all four may be made  
transparent at once. The MODE SELECT feature allows the  
output range and mode of the DACs to be selected via the data  
bus inputs. An internal mode select register stores the selec-  
Figure 1b. 28-Pin Block Diagram  
28-Pin Versions  
The 28-pin versions are dedicated versions of the 44-pin  
AD664. Each offers a reduced set of features from those offered  
in the 44-pin version. This accommodates the reduced number  
of package pins available. Data is written and read with 12-bit  
words only. Output range and mode select functions are also  
not available in 28-pin versions. As an alternative, users specify  
either the UNI (unipolar, 0 to VREF) models or the BIP (bipolar,  
–VREF to VREF) models depending on the application require-  
ments. Finally, the transparent mode is not available on the  
28-pin versions.  
D
REV.  
–4–  
AD664  
Table I. Transfer Functions  
Mode = UNI  
Mode = BIP  
000000000000 = 0 V  
Gain = 1 100000000000 = VREF/2  
111111111111 = VREF – 1 LSB  
000000000000 = – VREF/2  
100000000000 = 0 V  
111111111111 = VREF/2 –1 LSB  
000000000000 = 0 V  
Gain = 2 100000000000 = VREF  
111111111111 = 2 × VREF – 1 LSB  
000000000000 = VREF  
100000000000 = 0 V  
111111111111 = +VREF – 1 LSB  
DEFINITIONS OF SPECIFICATIONS  
UNIPOLAR OFFSET ERROR: Unipolar offset error is the dif-  
ference between the ideal output (0 V) and the actual output of  
a DAC when the input is loaded with all “0s” and the MODE is  
unipolar.  
LINEARITY ERROR: Analog Devices defines linearity error as  
the maximum deviation of the actual, adjusted DAC output  
from the ideal analog output (a straight line drawn from 0 to FS  
– 1 LSB) for any bit combination. This is also referred to as  
relative accuracy. The AD664 is laser-trimmed to typically  
maintain linearity errors at less than ±1/4 LSB.  
BIPOLAR ZERO ERROR: Bipolar zero error is the difference  
between the ideal output (0 V) and the actual output of a DAC  
when the input code is loaded with the MSB = “1” and the rest  
of the bits = “0” and the MODE is bipolar.  
MONOTONICITY: A DAC is said to be monotonic if the out-  
put either increases or remains constant for increasing digital  
inputs such that the output will always be a nondecreasing func-  
tion of input. All versions of the AD664 are monotonic over  
their full operating temperature range.  
SETTLING TIME: Settling time is the time required for the  
output to reach and remain within a specified error band about  
its final value, measured from the digital input transition.  
CROSSTALK: Crosstalk is the change in an output caused by  
a change in one or more of the other outputs. It is due to  
capacitive and thermal coupling between outputs.  
DIFFERENTIAL LINEARITY: Monotonic behavior requires  
that the differential linearity error be less than 1 LSB both at  
25°C as well as over the temperature range of interest. Differen-  
tial nonlinearity is the measure of the variation in analog value,  
normalized to full scale, associated with a 1 LSB change in digi-  
tal input code. For example, for a 10 V full-scale output, a  
change of 1 LSB in digital input code should result in a  
2.44 mV change in the analog output (VREF = 10 V, Gain = 1,  
1 LSB = 10 V × 1/4096 = 2.44 mV). If in actual use, however, a  
1 LSB change in the input code results in a change of only  
0.61 mV (1/4 LSB) in analog output, the differential non-  
linearity error would be –1.83 mV, or –3/4 LSB.  
REFERENCE FEEDTHROUGH: The portion of an ac refer-  
ence signal that appears at an output when all input bits are low.  
Feedthrough is due to capacitive coupling between the reference  
input and the output. It is specified in decibels at a particular  
frequency.  
REFERENCE 3 dB BANDWIDTH: The frequency of the ac  
reference input signal at which the amplitude of the full-scale  
output response falls 3 dB from the ideal response.  
GLITCH IMPULSE: Glitch impulse is an undesired output  
voltage transient caused by asymmetrical switching times in the  
switches of a DAC. These transients are specified by their net  
area (in nV-sec) of the voltage vs. time characteristic.  
GAIN ERROR: DAC gain error is a measure of the difference  
between the output span of an ideal DAC and an actual device.  
PIN CONFIGURATIONS  
28-Pin DIP Package  
44-Pin Package  
D
REV.  
–5–  
AD664  
ANALOG CIRCUIT CONSIDERATIONS  
Grounding Recommendations  
greater than both the external reference and the inverted exter-  
nal reference.  
The AD664 has two pins, designated ANALOG and DIGITAL  
ground. The analog ground pin is the “high quality” ground ref-  
erence point for the device. A unique internal design has  
resulted in low analog ground current. This greatly simplifies  
management of ground current and the associated induced volt-  
age drops. The analog ground pin should be connected to the  
analog ground point in the system. The external reference and  
any external loads should also be returned to analog ground.  
Output Considerations  
Each DAC output can source or sink 5 mA of current to an  
external load. Short-circuit protection limits load current to a  
maximum load current of 40 mA. Load capacitance of up to  
500 pF can be accommodated with no effect on stability.  
Should an application require additional output current, a cur-  
rent boosting element can be inserted into the output loop with  
no sacrifice in accuracy. Figure 3 details this method.  
The digital ground pin should be connected to the digital  
ground point in the circuit. This pin returns current from the  
logic portions of the AD664 circuitry to ground.  
Analog and digital grounds should be connected at one point in  
the system. If there is a possibility that this connection be bro-  
ken or otherwise disconnected, then two diodes should be con-  
nected between the analog and digital ground pins of the  
AD664 to limit the maximum ground voltage difference.  
Power Supplies and Decoupling  
The AD664 requires three power supplies for proper operation.  
Figure 3. Current-Boosting Scheme  
V
LL powers the logic portions of the device and requires  
AD664 output voltage settling time is 10 µs maximum. Figure 4  
shows the output voltage settling time with a fixed 10 V refer-  
ence, gain = 1 and all bits switched from 1 to 0.  
+5 volts. VCC and VEE power the remaining portions of the cir-  
cuitry and require +12 V to +15 V and –12 V to –15 V, respec-  
tively. VCC and VEE must also be a minimum of two volts greater  
then the maximum reference and output voltages anticipated.  
Decoupling capacitors should be used on all power supply pins.  
Good engineering practice dictates that the bypass capacitors be  
located as near as possible to the package pins. VLL should be  
bypassed to digital ground. VCC and VEE should be decoupled to  
analog ground.  
Driving the Reference Input  
The reference input of the AD664 can have an impedance as  
low as 1.3 k. Therefore, the external reference voltage must be  
able to source up to 7.7 mA of load current. Suitable choices  
include the 5 V AD586, the 10 V AD587 and the 8.192 V  
AD689.  
The architecture of the AD664 derives an inverted version of  
the reference voltage for some portions of the internal circuitry.  
This means that the power supplies must be at least 2 V  
Figure 4. Settling Time; All Bits Switched from On to Off  
Alternately, Figure 5 shows the settling characteristics when the  
reference is switched and the input bits remain fixed. In this  
case, all bits are “on,” the gain is 1 and the reference is switched  
from –5 V to +5 V.  
Figure 5. Settling Time; Input Bits Fixed, Reference  
Switched  
Figure 2. Recommended Circuit Schematic  
D
REV.  
–6–  
AD664  
Multiplying Mode Performance  
Figure 6 illustrates the typical open-loop gain and phase perfor-  
mance of the output amplifiers of the AD664.  
the DAC operating mode data. All registers are double-buffered  
to allow for simultaneous updating of all outputs. Register data  
may be read back to verify the respective contents. The digital  
port also allows transparent operation. Data from the input pins  
can be sent directly through both ranks of latches to the DAC.  
+20  
GAIN  
+15  
+90  
+45  
0
+10  
+5  
0
PHASE  
10k  
100k  
FREQUENCY – H  
1M  
z
Figure 6. Gain and Phase Performance of AD664 Outputs  
Figure 8. Typical Output Noise  
Crosstalk  
Partial address decoding is performed by the DS0, DS1, QS0,  
QS1 and QS2 address bits. QS0, QS1 and QS2 allow the 44-pin  
versions of the AD664 to be addressed in 4-bit nibble, 8-bit byte  
or 12-bit parallel words.  
Crosstalk is a spurious signal on one DAC output caused by a  
change in the output of one or more of the other DACs.  
Crosstalk can be induced by capacitive, thermal or load current  
induced feedthrough. Figure 7 shows typical crosstalk. DAC B  
is set to output 0 volts. The outputs of DAC A, C and D switch  
2 kloads from 10 V to 0 V. The first disturbance in the output  
of DAC B is caused by digital feedthrough from the input data  
lows. The second disturbance is caused by analog feedthrough  
from the other DAC outputs.  
The RST pin provides a simple method to reset all output  
voltages to zero. Its advantages are speed and low software  
overhead.  
INPUT DATA  
In general, two types of data will be input to the registers of the  
AD664, input code data and mode select data. Input code data  
sets the DAC inputs while the mode select data sets the gain  
and range of each DAC.  
The versatile I/O port of the AD664 allows many different types  
of data input schemes. For example, the input code for just one  
of the DACs may be loaded and the output may or may not be  
updated. Or, the input codes for all four DACs may be written,  
and the outputs may or may not be updated.  
The same applies for MODE SELECTION. The mode of just  
one or many of the DACs may be rewritten and the user can  
choose to immediately update the outputs or wait until a later  
time to transfer the mode information to the outputs.  
A user may also write both input code and mode information  
into their respective first ranks and then update all second ranks  
at once.  
Figure 7. Output Crosstalk  
Finally, transparent operation allows data to be transferred from  
the inputs to the outputs using a single control line. This feature  
is useful, for example, in a situation where one of the DACs is  
used in an A/D converter. The SAR register could be connected  
directly to a DAC by using the transparent mode of operation.  
Another use for this feature would be during system calibration  
where the endpoints of the transfer function of each DAC would  
be measured. For example, if the full-scale voltages of each  
DAC were to be measured, then by making all four DACs  
transparent and putting all “1s” on the input port, all four  
DACs would be at full-scale. This requires far less software  
overhead than loading each register individually.  
Output Noise  
Wideband output noise is shown in Figure 8. This measurement  
was made with a 7 MHz noise bandwidth, gain = 1 and all bits  
on. The total rms noise is approximately one fifth the visual  
peak-to-peak noise.  
DIGITAL INTERFACE  
As Table II shows, the AD664 makes a wide variety of operating  
modes available to the user. These modes are accessed or pro-  
grammed through the high speed digital port of the quad DAC.  
On-board registers program and store the DAC input codes and  
D
REV.  
–7–  
AD664  
Table II. AD664 Digital Truth Table  
Function  
DS1, DS0  
LS  
MS  
TR  
QS0, 1, 21  
RD  
CS  
RST  
Load 1st Rank (data)  
DACA  
DACB  
DACC  
DACD  
00  
01  
10  
11  
0
0
0
0
1
1
1
1
1
1
1
1
Select Quad  
Select Quad  
Select Quad  
Select Quad  
1
1
1
1
10  
10  
10  
10  
1
1
1
1
Load 2nd Rank (data)  
Readback 2nd Rank (data)  
Reset  
XX  
1
1
1
XXX  
1
10  
10  
X
1
1
0
Select D/A  
XX  
X
X
1
1
Select Quad  
XXX  
0
X
X
X
Transparent1  
All DACs  
DACA  
XX  
00  
01  
10  
11  
1
0
0
0
0
1
1
1
1
1
0
0
0
0
0
000  
000  
000  
000  
000  
1
1
1
1
1
10  
10  
10  
10  
10  
1
1
1
1
1
DACB  
DACC  
DACD  
Mode Select1, 2  
1st Rank  
2nd Rank  
XX  
XX  
0
1
0
0
1
1
00X  
XXX  
1
1
10  
10  
1
1
Readback Mode1  
XX  
X
0
1
00X  
0
10  
1
Update 2nd Rank  
and Mode  
XX  
1
0
0
XXX  
1
10  
1
NOTES  
X = Don’t Care.  
1For 44-pin versions only. Allow the AD664 to be addressed in 4-bit nibble, 8-bit byte or 12-bit parallel words.  
2For MS, TR, LS = 0, a MS 1st write occurs.  
The following sections detail the timing requirements for  
various data loading schemes. All of the timing specifica-  
tions shown assume VIH = 2.4 V, VIL = 0.4 V, VCC = +15 V,  
V
EE = –15 V and VLL = +5 V.  
Load and Update One DAC Output  
In this first example, the object is simply to change the output of  
one of the four DACs on the AD664 chip. The procedure is to  
select the address bits that indicate the DAC to be programmed,  
pull LATCH SELECT (LS) low, pull CHIP SELECT (CS)  
low, release LS and then release CS. When CS goes low, data  
enters the first rank of the input latch. As soon as LS goes high,  
the data is transferred into the second rank and produces the  
new output voltage. During this transfer, MS, TR, RD and RST  
should be held high.  
Figure 9a. Update Output of a Single DAC  
25؇C  
MIN (ns)  
TMIN to TMAX  
MIN (ns)  
SYMBOL  
tLS  
Preloading the First Rank of One DAC  
*
0
0
In this case, the object is to load new data into the first rank of  
one of the DACs but not the output. As in the previous case, the  
address and data inputs are placed on the appropriate pins. LS  
is then brought to “0” and then CS is asserted. Note that in this  
situation, however, CS goes high before LS goes high. The in-  
put data is prevented from getting to the second rank and affect-  
ing the output voltage.  
tDS  
tDH  
tLW  
tCH  
tAS  
tAH  
0
0
60  
30  
0
0
0
80  
50  
0
0
0
*FOR tLS > 0, THE WIDTH OF LS MUST BE  
INCREASED BY THE SAME AMOUNT THAT  
tLS IS GREATER THAN 0 ns.  
Figure 9b. Update Output of a Single DAC Timing  
D
REV.  
–8–  
AD664  
Figure 12. Preload First Rank Registers  
Load and Update Multiple DAC Outputs  
The following examples demonstrate two ways to update all  
DAC outputs. The first method involves doing all data transfers  
during one long CS low period. Note that in this case, shown in  
Figure 13, LS returns high before CS goes high. Data hold time,  
relative to an address change, is 70 ns. This updates the outputs  
of all DACs simultaneously.  
Figure 10a. Preload First Rank of a DAC  
25؇C  
MIN (ns)  
TMIN to TMAX  
MIN (ns)  
SYMBOL  
tLS  
tLH  
tCW  
tDS  
tDH  
tAS  
tAH  
0
0
15  
80  
0
15  
0
15  
100  
0
15  
0
15  
15  
Figure 10b. Preload First Rank of a DAC Timing  
This allows the user to “preload” the data to a DAC and strobe  
it into the output latch at some future time. The user could do  
this by reproducing the sequence of signals illustrated in the  
next section.  
Figure 13. Update All DAC Outputs  
Update Second Rank of a DAC  
The second method involves doing a CS assertion (low) and an  
LS toggle separately for each DAC. It is basically a series of  
preload operations (Figure 10). In this case, illustrated in Figure  
14, two LS signals are shown. One, labeled LS, goes high before  
CS returns high. This transfers the “new” input word to the  
DAC outputs sequentially. The second LS signal, labeled Alter-  
nate LS, stays low until CS returns high. Using this sequence  
loads the first ranks with each “new” input word but doesn’t up-  
date the DAC outputs. To then update all DAC outputs simul-  
taneously would require the signals illustrated in Figure 11.  
Assuming that a new input code had previously been placed into  
the first rank of the input latches, the user can update the out-  
put of the DAC by simply pulling CS low while keeping LS,  
MS, TR, RD and RST high. Address data is not needed in this  
case. In reality, all second ranks are being updated by this pro-  
cedure, but only those which receive data different from that  
already there would manifest a change. Updating the second  
rank does not change the contents of the first rank.  
Figure 11. Update Second Rank of a DAC  
The same options that exist for individual DAC input loading  
also exist for multiple DAC input loading. That is, the user can  
choose to update the first and second ranks of the registers or  
preload the first ranks and then update them at a future time.  
Figure 14. Load and Update Multiple DACs  
Preload Multiple First Rank Registers  
SELECTING GAIN RANGE AND MODES (44-PIN  
VERSIONS)  
The first ranks of the DAC input registers may be preloaded  
with new input data without disturbing the second rank data.  
This is done by transferring the data into the first rank by bring-  
ing CS low while LS is low. But CS must return high before LS.  
This prevents the data from the first rank from getting into the  
second rank. A simple second rank update cycle as shown in  
Figure 11 would move the “preloaded” information to the  
DACs.  
The AD664’s mode select feature allows a user to configure the  
gain ranges and output modes of each of the four DACs.  
On-board switches take the place of up to eight external relays  
that would normally be required to accomplish this task. The  
switches are programmed by the mode select word entered via  
the data I/O port. The mode select word is eight-bits wide and  
D
REV.  
–9–  
AD664  
occupies the topmost eight bits of the input word. The last four  
bits of the input word are “don’t cares.”  
Preloading the Mode Select Register  
Mode data can be written into the first rank of the mode select  
latch without changing the modes currently being used. This  
feature is useful when a user wants to preload new mode infor-  
mation in anticipation of strobing that in at a future time. Fig-  
ure 17 illustrates the correct sequence and timing of control  
signals to accomplish this task.  
Figure 15 shows the format of the MODE SELECT word. The  
first four bits determine the gain range of the DAC. When set to  
be a gain of 1, the output of the DAC spans a voltage of 1 times  
the reference. When set to a gain of 2, the output of the DAC  
spans a voltage of 2 times the reference.  
This allows the user to “preload” the data to a DAC and strobe  
it into the output latch at some future time. The user could do  
this by reproducing the sequence of signals illustrated in Figures  
17c and 17d.  
The next four bits determine the mode of the DAC. When set to  
UNIPOLAR, the output goes from 0 to REF or 0 to 2 REF.  
When the BIPOLAR mode is selected, the output goes from  
–REF/2 to REF/2 or –REF to REF.  
Figure 15. Mode Select Word Format  
Load and Update Mode of One DAC  
Figure 17a. Preload Mode Select Register  
In this next example, the object is to load new mode informa-  
tion for one of the DACs into the first rank of latches and then  
immediately update the second rank. This is done by putting the  
new mode information (8-bit word length) onto the databus.  
Then MS and LS are pulled low. Following that, CS is pulled  
low. This loads the mode information into the first rank of  
latches. LS is then brought high. This action updates the second  
rank of latches (and, therefore, the DAC outputs). The load  
cycle ends when CS is brought high.  
Figure 17b. Preload Mode Select Register Timing  
In reality, this load cycle really updates the modes of all the  
DACs, but the effect is to only change the modes of those  
DACs whose mode select information has actually changed.  
1
DATA  
INPUT/OUTPUT  
BITS  
0
1
ADDRESS  
___ ___ ___  
QS0,QS1,QS2  
DS0,DS1  
0
__  
MS  
tMS  
__  
CS  
tMH  
tW  
Figure 17c. Update Second Rank of Mode Select Latch  
25؇C  
TMIN to TMAX  
SYMBOL  
tMS  
tMH  
MIN (ns)  
0
0
MIN (ns)  
0
0
Figure 16a. Load and Update Mode of One DAC  
tW  
80  
100  
25؇C  
MIN (ns)  
TMIN to TMAX  
MIN (ns)  
Figure 17d. Update Second Rank of Mode Select Latch  
Timing  
SYMBOL  
tMS  
0
0
0
0
Transparent Operation (44-Pin Versions)  
tLS  
*
Transparent operation allows data from the inputs of the  
AD664 to be transferred into the DAC registers without the  
intervening step of being latched into the first rank of latches.  
Two modes of transparent operation exist, the “partially trans-  
parent” mode and a “fully transparent” mode. In the “partially  
transparent” mode, one of the DACs is transparent while the  
remaining three continue to use the data latched into their  
respective input registers. Both modes require a 12-bit wide  
input word!  
tDS  
tLW  
tCH  
tDH  
tMH  
0
0
60  
70  
0
70  
80  
0
0
0
*FOR tLS > 0, THE WIDTH OF LS MUST BE  
INCREASED BY THE SAME AMOUNT THAT  
tLS IS GREATER THAN 0 ns.  
Figure 16b. Load and Update Mode of One DAC Timing  
D
REV.  
–10–  
AD664  
Fully transparent operation can be thought of as a simultaneous  
load of data from Figure 9a where replacing LS with TR causes  
all 4 DACs to be loaded at once.  
OUTPUT DATA  
Two types of outputs may be obtained from the internal data  
registers of the AD664 chip, mode select and DAC input code  
data. Readback data may be in the same forms in which it can  
be entered; 4-, 8-, and 12-bit wide words (12 bits only for  
28-pin versions).  
The Fully transparent mode is achieved by asserting lows on  
QS0, QS1, QS2, TR and CS while keeping LS high in addition  
to MS and RB. Figure 18a illustrates the necessary timing rela-  
tionships. Fully transparent operation will also work with TR  
tied low (enabled).  
DAC Data Readback  
DAC input code readback data is obtained by setting the address  
of the DAC (DS0, DS1) and Quads (QS0, QS1, QS2) on the  
address pins and bringing the RD and CS pins low. The timing  
diagram for a DAC code readback operation appears in Figure 20.  
1
LS  
DATA INPUT/  
DATA VALID  
OUTPUT BITS  
tDH  
tQH  
tDS  
QS  
TR  
CS  
tQS  
tTW  
tTS  
tCH  
Figure 18a. Fully Transparent Mode  
25؇C  
MIN (ns)  
TMIN to TMAX  
MIN (ns)  
SYMBOL  
tAS  
tQS  
0
0
0
0
0
0
Figure 20a. DAC Input Code Readback  
tTS  
*
tTW  
tCH  
tDH  
tQH  
80  
90  
0
90  
110  
0
25°C  
MIN (ns)  
TMIN to TMAX  
MIN (ns)  
SYMBOL  
tAS  
tRS  
tDV  
tDF  
tAH  
tRH  
0
0
150  
60  
0
0
0
180  
75  
0
0
0
*FOR tTS > 0, THE WIDTH OF TR MUST BE  
INCREASED BY THE SAME AMOUNT THAT  
tTS IS GREATER THAN 0 ns.  
Figure 18b. Fully Transparent Mode Timing  
0
0
Partially transparent operation can be thought of as preloading  
the first rank in Figure 10a without requiring the additional CS  
pulse from Figure 11.  
Figure 20b. DAC Input Code Readback Timing  
Mode Data Readback  
Mode data is read back in a similar fashion. By settingMS, QS0,  
QS1, RD and CS low while setting TR and RST high, the mode  
select word is presented to the I/O port pins. Figure 21 shows the  
timing diagram for a readback of the mode select data register.  
The partially transparent mode is achieved by setting CS, QS0,  
QS1, QS2, LS, and TR low while keeping RD and MS high.  
The address of the transparent DAC is asserted on DS0 and  
DS1. Figure 19a illustrates the necessary timing relationships.  
Partially transparent operation will also work with TR tied low  
(enabled).  
DATA INPUT/  
DATA VALID  
OUTPUT BITS  
tDH  
tDS  
ADDRESS  
QS0, QS1, QS2  
DS0, DS1, LS  
ADDRESS VALID  
tAH  
tAS  
tTS  
TR  
tTH  
tW  
CS  
Figure 21a. Mode Data Readback  
Figure 19a. Partially Transparent  
25؇C  
MIN (ns)  
TMIN to TMAX  
MIN (ns)  
25°C  
MIN (ns)  
TMIN to TMAX  
MIN (ns)  
SYMBOL  
SYMBOL  
tDS  
tAS  
tTS  
tW  
tDH  
tAH  
tTH  
0
0
0
90  
15  
15  
15  
0
0
0
110  
15  
15  
15  
tAS  
tMS  
tDV  
tDF  
tAH  
tMH  
0
0
150  
60  
0
0
0
180  
75  
0
0
0
Figure 21b. DAC Mode Readback Timing  
Figure 19b. Partially Transparent Mode Timing  
D
REV.  
–11–  
AD664  
Output Loads  
+5V  
Readback timing is tested with the output loads shown in Figure  
22.  
AD664  
#1  
AD664  
#N  
10k  
RST  
RST  
100nF  
Figure 24. Power-On Reset  
It is obvious from inspection that the scheme shown in Figure  
24 is only appropriate for systems in which the RST is otherwise  
not used. Should the user wish to use the RST pin, an addi-  
tional logic gate may be included to combine the power-on reset  
with the reset signal.  
INTERFACING THE AD664 TO MICROPROCESSORS  
The AD664 is easy to interface with a wide variety of popular  
microprocessors. Common architectures include processors with  
dedicated 8-bit data and address buses, an 8-bit bus over which  
data and address are multiplexed, an 8-bit data and 16-bit  
address partially muxed, and separate 16-bit data and address  
buses.  
Figure 22. Output Loads  
Asynchronous Reset Operation  
AD664 addressing can be accomplished through either  
memory-mapped or I/O techniques. In memory-mapped  
schemes, the AD664 appears to the host microprocessor as  
RAM memory. Standard memory addressing techniques are  
used to select the AD664. In the I/O schemes, the AD664 is  
treated as an external I/O device by the host. Dedicated I/O pins  
are used to address the AD664.  
The asynchronous reset signal shown in Figure 23 may be  
asserted at any time. A minimum pulse width (tRW) of 90 ns is  
required. The reset feature is designed to return all DAC out-  
puts to 0 volts regardless of the mode or range selected. In the  
44-pin versions, the modes are reset to unipolar 10 V span (gain  
of 1), and the input codes are rewritten to be “0s.” Previous  
DAC code and mode information is erased.  
MC6801 Interface  
In Figures 25a–25d, we illustrate a few of the various methods  
that can be used to connect an AD664 to the popular MC6801  
microprocessor. In each of these cases, the MC6801 is intended  
to be configured in its expanded, nonmultiplexed mode of  
operation. In this mode, the MC6801 can address 256 bytes of  
external memory over 8-bit data (Port 3) and 8-bit address  
(Port 4) buses. Eight general-purpose I/O lines (Port 1) are also  
available. On-board RAM and ROM provide program and data  
storage space.  
Figure 23a. Asynchronous Reset Operation  
In Figure 25a, the three least significant address bits (P40, P41  
and P42) are employed to select the appropriate on-chip  
addresses for the various input registers of the AD664. Three  
I/O lines (P17, P16 and P15) are used to select various operat-  
ing features of the the AD664. IOS and E(nable) are combined  
to produce an appropriate CS signal. This addressing scheme  
leaves the five most significant address bits and five I/O lines  
free for other tasks in the system.  
Figure 23b. Asynchronous Reset Operation Timing  
In the 28-pin versions of the AD664, the mode remains  
unchanged, the appropriate input code is rewritten to reset the  
output voltage to 0 volts. As in the 44-pin versions, the previous  
input data is erased.  
At power-up, an AD664 may be activated in either the read or  
write modes. While at the device level this will not produce any  
problems, at the system level it may. Analog Devices recom-  
mends the addition of a simple power-on reset scheme to any  
system where the possibility of an unknown start-up state could  
be a problem. The simplest version of this scheme is illustrated  
in Figure 24.  
Figure 25b shows another way to interface an AD664 to the  
MC6801. Here we’ve used the six least significant address lines  
to select AD664 features and registers. This is a purely memory-  
mapped scheme while the one illustrated in Figure 25a uses  
some memory-mapping as well as some dedicated I/O pins. In  
Figure 25b, two address lines and all eight I/O lines remain free  
for other system tasks.  
D
REV.  
–12–  
AD664  
Expansion of the scheme employed in Figure 25a results in that  
shown in Figure 25c. Here, two AD664s are connected to an  
MC6801, providing a total of eight 12-bit, software program-  
mable DACs. Again, the three least significant bits of address  
are used to select the on-chip registers of the AD664. IOS and  
E, as well as a fourth address bit, are decoded to provide the  
appropriate CS signals. Four address and five I/O lines remain  
uncommitted.  
A slightly more sophisticated approach to system expansion is  
illustrated in Figure 25d. Here, a 74LS138 (1-of-8 decoder) is  
used to address one of the eight AD664s connected to the  
MC6801. The three least significant address bits are used to  
select on-chip register and DAC. The next three address bits are  
used to select the appropriate AD664. IOS and E gate the  
74LS138 output.  
Figure 25a. Simple AD664 to MC6801 Interface  
Figure 25b. Alternate AD664 to MC6801 Interface  
Figure 25c. Interfacing Two AD664s to an MC6801  
–13–  
D
REV.  
AD664  
The schemes in Figure 25 illustrate some of the trade-offs which  
a designer may make when configuring a system. For example,  
the designer may use I/O lines instead of address bits or vice  
versa. This decision may be influenced by other I/O tasks or sys-  
tem expansion requirements. He/she can also choose to imple-  
ment only a subset of the features available. Perhaps the RST  
pin isn’t really needed. Tying that input pin to VLOGIC frees up  
another I/O or address bit. The same consideration applies to  
Each of the schemes illustrated in Figure 25 operates with an  
MC6801 at clock rates up to and including 1.5 MHz. Similar  
schemes can be derived for other 8-bit microprocessors and  
microcontrollers such as the 8051/8086/8088/6502, etc. One  
such scheme developed for the 8051/AD664 is illustrated in  
Figure 26.  
8051 Interface  
Figure 26 shows the AD664 combined with an 8051 µcontroller  
chip. Three LSBs of address provide the quad and DAC select  
signals. Control signals from Port 1 select various operating  
modes such as readback, mode select and reset as well as pro-  
viding the LS signal. Read and write signals from the 8051 are  
decoded to provide the CS signal.  
mode select. In all of these cases TR is shown tied to VLOGIC  
because the MC6801 cannot provide the 12-bit-wide input  
word required for the transparent mode. In situations where  
,
transparent operation isn’t required, and mode select is also not  
needed, the designer may consider specifying the DIP version of  
the device (either the UNI or BIP version).  
Figure 25d. Interfacing Eight AD664s to an MC6801  
D
REV.  
–14–  
AD664  
IBM PC* Interface  
is required to transfer the word or words previously written to  
the second rank. A 12-bit-wide word again requires at least two  
read cycles; one for the 8 MSBs and four for the LSBs. The  
page select signal produces a CS strobe for any address from  
300H to 31FH.  
Figure 27 illustrates a simple interface between an IBM PC and  
an AD664. The three least significant address bits are used to  
select the Quad and DAC. The next two address bits are used  
for LS and MS. In this scheme, a 12-bit input word requires  
two load cycles, an 8-bit word and a 4-bit word. Another write  
Figure 26. AD664 to 8051 Interface  
Figure 27. AD664 to IBM PC Interface  
*IBM PC is a trademark of International Business Machines Corp.  
D
REV.  
–15–  
AD664  
Table III details the memory locations and addresses used by this interface.  
Table III. IBM PC Memory Map  
HEX  
A9  
A8  
A7  
A6  
A5  
A4  
A3  
A2  
A1  
A0  
REGISTER SELECTED  
300  
301  
302  
303  
304  
305  
306  
307  
308  
309  
30A  
30B  
30C  
30D  
30E  
30F  
310  
311  
312  
313  
314  
315  
316  
317  
318  
319  
31A  
31B  
31C  
31D  
31E  
31F  
1
1
0
0
0
0
0
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Illegal Address  
Mode Select, 1st Rank  
Illegal Address  
Mode Select, 1st Rank  
Illegal Address  
Mode Select, 1st Rank  
Illegal Address  
Mode Select, 1st Rank  
Mode Select, 2nd Rank  
1
1
0
DAC A, 4 LSBs, 1st Rank  
DAC A, 8 MSBs, 1st Rank  
DAC B, 4 LSBs, 1st Rank  
DAC B, 8 MSBs, 1st Rank  
DAC C, 4 LSBs, 1st Rank  
DAC C, 8 MSBs, 1st Rank  
DAC D, 4 LSBs, 1st Rank  
DAC D, 8 MSBs, 1st Rank  
2nd Rank  
1
Note: Shaded registers are readable.  
D
REV.  
–16–  
AD664  
The following IBM PC Basic routine produces four output volt-  
age ramps from one AD664. Line numbers 10 through 70 de-  
fine the hardware addresses for the first and second ranks of  
DAC registers as well as the first and second ranks of the mode  
select register. Program variables are initialized in line numbers  
110 through 130. Line number 170 writes “0s” out to the first  
rank and, then, the second rank of the mode select register.  
Line numbers 200 through 320 calculate output voltages. Fi-  
nally line numbers 410 through 450 update the first, then the  
second ranks of the DAC input registers. Hardware registers  
may be read with the “INP” instruction. For example, the con-  
tents of the DAC A register may be accessed with the following  
com mand: Line# A = INP(DACA).  
5
10  
REM----AD664 LISSAJOUS PATTERNS----  
REM ---ASSIGN HARDWARE ADDRESSES---  
20  
DACA = 785  
30  
DACB = 787  
40  
DACC = 789  
50  
DACD = 791  
60  
DAC2ND = 792  
70  
MODE1 = 769: MODE2 = 776  
80  
REM  
90  
REM  
100  
110  
120  
130  
140  
150  
160  
170  
180  
190  
200  
210  
220  
230  
240  
250  
260  
270  
280  
290  
300  
310  
320  
330  
340  
400  
410  
420  
430  
440  
450  
500  
510  
520  
530  
REM ---INITIALIZE VARIABLES---  
X = 0: Y1 = 128: Y2 = 64: Y3 = 32  
CX = 1: CY1 = 1: CY2 = -1: CY3= 1  
FX = 9: FY1 = 5: FY2 = 13: FY3 = 15  
REM  
REM  
REM ---INITIALIZE MODES AND GAINS---  
OUT MODE1,0: OUT MODE2,0  
REM  
REM  
REM ---CALCULATE VARIABLES---  
X = X + FX*CX  
Y1 = Y1 + FY1*CY1  
Y2 = Y2 + FY2*CY2  
Y3 = Y3 + FY3*CY3  
IF X > 255 THEN X = 255: CX = -1: GOTO 270  
IF X < 0 THEN X = 0: CX = 1  
IF Y1 > 255 THEN Y1 = 255: CY1 = -1: GOTO 290  
IF Y1 < 0 THEN Y1 = 0: CY1 = 1  
IF Y2 > 255 THEN Y2 = 255: CY2 = -1 GOTO 310  
IF Y2 < 0 THEN Y2 = 0: CY2 = -1  
IF Y3 > 255 THEN Y3 = 255: CY3 = -1: GOTO 400  
IF Y3 < 0 THEN Y3 = 0: CY3 = 1  
REM  
REM  
REM ---SEND DAC DATA---  
OUT DACA,X  
OUT DACB,Yl  
OUT DACC,Y2  
OUT DACD,Y3  
OUT DAC2ND,0  
REM  
REM  
REM ---LOOP BACK---  
GOTO 210  
D
REV.  
–17–  
AD664  
Simple AD664 to MC68000 Interface  
This scheme can be converted to write “right-justified’’ data by  
connecting the data inputs to DATA bits D0 through D11  
respectively. Other options include controlling the QS0, QS1  
and QS2 pins with UDS and LDS to provide a way to write  
8-bit input and read 8-bit output words.  
Figure 28 shows an AD664 connected to an MC68000. In this  
memory-mapped I/O scheme, the “left-justified” data is written  
in one 12-bit input word. Four address bits are used to perform  
the on-chip D/A selection as well as the various operating fea-  
tures. The R/W signal controls the RD function and system  
reset controls RST.  
Figure 28. AD664 to MC68000 Interface  
D
REV.  
–18–  
AD664  
Figure 29. AD664 in “Tester-per-Pin” Architecture  
APPLICATIONS OF THE AD664  
“Tester-Per-Pin” ATE Architecture  
some software where the previous example would require only a  
single reset strobe signal!  
Figure 29 shows the AD664 used in a single channel of a digital  
test system. In this scheme, the AD664 supplies four individual  
output voltages. Two are provided to the VHIGH and VLOW in-  
puts of the AD345 pin driver I.C. to set the digital output levels.  
Two others are routed to the inputs of the AD96687 dual com-  
parator to supply reference levels of the readback features. This  
approach can be replicated to give as many channels of stimulus/  
readback as the tester has pins. The AD664 is a particularly  
appropriate choice for a large-scale system because the low  
power requirements (under 500 mW) ease power supply and  
cooling requirements. Analog ground currents of 600 µA or less  
make the ground current management task simpler. All DACs  
can be driven from the same system reference and will track  
over time and temperature. Finally, the small board area  
required by the AD664 (and AD345 and AD96687) allows a  
high functional density.  
Drawing scaling can be achieved by taking advantage of the  
AD664’s software programmable gain settings. If, for example,  
an “A” size drawing is created with gain settings of 1, then a  
“C” size drawing can be created by simply resetting all DAC  
gains to 2 and redrawing the object. Conversely, a “C” size  
drawing created with gains of 2 can be reduced to “A” size sim-  
ply by changing the gains to 1 and redrawing. The same princi-  
pal applies for conversion from “B” size to “D” size or “D” size  
to “B” size. The multiplying capability of the AD664 provides  
another scaling option. Changing the reference voltage provides  
a proportional change in drawing size. Inverting the reference  
voltage would invert the drawing.  
Swapping digital input data from the X channel to the Y chan-  
nel would rotate the drawing 90 degrees.  
X-Y Plotters  
Figure 30 is a block diagram of the control section of a  
microprocessor-controlled X-Y pen plotter. In this conceptual  
exercise, two of the DACs are used for the X-channel drive and  
two are used for the Y-channel drive. Each provides either the  
coarse or fine movement control for its respective channel. This  
approach offers increased resolution over some other approaches.  
A designer can take advantage of the reset feature of the AD664  
in the following manner. If the system is designed such that the  
“HOME” position of the pen (or galvanometer, beam, head or  
similar mechanism) results when the outputs of all of the DACs  
are at zero, then no system software is required to home the  
pen. A simple reset signal is sufficient.  
Figure 30. X-Y Plotter Block Diagram  
Similarly, the transparent feature could be used to the same  
end. One code can be sent to all DACs at the same time to send  
the pen to the home position. Of course, this would require  
D
REV.  
–19–  
AD664  
OUTLINE DIMENSIONS  
0.100 (2.54)  
MAX  
0.005 (0.13)  
MIN  
28  
15  
0.610 (15.49)  
0.580 (12.73)  
PIN 1  
1
4
0.620 (15.75)  
0.590 (14.99)  
1.490 (37.85) MAX  
0.085 (2.16)  
0.060 (1.52)  
0.015 (0.38)  
MAX  
0.150  
(3.81)  
MIN  
0.018 (0.46)  
0.008 (0.20)  
0.200 (5.08)  
0.125 (3.18)  
SEATING  
PLANE  
0.026 (0.66)  
0.014 (0.36)  
0.070 (1.78)  
0.030 (0.76)  
0.100 (2.54)  
CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS  
(IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR  
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.  
Figure 31. 28-Lead Side-Brazed Ceramic Dual In-Line Package [SBDIP]  
(D-28-2)  
Dimensions shown in inches and (millimeters)  
1.565 (39.75)  
1.380 (35.05)  
28  
1
15  
0.580 (14.73)  
0.485 (12.31)  
14  
0.625 (15.88)  
0.600 (15.24)  
0.100 (2.54)  
BSC  
0.195 (4.95)  
0.125 (3.17)  
0.250 (6.35)  
MAX  
0.015 (0.38)  
GAUGE  
PLANE  
0.015  
(0.38)  
MIN  
0.200 (5.08)  
0.115 (2.92)  
0.015 (0.38)  
0.008 (0.20)  
SEATING  
PLANE  
0.700 (17.78)  
MAX  
0.022 (0.56)  
0.014 (0.36)  
0.005 (0.13)  
MIN  
0.070 (1.78)  
0.050 (1.27)  
COMPLIANT TO JEDEC STANDARDS MS-011  
CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS  
(IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR  
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.  
CORNER LEADS MAY BE CONFIGURED AS WHOLE LEADS.  
Figure 32. 28-Lead Plastic Dual In-Line Package [PDIP]  
Wide Body  
(N-28-2)  
Dimensions shown in inches and (millimeters)  
–20–  
REV. D  
AD664  
0.100 (2.54)  
0.064 (1.63)  
0.055 (1.40)  
0.045 (1.14)  
0.075 (1.91) REF  
6
40  
39  
0.020 (0.51)  
44  
7
1
REF 45°  
0.662 (16.82)  
0.640 (16.27)  
0.028 (0.71)  
0.022 (0.56)  
SQ  
0.050  
(1.27)  
BSC  
BOTTOM VIEW  
29  
28  
17  
0.040 (1.02)  
REF 45°  
3 PLACES  
18  
CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS  
(IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR  
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.  
Figure 33. 44-Terminal Ceramic Leadless Chip Carrier [LCC]  
(E-44-1)  
Dimensions shown in inches and (millimeters)  
0.078 (1.98)  
0.054 (1.37)  
0.040 (1.02)  
REF  
0.020 (0.51)  
REF  
45°  
0.662 (16.82)  
0.628 (15.95)  
SQ  
45°  
0.025 (0.64)  
MIN  
3 PLACES  
39  
29  
40  
28  
0.032 (0.81)  
0.020 (0.51)  
PIN 1 INDEX  
0.065 (1.65)  
0.050  
(1.27)  
BSC  
0.650 (16.51)  
0.610 (15.49)  
PIN 1  
0.500 (12.70)  
0.492 (12.50)  
TOP VIEW  
BOTTOM VIEW  
0.023 (0.58)  
0.013 (0.33)  
6
18  
7
17  
0.700 (17.78)  
0.680 (17.27)  
SQ  
0.135 (3.43)  
0.100 (2.54)  
CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETERS DIMENSIONS  
(IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR  
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.  
Figure 34. 44-Lead Ceramic Leaded Chip Carrier, J-Formed Leads [JLCC]  
(J-44)  
Dimensions shown in inches and (millimeters)  
REV. D  
–21–  
AD664  
0.180 (4.57)  
0.165 (4.19)  
0.048 (1.22)  
0.042 (1.07)  
0.056 (1.42)  
0.042 (1.07)  
0.020 (0.51)  
MIN  
6
7
40  
39  
0.048 (1.22)  
0.042 (1.07)  
0.021 (0.53)  
0.013 (0.33)  
PIN 1  
IDENTIFIER  
0.630 (16.00)  
0.590 (14.99)  
BOTTOM VIEW  
(PINS UP)  
0.050  
(1.27)  
BSC  
TOP VIEW  
(PINS DOWN)  
0.032 (0.81)  
0.026 (0.66)  
17  
18  
29  
28  
0.045 (1.14)  
0.025 (0.64)  
R
0.656 (16.66)  
0.650 (16.51)  
0.120 (3.05)  
0.090 (2.29)  
SQ  
0.695 (17.65)  
0.685 (17.40)  
SQ  
COMPLIANT TO JEDEC STANDARDS MO-047-AC  
CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS  
(IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR  
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.  
Figure 35. 44-Lead Plastic Leaded Chip Carrier [PLCC]  
(P-44)  
Dimensions shown in inches and (millimeters)  
ORDERING GUIDE  
Model1  
Temperature Range  
Package Description  
28-Lead Side-Brazed SBDIP  
28-Lead Side-Brazed SBDIP  
44-Lead LCC  
28-Lead Side-Brazed SBDIP  
28-Lead Side-Brazed SBDIP  
44-Lead JLCC  
28-Lead Side-Brazed SBDIP  
28-Lead Side-Brazed SBDIP  
44-Lead LCC  
44-Lead JLCC  
28-Lead PDIP  
28-Lead PDIP  
28-Lead PDIP  
28-Lead PDIP  
44-Lead PLCC  
Package Option  
5962-8871901MXA  
5962-8871902MXA  
5962-8871903MYA  
AD664AD-BIP  
AD664AD-UNI  
AD664AJ  
AD664BD-BIP  
AD664BD-UNI  
AD664BE  
−55°C to +125°C  
−55°C to +125°C  
−55°C to +125°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
0°C to +70°C  
D-28-2  
D-28-2  
E-44-1  
D-28-2  
D-28-2  
J-44  
D-28-2  
D-28-2  
E-44-1  
J-44  
N-28-2  
N-28-2  
N-28-2  
N-28-2  
P-44  
AD664BJ  
AD664JN-BIP  
AD664JN-UNI  
AD664JNZ-BIP  
AD664JNZ-UNI  
AD664JP  
0°C to +70°C  
0°C to +70°C  
0°C to +70°C  
0°C to +70°C  
AD664JPZ  
0°C to +70°C  
44-Lead PLCC  
P-44  
AD664KN-BIP  
AD664KNZ-BIP  
AD664KNZ-UNI  
AD664KP  
0°C to +70°C  
0°C to +70°C  
0°C to +70°C  
0°C to +70°C  
28-Lead PDIP  
28-Lead PDIP  
28-Lead PDIP  
44-Lead PLCC  
N-28-2  
N-28-2  
N-28-2  
P-44  
AD664KPZ  
0°C to +70°C  
44-Lead PLCC  
P-44  
AD664SD-BIP  
AD664SD-BIP/883B  
AD664SD-UNI  
AD664SD-UNI/883B  
AD664TD-BIP  
AD664TD-BIP/883B  
AD664TD-UNI/883B  
AD664TE/883B  
AD664TJ/883B  
−55°C to +125°C  
−55°C to +125°C  
−55°C to +125°C  
−55°C to +125°C  
−55°C to +125°C  
−55°C to +125°C  
−55°C to +125°C  
−55°C to +125°C  
−55°C to +125°C  
28-Lead Side-Brazed SBDIP  
28-Lead Side-Brazed SBDIP  
28-Lead Side-Brazed SBDIP  
28-Lead Side-Brazed SBDIP  
28-Lead Side-Brazed SBDIP  
28-Lead Side-Brazed SBDIP  
28-Lead Side-Brazed SBDIP  
44-Lead LCC  
D-28-2  
D-28-2  
D-28-2  
D-28-2  
D-28-2  
D-28-2  
D-28-2  
E-44-1  
J-44  
44-Lead JLCC  
1 Z = RoHS Compliant Part.  
–22–  
REV. D  
AD664  
REVISION HISTORY  
2/12—Rev. C to Rev. D  
Updated Outline Dimensions....................................................... 20  
Changes to Ordering Guide .......................................................... 21  
12/91—Rev. B to Rev. C  
©2012 Analog Devices, Inc. All rights reserved. Trademarks and  
registered trademarks are the property of their respective owners.  
D10590-0-2/12(D)  
REV. D  
–23–  

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