MAX4968ECM [MAXIM]
16-Channel, Linear, High-Voltage Analog Switches;
| 型号： | MAX4968ECM |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | 16-Channel, Linear, High-Voltage Analog Switches |
| 文件： | 总17页 (文件大小：1230K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-5786; Rev 2; 1/12
16-Channel, Linear, High-Voltage
Analog Switches
General Description
Features
S Latch Free
SOI HVCMOS Process Technology for High
The MAX4968/MAX4968A are 16-channel, high-linearity,
high-voltage, bidirectional SPST analog switches with
18I(typ) on-resistance. The devices are ideal for use in
applications requiring high-voltage switching controlled
by a low-voltage control signal, such as ultrasound imag-
ing and printers. The MAX4968A provides integrated
40kI (typ) bleed resistors on each switch terminal to
discharge capacitive loads. Using HVCMOS technol-
ogy, these switches combine high-voltage bilateral MOS
switches and low-power CMOS logic to provide efficient
control of high-voltage analog signals.
Performance and Robustness
S No Dedicated High-Voltage Supplies Required
S R
Flatness Guaranteed in Entire Input Range
ON
S Low-Power Dissipation
S Low-Charge Injection and Voltage Spike
S 25MHz Serial Interface (+2.5V to +5V)
S 2nd Harmonic Distortion < -45dB at 2MHz ꢀ9V
Pulse
The MAX4968 is pin-to-pin compatible with the MAX14802
and Supertex HV2601. The MAX4968A is pin-to-pin
compatible with the MAX14803 and Supertex HV2701.
S Low Parasitic Capacitance Guarantees High
Bandwidth
The only difference is the V
level. The MAX4968/MAX4968A require a low +10V (typ)
positive supply voltage
PP
S DC to 39MHz Small-Signal Analog Bandwidth
(C
= 299pF)
LOAD
voltage (V ), whereas the MAX14802/MAX14803 and
PP
S 599kHz to 29MHz High-Signal Analog Bandwidth
(C = 299pF)
HV2601/HV2701 require a high +100V supply voltage.
LOAD
In a typical ultrasound application, these devices do not
require a dedicated high-voltage supply that implies a sig-
nificant simplification of system requirement. The negative
voltage supply can be shared with the transmitter, and the
positive voltage supply is typically +10V.
S Extended Input Range Up to 219V
P-P
S -89dB (typ) Off-Isolation at 5MHz (59I)
S Shunt (Bleed) Resistors on Outputs (MAX4ꢀ68A
Only)
The devices are available in the 48-pin LQFP package
and are specified over the -40NC to +85NC extended
temperature range.
S Daisy-Chainable Serial Interface
Applications
Medical Ultrasound Imaging
Nondestructive Testing (NDT)/Industrial
Ultrasound Imaging
Printers
Ordering Information/Selector Guide
PART
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
SWITCH CHANNELS
BLEED RESISTOR
PIN-PACKAGE
48 LQFP
MAX4ꢀ68ECM+
MAX4ꢀ68AECM+
16
16
No
Yes
48 LQFP
+Denotes a lead(Pb)-free/RoHS-compliant package.
_______________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
16-Channel, Linear, High-Voltage
Analog Switches
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
Analog Signal Range (SW_) ........(V
- 0.3V) to (V
+ 220V)
NN
NN
V
V
V
V
Logic Supply Voltage Range ..........................-0.3V to +6V
Continuous Power Dissipation (T = +70NC)
DD
PP
PP
NN
A
LQFP (derate 22.7mW/NC above +70NC) .................1818mW
Operating Temperature Range.......................... -40NC to +85NC
Storage Temperature Range............................ -65NC to +150NC
Junction Temperature ................................................... +150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
- V
Supply Voltage................................................ +212V
NN
Supply Voltage Range ...................................-0.3V to +12V
Negative Supply Voltage............................................-200V
Logic Input Voltage Range (CLK, DIN, CLR) .........-0.3V to +6V
Logic Input Voltage Range
(LE)........................-0.3V to a minimum of (V + 0.3V) or 6V
PP
Logic Output Voltage Range (DOUT)...... -0.3V to (V
+ 0.3V)
DD
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
PACKAGE THERMAL CHARACTERISTICS (Note 1)
LQFP
Junction-to-Ambient Thermal Resistance (q ) ..........44°C/W
JA
Junction-to-Case Thermal Resistance (q )...............10°C/W
JC
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
ELECTRICAL CHARACTERISTICS
(V
DD
= +2.37V to +5.5V, V = +10V Q5%, V
= 0 to -200V, T = T
to T , unless otherwise noted. Typical values are
MAX
PP
NN
A
MIN
V
DD
= +3.3V, V
= -100V, V = +10V at T = +25NC.) (Note 2)
NN
PP
A
PARAMETER
POWER SUPPLIES
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
V
V
V
V
V
V
Logic Supply Voltage
Supply Voltage
Supply Voltage
Static Current
V
V
+2.37
-200
+5.5
0
V
V
DD
NN
PP
DD
NN
V
+9.5
+10
+10.5
4
V
PP
I
FA
FA
FA
DD
DD
NN
DDS
Dynamic Current
Static Current
I
V
= +5V, f
= 5MHz, f = 2.5MHz
DIN
200
25
DD
DD
CLK
I
All switches remain on or off, SW_ = GND
10
3.3
12
4
NNS
Supply Dynamic Current
NN
V
= +10V, V = -100V,
PP
NN
(All Channels Switching
Simultaneously)
I
5
25
6
mA
FA
NN
f
= 50kHz, SW_ = GND
TURN_ON/OFF
V
V
Supply Static Current
I
All switches remain on or off, SW_ = GND
= +10V, V = -100V,
PP
PPS
Supply Dynamic Current
PP
V
PP
NN
(All Channels Switching
Simultaneously)
I
mA
PP
f
= 50kHz, SW_ = GND
TURN_ON/OFF
SWITCH CHARACTERISTICS
V
210
+
NN
Analog Dynamic Signal Range
V
R
AC operation only, f > 500kHz
V
V
SW_
NN
V
= +10V, V
= 5mA
= -100V, V
= 0V,
PP
NN
SW_
Small-Signal On-Resistance
18
34
I
ONS
I
SW_
2
16-Channel, Linear, High-Voltage
Analog Switches
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.37V to +5.5V, V = +10V Q5%, V
= 0 to -200V, T = T
to T , unless otherwise noted. Typical values are
MAX
PP
NN
A
MIN
V
DD
= +3.3V, V
= -100V, V = +10V at T = +25NC.) (Note 2)
NN
PP
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Small-Signal On-Resistance
Matching
DR
V
= +10V, V
= -100V, I = 5mA
SW_
3
%
ONS
PP
NN
AC measured, f
= 0.5MHz,
SW_
Small-Signal On-Resistance
Flatness
R
ONF
V
V
= 80V , R
= -100V
= 50I, V = +10V,
2
%
SW_
P-P LOAD
PP
NN
Switch Output Bleed Resistor
Switch-Off Leakage
R
MAX4968A only
V = 0V, switch off (MAX4968 only)
SW_
30
40
0
50
1
kI
FA
INT
I
SW_(OFF)
Switch-Off DC Offset
Switch-On DC Offset
No load (MAX4968A only)
No load (MAX4968A only)
-15
-15
0
+15
+15
mV
mV
0
Switch Output Isolation Diode
Current
300ns pulse width, 2% duty cycle
3.0
A
SWITCH DYNAMIC CHARACTERISITICS
V
= +1V, R = 100I, V
= -100V,
= -100V,
SW_A
L
NN
Turn-On Time
Turn-Off Time
t
2
2
5
Fs
Fs
ON
from enable to V
= +0.9V
SW_B
V
= +1V, R = 100I, V
L NN
SW_A
t
3.5
OFF
from disable to V
= +0.9V
SW_B
Maximum V
Slew Rate
dV/dt
C = 100pF
20
V/ns
dB
dB
pF
SW_
L
Off-Isolation
Crosstalk
V
ISO
f = 2MHz, R = 50I
-76
-76
9
L
V
CT
f = 5MHz, R = 50I
L
SW_ Off-Capacitance
SW_ On-Capacitance
Output Voltage Spike
C
C
f = 1MHz, small signal close to zero
f = 1MHz, small signal close to zero
SW_(OFF)
SW_ (ON)
13
pF
V
SPK
R = 50I
L
mV
±70
Large-Signal Analog Bandwidth
(-3dB)
C
= 200pF, 60V amplitude sinusoidal
LOAD
f
30
MHz
MHz
pC
BW_L
BW_S
Q
burst, 1% duty cycle
C = 200pF, 100mV amplitude
LOAD
sinusoidal
Small-Signal Analog Bandwidth
(-3dB)
f
50
Charge Injection
V
= +10V, V
= -100V, Figure 1
150
PP
NN
LOGIC LEVELS
Logic-Input Low Voltage
V
0.75
0.4
V
V
V
V
IL
V
0.75
-
DD
Logic-Input High Voltage
Logic-Output Low Voltage
Logic-Output High Voltage
V
IH
V
I
= 1mA
SINK
OL
OH
V
DD
0.4
-
V
I
= 1mA
SOURCE
Logic-Input Capacitance
Logic-Input Leakage
C
5
pF
IN
I
-1
+1
FA
IN
3
16-Channel, Linear, High-Voltage
Analog Switches
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.37V to +5.5V, V = +10V Q5%, V
= 0 to -200V, T = T
to T , unless otherwise noted. Typical values are
MAX
PP
NN
A
MIN
V
DD
= +3.3V, V
= -100V, V = +10V at T = +25NC.) (Note 2)
NN
PP
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
TIMING CHARACTERISTICS (Figure 2)
CLK Frequency
f
25
MHz
ns
CLK
DIN to CLK Setup Time
DIN to CLK Hold Time
t
8
3
DS
DH
t
ns
t
t
8
ns
CLK to LE Setup Time
LE Low Pulse Width
CS
12
12
ns
WL
CLR High Pulse Width
CLK Rise and Fall Times
t
ns
WC
t , t
R
50
28
45
ns
F
V
V
= +5V Q10%, C
= 15pF
= 15pF
DD
DD
DOUT
CLK to DOUT Delay
t
ns
DO
= +2.5V Q5%, C
DOUT
Note 2: All devices are 100% tested at T = +85NC. Limits over the operating temperature range are guaranteed by design.
A
4
16-Channel, Linear, High-Voltage
Analog Switches
Test Circuits/Timing Diagrams
V
- 10V
PP
R
L
100kΩ
SW_A
SW_B
SW_A
SW_A
SW_B
V
OUT
V
OUT
I
I
LEAK
LEAK
SW_B
A
A
R
L
MAX4968
MAX4968A
MAX4968
MAX4968A
MAX4968
MAX4968A
100kΩ
V
V
V
V
5V
PP
PP
DD
V
V
V
V
5V
V
V
V
V
5V
PP
PP
DD
PP
PP
DD
V
GND
NN
NN
V
GND
V
NN
GND
NN
NN
NN
SWITCH-OFF LEAKAGE
DC OFFSET ON/OFF
t
/t TEST CIRCUIT
ON OFF
V = 10V
IN P-P
AT 5MHz
V = 10V
IN P-P
AT 5MHz
SW_A
SW_B
SW_A
V
OUT
SW_A
SW_B
SW_A
SW_B
I
ID
50Ω
V
OUT
V
NN
SW_B
50Ω
R
L
MAX4968
MAX4968A
MAX4968
MAX4968A
MAX4968
MAX4968A
V
V
V
5V
V
V
V
V
V
5V
V
V
V
5V
PP
PP
DD
PP
PP
DD
PP
PP
DD
V
V
GND
GND
V
V
GND
NN
NN
NN
NN
NN
NN
ISOLATION DIODE
CURRENT
V
V
OUT
OUT
V
= 20log
V
= 20log
CT
ISO
V
V
IN
IN
OFF-ISOLATION
CROSSTALK
+V
SPK
V
OUT
SW_A
SW_A
SW_B
V
OUT
V
OUT
-V
SPK
100pF
50Ω
SW_B
V
COM_
MAX4968
MAX4968A
R
1kΩ
L
MAX4968
MAX4968A
V
V
V
V
5V
V
V
V
V
5V
PP
PP
DD
PP
PP
DD
V
GND
V
NN
GND
NN
NN
NN
Q = 1000pF x V
OUT
OUTPUT VOLTAGE SPIKE
CHARGE INJECTION
V
V
V
V
OUT
IN SW_A
SW_B
OUT
IN SW_A
SW_B
200pF
200pF
60V BURST
P-P
(1% DUTY CYCLE)
10mV
P-P
MAX4968
MAX4968A
MAX4968
MAX4968A
V
V
V
V
5V
V
V
V
V
5V
PP
PP
DD
PP
PP
DD
V
GND
V
NN
GND
NN
NN
NN
SMALL-SIGNAL
BANDWIDTH MEASUREMENT
LARGE-SIGNAL
BANDWIDTH MEASUREMENT
Figure 1. Test Circuits
5
16-Channel, Linear, High-Voltage
Analog Switches
Test Circuits/Timing Diagrams (continued)
D
N
D
N-1
DIN
LE
D
50%
50%
N+1
50%
50%
t
WL
t
CS
50%
50%
CLK
t
t
DH
DS
t
DO
50%
DOUT
t
t
OFF
ON
OFF
ON
90%
SWITCH
CLR
10%
50%
50%
t
WC
Figure 2. Serial Interface Timing
LE
CLK
DIN
D15
D14
D14
D13
D13
D1
D1
D0
LSB
MSB
D15
D15
D0
DOUT
DATA FROM PREVIOUS DATA BYTE
POWER-UP DEFAULT: D[15:0] = 0
Figure 3. Latch-Enable Interface Timing
6
16-Channel, Linear, High-Voltage
Analog Switches
Typical Operating Characteristics
(V
DD
= +3V, V = +10V, V
= -100V, R = 100I, C = 100pF, T = +25NC, unless otherwise noted.)
PP
NN
L
L
A
TURN-ON/TURN-OFF TIME
vs.TEMPERATURE
SWITCH-OFF LEAKAGE CURRENT
vs.TEMPERATURE
OFF-ISOLATION vs. FREQUENCY
5
4
3
2
1
0
0
-20
1.0
0.8
0.6
0.4
0.2
0
-40
-60
T
A
= +85°C
T
= +25°C
= -40°C
A
t
t
OFF
ON
-80
I
SW_(0FF)
T
A
-100
-40
-15
10
35
60
85
0.001
0.01
0.1
1
10
100
-40
-15
10
35
60
85
TEMPERATURE (°C)
FREQUENCY (MHz)
TEMPERATURE (°C)
LOGIC POWER-SUPPLY CURRENT vs.
SUPPLY VOLTAGE
POSITIVE AND NEGATIVE POWER-SUPPLY
CURRENT vs. TEMPERATURE
3.0
2.5
2.0
1.5
1.0
0.5
0
20
18
16
14
12
10
8
V
= +10V
PP
T
= +85°C
A
V
= -100V
NN
T
A
= +25°C
T
A
= -40°C
V
= -70V
60
NN
V
= -40V
35
NN
2.3 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5
SUPPLY VOLTAGE (V)
-40
-15
10
85
V
TEMPERATURE (°C)
DD
HIGH-VOLTAGE SUPPLY CURRENT
vs. OUTPUT SWITCH FREQUENCY
LOGIC POWER-SUPPLY CURRENT
vs. SERIAL-CLOCK FREQUENCY
500
400
300
200
100
0
10
8
ALL SWITCHES SWITCHING
T
= +85°C
A
T
A
= +25°C
I
(T = +85°C)
A
PP
6
I
PP
(T = -40°C)
A
I
PP
(T = +25°C)
A
4
T
A
= +-40°C
I
(T = +85°C)
A
NN
2
I
(T = +25°C)
A
NN
I
(T = -40°C)
A
NN
0
0
2
4
6
8
10 12 14 16 18 20
0
10
20
30
40
85
SERIAL-CLOCK FREQUENCY(MHz)
OUTPUT SWITCH FREQUENCY (kHz)
7
16-Channel, Linear, High-Voltage
Analog Switches
Pin Configuration
TOP VIEW
35 34 33 32 31 30 29 28 27
36
26
25
N.C.
DOUT
CLR
LE
SW10B
SW10A
SW9B
24
23
22
21
20
19
18
17
16
15
14
13
37
38
39
SW9A 40
SW8B 41
CLK
DIN
MAX4968
MAX4968A
SW8A
SW7B
42
43
V
DD
GND
N.C.
SW7A 44
SW6B 45
V
SW6A
SW5B
SW5A
46
47
48
PP
N.C.
V
NN
+
2
3
4
5
6
7
8
9
10
1
11
12
LQFP
(7mm × 7mm)
Pin Description
PIN
NAME
FUNCTION
PIN
15
NAME
FUNCTION
1, 2, 14, 16,
24, 35, 36
No Connection. Not connected
internally.
Positive Voltage Supply. Bypass
V to GND with a 0.1FF or
PP
N.C.
V
PP
greater ceramic capacitor.
3
4
SW4B
SW4A
SW3B
SW3A
SW2B
SW2A
SW1B
SW1A
SW0B
SW0A
Analog Switch 4—Terminal
Analog Switch 4—Terminal
Analog Switch 3—Terminal
Analog Switch 3—Terminal
Analog Switch 2—Terminal
Analog Switch 2—Terminal
Analog Switch 1 —Terminal
Analog Switch 1—Terminal
Analog Switch 0—Terminal
Analog Switch 0—Terminal
17
GND
Ground
5
Logic Supply Voltage. Bypass
6
18
V
DD
V
DD
to GND with a 0.1FF or
greater ceramic capacitor.
7
8
19
20
21
22
23
25
26
27
DIN
Serial-Data Input
9
CLK
Serial-Clock Input
10
11
12
Active-Low Latch-Enable Input
Latch-Clear Input
LE
CLR
DOUT
Serial-Data Output
SW15B Analog Switch 15—Terminal
SW15A Analog Switch 15—Terminal
SW14B Analog Switch 14—Terminal
Negative High-Voltage Supply.
13
V
NN
Bypass V
to GND with a 0.1FF
NN
or greater ceramic capacitor.
8
16-Channel, Linear, High-Voltage
Analog Switches
Pin Description (continued)
PIN
40
41
42
43
44
45
46
47
48
NAME
SW9A
SW8B
SW8A
SW7B
SW7A
SW6B
SW6A
SW5B
SW5A
FUNCTION
PIN
28
29
30
31
32
33
34
37
38
39
NAME
FUNCTION
Analog Switch 9—Terminal
Analog Switch 8—Terminal
Analog Switch 8—Terminal
Analog Switch 7—Terminal
Analog Switch 7—Terminal
Analog Switch 6—Terminal
Analog Switch 6—Terminal
Analog Switch 5—Terminal
Analog Switch 5—Terminal
SW14A Analog Switch 14—Terminal
SW13B Analog Switch 13—Terminal
SW13A Analog Switch 13—Terminal
SW12B Analog Switch 12—Terminal
SW12A Analog Switch 12—Terminal
SW11B Analog Switch 11—Terminal
SW11A Analog Switch 11—Terminal
SW10B Analog Switch 10—Terminal
SW10A Analog Switch 10—Terminal
SW9B
Analog Switch 9—Terminal
Analog Switch
The devices can transmit analog signals up to 210V
Detailed Description
,
P-P
The MAX4968/MAX4968A are 16-channel, high-linearity,
high-voltage, bidirectional SPST analog switches with
18I(typ) on-resistance. The devices are ideal for use in
applications requiring high-voltage switching controlled
by a low-voltage control signal, such as ultrasound imag-
ing and printers. The MAX4968A provides integrated
40kI (typ) bleed resistors on each switch terminal to
discharge capacitive loads. Using HVCMOS technol-
ogy, these switches combine high-voltage, bilateral MOS
switches and low-power CMOS logic to provide efficient
control of high-voltage analog signals.
with an analog signal range from V
to V
+ 210V.
NN
NN
Before starting the high-voltage burst transmission (V
P-P
> +20V), the input voltage is required to be close to
GND to allow a proper settling of the pass FET. The high-
voltage burst frequency must be greater than 500kHz.
Extremely long high-voltage bursts (V
> +10V) with
P-P
duty cycle greater than 20% could result in signal deg-
radation, especially for unipolar transmission. In general,
this applies for burst transmission with a nonzero DC
content.
Low-voltage signal (V
lar transmission is supported for frequencies greater
than 500kHz. For very small signals, such as the small
echoes in typical ultrasound imaging systems (V
10V), the devices are not limited to a low-frequency
bandwidth and can transmit DC signals.
< 10V) continuous-wave bipo-
P-P
The MAX4968 is pin-to-pin compatible with the MAX14802
and Supertex HV2601. The MAX4968A is pin-to-pin
compatible with the MAX14803 and Supertex HV2701.
<
P-P
The only difference is the V
positive supply voltage
PP
level. The MAX4968/MAX4968A require a low +10V (typ)
voltage (V ), whereas the MAX14802/MAX14803 and
PP
HV2601/HV2701 require a high +100V supply voltage.
Voltage Supplies
In typical ultrasound applications, these devices do not
require dedicated high-voltage supply, which implies
a significant simplification of system requirement. The
negative voltage supply can be shared with the transmit-
ter and the positive voltage supply is typically +10V.
The devices operate with a high-voltage supply V
NN
from -200V to 0, V supply of +10V (typ), and a logic
PP
supply V
(+2.37V to +5.5V).
DD
ꢀ
16-Channel, Linear, High-Voltage
Analog Switches
(Figure 3). Drive LE logic-high to freeze the contents of
Bleed Resistors (MAX4968A)
The MAX4968A features integrated 40kI (typ) bleed
resistors to discharge capacitive loads such as piezo-
electric transducers. Each analog switch terminal is con-
nected to GND with a bleed resistor.
the latch and prevent changes to the switch states. To
reduce noise due to clock feedthrough, drive LE logic-
high while data is clocked into the shift register. After
the data shift register is loaded with valid data, pulse
LE logic-low to load the contents of the shift register into
the latch.
Serial Interface
The MAX4968/MAX4968A are controlled by a serial
interface with a 16-bit serial shift register and transparent
latch. Each of the 16 data bits controls a single analog
switch (see Table 1). Data on DIN is clocked with the
most significant bit (MSB) first into the shift register on
the rising edge of CLK. Data is clocked out of the shift
register onto DOUT on the rising edge of CLK. DOUT
reflects the status of DIN, delayed by 16 clock cycles
(see Figures 2 and 3).
Latch Clear (CLR)
The MAX4968/MAX4968A feature a latch-clear input.
Drive CLR logic-high to reset the contents of the latch
to zero and open all switches. CLR does not affect the
contents of the data shift register. Pulse LE logic-low to
reload the contents of the shift register into the latch.
Power-On Reset
The MAX4968/MAX4968A feature a power-on-reset cir-
cuit to ensure all switches are open at power-on. The
internal 16-bit serial shift register and latch are set to
zero on power-up.
Latch Enable (LE)
Drive LE logic-low to change the contents of the latch
and update the state of the high-voltage switches
Table 1. Serial Interface Programming (Notes 1–6)
CONTROL
DATA BITS
BITS
FUNCTION
D9
(LSB)
D1
D2
D3
D4
D5
D6
D7
CLR SW9 SW1 SW2 SW3 SW4 SW5 SW6 SW7
LE
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
H
X
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
H
Off
On
H
L
Off
On
H
L
Off
On
H
L
Off
On
H
L
Off
On
H
L
Off
On
H
L
Off
On
H
L
H
X
X
Off
On
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Hold Previous State
Off Off Off
Off
Off
Off
Off
Off
19
16-Channel, Linear, High-Voltage
Analog Switches
Table 1. Serial Interface Programming (Notes 1–6) (continued)
CONTROL
BITS
DATA BITS
FUNCTION
D15
(MSB)
D8
Dꢀ D19 D11 D12 D13 D14
CLR SW8 SWꢀ SW19 SW11 SW12 SW13 SW14 SW15
LE
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
H
X
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
H
Off
On
H
L
H
L
Off
On
Off
On
H
L
H
Off
On
L
H
Off
On
L
H
Off
On
L
Off
On
H
L
H
X
X
Off
On
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Hold Previous State
Off Off Off
Off
Off
Off
Off
Off
Note 1: The 16 switches operate independently.
Note 2: Serial data is clocked in on the rising edge of CLK.
Note 3: The switches go to a state retaining their present condition on the rising edge of LE. When LE is low, the shift register data
flows through the latch.
Note 4: DOUT is high when switch 15 is on.
Note 5: Shift register clocking has no effect on the switch states if LE is high.
Note 6: The CLR input overrides all other inputs.
chaining (Figure 4). Connect each DOUT to the DIN of
the subsequent device in the chain. Connect CLK, LE,
and CLR inputs of all devices, and drive LE logic-low
Applications Information
In typical ultrasound applications, the MAX4968/MAX4968A
do not require dedicated high-voltage supplies; the nega-
to update all devices simultaneously. Drive CLR high
tive voltage supply can be shared with the transmitter and
to open all the switches simultaneously. Additional shift
the positive voltage supply is typically +10V. See Figures 5,
registers can be included anywhere in series with the
6, and 7 for medical ultrasound applications.
MAX4968/MAX4968A daisy-chain.
Logic Levels
Supply Sequencing and Bypassing
The MAX4968/MAX4968A digital interface inputs CLK,
The MAX4968/MAX4968A do not require special
DIN, LE, and CLR operate on the V logic supply voltage.
DD
sequencing of the V , V
and V
supply voltages.
DD PP,
NN
Bypass V , V , and V
capacitor as close as possible to the device.
to GND with a 0.1FF ceramic
DD PP
NN
Daisy-Chaining Multiple Devices
Digital output DOUT is provided to allow the connec-
tion of multiple MAX4968/MAX4968A devices by daisy-
Note: Keep LE low during power-up.
11
16-Channel, Linear, High-Voltage
Analog Switches
Application Diagrams
U11
U10
U1n
DIN1
DOUT
DOUT
DOUT
DIN
DIN
DIN
MAX4968
MAX4968A
MAX4968
MAX4968A
MAX4968
MAX4968A
CLK
LE
CLK
LE
CLK
LE
CLK
LE
CLR
CLR
CLR
CLR
U21
U20
U2n
DOUT
DOUT
DOUT
DIN
DIN
DIN
DIN2
MAX4968
MAX4968A
MAX4968
MAX4968A
MAX4968
MAX4968A
CLK
LE
CLK
LE
CLK
LE
CLR
CLR
CLR
Figure 4. Interfacing Multiple Devices by Daisy-Chaining
12
16-Channel, Linear, High-Voltage
Analog Switches
Application Diagrams (continued)
PROBES
MAINFRAME
HIGH-VOLTAGE TRANSMIT
1 PER CHANNEL
PROBE SELECTION
2 TO 4 PROBES
CABLE
1 PER CHANNEL
TRANSDUCERS
2 TO 4 PER CHANNEL
1 TO 2A MAꢁ
1ꢀꢀV MAꢁ
RELAY
1 RELAY/CH/PROBE
PROBE
A
HIGH-VOLTAGE ANALOG
SWITCHES
2 TO 4 PER CHANNEL
PROBE
B
+V
1ꢀmA TYP
LOW-VOLTAGE RECEIVE
64 TO 128 CHANNELS
PROBE
C
1V MAꢁ
HIGH-
VOLTAGE
ISOLATION
PROBE
D
-V
Figure 5. Medical Ultrasound Application—High-Voltage Analog Switches in Probe
13
16-Channel, Linear, High-Voltage
Analog Switches
Application Diagrams (continued)
PROBES
MAINFRAME
HIGH-VOLTAGE
TRANSMIT
1 PER CHANNEL
PROBE SELECTION
2 TO 4 PROBES
HIGH-VOLTAGE ANALOG
SWITCHES
2 TO 4 PER CHANNEL
CABLE
2 TO 4 PER CHANNEL
TRANSDUCERS
2 TO 4 PER CHANNEL
1ꢀꢀV MAꢁ
1 TO 2A MAꢁ
+V
PROBE
A
RELAYS
2 TO 4 RELAYS/CH/PROBE
1ꢀmA TYP
LOW-VOLTAGE
RECEIVE
64 TO 128 CHANNELS
1V MAꢁ
HIGH-
VOLTAGE
ISOLATION
PROBE
B
-V
PROBE
C
PROBE
D
Figure 6. Medical Ultrasound Application—High-Voltage Analog Switches in Mainframe
14
16-Channel, Linear, High-Voltage
Analog Switches
Application Diagrams (continued)
PROBES
MAINFRAME
HIGH-VOLTAGE TRANSMIT
2 TO 4 PER CHANNEL
PROBE SELECTION
2 TO 4 PROBES
CABLE
2 TO 4 PER CHANNEL
TRANSDUCERS
2 TO 4 PER CHANNEL
1 TO 2A MAꢁ
1ꢀꢀV MAꢁ
RELAYS
PROBE
2 TO 4 RELAYS/CH/PROBE
A
+V
-V
LOW-VOLTAGE RECEIVE
64 TO 128 CHANNELS
1ꢀmA TYP
1V MAꢁ
PROBE
B
+V
-V
+V
-V
+V
-V
PROBE
C
+V
-V
+V
-V
PROBE
D
+V
-V
+V
-V
HIGH-VOLTAGE
ISOLATION AND
CHANNEL SELECT
2 TO 4 PER CHANNEL
Figure 7. Medical Ultrasound Application—Multiple Transmit and Isolation per Receiver Channel
15
16-Channel, Linear, High-Voltage
Analog Switches
Functional Diagram
V
DD
V
PP
CLR
SW0B
*
*
LEVEL
SHIFTER
LATCH
V
NN
DIN
SW0A
V
NN
MAX4968
MAX4968A
16-BIT
SHIFT
CLK
REGISTER
SW15B
SW15A
DOUT
*
*
LEVEL
SHIFTER
LATCH
V
NN
V
NN
LE
GND
V
NN
*BLEED RESISTORS AVAILABLE ON THE MAX4968A ONLY.
Chip Information
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maxim-ic.com/packages. Note that a
“+”, “#”, or “-“ in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PROCESS: BiCMOS
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
48 LQFP
C48+6
21-9954
ꢀ9-99ꢀ3
16
16-Channel, Linear, High-Voltage
Analog Switches
Revision History
REVISION REVISION
PAGES
DESCRIPTION
CHANGED
NUMBER
DATE
0
3/11
Initial release
—
Removed future product asterisk from MAX4968 in Ordering Information, corrected
Off-Isolation specification in Electrical Characteristics
1
2
5/11
1/12
1, 3
Updated V
specifications in Absolute Maximum Ratings and Electrical
NN
2, 3, 4, 9
Characteristics supply voltage and V
static current specifications
NN
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
17
©
2012 Maxim Integrated Products
Maxim is a registered trademark of Maxim Integrated Products, Inc.
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