DS1746W-120 [DALLAS]

Y2K-Compliant, Nonvolatile Timekeeping RAMs; Y2K兼容,非易失时钟RAM
DS1746W-120
型号: DS1746W-120
厂家: DALLAS SEMICONDUCTOR    DALLAS SEMICONDUCTOR
描述:

Y2K-Compliant, Nonvolatile Timekeeping RAMs
Y2K兼容,非易失时钟RAM

时钟
文件: 总18页 (文件大小:226K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
DS1746/DS1746P  
Y2KC Nonvolatile Timekeeping RAM  
www.dalsemi.com  
FEATURES  
PIN ASSIGNMENT  
Integrated NV SRAM, real time clock,  
crystal, power-fail control circuit and lithium  
energy source  
Clock registers are accessed identical to the  
static RAM. These registers are resident in the  
eight top RAM locations.  
Century byte register; ie., Y2K compliant  
Totally nonvolatile with over 10 years of  
operation in the absence of power  
BCD coded century, year, month, date, day,  
hours, minutes, and seconds with automatic  
leap year compensation valid up to the year  
2100  
NC  
A16  
A14  
A12  
A7  
A6  
A5  
A4  
A3  
1
32  
31  
VCC  
A15  
NC  
WE  
A13  
A8  
2
3
4
30  
29  
5
6
28  
27  
A9  
7
8
26  
25  
A11  
OE  
A10  
CE  
9
10  
24  
23  
A2  
A1  
11  
12  
22  
21  
DQ7  
DQ6  
DQ5  
DQ4  
DQ3  
A0  
13  
14  
15  
16  
20  
19  
18  
17  
DQ0  
DQ1  
DQ2  
Battery voltage level indicator flag  
Power-fail write protection allows for ±10%  
GND  
32-Pin Encapsulated Package  
VCC power supply tolerance  
Lithium energy source is electrically  
disconnected to retain freshness until power is  
applied for the first time  
34  
NC  
NC  
A14  
1
2
3
4
5
6
7
8
9
10  
11  
12  
13  
14  
15  
16  
17  
NC  
A15  
A16  
33  
32  
31  
30  
29  
28  
27  
26  
25  
24  
23  
22  
21  
20  
19  
18  
DIP Module only  
-
Standard JEDEC bytewide 128k x 8 static  
RAM pinout  
A13  
A12  
A11  
A10  
A9  
RST  
VCC  
WE  
OE  
CE  
PowerCap Module Board only  
A8  
DQ7  
DQ6  
DQ5  
DQ4  
DQ3  
-
Surface mountable package for direct  
connection to PowerCap containing  
battery and crystal  
A7  
A6  
A5  
A4  
A3  
A2  
A1  
A0  
DQ2  
DQ1  
DQ0  
GND  
-
-
-
Replaceable battery (PowerCap)  
Power-On Reset Output  
Pin for pin compatible with other densities  
of DS174XP Timekeeping RAM  
VBAT X2  
X1 GND  
34-Pin PowerCap Module Board  
(Uses DS9034PCX PowerCap)  
1 of 18  
022101  
DS1746/DS1746P  
PIN DESCRIPTION  
A0–A16  
– Address Input  
CE  
– Chip Enable  
OE  
– Output Enable  
WE  
– Write Enable  
VCC  
– Power Supply Input  
– Ground  
– Data Input/Output  
– No Connection  
GND  
DQ0–DQ7  
NC  
RST  
– Power–on Reset Output (Power–  
Cap Module board only)  
– Crystal Connection  
X1, X2  
VBAT  
– Battery Connection  
ORDERING INFORMATION  
DS1746P  
(5V)  
blank 32-pin DIP Module  
P
34-pin PowerCap Module board*  
DS1746WP (3.3V)  
blank 32-pin DIP Module  
34-pin PowerCap Module board*  
P
*DS9034PCX (PowerCap) Required:  
(must be ordered separately)  
DESCRIPTION  
The DS1746 is a full function, year 2000 compliant (Y2KC), real-time clock/calendar (RTC) and 128k x  
8 non-volatile static RAM. User access to all registers within the DS1746 is accomplished with a  
bytewide interface as shown in Figure 1. The Real Time Clock (RTC) information and control bits reside  
in the eight uppermost RAM locations. The RTC registers contain century, year, month, date, day, hours,  
minutes, and seconds data in 24-hour BCD format. Corrections for the date of each month and leap year  
are made automatically. The RTC clock registers are double buffered to avoid access of incorrect data  
that can occur during clock update cycles. The double buffered system also prevents time loss as the  
timekeeping countdown continues unabated by access to time register data. The DS1746 also contains its  
own power-fail circuitry which deselects the device when the VCC supply is in an out of tolerance  
condition. This feature prevents loss of data from unpredictable system operation brought on by low VCC  
as errant access and update cycles are avoided.  
2 of 18  
DS1746/DS1746P  
DS1746 BLOCK DIAGRAM Figure 1  
PACKAGES  
The DS1746 is available in two packages (32-pin DIP and 34-pin PowerCap module). The 32-pin DIP  
style module integrates the crystal, lithium energy source, and silicon all in one package. The 34-pin  
PowerCap Module Board is designed with contacts for connection to a separate PowerCap (DS9034PCX)  
that contains the crystal and battery. This design allows the PowerCap to be mounted on top of the  
DS1746P after the completion of the surface mount process. Mounting the PowerCap after the surface  
mount process prevents damage to the crystal and battery due to the high temperatures required for solder  
reflow. The PowerCap is keyed to prevent reverse insertion. The PowerCap Module Board and PowerCap  
are ordered separately and shipped in separate containers. The part number for the PowerCap is  
DS9034PCX.  
CLOCK OPERATIONS-READING THE CLOCK  
While the double buffered register structure reduces the chance of reading incorrect data, internal updates  
to the DS1746 clock registers should be halted before clock data is read to prevent reading of data in  
transition. However, halting the internal clock register updating process does not affect clock accuracy.  
Updating is halted when a one is written into the read bit, bit 6 of the century register, see Table 2. As  
long as a one remains in that position, updating is halted. After a halt is issued, the registers reflect the  
count, that is day, date, and time that was current at the moment the halt command was issued. However,  
the internal clock registers of the double buffered system continue to update so that the clock accuracy is  
not affected by the access of data. All of the DS1746 registers are updated simultaneously after the  
internal clock register updating process has been re-enabled. Updating is within a second after the read bit  
is written to zero. The READ bit must be a zero for a minimum of 500 µs to ensure the external registers  
will be updated.  
3 of 18  
DS1746/DS1746P  
DS1746 TRUTH TABLE Table 1  
VCC  
MODE  
DQ  
POWER  
CE  
OE  
WE  
VIH  
VIL  
VIL  
VIL  
X
X
X
VIL  
VIH  
X
X
VIL  
VIH  
VIH  
X
DESELECT  
WRITE  
READ  
READ  
DESELECT  
DESELECT  
HIGH-Z  
DATA IN  
DATA OUT  
HIGH-Z  
HIGH-Z  
HIGH-Z  
STANDBY  
ACTIVE  
ACTIVE  
VCC>VPF  
ACTIVE  
VSO<VCC<VPF  
VCC<VSO<VPF  
CMOS STANDBY  
DATA RETENTION  
MODE  
X
X
X
SETTING THE CLOCK  
As shown in Table 2, bit 7 of the century register is the write bit. Setting the write bit to a one, like the  
read bit, halts updates to the DS1746 registers. The user can then load them with the correct day, date and  
time data in 24 hour BCD format. Resetting the write bit to a zero then transfers those values to the actual  
clock counters and allows normal operation to resume.  
STOPPING AND STARTING THE CLOCK OSCILLATOR  
The clock oscillator may be stopped at any time. To increase the shelf life, the oscillator can be turned off  
to minimize current drain from the battery. The OSC bit is the MSB (bit 7) of the seconds registers, see  
Table 2. Setting it to a one stops the oscillator.  
FREQUENCY TEST BIT  
As shown in Table 2, bit 6 of the day byte is the frequency test bit. When the frequency test bit is set to  
logic “1” and the oscillator is running, the LSB of the seconds register will toggle at 512 Hz. When the  
seconds register is being read, the DQ0 line will toggle at the 512 Hz frequency as long as conditions for  
access remain valid (i.e., CE low, OE low, WE high, and address for seconds register remain valid and  
stable).  
CLOCK ACCURACY (DIP MODULE)  
The DS1746 is guaranteed to keep time accuracy to within ±1 minute per month at 25°C. The RTC is  
calibrated at the factory by Dallas Semiconductor using nonvolatile tuning elements, and does not require  
additional calibration. For this reason, methods of field clock calibration are not available and not  
necessary. Clock accuracy is also effected by the electrical environment and caution should be taken to  
place the RTC in the lowest level EMI section of the PCB layout. For additional information please see  
application note 58.  
CLOCK ACCURACY (POWERCAP MODULE)  
The DS1746 and DS9034PCX are each individually tested for accuracy. Once mounted together, the  
module will typically keep time accuracy to within ±1.53 minutes per month (35 ppm) at 25°C. Clock  
accuracy is also effected by the electrical environment and caution should be taken to place the RTC in  
the lowest level EMI section of the PCB layout. For additional information please see application note  
58.  
4 of 18  
DS1746/DS1746P  
DS1746 REGISTER MAP Table 2  
DATA  
B4  
ADDRESS  
FUNCTION/RANGE  
B7  
B6  
B5  
10 YEAR  
X
B3  
X
B2  
B1  
B0  
1FFFF  
1FFFE  
1FFFD  
1FFFC  
1FFFB  
1FFFA  
1FFF9  
YEAR  
YEAR  
MONTH  
DATE  
00-99  
01-12  
01-31  
01-07  
00-23  
00-59  
00-59  
00-39  
X
X
BF  
X
X
X
FT  
X
10 MO  
10 DATE  
MONTH  
DATE  
X
X
DAY  
DAY  
10 HOUR  
HOUR  
HOUR  
X
10 MINUTES  
10 SECONDS  
10 CENTURY  
MINUTES  
SECONDS  
CENTURY  
MINUTES  
SECONDS  
CENTURY  
OSC  
W
1FFF8  
R
OSC = STOP BIT  
= WRITE BIT  
R
X
= READ BIT  
= SEE NOTE BELOW  
FT = FREQUENCY TEST  
BF = BATTERY FLAG  
W
NOTE:  
All indicated “X” bits are not dedicated to any particular function and can be used as normal RAM bits.  
RETRIEVING DATA FROM RAM OR CLOCK  
The DS1746 is in the read mode whenever OE (output enable) is low, WE (write enable) is high, and CE  
(chip enable) is low. The device architecture allows ripple-through access to any of the address locations  
in the NV SRAM. Valid data will be available at the DQ pins within tAA after the last address input is  
stable, providing that the CE and OE access times and states are satisfied. If CE or OE access times  
and states are not met, valid data will be available at the latter of chip enable access (tCEA) or at output  
enable access time (tOEA). The state of the data input/output pins (DQ) is controlled by CE and OE . If the  
outputs are activated before tAA , the data lines are driven to an intermediate state until tAA . If the address  
inputs are changed while CE and OE remain valid, output data will remain valid for output data hold  
time (tOH) but will then go indeterminate until the next address access.  
WRITING DATA TO RAM OR CLOCK  
The DS1746 is in the write mode whenever WE , and CE are in their active state. The start of a write is  
referenced to the latter occurring transition of WE , or CE . The addresses must be held valid throughout  
the cycle. CE or WE must return inactive for a minimum of tWR prior to the initiation of another read or  
write cycle. Data in must be valid tDS prior to the end of write and remain valid for tDS afterward. In a  
typical application, the OE signal will be high during a write cycle. However, OE can be active  
provided that care is taken with the data bus to avoid bus contention. If OE is low prior to  
WE transitioning low the data bus can become active with read data defined by the address inputs. A low  
transition on WE will then disable the output tWEZ after WE goes active.  
5 of 18  
DS1746/DS1746P  
DATA RETENTION MODE  
The 5-volt device is fully accessible and data can be written or read only when VCC is greater than VPF  
.
However, when VCC is below the power fail point, VPF , (point at which write protection occurs) the  
internal clock registers and SRAM are blocked from any access. At this time the power fail reset output  
signal (RST) is driven active and will remain active until VCC returns to nominal levels. When VCC falls  
below the battery switch point VSO (battery supply level), device power is switched from the VCC pin to  
the backup battery. RTC operation and SRAM data are maintained from the battery until VCC is returned  
to nominal levels. The 3.3 volt device is fully accessible and data can be written or read only when VCC is  
greater than VPF . When VCC falls below the power fail point, VPF , access to the device is inhibited. At this  
time the power fail reset output signal (RST ) is driven active and will remain active until VCC returns to  
nominal levels. If VPF is less than VSO, the device power is switched from VCC to the backup supply  
(VBAT) when VCC drops below VPF  
.
If VPF is greater than VSO  
,
the device power is switched from VCC to  
the backup supply (VBAT when VCC drops below VSO  
)
.
RTC operation and SRAM data are maintained  
from the battery until VCC is returned to nominal levels. The RST signal is an open drain output and  
requires a pull up. Except for the RST , all control, data, and address signals must be powered down  
when VCC is powered down.  
BATTERY LONGEVITY  
The DS1746 has a lithium power source that is designed to provide energy for clock activity, and clock  
and RAM data retention when the VCC supply is not present. The capability of this internal power supply  
is sufficient to power the DS1746 continuously for the life of the equipment in which it is installed. For  
specification purposes, the life expectancy is 10 years at 25°C with the internal clock oscillator running in  
the absence of VCC power. Each DS1746 is shipped from Dallas Semiconductor with its lithium energy  
source disconnected, guaranteeing full energy capacity. When VCC is first applied at a level greater than  
VPF , the lithium energy source is enabled for battery backup operation. Actual life expectancy of the  
DS1746 will be much longer than 10 years since no lithium battery energy is consumed when VCC is  
present.  
BATTERY MONITOR  
The DS1746 constantly monitors the battery voltage of the internal battery. The Battery Flag bit (bit 7) of  
the day register is used to indicate the voltage level range of the battery. This bit is not writable and  
should always be a one when read. If a zero is ever present, an exhausted lithium energy source is  
indicated and both the contents of the RTC and RAM are questionable.  
6 of 18  
DS1746/DS1746P  
ABSOLUTE MAXIMUM RATINGS*  
Voltage on Any Pin Relative to Ground  
Storage Temperature  
–0.3V to +6.0V  
–40°C to +85°C  
Soldering Temperature  
260°C for 10 seconds (DIP Package) (See Note 7)  
See IPC/JEDEC Standard J-STD-020A for  
Surface Mount Devices  
* This is a stress rating only and functional operation of the device at these or any other condition above  
those indicated in the operation sections of this specification is not implied. Exposure to absolute  
maximum rating conditions for extended periods of time may affect reliability.  
OPERATING RANGE  
Range  
Temperature  
VCC  
Commercial  
0°C to +70°C  
3.3V ± 10% or 5V ± 10%  
RECOMMENDED DC OPERATING CONDITIONS (Over the Operating Range)  
PARAMETER  
Logic 1 Voltage All Inputs  
VCC = 5V±10%  
SYMBOL  
MIN  
TYP  
MAX  
VCC+0.3  
V
VCC+0.3  
V
UNITS NOTES  
VIH  
2.2  
V
V
1
1
VCC = 3.3V±10%  
VIH  
2.0  
Logic 0 Voltage All Inputs  
VCC = 5V±10%  
VIL  
VIL  
-0.3  
-0.3  
0.8  
0.6  
V
V
1
1
VCC = 3.3V±10%  
DC ELECTRICAL CHARACTERISTICS  
(Over the Operating Range; VCC = 5.0V ± 10%)  
PARAMETER  
SYMBOL  
MIN  
TYP  
MAX  
UNITS NOTES  
Active Supply Current  
TTL Standby Current  
Icc  
85  
mA  
2,3  
Icc1  
6
mA  
2,3  
(CE = VIH)  
CMOS Standby Current  
Icc2  
IIL  
4
mA  
2,3  
(CE VCC-0.2V)  
Input Leakage Current (any input)  
Output Leakage Current  
(any output)  
-1  
-1  
+1  
+1  
µA  
µA  
IOL  
Output Logic 1 Voltage  
(IOUT = -1.0 mA)  
Output Logic 0 Voltage  
(IOUT = +2.1 mA)  
VOH  
VOL  
2.4  
1
1
0.4  
Write Protection Voltage  
Battery Switch Over Voltage  
VPF  
VSO  
4.25  
4.50  
V
1
1,4  
VBAT  
7 of 18  
DS1746/DS1746P  
DC ELECTRICAL CHARACTERISTICS  
(Over the Operating Range; VCC = 3.3V ± 10%)  
PARAMETER  
SYMBOL  
MIN  
TYP  
MAX  
UNITS NOTES  
Active Supply Current  
TTL Standby Current  
Icc  
30  
mA  
2,3  
Icc1  
2
mA  
2,3  
(CE = VIH)  
CMOS Standby Current  
Icc2  
IIL  
2
mA  
2,3  
(CE VCC-0.2V)  
Input Leakage Current (any input)  
Output Leakage Current  
(any output)  
-1  
-1  
+1  
+1  
µA  
µA  
IOL  
Output Logic 1 Voltage  
(IOUT = -1.0 mA)  
VOH  
2.4  
1
Output Logic 0 Voltage  
(IOUT = +2.1 mA)  
Write Protection Voltage  
Battery Switch Over Voltage  
VOL  
VPF  
0.4  
1
1
2.80  
2.97  
V
V
VBAT  
or  
VSO  
1,4  
VPF  
READ CYCLE, AC CHARACTERISTICS  
(Over the Operating Range; VCC = 5.0V ± 10%)  
PARAMETER  
SYMBOL  
MIN  
TYP  
MAX  
UNITS NOTES  
tRC  
70  
ns  
Read Cycle Time  
Address Access Time  
CE to DQ Low-Z  
CE Access Time  
tAA  
tCEL  
tCEA  
tCEZ  
tOEL  
tOEA  
tOEZ  
tOH  
70  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
5
5
5
70  
25  
CE Data Off Time  
OE to DQ Low-Z  
OE Access Time  
35  
25  
OE Data Off Time  
Output Hold from Address  
8 of 18  
DS1746/DS1746P  
READ CYCLE, AC CHARACTERISTICS  
(Over the Operating Range; VCC = 3.3V ± 10%)  
PARAMETER  
SYMBOL  
MIN  
TYP  
MAX  
UNITS NOTES  
tRC  
120  
ns  
Read Cycle Time  
Address Access Time  
CE to DQ Low-Z  
CE Access Time  
tAA  
tCEL  
tCEA  
tCEZ  
tOEL  
tOEA  
tOEZ  
tOH  
120  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
5
5
5
120  
40  
CE Data Off Time  
OE to DQ Low-Z  
OE Access Time  
100  
35  
OE Data Off Time  
Output Hold from Address  
READ CYCLE TIMING DIAGRAM  
9 of 18  
DS1746/DS1746P  
WRITE CYCLE, AC CHARACTERISTICS  
(Over the Operating Range; VCC = 5.0V ± 10%)  
PARAMETER  
SYMBOL  
MIN  
TYP  
MAX  
UNITS  
NOTES  
Write Cycle Time  
tWC  
70  
ns  
Address Setup Time  
tAS  
tWEW  
tCEW  
tDS  
0
50  
60  
30  
0
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
WE Pulse Width  
CE Pulse Width  
Data Setup Time  
Data Hold Time  
Data Hold Time  
Address Hold Time  
Address Hold Time  
tDH1  
tDH2  
tAH1  
tAH2  
tWEZ  
tWR  
8
9
8
9
0
5
5
25  
WE Data Off Time  
Write Recovery Time  
5
WRITE CYCLE, AC CHARACTERISTICS  
(Over the Operating Range; VCC = 3.3V ± 10%)  
PARAMETER  
SYMBOL  
MIN  
TYP  
MAX  
UNITS  
NOTES  
Write Cycle Time  
tWC  
120  
ns  
Address Setup Time  
tAS  
tWEW  
tCEW  
tCEW  
tDS  
0
100  
110  
110  
80  
0
120  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
WE Pulse Width  
CE Pulse Width  
CE and CE2 Pulse Width  
Data Setup Time  
Data Hold Time  
tDH1  
tDH2  
tAH1  
tAH2  
tWEZ  
tWR  
8
9
8
9
Data Hold Time  
0
Address Hold Time  
Address Hold Time  
0
10  
40  
WE Data Off Time  
Write Recovery Time  
10  
10 of 18  
DS1746/DS1746P  
WRITE CYCLE TIMING DIAGRAM, WRITE ENABLE CONTROLLED  
WRITE CYCLE TIMING DIAGRAM, CHIP ENABLE CONTROLLED  
11 of 18  
DS1746/DS1746P  
POWERUP/DOWN AC CHARACTERISTICS  
(Over the Operating Range; VCC = 5.0V ± 10%)  
PARAMETER  
SYMBOL  
MIN  
TYP  
MAX  
UNITS NOTES  
tPD  
0
µs  
CE or WE at VH  
Before Power-down  
VCC Fall Time: VPF(MAX) to  
VPF(MIN)  
tF  
300  
µs  
VCC Fall Time: VPF(MIN) to VSO  
VCC Rise Time: VPF(MIN) to  
VPF(MAX)  
tFB  
tR  
10  
0
µs  
µs  
Power-up Recover Time  
Expected Data Retention Time  
(Oscillator ON)  
tREC  
tDR  
35  
ms  
years  
10  
5,6  
POWER–UP/POWER–DOWN TIMING 5 VOLT DEVICE  
12 of 18  
DS1746/DS1746P  
POWER–UP/DOWN CHARACTERISTICS  
(Over the Operating Range; VCC = 3.3V ± 10%)  
PARAMETER  
SYMBOL  
MIN  
TYP  
MAX  
UNITS  
NOTES  
tPD  
0
µs  
CE or WE at VH, Before  
Power-down  
VCC Fall Time: VPF(MAX) to  
VPF(MIN)  
VCC Rise Time: VPF(MIN) to  
VPF(MAX)  
tF  
300  
0
µs  
µs  
tR  
tREC  
tDR  
35  
ms  
VPF to RST High  
Expected Data Retention Time  
(Oscillator ON)  
10  
years  
5,6  
POWER–UP/DOWN WAVEFORM TIMING 3.3 VOLT DEVICE  
CAPACITANCE  
t A = 25°C)  
PARAMETER  
SYMBOL  
CIN  
MIN  
TYP  
MAX  
7
10  
UNITS  
NOTES  
Capacitance on all input pins  
Capacitance on all output pins  
pF  
pF  
CO  
13 of 18  
DS1746/DS1746P  
AC TEST CONDITIONS  
Output Load:  
Input Pulse Levels:  
100 pF + 1TTL Gate  
0.0 to 3.0V  
Timing Measurement Reference Levels:  
Input: 1.5V  
Output: 1.5V  
Input Pulse Rise and Fall Times: 5 ns  
NOTES:  
1. Voltages are referenced to ground.  
2. Typical values are at 25°C and nominal supplies.  
3. Outputs are open.  
4. Battery switch over occurs at the lower of either the battery terminal voltage or VPF  
.
5. Data retention time is at 25°C.  
6. Each DS1746 has a built–in switch that disconnects the lithium source until VCC is first applied by the  
user. The expected tDR is defined for DIP modules and assembled PowerCap modules as a cumulative  
time in the absence of V CC starting from the time power is first applied by the user.  
7. Real–Time Clock Modules (DIP) can be successfully processed through conventional wave–soldering  
techniques as long as temperatures as long as temperature exposure to the lithium energy source  
contained within does not exceed +85°C. Post solder cleaning with water washing techniques is  
acceptable, provided that ultra-sonic vibration is not used.  
In addition, for the PowerCap:  
a. Dallas Semiconductor recommends that PowerCap Module bases experience one pass through  
solder reflow oriented with the label side up (“live – bug”).  
b. Hand Soldering and touch–up: Do not touch or apply the soldering iron to leads for more than  
3 (three) seconds. To solder, apply flux to the pad, heat the lead frame pad and apply solder. To  
remove the part, apply flux, heat the lead frame pad until the solder reflows and use a solder wick  
to remove solder.  
8.tAH1 , tDH1 are measured from WE going high.  
9. tAH2 , tDH2 are measured from CE going high.  
14 of 18  
DS1746/DS1746P  
DS1647 32–PIN PACKAGE  
PKG  
DIM  
A IN.  
MM  
32-PIN  
MAX  
MIN  
1.670  
38.42  
0.715  
18.16  
0.335  
8.51  
1.690  
38.93  
0.740  
18.80  
0.365  
9.27  
B
C
D
E
F
IN.  
MM  
IN.  
MM  
IN.  
MM  
IN.  
MM  
IN.  
MM  
IN.  
MM  
IN.  
MM  
IN.  
MM  
IN.  
MM  
0.075  
1.91  
0.105  
0.67  
0.015  
0.38  
0.030  
0.76  
0.140  
3.56  
0.180  
4.57  
G
H
J
0.090  
2.29  
0.110  
2.79  
0.590  
14.99  
0.010  
0.25  
0.630  
16.00  
0.018  
0.45  
K
0.015  
0.38  
0.025  
0.64  
15 of 18  
DS1746/DS1746P  
DS1746P  
PKG  
DIM  
A
B
C
D
E
F
G
INCHES  
MIN  
0.920  
0.980  
-
0.052  
0.048  
0.015  
0.025  
NOM  
0.925  
0.985  
-
0.055  
0.050  
0.020  
0.027  
MAX  
0.930  
0.990  
0.080  
0.058  
0.052  
0.025  
0.030  
NOTE:  
Dallas Semiconductor recommends that PowerCap Module bases experience one pass through solder  
reflow oriented with the label side up (“live – bug”).  
Hand Soldering and touch–up: Do not touch or apply the soldering iron to leads for more than 3 (three)  
seconds. To solder, apply flux to the pad, heat the lead frame pad and apply solder. To remove the part,  
apply flux, heat the lead frame pad until the solder reflows and use a solder wick to remove solder.  
16 of 18  
DS1746/DS1746P  
DS1746P WITH DS9034PCX ATTACHED  
PKG  
INCHES  
DIM MIN NOM MAX  
A
B
C
D
E
F
0.920 0.925 0.930  
0.955 0.960 0.965  
0.240 0.245 0.250  
0.052 0.055 0.058  
0.048 0.050 0.052  
0.015 0.020 0.025  
0.020 0.025 0.030  
G
COMPONENTS AND PLACEMENT MAY  
VARY FROM EACH DEVICE TYPE  
17 of 18  
DS1746/DS1746P  
RECOMMENDED POWERCAP MODULE LAND PATTERN  
PKG  
INCHES  
DIM  
MIN  
NOM MAX  
A
B
C
D
E
-
-
-
-
-
1.050  
0.826  
0.050  
0.030  
0.112  
-
-
-
-
-
18 of 18  

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