DS1642-100+ Maxim Integrated Products, DS1642-100+ Datasheet - Page 2

• Manufacturer Part Number: DS1642-100+
• Description: IC RAM TIMEKEEP NV 100NS 24-EDIP
• Manufacturer: Maxim Integrated Products
• Type: Clock/Calendar/NVSRAMr

Specifications of DS1642-100+

• Memory Size: 16K (2K x 8)
• Time Format: HH:MM:SS (24 hr)
• Date Format: YY-MM-DD-dd
• Interface: Parallel
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 24-DIP (600 mil) Module
• Function: Clock/Calendar/NV Timekeeping RAM
• Rtc Memory Size: 2048 Byte
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4.5 V
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: Through Hole
• Rtc Bus Interface: Parallel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PIN DESCRIPTION
DESCRIPTION
The DS1642 is a 2k x 8 nonvolatile static RAM and a full-function real-time clock (RTC), both of which
are accessible in a bytewide format. The nonvolatile time keeping RAM is pin and function equivalent to
any JEDEC-standard 2k x 8 SRAM. The device can also be easily substituted in ROM, EPROM, and
EEPROM sockets, providing read/write nonvolatility and the addition of the real-time clock function. The
real-time clock information resides in the eight uppermost RAM locations. The RTC registers contain
year, month, date, day, hours, minutes, and seconds data in 24-hour BCD format. Corrections for the day
of the 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
DS1642 also contains its own power-fail circuitry, which deselects the device when the V
an out-of-tolerance condition. This feature prevents loss of data from unpredictable system operation
brought on by low V
PIN
19
22
23
10
11
13
14
15
16
17
12
18
20
21
24
1
2
3
4
5
6
7
8
9
NAME
GND
DQ0
DQ1
DQ2
DQ3
DQ4
DQ5
DQ6
DQ7
A10
V
WE
OE
A7
A6
A5
A4
A3
A2
A1
A0
A9
A8
CE
CC
CC
Address Input
Data Input/Output
Ground
Active-Low Chip-Enable Input
Active-Low Output-Enable Input
Active-Low Write-Enable Input
Power-Supply Input
as errant access and update cycles are avoided.
FUNCTION
2 of 13
CC
supply is in
DS1642