M48T58 Datasheet, PDF (1/17 Pages) STMicroelectronics – 64 Kbit 8Kb x8 TIMEKEEPER SRAM

M48T58
M48T58Y
64 Kbit (8Kb x8) TIMEKEEPER^® SRAM
INTEGRATED ULTRA LOW POWER SRAM,
REAL TIME CLOCK, POWER-FAIL CONTROL
CIRCUIT and BATTERY
BYTEWIDE™ RAM-LIKE CLOCK ACCESS
BCD CODED YEAR, MONTH, DAY, DATE,
HOURS, MINUTES and SECONDS
FREQUENCY TEST OUTPUT for REAL TIME
CLOCK
AUTOMATIC POWER-FAIL CHIP DESELECT and
WRITE PROTECTION
WRITE PROTECT VOLTAGES
(VPFD = Power-fail Deselect Voltage):
– M48T58: 4.5V ≤ VPFD ≤ 4.75V
– M48T58Y: 4.2V ≤ VPFD ≤ 4.5V
SELF-CONTAINED BATTERY and CRYSTAL
in the CAPHAT DIP PACKAGE
PACKAGING INCLUDES a 28-LEAD SOIC
and SNAPHAT^® TOP
(to be Ordered Separately)
SOIC PACKAGE PROVIDES DIRECT
CONNECTION for a SNAPHAT TOP which
CONTAINS the BATTERY and CRYSTAL
PIN and FUNCTION COMPATIBLE with
JEDEC STANDARD 8K x 8 SRAMs
DESCRIPTION
The M48T58/58Y TIMEKEEPER^® RAM is an 8K x
8 non-volatile static RAM and real time clock. The
monolithic chip is available in two special packages
to provide a highly integrated battery backed-up
memory and real time clock solution.
Table 1. Signal Names
A0-A12
DQ0-DQ7
FT
E1
E2
G
W
V_CC
V_SS
Address Inputs
Data Inputs / Outputs
Frequency Test Output (Open Drain)
Chip Enable 1
Chip Enable 2
Output Enable
Write Enable
Supply Voltage
Ground
July 1999
SNAPHAT (SH)
Battery/Crystal
28
1
SOH28 (MH)
28
1
PCDIP28 (PC)
Battery/Crystal
CAPHAT
Figure 1. Logic Diagram
VCC
13
A0-A12
8
DQ0-DQ7
W
M48T58
E1
M48T58Y
FT
E2
G
VSS
AI01374B
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