M48T129Y, M48T129V

2/22

Figure 2. DIP Connections

A1

A0

DQ0

A7

A4

A3

A2

A6

A5

A13

A10

A8

A9

DQ7

A15

A11

G

E

DQ5

DQ1

DQ2

DQ3

VSS

DQ4

DQ6

A16

RST

VCC

AI02261

10

1

2

5

6

7

8

9

11

12

13

14

15

16

30

29

26

25

24

23

22

21

20

19

18

17

A12

A14

W

IRQ/FT

3

4

28

27

32

31

M48T129Y

M48T129V

Table 2. Absolute Maximum Ratings

(1)

Note: 1. Stresses greater than 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 the absolute maximum rating conditions for extended periods of time may affect

reliability.

2. Soldering temperature not to exceed 260

°C for 10 seconds (total thermal budget not to exceed 150°C for longer than 30 seconds).

CAUTION: Negative undershoots below –0.3V are not allowed on any pin while in the Battery Back-up mode.

Symbol

Parameter

Value

Unit

Ambient Operating Temperature

0 to 70

°C

–40 to 85

°C

Input or Output Voltages

V

Supply Voltage

M48T129Y

–0.3 to 7.0

V

M48T129V

–0.3 to 4.6

V

Output Current

20

mA

Power Dissipation

1

W

For surface mount environments ST provides a

Chip Set solution consisting of a 44 pin 330mil

SOIC TIMEKEEPER Supervisor (M48T201V/Y)

and a 32 pin TSOP (8 x 20mm) LPSRAM

(M68Z128/W) packages.

The 44 pin 330mil SOIC provides sockets with

gold plated contacts at both ends for direct con-

nection to a separate SNAPHAT housing contain-

ing the battery.

The unique design allows the SNAPHAT battery

package to be mounted on top of the SOIC pack-

age after the completion of the surface mount pro-

Table 1. Signal Names

A0-A16

Address Inputs

DQ0-DQ7

Data Inputs / Outputs

E

Chip Enable Input

G

Output Enable Input

W

Write Enable Input

RST

Reset Output (open drain)

IRQ/FT

Interrupt / Frequency Test Output

(open drain)

Supply Voltage

Ground

DESCRIPTION

The M48T129Y/V TIMEKEEPER RAM is a 128Kb

x 8 non-volatile static RAM and real time clock,

with programmable alarms and a watchdog timer.

The special DIP package provides a fully integrat-

ed battery back-up memory and real time clock so-

lution. The M48T129Y/V directly replaces industry

standard 128Kb x 8 SRAM. It also provides the

non-volatility of Flash without any requirement for

special write timing or limitations on the number of

writes that can be performed.