DS1244/DS1244P

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PIN DESCRIPTION

- Address Inputs

CE

- Chip Enable

OE

- Output Enable

WE

- Write Enable

- Power-Supply Input

GND

- Ground

- Data In/Data Out

N.C.

- No Connection

X1, X2

- Crystal Connection

- Battery Connection

RST

- Reset

TYPICAL OPERATING CIRCUIT

ORDERING INFORMATION

PART

PIN-PACKAGE

TEMP RANGE

TOP MARK

DS1244Y-70

28-Module (740mil)

0°C to +70°C

DS1244Y-70

DS1244YP-70

0°C to +70°C

DS1244YP-70

DS1244W-120

28-Module (740mil)

0°C to +70°C

DS1244W-120

DS1244W-120IND

28-Module (740mil)

-40°C to +85°C

DS1244W-120IND

DS1244WP-120

0°C to +70°C

DS1244WP-120

-40°C to +85°C

DS1244WP-120IND

*

DS9034PCX (PowerCap) Required. (Must be ordered separately.)

DESCRIPTION

The DS1244 256k NV SRAM with a Phantom clock is a fully static nonvolatile RAM (NV SRAM)

(organized as 32k words by 8 bits) with a built-in real-time clock. The DS1244 has a self-contained

condition. When such a condition occurs, the lithium energy source is automatically switched on and

write protection is unconditionally enabled to prevent garbled data in both the memory and real-time

clock.

The phantom clock provides timekeeping information for hundredths of seconds, seconds, minutes, hours,

days, date, months, and years. The date at the end of the month is automatically adjusted for months with

fewer than 31 days, including correction for leap years. The phantom clock operates in either 24-hour or

12-hour format with an AM/PM indicator.

PACKAGES

The DS1244 is available in two packages: 28-pin DIP and 34-pin PowerCap module. The 28-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

DS1244P 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.