DS17885/DS17887

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ORDERING INFORMATION

PART #

DESCRIPTION

DS17885XX-X RTC Chip

DS17887X-X

RTC Module; 24-pin DIP

PIN DESCRIPTION

X1

- Crystal Input

X2

- Crystal Output

RCLR

- RAM Clear Input

AD0–AD7 - Multiplexed Address/Data Bus

PWR

- Power-On Interrupt Output (Open Drain)

KS

- Kickstart Input

CS

- RTC Chip-Select Input

ALE

- RTC Address Strobe

WR

- RTC Write Data Strobe

RD

- RTC Read Data Strobe

IRQ

- Interrupt Request Output (Open Drain)

SQW

- Square-Wave Output

VCC

- +3V or +5V Main Supply

GND

- Ground

VBAT

- Battery + Supply

VBAUX

- Auxiliary Battery Supply

NC

- No Connect

DESCRIPTION

The DS17885/DS17887 are real-time clocks (RTCs) designed as successors to the industry standard

DS1285, DS1385, DS1485, DS1585, and DS1685 PC real-time clocks. These devices provide the

industry standard DS1285 clock function with either +3V or +5V operation. The DS17885 also

incorporates a number of enhanced features including a silicon serial number, power-on/off control

circuitry, 114 bytes of user NV SRAM plus 8kB of additional NV RAM, and 32.768kHz output for

sustaining power management activities.

3

+3V operating rang

5

+5V operating range

blank commercial temp range

N

industrial

3

+3V operating range

5

+5V operating range

blank commercial temp range

N

industrial temp range

blank 24-pin DIP

E

28- pin TSOP

S

24- pin SO