Rainbow Electronics DS17887 - Manual (Page 2)

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