DS17887-5 Maxim Integrated Products, DS17887-5 Datasheet - Page 9

• Manufacturer Part Number: DS17887-5
• Description: IC RTC 5V 8K NV RAM 24-EDIP
• Manufacturer: Maxim Integrated Products
• Type: Clock/Calendar/NVSRAMr

Specifications of DS17887-5

• Memory Size: 64K (8K x 8)
• Time Format: HH:MM:SS (12/24 hr)
• Date Format: YY-MM-DD-dd
• Interface: Parallel
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 24-DIP (600 mil) Module
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: DS178875

(DS17x87
2, 3, 16,
only)
24
21
22
23
24
20
PIN
11, 18
6, 7
28
3
4
5
NAME
V
SQW
N.C.
V
BAUX
CC
Active-Low RAM Clear Input. This pin is used to clear (set to logic 1) all the 114 bytes of
general-purpose RAM but does not affect the RAM associated with the real time clock or
extended RAM.
or by a switch) and not to be driven with external buffers. This pin is internally pulled up. Do
not use an external pullup resistor on this pin.
Auxiliary Battery Input. Required for kickstart and wake-up functions. This input also
supports clock/calendar and user RAM if V
+3V lithium cell or other energy source can be used. Diodes placed in series between
V
reverse charging current when used with a lithium battery (www.maxim-ic.com/qa/info/ul/).
For 3V V
V
and the auxiliary-battery-enable bit bank 1, register 4BH, should = 0.
Square-Wave Output. When V
condition enables a 32kHz square-wave output. A square wave is output if either SQWE = 1
or E32k = 1. If E32k = 1, then 32kHz is output regardless of the other control bits. If E32k =
0, then the output frequency is dependent on the control bits in Register A. The SQW pin
can output a signal from one of 13 taps provided by the 15 internal divider stages of the
RTC. The frequency of the SQW pin can be changed by programming Register A, as shown
in Table 3. The SQW signal can be turned on and off using the SQWE bit in Register B or the
E32k bit in extended register 4Bh. A 32kHz square wave is also available when V
than V
SQW is high impedance when V
DC Power Pin for Primary Power Supply. When V
device is fully accessible and data can be written and read. When V
and writes are inhibited.
No Connection
BAUX
BAUX
_____________________________________________________________________
PF
function is designed to be used via a human interface (shorting to ground manually
and the battery may prevent proper operation. UL recognized to ensure against
must be held between +2.5V and +5.2V. If V
CC
if E32k = 1, ABE = 1, and voltage is applied to the V
operation, V
may be invoked while the part is powered from any supply. The
BAUX
must be held between +2.5V and +3.7V. For 5V V
CC
CC
rises above V
is below V
FUNCTION
BAT
Pin Description (continued)
PF
Real-Time Clocks
PF
is at lower voltage or is not used. A standard
.
CC
, bits DV1 and E32k are set to 1. This
is applied within normal limits, the
BAUX
is not used it should be grounded
BAUX
pin. When disabled,
CC
is below V
CC
operation,
PF
CC
reads
is less
9