DS1689S/T&R Maxim Integrated, DS1689S/T&R Datasheet - Page 12

• Manufacturer Part Number: DS1689S/T&R
• Description: Real Time Clock
• Manufacturer: Maxim Integrated
• Series: DS1689, DS1693r

Specifications of DS1689S/T&R

• Function: Clock, Calendar, NV SRAM Control
• Rtc Bus Interface: Multiplexed
• Date Format: DW
• Time Format: HH
• Rtc Memory Size: 114 B
• Supply Voltage - Max: 5.5 V
• Supply Voltage - Min: 2.7 V
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Package / Case: SOIC-28
• Part # Aliases: 90-1689S-TRL

Table 2. Periodic Interrupt Rate and Square-Wave Output Frequency
Note: RS3–RS0 determine periodic interrupt rates as listed for E32K = 0.
The third method uses a periodic interrupt to determine if an update cycle is in progress. The UIP bit in
Register A is set high between the setting of the PF bit in Register C (see Figure 3). Periodic interrupts
that occur at a rate of greater than t
occurrence of the periodic interrupt. The reads should be complete within (t
data is not read during the update cycle.
Figure 3. Update-Ended and Periodic Interrupt Relationship
EXT. REG. B
E32K
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
RS3
SELECT BITS REGISTER A
X
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
RS2
X
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
BUC
RS1
X
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
allow valid time and date information to be reached at each
RS0
X
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
12 of 36
INTERRUPT RATE
None
3.90625ms
7.8125ms
122.070µs
244.141µs
488.281µs
976.5625µs
1.953125ms
3.90625ms
7.8125ms
15.625ms
31.25ms
62.5ms
125ms
250ms
500ms
(See Note)
t
PI
PERIODIC
PI
/ 2 + t
None
256Hz
128Hz
8.192kHz
4.096kHz
2.048kHz
1.024kHz
512Hz
256Hz
128Hz
64Hz
32Hz
16Hz
8Hz
4Hz
2Hz
32.768kHz
SQW OUTPUT
FREQUENCY
BUC
) to ensure that