M41T81S Datasheet, PDF (5/29 Pages) STMicroelectronics – Serial Access Real-Time Clock with Alarms

Figure 3. 8-pin SOIC (M) Connections
XI
XO
V_BAT
V_SS
1
8
2
7
3 ^M41T81S 6
4
5
V_CC
IRQ/FT/OUT/SQW⁽¹⁾
SCL
SDA
AI09161
Note: 1. Open Drain Output
Figure 5. Block Diagram
CRYSTAL
SDA
SCL
V_CC
32KHz
OSCILLATOR
I²C
INTERFACE
WRITE
PROTECT
M41T81S
Figure 4. 18-pin, 300mil SOIC (MY)
Connections
NC
NF(1)
NF(1)
NC
NC
NC
NC
V_BAT
V_SS
1
18
2
17
3
16
4
15
5 _M41T81S 14
6
13
7
12
8
11
9
10
NC
NF(1)
NF(1)
VCC
NC
IRQ/FT/OUT/SQW(2)
NC
SCL
SDA
AI09162
Note: 1. NC and NF pins should be tied to VSS. Pins 2 and 3 are
internally shorted together. Pins 17 and 16 are internally
shorted together.
2. Open Drain Output
REAL TIME CLOCK
CALENDAR
OSCILLATOR FAIL OFIE
CIRCUIT
RTC W/ALARM ^AFE
& CALIBRATION
WATCHDOG
SQWE⁽²⁾
SQUARE WAVE
FREQUENCY TEST ^FT
OUTPUT DRIVER ^OUT
INTERNAL
POWER
IRQ/FT/OUT/SQW⁽¹⁾
V_BAT
V_SO
V_PFD
COMPARE
Note: 1. Open Drain Output
2. Square Wave function has the highest priority on IRQ/FT/OUT/SQW output.
AI09163
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