FM31T372/374/376/378-G
A general-purpose comparator compares an external
input pin to the onboard 1.2V reference. This is
useful for generating a power-fail interrupt (NMI) but
can be used for any purpose. The family also includes
a programmable 64-bit serial number that can be
locked making it unalterable. Additionally it offers a
dual battery-backed event counter that tracks the
number of rising or falling edges detected on
dedicated input pins.
Pin Configuration
CNT1
CNT2
A0
A1
CAL/PFO
RST
VSS
1
2
3
4
5
6
7
14
13
12
11
10
9
8
Pin Name
CNT1, CNT2
A0, A1
CAL/PFO
VDD
SCL
SDA
F
OUT
/INT
PFI
VBAK
/RST
VSS
VBAK
PFI
/INT
FOUT
SDA
SCL
VDD
Function
Event Counter Inputs
Device Select inputs
Clock Calibration and Early
Power-Fail Output
Reset Input/Output
Ground
Battery-Backup Supply
Early Power-fail Input
Event Counter Driven Interrupt
Output
32.768 kHz Clock Output
Serial Data
Serial Clock
Supply Voltage
Ordering Information
Base Configuration
FM31T378
FM31T376
FM31T374
FM31T372
Memory Size
256Kb
64Kb
16Kb
4Kb
Operating Voltage
2.7-5.5V
2.7-5.5V
2.7-5.5V
2.7-5.5V
Reset Threshold
2.6V, 2.9, 3.9, 4.4V
2.6V, 2.9, 3.9, 4.4V
2.6V, 2.9, 3.9, 4.4V
2.6V, 2.9, 3.9, 4.4V
Ordering Part Number
FM31T378-G
FM31T376-G
FM31T374-G
FM31T372-G
Rev. 1.1
Apr. 2011
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