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 Name
CNT1, CNT2
A0, A1
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
Pin Configuration
CAL/PFO
VDD
SCL
1
2
14
13
CNT1
CNT2
A0
/RST
VSS
VBAK
PFI
3
4
12
11
SDA
FOUT
/INT
PFI
A1
/INT
5
6
7
10
9
CAL/PFO
FOUT
SDA
SCL
32.768 kHz Clock Output
Serial Data
Serial Clock
RST
VSS
8
VBAK
VDD
Supply Voltage
Ordering Information
Base Configuration Memory Size Operating Voltage Reset Threshold
Ordering Part Number
FM31T378-G
FM31T376-G
FM31T374-G
FM31T372-G
FM31T378
FM31T376
FM31T374
FM31T372
256Kb
64Kb
16Kb
4Kb
2.7-5.5V
2.7-5.5V
2.7-5.5V
2.7-5.5V
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
Rev. 1.1
Apr. 2011
Page 2 of 26