FM3540 Datasheet, PDF (1/10 Pages) Fairchild Semiconductor – 4/5 Bit Multiplexed, 1 Bit Latched Port with Standard 2-Wire Bus Interface and Non-Volatile Latches

October 2001
FM3540/60
4/5 Bit Multiplexed, 1 Bit Latched Port with Standard
2-Wire Bus Interface and Non-Volatile Latches
General Description
The FM3540/60 multiplexes the I-port input signals with two
internal non-volatile registers that can be loaded through the serial
port. The multiplexer is selected via the serial port and defaults to
the I-Port upon power-up. Pull-up resistors are provided on the
input port to accommodate connections to open drain outputs and
to eliminate the need for external resistors. The device supports
a choice of either 2.5V output or Open Drain Outputs for easy
interface to devices with different VDD Levels.
The serial port is an IIC compatible slave only interface and
supports both 100kbits and 400kbits modes of operation. The port
is used to read the I-Port, Write Data to the internal non-volatile
registers and select whether the I-Port or one of the internal non-
volatile registers is output to the Y-port. The FM3540/60 is
fabricated with an advanced CMOS technology to achieve high
density and low power.
Features
I Extended Operating Voltage Range 3.0V-5.5V
I IIC Compatible Slave Interface.
I ESD performance: Human body model > 2000V
I Choice of 2.5V outputs or Open-Drain Outputs
Block Diagram
Non_Mux_Out
I[4:0]
SOPRA
SOPRB
IIC Read Logic
Mux3
SDA
SCL
IIC
Interface
Start/Stop
Logic
Shift
Register
Mux2
MXSB, MXSA
Y[4:0]
Mux1
Control Logic
MUXSEL
OVRD
Slave Address
Register
Comparator
ASEL
© 2001 Fairchild Semiconductor Corporation
1
FM3540/60 Rev. C
www.fairchildsemi.com