Five/Six Channel Push/Pull I/O Expander
Functional Block Diagram
VCC
AAT4296/98
AAT4298
OUT1
EN/SET
S
2
Cwire
Serial
Interface
OUT2
OUT3
OUT4
OUT5
OUT6
GND
Functional Description
The AAT4296/98 is comprised of five/six push/pull
output slew rate limited load switches primarily tar-
geted for microcontroller general purpose
input/output (I/O) expansion applications. Each
push/pull output is supplied by the common V
CC
input and is controlled via the digital EN/SET input
pin. When a given output is enabled, the voltage
source applied to the VCC pin is then switched to
the respective output. The high-side P-channel
MOSFET transistor has a typical on resistance
(R
DS(ON)
) of 3Ω when operating from a 3.6V supply.
When a respective output is disabled or turned off,
the given output pin is then connected to ground
through a low side N-channel MOSFET with a typi-
cal on resistance (R
DS(ON)
) of 2Ω. This circuit archi-
tecture affects a simple logic control with the high
level based on the applied V
CC
. For the AAT4296,
this creates a 1-to-5 I/O expander, and for the
AAT4298 this creates a 1-to-6 I/O expander. Both
the AAT4296 and AAT4298 have been designed to
operate with an input voltage range of 1.8V to 5.5V,
making them ideal for battery-powered applications.
4296.2006.12.1.3
9
AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
