Information
Microchip Technology Inc.• The Embedded Control Solutions Company®
MCP23016, Serial Peripherals - 16-bit I/O Expander
The Microchip MCP23016 is a 16-bit input/output 
expander designed to provide embedded systems with 
general purpose remote I/O expansion through an 
I
2
C™ serial port. The fully bi-directional 16 I/Os default 
to inputs and can be confi gured as inputs or outputs. 
Additionally, there are four sets of registers that are 
programmable and provide for confi guration (input or 
output control), output value, and polarity (active low 
or high). The MCP23016 open drain interrupt (INT) 
output is activated when any input state differs from 
its corresponding input port register state. By sending 
an interrupt signal on the interrupt logic of the master, 
this remote slave device informs the master that 
there is incoming data on the port without having to 
communicate via the I
2
C bus. Three external hardware 
pins (A0, A1 and A2) vary the fixed I
2
C address and 
allow up to eight devices to share the same bus. 
The MCP23016 has low current consumption and 
includes latched outputs with high current drive 
capability for directly driving LEDs. 
Applications: 
•   General purpose I/O expansion for systems utilizing 
  I
2
C and SMBus™ ports, such as, driving ACPI power 
  switches, sensors, push-buttons, keypads, LEDs 
  and fans
•  Servers, workstations, backplanes and PC 
  applications supporting microprocessors for   
  examining input lines from peripherals, such as,   
  keyboards and temperature sensors
•  Power supply applications (driving LEDs and sensor   
  type applications)
•  PCs, cell phones, washers, dryers and industrial   
  applications
•  Board version tracking and configuration
•  Board monitoring and status reporting 
  (AC/DC good or bad conditions)
•  Multiple card systems in telecom, networking and  
  base station infrastructure equipment
•  Field recall and troubleshooting functions for   
  installed boards
Features: 
•   I
2
C and SMBus compatible clock frequency
  (0 to 400 kbits/s)
•  2.0 – 5.5V operating supply voltage range
•  16 programmable bi-directional I/Os compatible with 
  most processors
•  Outputs can directly drive LEDs (source and sink   
  current 25 mA)
•  Polarity inversion register to configure the polarity of 
  the input port data
•  Internal Power-on Reset (POR)
•  Open-drain interrupt output activated when input 
  changes state
•  Three external address pins allow user to connect   
  up to eight of these devices on the same bus
•  Low supply current
•  Specified over industrial temperature range 
  (-40°C to +85°C) 
•  Available in 28-pin PDI
P
, SSO
P
, SOIC and QFN 
  packages
MCP23016
LEDs,
Displays,
etc.
Keypad
Relays
I
2
C™
Bus
I
2
C
Port
Master 
MCU
MCP23016
 Interface Devices


