Microchip Technology MCP23016T-I/SS

Overview

MCP23016T-I/SS from Microchip Technology is a 16-bit I²C-bus I/O expander IC with dual 8-bit GPIO ports (GP0 and GP1), ±25 mA per-pin drive capability, 2.0–5.5 V operating supply, and open-drain interrupt output triggered on input state change. It supports up to 400 kbit/s I²C communication and is used in industrial control panels for remote LED status indication, push-button interface expansion, and sensor signal conditioning.

For engineers reviewing the MCP23016T-I/SS datasheet, MCP23016T-I/SS pinout, MCP23016T-I/SS application, or MCP23016T-I/SS equivalent, key selection factors include its IARES-configurable interrupt sampling rate (200 µs fast vs. 32 ms low-power mode), polarity inversion register per port, and hardware address pins (A0–A2) enabling eight devices on one I²C bus.

Technical Context

The MCP23016T-I/SS implements a register-mapped I²C slave interface with twelve 8-bit configuration registers grouped into six 16-bit functional pairs (e.g., GP0/GP1, IODIR0/IODIR1). Its internal clock generator relies on an external RC network (3.9 kΩ + 33 pF) to produce a nominal 1 MHz clock, measured at the TP test pin.

Interrupt logic monitors input pin transitions against stored port values and captures the changed port state in dedicated INTCAP0/INTCAP1 registers. The IARES bit in IOCON0 selects between two interrupt detection modes: normal (32 ms max latency, 25 µA standby) or fast (200 µs max latency, 0.4 mA standby), directly trading current consumption for responsiveness.

Key Specifications

Pinout & Package

Package: 28-pin SSOP (209 mil), RoHS-compliant, surface-mount.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I²C I/O expander applications.

Compared with PCA9555D,118 and PCF8575CPW, the MCP23016T-I/SS uniquely combines interrupt capture, polarity inversion, and user-configurable interrupt latency - making it optimal for responsive, low-power, and debuggable I/O expansion in industrial designs.

Availability

MCP23016T-I/SS is available at Aetrix Electronics and suitable for industrial HMI panels, smart sensor nodes, ACPI power management subsystems, and automated test fixtures requiring stable component supply and long-term manufacturability.

Supply support for MCP23016T-I/SS includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, and interface solutions for industrial, automotive, and consumer markets.

The MCP23016 product line delivers scalable I²C-based GPIO expansion for resource-constrained embedded systems, emphasizing low-power operation, interrupt efficiency, and robust register-level configurability.

FAQ

What is the maximum I²C clock frequency supported by the MCP23016T-I/SS?

The MCP23016T-I/SS supports I²C bus speeds up to 400 kbit/s in Fast-mode. This is confirmed in the device features and electrical specifications (DS20090C, Section 2.5). The I²C interface meets standard timing requirements for both 100 kbit/s and 400 kbit/s operation, including setup/hold times for START/STOP conditions and data validity windows. No external clock stretching or arbitration is required for compliance.

Does the MCP23016T-I/SS require external components to operate?

Yes - the MCP23016T-I/SS requires an external RC network (3.9 kΩ resistor + 33 pF capacitor) connected to the CLK pin to generate its internal 1 MHz clock. This clock is essential for interrupt sampling and register access timing. Additionally, external pull-up resistors on SCL and SDA lines are mandatory per I²C specification. The TP pin allows verification of the generated clock frequency during bring-up.

How does the interrupt functionality work on the MCP23016T-I/SS?

The MCP23016T-I/SS asserts its open-drain INT pin low when any input-configured GPIO pin changes state relative to its last-read value. The corresponding port value is captured in INTCAP0 or INTCAP1. Reading either the port register (GP0/GP1) or its INTCAP register clears the interrupt. The IARES bit in IOCON0 determines whether detection uses a 32 ms (low-power) or 200 µs (fast) sampling window.

Can the MCP23016T-I/SS drive LEDs directly without current-limiting resistors?

No - while the MCP23016T-I/SS provides ±25 mA per I/O pin, external current-limiting resistors are mandatory for LED connections. The device's VOL and VOH specifications (e.g., VOL ≤ 0.6 V at 8.5 mA) confirm it operates as a voltage source/sink, not a constant-current driver. Omitting resistors risks exceeding absolute maximum ratings and damaging the I/O structure or LED.

What is the purpose of the TP pin on the MCP23016T-I/SS?

The TP (Test Pin) outputs the internal 1 MHz clock signal used by the MCP23016T-I/SS for register access and interrupt sampling. It is enabled when the IARES bit is set to '1'. Engineers use TP with an oscilloscope to verify correct RC oscillator operation, debug timing-related issues, and validate clock stability during power-up or temperature variation - a unique diagnostic capability not found in most competing I/O expanders.