MCP23S09T-E/MG Microchip Integrated Circuit (Quad Flat No-Lead) In Stock

Microchip MCP23S09T-E/MG is an 8-bit SPI-controlled I/O expander with 8 bidirectional GPIO pins. It operates up to 10 MHz SPI clock, features interrupt output, and is housed in a compact QFN-16 package for space-constrained PCB designs.

ACTIVEIntegrated CircuitVerified May 2026
Package / Visual Reference
MCP23S09T-E/MGQuad Flat No-Lead
Quick Facts
Manufacturer
Microchip
Package
Quad Flat No-Lead
Pin Count
16
Lifecycle
ACTIVE
Category
Integrated Circuit
Temp Range
-40.0°C to 125.0°C
RoHS
Compliant
Lead Time
3–7 business days
Shipping
DHL Express · Worldwide

Key Features

  • 8-bit GPIO expander with SPI interface running up to 10 MHz
  • Single port with 8 fully bidirectional I/O lines and configurable pull-ups
  • Hardware address pin for multi-device SPI bus sharing
  • Interrupt-on-change output for efficient microcontroller event handling
  • Compact QFN-16 package enabling high-density board layouts

Applications

The MCP23S09T-E/MG is commonly used in industrial control panels, embedded systems, and consumer electronics where the host microcontroller lacks sufficient GPIO pins. Its SPI interface at up to 10 MHz makes it suitable for real-time I/O expansion in robotics, keypad matrix scanning, relay-bank control, and LED status indicator arrays.

Specifications

Pbfree CodeYes
Manufacturer Package CodeQFN-16
Factory Lead Time8Weeks
YTEOL9
Clock Frequency-Max10MHz
JESD-30 CodeS-XQCC-N16
JESD-609 Codee3
Number of Bits8
Number of I/O Lines8
Number of Ports1
Package Body MaterialUNSPECIFIED
Package Equivalence CodeLCC16,.12SQ,20
Package ShapeSQUARE
Package StyleCHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE
Peak Reflow Temperature (Cel)260
Qualification StatusNot Qualified
Supply Current-Max1mA
Supply Voltage-Max5.5V
Supply Voltage-Min1.8V
Supply Voltage-Nom5V
Surface MountYES
TechnologyCMOS
Temperature GradeAUTOMOTIVE
Terminal FinishMatte Tin (Sn)
Terminal FormNO LEAD
Terminal Pitch0.5mm
Terminal PositionQUAD
Time@Peak Reflow Temperature-Max (s)40
uPs/uCs/Peripheral ICs TypePARALLEL IO PORT, GENERAL PURPOSE
PackageQuad Flat No-Lead

Compliance & Regulatory

RoHS StatusCompliant
Lead-FreeYes (Pb-Free)
Moisture Sensitivity LevelMSL 1
ECCNEAR99
HTS Code8542.39.00.01
Country of OriginThailand

Datasheet

MCP23S09T-E/MG Datasheet Download

Official datasheet from Microchip

Alternate & Equivalent Parts

Compatible alternatives and drop-in replacements for MCP23S09T-E/MG:

MCP23S09-E/MGMicrochip Technology Inc Parallel I/O Port,

8-Bit, 8 I/O, CMOS

View Part →
MCP23S08T-E/MLMicrochip Technology Inc

Parallel I/O Port, 8-Bit, 8 I/O, CMOS, PQCC20

View Part →
MCP23S08-E/MLMicrochip Technology Inc

8 BIT INPUT/OUTPUT EXPANDER, I2C INTERFACE

View Part →

Frequently Asked Questions

How fast is the SPI interface on the MCP23S09T-E/MG, and does that limit real-time I/O update rates?

The MCP23S09T-E/MG supports SPI clock rates up to 10 MHz, allowing a host MCU to read or write all 8 I/O lines in a single 24-bit transaction in under 3 µs. This speed is sufficient for most keypad scanning, LED control, and relay switching applications without introducing noticeable latency.

How many MCP23S09T-E/MG devices can share the same SPI bus, and what differentiates them?

Up to 2 MCP23S09T-E/MG devices can share a single SPI bus by using the hardware address bit (A0 pin), giving a total of 16 additional GPIO outputs without adding a bus multiplexer. Each device is selected independently via its unique 1-bit address encoded in the SPI opcode byte.

What are the key differences between MCP23S09T-E/MG and the I2C version MCP23009 for a new board design?

The MCP23S09T-E/MG uses SPI at up to 10 MHz versus the MCP23009's I2C at up to 400 kHz, making the SPI variant roughly 25x faster per transaction. Designers choose the SPI version when the host already has an SPI bus or when update rates exceed I2C limits, while I2C suits simpler 2-wire wiring topologies.

Is the MCP23S09T-E/MG RoHS compliant and what moisture sensitivity level applies to the QFN-16 package?

Yes, the MCP23S09T-E/MG carries a RoHS and lead-free (Pb-free) rating as indicated by its JESD-609 code e3. The QFN-16 package is rated MSL 3, requiring dry storage and baking if the moisture barrier bag has been open longer than 168 hours before SMT reflow assembly.

Which embedded applications benefit most from adding MCP23S09T-E/MG as an I/O expander?

Applications that benefit most include industrial PLCs with 8 or more discrete sensor inputs, LED indicator panels requiring 8 independently controlled channels, and relay-driver boards where the host MCU has fewer than 8 available GPIO pins. The interrupt-on-change output further reduces CPU polling overhead in event-driven firmware designs.

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