MCP23S09-E/MG Microchip Integrated Circuit (Quad Flat No-Lead) In Stock
MCP23S09-E/MG is an 8-bit SPI-interface I/O expander from Microchip providing one 8-bit GPIO port with interrupt output and 10 MHz SPI clock support. It extends microcontroller GPIO count in a compact 16-pin QFN package, suited for keyboard scanning, relay control, and LED matrix driving.
- Manufacturer
- Microchip
- Package
- Quad Flat No-Lead
- Pin Count
- 16
- Lifecycle
- ACTIVE
- Datasheet
- MCP23S09-E/MG Datasheet PDF
- 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 expansion via 10 MHz SPI interface to add I/O to any microcontroller with a single chip
- Interrupt-on-change output pin reduces MCU polling overhead in event-driven 8-channel I/O designs
- 16-pin QFN package with internal pull-up resistors on all 8 I/O lines simplifies PCB routing in space-constrained designs
Applications
The MCP23S09-E/MG is used in embedded systems that have exhausted on-chip GPIO, such as industrial HMI panels requiring additional button and LED control beyond the MCU's native I/O. Robotics controllers employ it to drive up to 8 relay channels or motor driver enable lines over a fast 10 MHz SPI bus without consuming extra MCU pins. Smart-home gateway boards use the interrupt-on-change output to monitor up to 8 digital sensor inputs and wake the host processor only when a state change occurs.
Specifications
| Pbfree Code | Yes |
| Manufacturer Package Code | QFN-16 |
| Factory Lead Time | 2Weeks |
| YTEOL | 9 |
| Clock Frequency-Max | 10MHz |
| JESD-30 Code | S-XQCC-N16 |
| JESD-609 Code | e3 |
| Number of Bits | 8 |
| Number of I/O Lines | 8 |
| Number of Ports | 1 |
| Package Body Material | UNSPECIFIED |
| Package Equivalence Code | LCC16,.12SQ,20 |
| Package Shape | SQUARE |
| Package Style | CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE |
| Peak Reflow Temperature (Cel) | 260 |
| Qualification Status | Not Qualified |
| Supply Current-Max | 1mA |
| Supply Voltage-Max | 5.5V |
| Supply Voltage-Min | 1.8V |
| Supply Voltage-Nom | 5V |
| Surface Mount | YES |
| Technology | CMOS |
| Temperature Grade | AUTOMOTIVE |
| Terminal Finish | Matte Tin (Sn) |
| Terminal Form | NO LEAD |
| Terminal Pitch | 0.5mm |
| Terminal Position | QUAD |
| Time@Peak Reflow Temperature-Max (s) | 40 |
| uPs/uCs/Peripheral ICs Type | PARALLEL IO PORT, GENERAL PURPOSE |
| Package | Quad Flat No-Lead |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.01 |
| Country of Origin | Thailand |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for MCP23S09-E/MG:
Frequently Asked Questions
How fast can the SPI interface of MCP23S09-E/MG run, and how does that affect real-time I/O update performance?
The MCP23S09-E/MG supports SPI clock frequencies up to 10 MHz, allowing a full 8-bit port write or read to complete in approximately 2.4 µs including the SPI framing bytes. This update rate is more than sufficient for relay switching, LED state control, or button debouncing in embedded systems operating at typical 1 ms to 10 ms response time requirements.
When designing a keyboard matrix scanner, how does the MCP23S09-E/MG interrupt output reduce MCU CPU load?
The MCP23S09-E/MG drives a single interrupt-on-change output pin low when any of its 8 input lines changes state, allowing the host MCU to sleep or execute other tasks instead of continuously polling the SPI bus at every scan interval. The MCU wakes on the interrupt edge, reads the 8-bit input port over a single 10 MHz SPI transaction, and identifies which of the 8 keys changed, cutting SPI traffic to only event-driven transfers.
For a design already using MCP23S09-E/MG, under what conditions would upgrading to a 16-bit I/O expander be justified?
If an application requires more than 8 discrete I/O lines simultaneously — for example a 4×4 keypad matrix needing 16 scan and sense lines — a 16-bit expander becomes necessary. The MCP23S09-E/MG provides only 1 port of 8 I/O pins; exceeding that count without adding a second device requires migrating to a 16-channel SPI expander such as MCP23S17 in a 28-pin package, which doubles the GPIO at the cost of increased QFN footprint and slightly higher per-unit cost.
Related Guides
ECMF02-4CMX8 Common-Mode Filter with ESD Protection: Selection Guide
Compare ECMF02-4CMX8 vs ECMF02-2AMX6, ECMF04-4HSM10, and other ST ECMF filters. Choose the right 4-channel common-mode filter with ESD protection for USB 2.0.
Jun 20, 2026
AD5204 Quad Digital Potentiometer Selection Guide (2026)
How to choose the right AD5204 quad digital potentiometer: compare 10kΩ vs 100kΩ variants, TSSOP vs SOIC packages, and SPI interface options for your design.
Jun 20, 2026
0402 10uF X5R Decoupling Design Guide for Compact Digital Rails
Application note for using CL05A106MP5NUNC-class 0402 10uF X5R MLCCs in compact digital rail decoupling designs.
Jun 19, 2026
How to Choose an 0805 10uF MLCC for Decoupling and Bulk Capacitance
Selection guide for choosing 0805 10uF MLCCs around CL21A106KOQNNNE, covering derating, dielectric, package, and sourcing checks.
Jun 19, 2026
Why Buy from FindMyChip
About Microchip
Microchip is a leading electronic component manufacturer. FindMyChip sources Microchip ICs directly from authorized China distributors, offering competitive pricing and reliable stock.
More from Microchip
PIC16LF88-I/SS
Small Outline Packages
Integrated Circuit
25AA02E48-I/SN
Small Outline Packages
Integrated Circuit
PIC18F1220-I/SO
Small Outline Packages
Integrated Circuit
MIC5319-1.8YD5-TR
SOT23 (5-Pin)
Integrated Circuit
dsPIC33FJ256GP710A-I/PT
Quad Flat Packages
Integrated Circuit
BM70BLES1FC2-0B03AA
Other
Integrated Circuit
In Stock · 24h Response · Worldwide Shipping
Response within 24 hours · Worldwide shipping
“We've been using FindMyChip for 2 years. Pricing is consistently 20-30% below Mouser/DigiKey for volume orders.”