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
- Price
- From $1.1475(MOQ 1)
- Temp Range
- -40.0°C to 125.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
What are the key features of MCP23S09-E/MG?
- 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
What is MCP23S09-E/MG used for?
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.
What are the specifications of MCP23S09-E/MG?
| 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 |
Where can I find the MCP23S09-E/MG datasheet?
MCP23S09-E/MG Datasheet DownloadOfficial datasheet from Microchip
What are equivalent replacements for MCP23S09-E/MG?
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.
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