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Microchip Technology MCP23S09-E/P
- Part No.:
- MCP23S09-E/P
- Manufacturer:
- Microchip Technology
- Category:
- I/O Expanders
- Package:
- 18-DIP (0.300", 7.62mm)
- Datasheet:
-
MCP23S09-E/P.pdf
- Description:
- IC XPNDR 10MHZ SPI 18DIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,604
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Product details
Overview
MCP23S09-E/P from Microchip Technology is an 8-bit SPI-based I/O expander with open-drain outputs, 5.5V-tolerant inputs, and configurable interrupt output. It operates from 1.8V to 5.5V, supports up to 10 MHz SPI clock, and delivers 25 mA sink per pin (200 mA total). Used in microcontroller GPIO expansion for industrial control panels requiring robust level-shifting and interrupt-driven input monitoring.
For engineers reviewing the MCP23S09-E/P datasheet, MCP23S09-E/P pinout, MCP23S09-E/P application, or MCP23S09-E/P equivalent, key selection criteria include SPI interface compatibility, 5.5V input tolerance, interrupt configuration flexibility (active-high/low/open-drain), and support for multi-device bus addressing via hardware reset and chip select.
Technical Context
The MCP23S09-E/P implements a dedicated SPI slave interface operating in Mode 0,0 or Mode 1,1, with automatic address pointer incrementing in Sequential mode and static addressing in Byte mode. Its 11-register memory map includes IODIR, IPOL, GPINTEN, DEFVAL, INTCON, IOCON, GPPU, INTF, INTCAP, GPIO, and OLAT - enabling full bidirectional port control, polarity inversion, and interrupt-on-change detection.
Interrupt logic supports two mutually exclusive triggering modes: change-from-default (using DEFVAL and INTCON) or change-from-previous-state. The INT pin is software-configurable for active-high, active-low, or open-drain operation, and interrupt clearing is selectable via INTCAP or GPIO register read - critical for deterministic real-time response in embedded systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| SPI Interface | Mode 0,0 and Mode 1,1; supports 10 MHz max clock - enables high-speed communication with host MCUs without timing margin constraints. |
| I/O Count | 8-bit bidirectional port (GP0–GP7); all pins support interrupt-on-change and internal pull-up - allows single-chip expansion of digital sensing and actuation. |
| Input Voltage Tolerance | 5.5V tolerant inputs - permits direct connection to 5V logic or sensors without external level shifters in mixed-voltage systems. |
| Output Type | Open-drain outputs with 25 mA sink per pin (200 mA total) - drives LEDs, relays, or wired-AND buses directly; eliminates need for external pull-ups in many cases. |
| Supply Range | 1.8V to 5.5V operation - interoperates with low-power microcontrollers (1.8V/3.3V) and legacy 5V systems without voltage translation. |
| Interrupt Output | Configurable as active-high, active-low, or open-drain via IOCON register - simplifies integration with diverse host interrupt controllers and signal routing requirements. |
| Standby Current | 1 µA at –40°C to +85°C - enables ultra-low-power sleep modes in battery-operated remote I/O nodes. |
Pinout & Package
Package: 18-Lead PDIP (300 mil), through-hole compatible with standard prototyping and industrial PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD | Power supply input | Primary power rail (1.8V–5.5V); high-current capable for driving multiple open-drain loads. |
| VSS | Ground reference | System ground return; high-current capable to support 200 mA total sink current. |
| CS | Chip select input | Active-low enable for SPI communication; allows daisy-chaining or independent addressing of multiple expanders. |
| SCK | SPI clock input | Master-generated clock up to 10 MHz; idle state configurable for Mode 0,0 (low) or Mode 1,1 (high). |
| SI | SPI data input | Serial command/data input path for writes and register configuration; latched on rising clock edge. |
| SO | SPI data output | Serial data output path for reads; driven on falling clock edge; tri-stated when CS is high. |
| RESET | Hardware reset input | Active-low asynchronous reset; must be externally biased to VDD for normal operation. |
| INT | Interrupt output | Configurable interrupt flag; asserts when enabled GPIO pins change state - used for event-driven host wake-up. |
| GP0–GP7 | Bidirectional I/O terminals | 8 general-purpose pins; 5.5V-tolerant inputs, open-drain outputs; individually configurable for pull-up, polarity, and interrupt enable. |
Key Features
| Feature | Design Value |
|---|---|
| Configurable interrupt source | Supports both "change-from-previous" and "change-from-DEFVAL" modes - enables precise edge detection or threshold-triggered alerts without host polling. |
| Interrupt capture register (INTCAP) | Latches exact GPIO state at interrupt time - eliminates race conditions during host read and ensures deterministic fault logging. |
| Software-selectable interrupt clear method | Clear via INTCAP or GPIO read (IOCON.INTCC bit) - allows flexible interrupt handling strategies aligned with system firmware architecture. |
| Internal pull-up resistors | Individually enabled per pin (GPPU register); current scales with VDD (e.g., ~100 µA at 3.3V) - reduces BOM count and board space for switch/button interfaces. |
| Polarity inversion register (IPOL) | Inverts input logic level per pin - accommodates active-low sensors or switches without external inverters or firmware bit-flipping. |
Applications
| Industrial HMI Panel | Smart Sensor Node |
|---|---|
Use Scenario: Expansion of GPIO on a Cortex-M4-based HMI controller to drive 8 LED status indicators and read 8 mechanical pushbuttons. IC Role / Device Role / Timing Role: SPI-connected I/O expander providing level-shifted, interrupt-driven input sampling and open-drain LED sinking. Use Value: Reduces MCU pin count pressure; enables immediate button-press notification via INT pin; 5.5V tolerance avoids external level shifters for 5V panel components. | Use Scenario: Remote environmental sensor node using a low-power MCU to monitor 8 digital alarm inputs (door/window contacts, smoke detector outputs). IC Role / Device Role / Timing Role: Low-quiescent-current I/O expander with interrupt-on-change capability for wake-on-event operation. Use Value: 1 µA standby current extends battery life; INTCAP register captures alarm state at trigger instant; open-drain outputs interface directly with dry-contact sensors. |
| Programmable Logic Controller I/O Module | Automated Test Equipment Fixture |
Use Scenario: Modular PLC backplane I/O card aggregating 8 isolated digital inputs from field devices into a single SPI bus. IC Role / Device Role / Timing Role: Robust, configurable I/O interface with hardware reset and interrupt signaling for diagnostics and fault reporting. Use Value: RESET pin enables system-level recovery; configurable INT polarity matches PLC controller's interrupt polarity; 25 mA sink handles industrial LED indicators. | Use Scenario: ATE fixture using an FPGA host to control 8 test-point relays and monitor 8 DUT response signals during functional testing. IC Role / Device Role / Timing Role: High-speed (10 MHz SPI) GPIO extender synchronizing relay actuation and response capture with sub-microsecond timing margins. Use Value: 10 MHz SPI bandwidth supports tight test cycle times; sequential register access simplifies burst-read of all 8 input states; open-drain outputs safely drive relay coils. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar I/O expansion applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MCP23S17-E/P | 16-bit I/O, identical SPI interface, same package options, but adds banked register architecture and additional interrupt features (INTA/INTB). | Required when >8 I/O lines or dual-interrupt vectoring is needed; higher pin count and register complexity. | Select MCP23S17-E/P only if 16-bit expansion or banked interrupt handling is required; MCP23S09-E/P remains optimal for cost- and size-constrained 8-bit use cases. |
| PCA9554APW,118 | I2C-only interface (no SPI), 8-bit, 5V-tolerant inputs, but lacks DEFVAL/INTCON registers for advanced interrupt modes and has no hardware reset pin. | Suitable for I2C-bus-limited designs where SPI is unavailable; limited interrupt flexibility and no external reset control. | Choose PCA9554APW,118 only in I2C-only systems with simpler interrupt needs; MCP23S09-E/P provides superior configurability and SPI compatibility. |
Compared with MCP23S17-E/P and PCA9554APW,118, the MCP23S09-E/P uniquely balances 8-bit I/O expansion, SPI speed (10 MHz), 5.5V input tolerance, and full interrupt configurability - making it ideal for compact, interrupt-driven embedded control where pin count, interface choice, and voltage interoperability are critical.
Availability
MCP23S09-E/P is available at Aetrix Electronics and suitable for industrial HMI panels, smart sensor nodes, PLC I/O modules, and automated test equipment fixtures requiring stable component supply and long-term manufacturability.
Supply support for MCP23S09-E/P 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 Inc. is a leading provider of microcontrollers, analog components, and connectivity solutions, serving industrial, automotive, and consumer markets with high-reliability silicon and development tools.
The MCP23X09 product line delivers scalable, low-power I/O expansion for resource-constrained embedded systems - designed specifically to extend GPIO count while maintaining interrupt responsiveness, voltage flexibility, and minimal firmware overhead.
FAQ
What interface protocol does the MCP23S09-E/P support?
The MCP23S09-E/P supports only the SPI interface - not I2C. It operates in SPI Mode 0,0 or Mode 1,1 with a maximum clock frequency of 10 MHz. This distinguishes it from the pin-compatible MCP23009, which uses I2C. The MCP23S09-E/P requires CS, SCK, SI, and SO connections for full functionality.
Does the MCP23S09-E/P have internal pull-up resistors?
Yes, the MCP23S09-E/P includes individually controllable internal pull-up resistors for each GP0–GP7 pin, enabled via the GPPU register. Pull-up current varies with VDD (e.g., ~100 µA at 3.3V), eliminating the need for external resistors in many switch or button interface applications - reducing BOM cost and PCB area.
How is the interrupt output configured on the MCP23S09-E/P?
The INT pin on the MCP23S09-E/P is software-configurable via the IOCON register: ODR bit selects open-drain vs. active driver; INTPOL bit sets active-high or active-low polarity (when ODR = 0); and INTCC bit determines whether reading INTCAP or GPIO clears the interrupt. This enables precise matching to host controller requirements without external logic.
What is the maximum sink current per I/O pin on the MCP23S09-E/P?
Each GP0–GP7 pin on the MCP23S09-E/P supports up to 25 mA sink current when configured as an open-drain output. The device supports a total sink current of 200 mA across all pins. This allows direct driving of LEDs, small relays, or logic inputs without external drivers - provided thermal limits and package derating are observed.
Is the MCP23S09-E/P compatible with 1.8V microcontrollers?
Yes, the MCP23S09-E/P operates over a 1.8V to 5.5V supply range and supports 5.5V-tolerant inputs. When powered at 1.8V, it maintains full SPI functionality and I/O control, enabling seamless interfacing with modern ultra-low-power MCUs - while still accepting 3.3V or 5V input signals without damage or level-shifting circuitry.
MCP23S09-E/P Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 18-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not Verified
- Number of I/O:
- 8
- Interface:
- SPI
- Interrupt Output:
- Yes
- Features:
- -
- Output Type:
- Open Drain
- Current - Output Source/Sink:
- 25mA
- Clock Frequency:
- 10 MHz
- Voltage - Supply:
- 1.8V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 18-PDIP
MCP23S09-E/P FAQ
1.How can I place an order for MCP23S09-E/P through Aetrix?
Please submit a Request for Quotation (RFQ) for MCP23S09-E/P on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MCP23S09-E/P reliable?
The price and inventory of MCP23S09-E/P are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MCP23S09-E/P is usually 5 days.
3.What payment methods are accepted for MCP23S09-E/P?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MCP23S09-E/P transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MCP23S09-E/P?
MCP23S09-E/P orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MCP23S09-E/P order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MCP23S09-E/P?
For technical support, including MCP23S09-E/P datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MCP23S09-E/P requirements.
6.How does Aetrix verify that MCP23S09-E/P is sourced from the original manufacturer or authorized distributors?
All MCP23S09-E/P products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MCP23S09-E/P meets industry standards.
7.What is the process for return or replacement of MCP23S09-E/P?
All MCP23S09-E/P units undergo pre-shipment inspection (PSI). If there is an issue with MCP23S09-E/P, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MCP23S09-E/P part is unused and in its original packaging.
Return procedure for MCP23S09-E/P:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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