MCP23S08-E/SS Microchip Integrated Circuit (Small Outline Packages) In Stock
Microchip MCP23S08-E/SS is an 8-bit SPI general-purpose I/O port expander with interrupt output in a 20-pin SSOP package. Operates from 1.8 V to 5.5 V with SPI clock speeds up to 10 MHz and supports hardware address pins for multi-device configurations. Available for worldwide shipping.
- Manufacturer
- Microchip
- Package
- Small Outline Packages
- Pin Count
- 20
- Lifecycle
- ACTIVE
- Datasheet
- MCP23S08-E/SS Datasheet PDF
- Category
- Integrated Circuit
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- 8 bidirectional GPIO pins expandable over SPI at up to 10 MHz, adding parallel I/O capacity to any microcontroller without additional bus wiring
- Wide supply range from 1.8 V to 5.5 V allows direct interfacing to both 3.3 V and 5 V microcontrollers without level shifters
- Configurable interrupt-on-change output with pin-level masking reduces polling overhead in low-power IoT and industrial designs
- Hardware address pins support up to 8 MCP23S08 devices on a single SPI bus, scaling I/O count to 64 pins with one CS line per device
Applications
MCP23S08-E/SS is used in industrial control panels and PLC expansion modules to add relay driver outputs, button inputs, and status LED controls without consuming scarce microcontroller GPIO pins. Embedded Linux boards with limited I/O use it to interface to front-panel switches, DIP configuration inputs, and diagnostic LEDs through a standard SPI port. It also serves in smart home gateway designs where multiple sensor zones each require a dedicated I/O expander.
Specifications
| Pbfree Code | Yes |
| Manufacturer Package Code | SSOP-20 |
| Reach Compliance Code | Compliant |
| Factory Lead Time | 6Weeks |
| YTEOL | 9 |
| Qualification Status | Not Qualified |
| uPs/uCs/Peripheral ICs Type | PARALLEL IO PORT, GENERAL PURPOSE |
| ## MCP23S08-E/SS Alternates Showing results | Image |
| Package | Small Outline Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.01 |
| Country of Origin | Philippines, Thailand |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for MCP23S08-E/SS:
suggested
suggested
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Frequently Asked Questions
How fast can MCP23S08-E/SS transfer data over SPI, and does it support standard SPI modes?
MCP23S08-E/SS supports SPI clock frequencies up to 10 MHz and is compatible with SPI modes 0,0 and 1,1 (CPOL/CPHA combinations), covering the default mode used by most microcontrollers. At 10 MHz with 8-bit transfers, a full GPIO port state update requires under 5 µs including CS assertion, which is fast enough for real-time control loops.
How many MCP23S08-E/SS devices can share a single SPI bus, and how is address selection done?
Up to 8 MCP23S08-E/SS devices can be addressed on one SPI bus using the 3 hardware address pins (A2, A1, A0), which are wired to VDD or GND to set a 3-bit address. This allows a total of 64 additional GPIO pins from a single SPI bus, useful in keyboard matrix controllers, industrial relay boards, and multi-zone I/O expansion cards.
What voltage rails does MCP23S08-E/SS support, and can it interface directly to both 3.3 V and 5 V microcontrollers?
MCP23S08-E/SS operates from 1.8 V to 5.5 V supply voltage. When powered at 3.3 V it accepts SPI signals from a 3.3 V MCU directly, and when powered at 5 V it accepts 5 V logic levels, eliminating level-translation ICs in mixed-voltage designs. The wide range covers virtually all mainstream microcontroller families.
How does the interrupt-on-change feature of MCP23S08-E/SS reduce MCU CPU load in event-driven designs?
The interrupt pin asserts whenever any configured GPIO pin changes state, signalling the host MCU to read only the INT flag and INTCAP registers rather than polling all 8 pins continuously. With per-pin interrupt masking, up to 8 independent events can be monitored in a single interrupt service routine reading just 2 bytes over SPI, reducing CPU wake cycles by orders of magnitude compared to polling.
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