MCP23S17-E/SS - 16-bit SPI I/O Expander 10MHz 28-SSOP | Microchip
N.º de pieza: MCP23S17-E/SS ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $2.95 | $2,95 |
| 10 | $2.62 | $26,20 |
| 100 | $2.18 | $218,00 |
| 500 | $1.85 | $925,00 |
| 1.000 | $1.62 | $1.620,00 |
MCP23S17-E/SS Descripción general
An I/O expander (or GPIO expander) is a peripheral IC that adds general-purpose input/output lines to a host microcontroller through a low-pin-count serial bus such as SPI or I²C. The I/O expander sits in the connectivity / interface IC hierarchy: GPIO expander -> I/O expander -> interface IC -> peripheral IC -> integrated circuit. By offloading up to 16 GPIO to a separate chip, designers keep host MCUs small and inexpensive while still controlling relays, keypads, LEDs, sensors, and segment displays.
Key features of the MCP23S17 include 16 individually configurable bidirectional I/O lines, two interrupt outputs (INTA and INTB) that can be mirrored or linked, hardware-address pins that allow up to eight devices on a single SPI bus (128 GPIOs total), configurable internal pull-up resistors per pin, and sequential or byte-mode register access for fast throughput. The interrupt output feature lets the host sleep until a defined edge event occurs, reducing average system power.
The device uses a simple 8-bit command word followed by a register address and data, allowing reads and writes to all 22 internal registers. Its 10 MHz SPI clock supports rapid update of many I/O lines, while the cascading-address scheme (A0/A1/A2 + banked IOCON.HAEN) lets eight MCP23S17 chips share one CS line, expanding a single SPI peripheral into 128 GPIO. The internal architecture combines a robust CMOS I/O structure with hardware interrupts, making the part well suited to industrial field wiring.
Typical applications include LED signage and keypad interfacing, industrial control and PLC signal conditioning, multi-segment LCD/segment-display drivers via shift-register style cascading, home appliance user interfaces, and any MCU-limited design that needs more GPIO than the host package offers. The wide 1.8 V to 5.5 V supply range lets the same part work with 3.3 V MCUs and 5 V logic boards alike.
When designing with the MCP23S17, place a 0.1 µF decoupling capacitor close to VDD and consider the SSOP-28 thermal pad layout. The RESET pin should be pulled high through a 10 kΩ resistor or controlled by the host to put all registers into a defined state at power-up.
This page synthesizes distributor pricing, drop-in alternatives and practical design notes not found in the standalone Microchip datasheet.
Alternativas directas para MCP23S17-E/SS — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con MCP23S17-E/SS (mismo factor de forma y huella) — difiere en MSL Level, ESD Protection (HBM), Function, Hardware Address Pins, Internal Pull-up Resistors.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
MCP23S17T-E/SS
✅ Sustitución directa✓ En stock
$1.65 / unidad
Ver hoja de datos →MCP23S17-E/SO
✅ Sustitución directa✓ En stock
$1.55 / unidad
Ver hoja de datos →MCP23S17-E/ML
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MCP23S17T-E/SO
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MCP23S17T-E/ML
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MCP23S17-E/SS Especificaciones
| Part Number | MCP23S17-E/SS |
| Manufacturer | Microchip Technology |
| Función | 16-bit I/O Expander |
| Interfaz | SPI (Serial Peripheral Interface) |
| Serial Clock Frequency (max) | 10 MHz |
| Number of I/O Lines | 16 |
| Supply Voltage (VDD) | 1.8 V to 5.5 V |
| Temperatura de funcionamiento | -40 °C to +125 °C |
| ESD Protection (HBM) | 4 kV |
| Interrupt Outputs | 2 (INTA, INTB) |
| Hardware Address Pins | 3 (A0, A1, A2) - supports 8 devices per SPI bus |
| Cascadable GPIO (with 8 devices) | 128 GPIOs |
| Internal Pull-up Resistors | 100 kΩ typical, configurable per pin |
| Encapsulado / Carcasa | 28-SSOP (5.30 mm body) |
| Tipo de montaje | Surface Mount |
| Nivel MSL | 1 (unlimited) |
| Estado RoHS | Compliant |
| Logic Family | MCP23X17 |
| Packaging | Tube |
Configuración de pines de MCP23S17-E/SS
| Pin 1 | SCLK — SPI serial clock input (max 10 MHz) |
| Pin 2 | MISO — SPI serial data output (SDO) |
| Pin 3 | MOSI — SPI serial data input (SDI) |
| Pin 4 | CS — Chip select, active low |
| Pin 5 | A0 — Hardware address input 0 |
| Pin 6 | A1 — Hardware address input 1 |
| Pin 7 | A2 — Hardware address input 2 |
| Pin 8 | RESET — External reset, active low; tie high through 10 kΩ |
| Pin 9 | VSS — Ground reference |
| Pin 10 | INTA — Interrupt output for GPA bank, active low |
| Pin 11 | INTB — Interrupt output for GPB bank, active low |
| Pin 12 | GPB0 — General-purpose I/O B0 |
| Pin 13 | GPB1 — General-purpose I/O B1 |
| Pin 14 | GPB2 — General-purpose I/O B2 |
| Pin 15 | GPB3 — General-purpose I/O B3 |
| Pin 16 | GPB4 — General-purpose I/O B4 |
| Pin 17 | GPB5 — General-purpose I/O B5 |
| Pin 18 | GPB6 — General-purpose I/O B6 |
| Pin 19 | GPB7 — General-purpose I/O B7 |
| Pin 20 | VDD — Positive supply, 1.8 V to 5.5 V |
| Pin 21 | GPA0 — General-purpose I/O A0 |
| Pin 22 | GPA1 — General-purpose I/O A1 |
| Pin 23 | GPA2 — General-purpose I/O A2 |
| Pin 24 | GPA3 — General-purpose I/O A3 |
| Pin 25 | GPA4 — General-purpose I/O A4 |
| Pin 26 | GPA5 — General-purpose I/O A5 |
| Pin 27 | GPA6 — General-purpose I/O A6 |
| Pin 28 | GPA7 — General-purpose I/O A7 |
Aplicaciones típicas
MCP23S17-E/SS es adecuado para 7 aplicacións: LED Matrix and Signage Driver, Keypad and Button-Matrix Interface, Industrial PLC and Relay Control, Home Appliance User Interface, Segment LCD and Character Display Driving, Sensor Aggregation and Fan-Out Hub, MCU-Constrained Add-On Boards.
LED Matrix and Signage Driver
The MCP23S17-E/SS drives large LED matrices and signage panels by cascading up to eight devices on a single SPI bus for 128 GPIO. Each pin can source or sink up to 25 mA per the Microchip datasheet absolute maximums, sufficient to multiplex rows of LEDs at low duty cycle while the host MCU runs the high-level animation. The 10 MHz SPI clock lets the host reframe a 16x8 display in well under 1 ms, eliminating visible flicker even on 32x32 panels. Place a 100 Ω series resistor on each GPIO to limit peak LED current.
Recomendado
Keypad and Button-Matrix Interface
The MCP23S17-E/SS scans a 4x4 or larger keypad matrix by using 8 GPIOs as column drivers and 8 GPIOs as row inputs with internal pull-ups enabled. Hardware interrupt on INTB wakes the host MCU only when a key is pressed, reducing average current to microamps in battery-powered appliances. The configurable per-pin pull-ups save external resistors, and 4 kV ESD protection guards field-wired panels in industrial human-machine interfaces. Pair with a low-power MCU and the keypad driver runs from a coin cell for years.
Recomendado
Industrial PLC and Relay Control
The MCP23S17-E/SS expands a small industrial PLC or remote I/O module from 8 to 24 relay outputs without changing the host MCU footprint. Two interrupt outputs let the firmware differentiate 'input changed' from 'output watchdog' events, and the 1.8 V to 5.5 V supply rail accepts both 3.3 V MCUs and legacy 5 V PLC backplanes. The -40 °C to +125 °C industrial temperature range covers unheated control cabinets, and 4 kV ESD protection survives installer handling. Use external TVS diodes on field wiring for full IEC 61000-4-2 compliance.
Recomendado
Home Appliance User Interface
White goods and HVAC user interfaces routinely need 20 to 40 GPIOs for seven-segment displays, status LEDs, capacitive touchpads and rotary encoders. The MCP23S17-E/SS provides 16 of those lines through a single SPI peripheral, leaving the host MCU free to run its main motor-control or thermostat algorithm. The internal 100 kΩ pull-ups cleanly bias button inputs, and the wide supply range lets the part share the appliance's 3.3 V or 5 V rail. Up to eight devices (128 GPIO) easily serve a full oven-and-cooktop control board.
Recomendado
Segment LCD and Character Display Driving
The MCP23S17-E/SS drives character LCDs and segmented LCD/LED panels by serving as a high-current shift-register-style expander. Two cascaded MCP23S17 chips give 32 GPIOs, enough to refresh a 16-character alphanumeric LCD plus status icons without burdening the host MCU. The 10 MHz SPI throughput supports full-frame refresh in well under a millisecond, eliminating ghosting even with PWM-dimmed backlights. Use current-limiting resistors on each segment line to share the 25 mA per-pin budget across multiple digits.
Recomendado
Sensor Aggregation and Fan-Out Hub
Sensor aggregation hubs aggregate dozens of digital sensors (door switches, PIR motion, temperature, vibration) into a single SPI-managed port. The MCP23S17-E/SS reads 16 sensors per chip while the INTB output wakes the host only on a state change, enabling deep-sleep modes below 10 µA. Cascading eight devices lets one host handle 128 sensors - typical for security panels, building automation gateways, and HVAC multi-zone controllers. The 4 kV ESD rating protects against installer-induced transients on long sensor cables.
Recomendado
MCU-Constrained Add-On Boards
The MCP23S17-E/SS is the go-to solution for hobbyist and education boards that pair small-pin-count MCUs (e.g. 8-pin or 14-pin PIC/AVR) with rich peripherals. A single SSOP-28 chip on an Adafruit- or SparkFun-style breakout board adds 16 plug-and-play GPIO accessible over SPI from any MCU. The 1.8 V to 5.5 V supply is forgiving for breadboard power rails, and the documented register map simplifies Arduino library porting. Cascading two boards yields 32 GPIOs - enough to drive a small robot's motors, sensors and indicators from a single ATTiny.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para MCP23S17-E/SS — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | MCP23S17T-E/SS | MCP23S17-E/SO | MCP23S17-E/ML | MCP23S17T-E/SO | MCP23S17T-E/ML |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SSOP (5.30 mm) | 28-SSOP (5.30 mm) - same | 28-SOIC (7.50 mm) - PCB rework | 28-QFN (6x6 mm) - PCB rework | 28-SOIC (7.50 mm) - PCB rework | 28-QFN (6x6 mm) - PCB rework |
| Function | 16-bit SPI I/O Expander | 16-bit SPI I/O Expander | 16-bit SPI I/O Expander | 16-bit SPI I/O Expander | 16-bit SPI I/O Expander | 16-bit SPI I/O Expander |
| SPI Clock (max) | 10 MHz | 10 MHz | 10 MHz | 10 MHz | 10 MHz | 10 MHz |
| Supply Voltage | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Operating Temperature | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C |
| Interrupt Outputs | 2 (INTA, INTB) | 2 (INTA, INTB) | 2 (INTA, INTB) | 2 (INTA, INTB) | 2 (INTA, INTB) | 2 (INTA, INTB) |
| Hardware Address Pins | 3 (A0, A1, A2) | 3 (A0, A1, A2) | 3 (A0, A1, A2) | 3 (A0, A1, A2) | 3 (A0, A1, A2) | 3 (A0, A1, A2) |
| Packaging | Tube (47 / tube) | Tape & Reel (2500 / reel) | Tube | Tube | Tape & Reel (1000 / reel) | Tape & Reel (2500 / reel) |
Diferenciadores clave
- Higher SPI clock speed than legacy I/O expanders (frente a MCP23017-E/SS (I²C variant))
- Two independent hardware interrupts instead of one shared line (frente a PCF8574 / PCF8575 (NXP I²C expanders))
- True bidirectional GPIO with per-pin configuration (frente a PCF8574 quasi-bidirectional I/O)
- 8-device cascading for up to 128 GPIOs on one SPI bus (frente a SX1509 (16-bit I²C expander, limited cascading))
Notas de diseño
Estimated: with VDD = 5 V and all 16 GPIOs sourcing 25 mA simultaneously, the chip can dissipate up to ~2 W internally. In practice duty cycle and load distribution keep average dissipation well under 1 W. Always place a 0.1 µF ceramic decoupling capacitor within 5 mm of the VDD pin and a 10 µF bulk capacitor on the same supply rail. The SSOP-28 thermal pad (pin 0 / exposed pad if present) should be soldered to a copper pour to spread heat on hot-output applications like LED matrices.
Keep SPI traces (SCLK, MOSI, MISO, CS) below 50 mm and route them over a continuous ground plane to avoid ringing at the 10 MHz clock edge. Place a 33 Ω series resistor near the host MCU on SCLK and MOSI to dampen reflections when multiple MCP23S17 chips are chained. If using long cables between the host and the expander (>100 mm), lower the SPI clock to 1 MHz or add a SPI buffer/repeater such as the MAX3191X to preserve signal integrity.
Do not leave RESET floating - tie high through a 10 kΩ resistor or drive it from the host MCU; floating reset can latch the part in an undefined state on power-up. When cascading more than one MCP23S17 on the same SPI bus, set IOCON.HAEN=1 on every device but the last so the hardware address pins are decoded correctly. Avoid substituting the I²C MCP23017 for the SPI MCP23S17 without rewriting the driver - the bus protocols differ even though the GPIO register map is identical.
Route INTA and INTB to host MCU external-interrupt-capable pins, and use a 10 kΩ pull-up to VDD on each since they are open-drain active-low outputs. If the application uses only one interrupt, configure IOCON.MIRROR=1 to mirror both banks on a single output. Keep the CS trace short and never run it parallel to noisy signal lines for more than a few millimetres to avoid unintended chip-select glitches during SPI transactions.
Estimated: at room temperature with all GPIO unloaded, the MCP23S17 draws ~1 mA quiescent current and dissipates ~5 mW - thermal is not a concern. Under heavy GPIO loading (e.g. LED matrix driving 16 x 5 mA continuously), dissipation may reach 0.4 W, still within the SSOP-28 θJA of ~80 °C/W. No external heatsink is required, but for high-density designs maintain at least 50 mm² of copper pour under the exposed thermal pad (if your PCB layout includes one) for margin at +85 °C ambient.
Información de cumplimiento
RoHS and REACH compliant per Microchip product page. The -E suffix indicates the industrial temperature grade (-40 °C to +125 °C); an automotive-grade -V variant may be available separately - confirm with Microchip if AEC-Q100 is required.
