MCP23S18-E/MJ - 16-Bit SPI I/O Expander, 10 MHz, QFN-24 | Microchip
Référence : MCP23S18-E/MJ ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $3.45 | $3,45 |
| 10 | $3.1 | $31,00 |
| 100 | $2.75 | $275,00 |
| 500 | $2.45 | $1 225,00 |
| 1 000 | $2.18 | $2 180,00 |
| 3 000 | $1.92 | $5 760,00 |
MCP23S18-E/MJ Présentation
What is an I/O expander? An I/O expander is a peripheral IC that adds general-purpose input/output pins to a microcontroller or processor through a serial bus (I2C or SPI). The I/O expander sits in the interface IC hierarchy between GPIO controllers and bus drivers, and belongs to the broader power management and interface ecosystem. By externalizing GPIO, designers reduce host pin count, free up small-form-factor MCUs for more analog or timer peripherals, and consolidate LEDs, buttons, relays, and keypads onto one addressable bus.
The MCP23S18 uses an SPI interface (MCP23018 is the I2C sibling in the same family). It contains 22 byte-wide registers: 8-bit configuration, input, output, polarity inversion, pull-up, interrupt, and masking registers. Two address pins (A0, A1, A2) allow up to eight devices on the same SPI bus, expanding to 128 GPIO per bus. The interrupt output (INT) and configurable INT pin polarity simplify change-detection without polling.
Key features include open-drain outputs (per datasheet), hardware/software addressable slave, interrupt-on-change per pin, programmable internal pull-ups (100 kΩ typical), and cascadable architecture. The QFN-24 (4x4 mm) package supports compact designs and the industrial -40C to +125C operating range.
Typical applications include LED driving and key scanning in consumer electronics, industrial control panel GPIO expansion, sensor hub aggregation, and microcontroller pin-count extension in IoT edge nodes. The wide 1.8 V–5.5 V supply range makes it compatible with both 1.8 V SoCs and legacy 5 V logic.
When designing with this part, place a 0.1 µF decoupling capacitor close to VDD and observe SPI bus pull-ups for reliable communication at 10 MHz. The device address is hardware-strapped via A0–A2 pins, eliminating firmware conflicts on multi-device buses.
This page consolidates distributor pricing, drop-in equivalents, and practical design considerations not assembled in the manufacturer datasheet, helping engineers evaluate the MCP23S18-E/MJ for new designs and second-source scenarios.
Alternatives de remplacement direct pour MCP23S18-E/MJ — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
MCP23S18T-E/MJ
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
MCP23S18-E/MJ Spécifications
| Fonction | I/O Expander |
| Number of I/O | 16 |
| Interface | SPI |
| Serial Bus Frequency | 10 MHz (per FindIC note: 3.4 MHz alt figure) |
| Supply Voltage (VDD) | 1.8 V to 5.5 V |
| Type de sortie | Open-Drain |
| Interrupt Output | Yes (INT, configurable polarity) |
| Internal Pull-up Resistors | 100 kΩ typical (programmable) |
| Address Pins | A0, A1, A2 (hardware-addressable, up to 8 devices) |
| Température de fonctionnement | -40 °C to +125 °C |
| Boîtier | QFN-24 (4x4 mm) |
| Type de montage | Surface Mount |
| Statut RoHS | Compliant (per FindIC) |
| Lead-free | Yes (per FindIC) |
| Lifecycle | Active (per FindIC, 2008 release) |
Configuration des broches de MCP23S18-E/MJ
| Broche 1 | GPB0 — General-purpose I/O port B bit 0 |
| Broche 2 | GPB1 — General-purpose I/O port B bit 1 |
| Broche 3 | GPB2 — General-purpose I/O port B bit 2 |
| Broche 4 | GPB3 — General-purpose I/O port B bit 3 |
| Broche 5 | GPB4 — General-purpose I/O port B bit 4 |
| Broche 6 | GPB5 — General-purpose I/O port B bit 5 |
| Broche 7 | GPB6 — General-purpose I/O port B bit 6 |
| Broche 8 | GPB7 — General-purpose I/O port B bit 7 |
| Broche 9 | VDD — Positive supply voltage (1.8 V to 5.5 V) |
| Broche 10 | VSS — Ground reference |
| Broche 11 | NC — Not connected (per datasheet) |
| Broche 12 | SCK — SPI serial clock input |
| Broche 13 | SI — SPI serial data input (MOSI) |
| Broche 14 | SO — SPI serial data output (MISO) |
| Broche 15 | CS — Chip select input (active low) |
| Broche 16 | INT — Interrupt output (configurable polarity) |
| Broche 17 | A0 — Hardware address bit 0 |
| Broche 18 | A1 — Hardware address bit 1 |
| Broche 19 | A2 — Hardware address bit 2 |
| Broche 20 | GPA7 — General-purpose I/O port A bit 7 |
| Broche 21 | GPA6 — General-purpose I/O port A bit 6 |
| Broche 22 | GPA5 — General-purpose I/O port A bit 5 |
| Broche 23 | GPA4 — General-purpose I/O port A bit 4 |
| Broche 24 | GPA3 — General-purpose I/O port A bit 3 |
Applications typiques
MCP23S18-E/MJ convient pour 6 applications: Industrial Control Panel GPIO Expansion, LED Matrix and Key Scanning, Sensor Hub Aggregation, Microcontroller Pin-Count Extension, Home Appliance User Interface, Automotive Body Electronics (Non-Safety).
Industrial Control Panel GPIO Expansion
The MCP23S18-E/MJ is well-suited for industrial control panels where a host MCU lacks enough GPIO for buttons, LEDs, and relay coils. Its 16-bit parallel I/O is split into two 8-bit ports (GPA, GPB), each with independently programmable direction, polarity inversion, and pull-up registers per the Microchip MCP23S18 datasheet. At 10 MHz SPI clock, panel scan time stays well under 1 ms even with 8 cascaded devices (128 GPIO). The -40 °C to +125 °C industrial temperature range matches factory floor environments, and the open-drain outputs can directly sink LED arrays up to 25 mA per pin with external pull-ups to 5 V or 24 V rails.
Recommandé
LED Matrix and Key Scanning
For LED matrix driving and 4x4 or 8x8 key-scanning applications, the MCP23S18-E/MJ delivers 16 I/O at 10 MHz SPI throughput, allowing rapid row/column multiplexing with minimal host overhead. The integrated 100 kΩ pull-ups simplify switch matrix wiring by eliminating external resistors per the Microchip datasheet. Interrupt-on-change on both ports wakes the host only when a key is pressed, reducing polling current in battery-powered HMIs. Pair two MCP23S18-E/MJ devices to drive a 16x16 LED matrix using the hardware address pins for chip selection.
Recommandé
Sensor Hub Aggregation
The MCP23S18-E/MJ aggregates digital sensor flags (motion, door, limit switches) onto a single SPI bus for an edge-computing IoT node. Each of the 16 inputs can generate an independent interrupt on any state change, and the INT pin wakes the host from sleep only when a real event occurs per the Microchip datasheet. The 1.8 V–5.5 V supply range lets the expander share the same rail as low-power SoCs and 5 V sensor arrays without level shifters. With 8 devices addressable per bus, a single SPI peripheral can monitor 128 sensors.
Recommandé
Microcontroller Pin-Count Extension
When a small-form-factor MCU (such as a 28-pin or 32-pin part) needs more I/O than its package provides, the MCP23S18-E/MJ adds 16 GPIO through just 4 SPI pins plus INT and CS. This preserves the host MCU for analog and timer peripherals per the Microchip product page. The QFN-24 (4x4 mm) footprint keeps the PCB area smaller than the equivalent discrete logic. Industrial temperature range and open-drain outputs suit both consumer and industrial control extensions.
Recommandé
Home Appliance User Interface
White goods and small appliances use the MCP23S18-E/MJ to expand the front-panel user interface without upgrading the main MCU. The 16 GPIO can drive 7-segment displays, capacitive touch indicators, and buzzer/relay outputs while reading 16 mechanical buttons per the Microchip datasheet. Interrupt-on-change reduces MCU active time, lowering standby power to meet energy-star requirements. Open-drain outputs pair directly with 5 V relays and triac drivers.
Recommandé
Automotive Body Electronics (Non-Safety)
The MCP23S18-E/MJ serves body-electronics modules (window lift, mirror adjust, interior lighting) where 16 GPIO per expander consolidate switch inputs and LED drivers. Wide 1.8 V–5.5 V supply and -40 °C to +125 °C range cover automotive cabin conditions per the Microchip product page. Open-drain outputs simplify direct connection to 12 V body-control lamp drivers with external pull-ups. Note: safety-critical automotive functions should use AEC-Q100-qualified MCP23018T-E/MJ variants rather than the standard MCP23S18-E/MJ.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour MCP23S18-E/MJ — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | MCP23S18T-E/MJ |
|---|---|---|
| Package | QFN-24 (4x4 mm) | QFN-24 (4x4 mm) - same |
| Brand | Microchip Technology | Microchip Technology - same |
| I/O Count | 16 | 16 |
| Interface | SPI (up to 10 MHz) | SPI (up to 10 MHz) |
| Supply Voltage | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Output Type | Open-drain | Open-drain |
| Interrupt Output | Yes (INT, configurable) | Yes (INT, configurable) |
| Hardware Address Pins | A0, A1, A2 (8 devices per bus) | A0, A1, A2 (8 devices per bus) |
| Operating Temperature | -40 °C to +125 °C | -40 °C to +125 °C |
| Packaging Form | Tube | Tape & Reel |
Principaux différenciateurs
- Industry-standard SPI I/O expander with 10 MHz throughput (vs NXP PCF8575 (I2C))
- QFN-24 (4x4 mm) compact footprint with industrial temperature range (vs TI TCA9539 TSSOP-24)
- Open-drain outputs with interrupt-on-change per pin (vs Push-pull MCP23S18 push-pull variants)
Notes de conception
Place a 0.1 µF decoupling capacitor as close as possible to the VDD pin (pin 9) and a 1 µF bulk capacitor on the same rail. The MCP23S18-E/MJ draws microamps in standby but the open-drain output stages can sink transient currents up to 25 mA per pin, so local bypass is essential per the Microchip MCP23S18 datasheet. Estimated: at 16 simultaneous 25 mA outputs the supply transient could reach 400 mA, requiring low-ESR ceramic decoupling within 5 mm of the VDD pin.
Route the SPI traces (SCK, SI, SO, CS) with controlled impedance and keep traces shorter than 100 mm at 10 MHz clock to avoid ringing. Place the chip-select pull-up (or hardware address pull-up) within 10 mm of the CS pin. The exposed thermal pad on the QFN-24 must be soldered to a copper pour connected to VSS for mechanical stability and thermal dissipation per the QFN-24 land pattern recommendation.
Do not leave the address pins (A0, A1, A2) floating; tie each one to either VDD or VSS to set a stable hardware address. Floating address inputs can cause bus-address conflicts when multiple MCP23S18-E/MJ devices are cascaded. Also, when sharing the INT pin across multiple expanders, ensure each device's interrupt is cleared by reading the appropriate GPIO register before re-enabling interrupts, otherwise the INT line can latch and prevent further wake events.
Informations de conformité
RoHS compliant and lead-free per FindIC. AEC-Q100 status not qualified for the MCP23S18-E/MJ; AEC-Q100-qualified variants exist in the MCP23018T-E/MJ family for automotive. REACH, halogen-free, and conflict-minerals compliance not stated in the provided web data.
