PCA9554ABS3,118 - 8-bit I2C/SMBus GPIO Expander w/ Interrupt | NXP
Référence : PCA9554ABS3,118 ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $1.85 | $1,85 |
| 10 | $1.55 | $15,50 |
| 100 | $1.18 | $118,00 |
| 500 | $0.94 | $470,00 |
| 1 000 | $0.78 | $780,00 |
PCA9554ABS3,118 Présentation
An I/O expander (also called a GPIO expander or port expander) is a type of interface IC that adds parallel digital I/O lines to a microcontroller or processor over a low-pin-count serial bus (typically I2C or SMBus). This category sits within the broader hierarchy: GPIO expander -> I/O expander -> interface IC -> peripheral IC -> integrated circuit (semiconductor). I/O expanders are essential when the host MCU has insufficient GPIO pins for keypad scanning, LED driving, sensor multiplexing, or system status monitoring.
Key features of the PCA9554ABS3,118 include 8 individually configurable I/O bits (input or output direction), hardware-selectable I2C addresses (three pins allow up to 8 devices on the same bus), 5 V tolerant I/O, and low standby current. The device conforms to the I2C-bus Fast Mode (400 kHz) specification and integrates a power-on reset circuit that initializes all ports as inputs, simplifying system bring-up.
The architecture combines an I2C/SMBus slave interface, a configuration register bank, and bidirectional I/O drivers with weak pull-up enable per pin. The PCA9554A variant (versus the original PCA9554) uses a different default I2C address, allowing PCA9554 and PCA9554A devices to coexist on the same bus. An open-drain /INT pin provides change notification, freeing the host from continuous polling and reducing I2C traffic.
Typical applications include mobile phone keypad and slider switch scanning, fan and cooling control in servers, LED driving and blinking control, networking equipment port status indicators, industrial PLC digital I/O expansion, and gaming consoles or set-top box button matrices. The wide 2.3 V to 5.5 V supply range allows direct interfacing with 1.8 V, 3.3 V, and 5 V MCUs without level shifters.
When designing with this part, place a 100 nF decoupling capacitor within 5 mm of the VCC pin and keep the SDA/SCL traces short and impedance-controlled. Add external pull-ups (typically 4.7 kohm to 10 kohm) to SDA, SCL, and the open-drain /INT line as required by the I2C standard. Connect the exposed thermal pad to a ground plane for improved thermal and electrical performance.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the manufacturer datasheet alone, providing actionable engineering guidance beyond what distributor catalogs typically publish.
Alternatives de remplacement direct pour PCA9554ABS3,118 — 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 :
PCA9554A
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
PCA9554ABS3,118 Spécifications
| Interface Bus | I2C, SMBus |
| Number of I/O | 8 |
| Clock Frequency (Max) | 400 kHz |
| Tension d'alimentation | 2.3 V to 5.5 V |
| I/O Voltage Tolerance | 5.5 V |
| I2C Address Selection | 3 hardware address pins (up to 8 devices) |
| Interrupt Output | /INT, open-drain |
| Default I2C Address (PCA9554A) | 0x38 (3-bit addr 000 = 0x38) |
| I/O Direction Configurability | Per-bit input or output |
| Internal Pull-ups | Configurable weak pull-ups per pin |
| Power-On Reset | Yes (all ports initialized as inputs) |
| Température de fonctionnement | -40 C to +85 C |
| Boîtier | 16-HVQFN (3x3 mm) with exposed pad |
| Type de montage | Surface Mount |
| Statut RoHS | Compliant |
Configuration des broches de PCA9554ABS3,118
| Broche 1 | A0 — I2C address select bit 0 |
| Broche 2 | A1 — I2C address select bit 1 |
| Broche 3 | A2 — I2C address select bit 2 |
| Broche 4 | IO0 — Bidirectional I/O bit 0 |
| Broche 5 | IO1 — Bidirectional I/O bit 1 |
| Broche 6 | IO2 — Bidirectional I/O bit 2 |
| Broche 7 | IO3 — Bidirectional I/O bit 3 |
| Broche 8 | GND — Ground |
| Broche 9 | IO4 — Bidirectional I/O bit 4 |
| Broche 10 | IO5 — Bidirectional I/O bit 5 |
| Broche 11 | IO6 — Bidirectional I/O bit 6 |
| Broche 12 | IO7 — Bidirectional I/O bit 7 |
| Broche 13 | /INT — Interrupt output (open-drain, active low) |
| Broche 14 | SCL — I2C serial clock line |
| Broche 15 | SDA — I2C serial data line |
| Broche 16 | VCC — Supply voltage (2.3 V to 5.5 V) |
Applications typiques
PCA9554ABS3,118 convient pour 6 applications: Mobile Phone Keypad and Slider Scanning, Server Fan and Cooling Control, LED Status and Blinking Control, Networking Equipment Port Status Indicators, Industrial PLC Digital I/O Expansion, Set-Top Box and Game Console Button Matrix.
Mobile Phone Keypad and Slider Scanning
The PCA9554ABS3,118's 3x3 mm HVQFN16 footprint and 8 GPIO pins make it ideal for mobile phone keypad matrices and slider switch scanning. Its 2.3 V to 5.5 V supply range directly interfaces with 1.8 V baseband processors without level shifters, while the /INT output wakes the host only when a key press changes input state, cutting I2C polling traffic. The 5.5 V tolerant I/O pins survive ESD events common in handheld designs. Place the IC near the connector side of the keypad flex, route SDA/SCL to the host, and configure internal pull-ups for the matrix rows.
Recommandé
Server Fan and Cooling Control
Servers require multi-channel PWM fan tach and control signals, which the PCA9554ABS3,118 provides via 8 GPIOs over I2C. The PCA9554A's wide supply (2.3 V to 5.5 V) accepts 3.3 V from baseboard management controllers, while the /INT pin alerts the BMC to tach changes without continuous polling, reducing CPU overhead. Internal pull-ups eliminate external resistors on tach inputs. Multiple PCA9554ABS3,118 chips can share one I2C bus using A0/A1/A2 address pins, supporting up to 64 fan channels in a single managed zone.
Recommandé
LED Status and Blinking Control
The PCA9554ABS3,118 drives up to 8 LEDs per chip via direct GPIO outputs, sinking up to the per-pin current limit set by external resistors. Its 400 kHz I2C allows fast LED update rates for chasing effects, while the /INT pin is unused in output-only mode. Multiple PCA9554A chips address-share on the same bus, scaling to 64+ LEDs without adding MCU GPIO load. Its compact 3x3 mm HVQFN footprint fits in tight indicator clusters on routers, switches, and front-panel displays.
Recommandé
Networking Equipment Port Status Indicators
Ethernet switches and routers use per-port Link/Activity LEDs, which the PCA9554ABS3,118 can drive with 8 GPIOs each. The 5.5 V tolerant I/O allows direct connection to multi-color LEDs without level shifting, and the I2C bus handles status updates without burdening the main switch ASIC. Three address pins allow up to 8 PCA9554A devices on a single bus, scaling to 64 ports. The exposed thermal pad ensures reliable operation when LEDs are continuously on in warm networking closets.
Recommandé
Industrial PLC Digital I/O Expansion
Industrial PLCs use the PCA9554ABS3,118 to add isolated digital I/O channels over I2C, with the 2.3 V to 5.5 V supply directly compatible with 24 V tolerant optocoupler front-ends when properly designed. The /INT output triggers PLC scan cycles only when an input changes, reducing bus traffic and CPU load. Eight hardware-selectable addresses enable multi-module I/O racks on a single I2C line. Industrial operating temperature range of -40 C to +85 C is met per the NXP datasheet for harsh factory environments.
Recommandé
Set-Top Box and Game Console Button Matrix
Set-top boxes and game consoles use the PCA9554ABS3,118 for compact button matrix scanning on front panels and remote receivers. The 3x3 mm HVQFN16 footprint fits inside the smallest enclosures, while the I2C interface avoids running dozens of GPIO traces back to the main SoC. The /INT pin signals button presses to wake the host from low-power standby. Combined with PCA9554A companions, up to 64 buttons can be scanned via shared I2C, ideal for full keyboards on premium gaming peripherals.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour PCA9554ABS3,118 — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | PCA9554A | PCA9554ABS,118 | PCA9554AD,118 | PCA9554APW,118 | PCF8574ADW |
|---|---|---|---|---|---|---|
| Package | 16-HVQFN (3x3 mm) | 16-HVQFN (3x3 mm) - same | 16-HVQFN (4x4 mm) - different footprint | 16-SOIC - different footprint | 16-TSSOP - different footprint | 16-SOIC - different footprint |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Number of I/O | 8 | 8 | 8 | 8 | 8 | 8 |
| Supply Voltage | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.6 V |
| I2C Clock Frequency | 400 kHz | 400 kHz | 400 kHz | 400 kHz | 400 kHz | 100 kHz (Standard Mode only) |
| Default I2C Address | 0x38 (PCA9554A family) | 0x38 | 0x38 | 0x38 | 0x38 | 0x20 (PCF8574 family) |
| Interrupt Output | Yes (/INT, open-drain) | Yes | Yes | Yes | Yes | Yes |
| I/O Architecture | Push-pull with configurable pull-ups | Push-pull with pull-ups | Push-pull with pull-ups | Push-pull with pull-ups | Push-pull with pull-ups | Quasi-bidirectional (no separate direction register) |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
Principaux différenciateurs
- Smallest footprint in the PCA9554A family at 3x3 mm HVQFN16 (vs PCA9554ABS,118 (4x4 mm HVQFN))
- 5 V tolerant I/O with internal weak pull-ups per pin (vs PCF8574ADW (quasi-bidirectional, weak fixed pull-ups))
- Differentiated I2C address (0x38 default) allows PCA9554 and PCA9554A coexistence (vs PCA9554 (0x20 default))
Notes de conception
Place a 100 nF (0.1 uF) X7R ceramic decoupling capacitor as close as possible (within 5 mm) to the VCC pin (pin 16) of the PCA9554ABS3,118, with the ground return via the exposed thermal pad to a continuous ground plane. The wide 2.3 V to 5.5 V supply range allows direct connection to common rail voltages (3.3 V, 5 V), but the I/O pins remain 5.5 V tolerant even when VCC is 1.8 V - useful for level-shifting legacy buses without external translators.
I2C SDA, SCL, and the open-drain /INT pin all require external pull-up resistors to VCC; the PCA9554ABS3,118 does not include internal pull-ups on these lines. Typical values are 4.7 kohm for Fast Mode (400 kHz) buses shorter than 100 mm, or 10 kohm for longer buses or lower-power designs. Forgetting these pull-ups is the most common reason the device appears non-responsive on first prototype builds.
The 16-HVQFN (3x3 mm) package requires a footprint with a central exposed pad (pin 17 in schematic, though not externally bonded) that must be soldered to a ground plane for thermal dissipation and electrical reference. Use an array of thermal vias under the pad (typically 9 vias in a 3x3 grid, 0.3 mm drill, 0.5 mm pitch) to connect the top-side ground pad to inner ground layers. Without this connection, the device may exhibit reset issues or communication failures under high I/O switching loads.
Keep SDA and SCL traces short and parallel with controlled impedance (typically 50 ohm microstrip or stripline). Avoid running them adjacent to high-current switching traces; cross perpendicular if necessary. When multiple PCA9554ABS3,118 chips share a bus, place address-setting resistors on A0/A1/A2 close to the IC and star-route the bus to minimize stub reflections. Add a 100 ohm series ferrite bead at the cable interface if the I2C bus exits the PCB.
Informations de conformité
RoHS and REACH compliant per NXP product page. Not AEC-Q100 qualified (industrial grade -40 C to +85 C). Lead-free and halogen-free packaging confirmed by distributor listings.
