NXP Semiconductors PCA9553D/01,112

Overview

The PCA9553D/01 from NXP Semiconductors is a 4-bit I²C-bus LED blinker with integrated oscillator, designed to offload LED timing control from the host MCU in embedded systems. It provides two fully programmable blink rates (0.172–44 Hz), 4 open-drain outputs with 25 mA sink per channel and 100 mA package limit, and operates across 2.3–5.5 V supply. It is used in status indication for industrial HMIs, telecom rack LEDs, and consumer device power/activity indicators.

For engineers reviewing the PCA9553D/01 datasheet, PCA9553D/01 pinout, PCA9553D/01 application, or PCA9553D/01 equivalent, key selection criteria include its fixed I²C address (0xC4), internal blink rate programming without host timer usage, GPIO reuse capability for unused LED pins, and SO8 package compatibility with standard 3.9 mm body width layouts.

Technical Context

The PCA9553D/01 implements an autonomous blink engine using two independent PWM channels (BLINK0 and BLINK1), each controlled by dedicated prescaler (PSC0/PSC1) and duty-cycle (PWM0/PWM1) registers. Its internal oscillator eliminates external timing components and supports precise blink period calculation: period = (PSCx + 1) / 44 Hz.

It features I²C-bus logic compliant with SMBus standards, noise filtering on SCL/SDA inputs, controlled edge rates to minimize ground bounce, and Power-On Reset that initializes all registers to default states - setting outputs HIGH (LED off) and LED selector bits to high-impedance mode.

Key Specifications

Pinout & Package

PCA9553D/01 is supplied in SO8 package (SOT96-1), 8-lead plastic small outline, 3.9 mm body width, with standard gull-wing lead form. Pin 1 is LED0; pin 4 is VSS (supply ground); pin 8 is VDD (supply voltage).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LED blinker applications.

Compared with PCA9553DP/01, the PCA9553D/01 offers identical functionality in a more robust SO8 package with higher thermal dissipation; compared with PCA9555D, it delivers true autonomous blink control - reducing firmware complexity and I²C bandwidth use by eliminating host-side timing loops.

Availability

PCA9553D/01 is available at Aetrix Electronics and suitable for industrial HMIs, telecom rack management, and consumer device status indication requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for PCA9553D/01 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

NXP Semiconductors is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT applications, with core expertise in mixed-signal and interface ICs.

The PCA9553D/01 belongs to NXP's I²C peripheral portfolio designed specifically for intelligent LED control in resource-constrained embedded systems - emphasizing autonomous operation, low power, and bus efficiency.

FAQ

What is the I²C slave address of the PCA9553D/01?

The PCA9553D/01 has a fixed 7-bit I²C slave address of 0xC4 (1100010b). This address is hardwired and cannot be changed via hardware pins. The PCA9553D/02 variant uses 0xC6, allowing both devices to coexist on the same I²C bus. The R/W bit occupies the LSB, making the full write address 0xC4 and read address 0xC5. This fixed addressing simplifies system integration but requires careful bus topology planning when multiple PCA9553 variants are deployed.

How do I configure the PCA9553D/01 to blink an LED at 2 Hz with 50 % duty cycle?

To achieve 2 Hz blink at 50 % duty cycle on PCA9553D/01, write PSC0 = 87 (0x57) to set period = (87 + 1)/44 = 2 Hz, and PWM0 = 128 (0x80) to set duty cycle = (256 − 128)/256 = 50 %. Then set the LED selector register (LS0) bits for the target pin (e.g., bits 1:0 = 10b for LED0) to route output to BLINK0. The PCA9553D/01 executes this autonomously - no further host intervention is needed after initial configuration.

Can unused LED pins on the PCA9553D/01 be used as general-purpose inputs or outputs?

Yes, unused LED pins on the PCA9553D/01 can serve as GPIOs. To use as input: configure the corresponding LS0 bits to 01b (high-impedance), then read the state from the INPUT register. To use as output: connect an external pull-up resistor and program LS0 bits to 00b (LOW) or 10b/11b (blink mode). The PCA9553D/01 does not support push-pull output - all GPIO operation relies on open-drain topology with external pull-ups.

What is the maximum sink current per LED pin on the PCA9553D/01, and how does it affect thermal design?

The PCA9553D/01 supports up to 25 mA sink current per LED pin, with a total package limit of 100 mA. Exceeding 25 mA per pin risks output transistor saturation and increased VOL; exceeding 100 mA total triggers thermal shutdown. For continuous 25 mA per pin across all four outputs, PCB layout must ensure adequate copper area on VSS and thermal vias under the SO8 package - especially critical at 5.5 V supply where power dissipation reaches ~110 mW.

Does the PCA9553D/01 require external components for its internal oscillator to function?

No, the PCA9553D/01 requires no external components for its internal oscillator - it is fully self-contained and factory-trimmed. The oscillator drives both BLINK0 and BLINK1 PWM channels and operates across the full 2.3–5.5 V supply range and −40 °C to +85 °C ambient temperature. This eliminates BOM cost, layout area, and calibration effort associated with external RC or crystal timing networks - a key differentiator versus generic I/O expanders like the PCA9554.