NXP Semiconductors PCA9533D/01,112

Overview

PCA9533D/01 from NXP Semiconductors is a 4-bit I²C-bus LED dimmer IC optimized for RGB color mixing and backlight control, featuring two fully programmable PWM blink rates (0.591–152 Hz), 256 brightness steps, 25 mA per output sink current, and operation from 2.3 V to 5.5 V supply. It integrates an internal oscillator and supports GPIO expansion on unused LED driver pins.

For engineers reviewing the PCA9533D/01 datasheet, PCA9533D/01 pinout, PCA9533D/01 application, or PCA9533D/01 equivalent, key selection criteria include its fixed I²C address (0xC4), SO8 package with 3.9 mm body width, dual PWM register architecture (PSC0/PWM0 and PSC1/PWM1), and suitability for low-power LED dimming in space-constrained consumer and industrial displays.

Technical Context

The PCA9533D/01 implements a dedicated LED dimming architecture using two independent PWM channels driven by internal prescalers (PSC0/PSC1) and duty-cycle registers (PWM0/PWM1), enabling simultaneous control of four open-drain outputs at distinct blink frequencies and intensities. Its I²C interface complies with SMBus timing and includes noise filtering on SCL/SDA inputs.

Each LED output is controlled via the LED selector (LS0) register, supporting four states per bit: high-impedance (off), active-low (on), BLINK RATE 0, or BLINK RATE 1. Power-on reset initializes all outputs to HIGH (LED off), and edge-rate control minimizes EMI during switching.

Key Specifications

Pinout & Package

PCA9533D/01 is housed in an 8-pin SO8 package (SOT96-1) with 3.9 mm body width, 1.27 mm lead pitch, and surface-mount footprint compatible with standard reflow processes.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TCA6507PWR and PCA9632DP, the PCA9533D/01 delivers optimal balance of simplicity, dual-PWM flexibility, and SO8 footprint for cost-sensitive 4-LED RGB or backlight systems where independent blink rate assignment is essential and channel count is fixed.

Availability

PCA9533D/01 is available at Aetrix Electronics and suitable for RGB backlight control, industrial status indication, consumer UI lighting, and ACPI power switch interfacing requiring stable component supply and long-term industrial temperature support (−40 °C to +85 °C).

Supply support for PCA9533D/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 specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with deep expertise in I²C peripheral design and power-efficient mixed-signal ICs.

The PCA9533D/01 belongs to NXP's I²C-bus I/O expander family, engineered specifically for LED dimming and GPIO extension in resource-constrained embedded systems where low power, small footprint, and deterministic PWM timing are critical.

FAQ

What is the fixed I²C address of the PCA9533D/01 and how does it differ from PCA9533D/02?

The PCA9533D/01 has a fixed 7-bit I²C slave address of 0xC4 (1100010b), while PCA9533D/02 uses 0xC6 (1100011b). This dual-address scheme allows both variants to operate simultaneously on the same I²C bus without address conflict, enabling flexible system-level LED control partitioning. The PCA9533D/01 address is hardwired and not configurable via external pins.

Can unused LED driver pins on the PCA9533D/01 be repurposed as general-purpose inputs or outputs?

Yes - LED0 through LED3 pins on the PCA9533D/01 can function as GPIOs when not used for LED control. As inputs, they are read via the INPUT register after setting the corresponding LS0 bits to 00 (high-impedance). As outputs, they drive low when LS0 bits are set to 01, and support PWM modulation when configured for BLINK RATE 0 or 1. External pull-up resistors are required for output use.

What are the minimum and maximum PWM frequencies supported by the PCA9533D/01?

The PCA9533D/01 supports PWM frequencies from 0.591 Hz (1.69 s period) to 152 Hz (6.58 ms period), determined by the 8-bit PSC0 and PSC1 prescaler registers using the formula (PSCn + 1)/152 Hz. This range enables both visible blinking effects and flicker-free dimming above 100 Hz, with 256-step duty cycle control via PWM0/PWM1 registers.

Does the PCA9533D/01 require external components to generate its PWM signals?

No - the PCA9533D/01 contains a fully integrated internal oscillator and requires no external capacitors, resistors, or crystals to generate its two independent PWM outputs. This eliminates BOM cost and board space associated with external timing components while ensuring consistent frequency accuracy across voltage and temperature ranges.

What is the maximum sink current per output and total package current rating for the PCA9533D/01?

The PCA9533D/01 provides a maximum sink current of 25 mA per LED output (LED0–LED3), with a total package limit of 100 mA. These ratings are specified under DC conditions and must be observed simultaneously across all active outputs; exceeding either rating risks thermal shutdown or permanent damage. Derating is recommended at elevated ambient temperatures.