NXP Semiconductors PCA9553TK/02,118

Overview

PCA9553TK/02 from NXP Semiconductors is a 4-bit I²C-bus LED blinker with integrated oscillator, designed to offload LED timing control from the host MCU. It provides two fully programmable blink rates (0.172–44 Hz), 4 open-drain outputs with 25 mA sink per channel, and operates across 2.3–5.5 V supply. Used in status indication systems where bus traffic reduction and timer conservation are critical.

For engineers reviewing the PCA9553TK/02 datasheet, PCA9553TK/02 pinout, PCA9553TK/02 application, or PCA9553TK/02 equivalent, this page delivers verified functional identity, validated HVSON8 package mapping, confirmed I²C slave address (0xC6), exact blink rate calculation formulas, and real-world GPIO reuse capability - all extracted from NXP's official Rev. 06 product data sheet.

Technical Context

The PCA9553TK/02 implements an internal oscillator with dual prescaler/PWM register pairs (PSC0/PWM0 and PSC1/PWM1) enabling independent blink frequency and duty cycle control for each output. Blink period is calculated as (PSCn + 1)/44 seconds; duty cycle = (256 − PWMn)/256. All four LED outputs double as general-purpose open-drain I/Os when configured via the LS0 register.

It features noise-filtered SCL/SDA inputs, controlled edge rates to suppress ground bounce, hot-insertion support, and Power-On Reset that initializes all registers to default states (LEDs OFF). The device uses fixed I²C address 0xC6 (7-bit, R/W bit = 0), distinct from the /01 variant's 0xC4 address, enabling coexistence on the same bus.

Key Specifications

Pinout & Package

HVSON8 package: plastic thermal-enhanced very thin small outline, no leads, 8 terminals, body size 3 × 3 × 0.85 mm. Exposed center pad must be soldered to PCB thermal pad with vias for optimal thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9553TK/02, the PCA9553DP/02 offers identical timing control and I²C behavior in a rework-friendly TSSOP8 package, while the PCA9553D/02 provides mechanical robustness and wave-solder compatibility at the expense of thermal efficiency and board area - making the TK/02 optimal for space-constrained, thermally demanding embedded applications.

Availability

PCA9553TK/02 is available at Aetrix Electronics and suitable for industrial HMI panels, network equipment status indicators, and medical device user interfaces requiring stable component supply and long-term lifecycle assurance.

Supply support for PCA9553TK/02 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.

The PCA9553 belongs to NXP's I²C peripheral portfolio, engineered to reduce host processor load in resource-constrained embedded systems through autonomous LED timing control and flexible GPIO expansion.

FAQ

What is the I²C slave address of the PCA9553TK/02?

The PCA9553TK/02 uses a fixed 7-bit I²C slave address of 0xC6 for write operations and 0xC7 for read operations. This address is hardwired and differs from the PCA9553/01 variant (0xC4), allowing both versions to coexist on the same I²C bus without address conflict. The address is defined in Figure 6 of the NXP PCA9553 datasheet Rev. 06.

How do I configure the PCA9553TK/02 to blink an LED at exactly 2 Hz with 50% duty cycle?

To achieve 2 Hz blinking on PCA9553TK/02, calculate PSC0 = (1/2 × 44) − 1 = 21 (0x15), then set PWM0 = 256 − (0.5 × 256) = 128 (0x80). Write 0x15 to PSC0 register (subaddress 0x01), 0x80 to PWM0 (subaddress 0x02), and configure the target LED pin (e.g., LED0) to "blink at PWM0" (0b10) in the LS0 register (subaddress 0x05). This sequence is validated in Table 11 of the datasheet.

Can unused LED pins on the PCA9553TK/02 be used as general-purpose inputs or outputs?

Yes - unused LED pins on the PCA9553TK/02 can serve as GPIOs. To use as input: set the pin to high-impedance (0b01 in LS0 bits) and read its state via the INPUT register. To use as output: connect an external pull-up resistor and drive LOW via LS0 (0b00) or HIGH-impedance (0b01). The pin retains full 25 mA sink capability when actively driven LOW.

What is the maximum total current the PCA9553TK/02 can sink across all outputs?

The PCA9553TK/02 has a maximum total package sink current limit of 100 mA, with each of the four LED outputs rated for up to 25 mA. This limit applies regardless of combination - e.g., driving two outputs at 25 mA each and one at 30 mA violates the 100 mA total constraint. Exceeding this risks thermal shutdown or permanent damage per Table 12 limiting values.

Does the PCA9553TK/02 require external components for its internal oscillator to function?

No - the PCA9553TK/02's internal oscillator requires no external capacitors, resistors, or crystals. It is fully self-contained and calibrated to deliver stable blink timing across the full 0.172–44 Hz range. This eliminates BOM cost, layout area, and calibration effort, distinguishing it from discrete timer-based LED solutions.