PCA9551BSHP

Overview

The PCA9551BSHP is an 8-bit I²C bus LED driver manufactured by NXP USA Inc., housed in a 16-pin HVQFN package. It features two fully programmable blink rates generated by an internal oscillator, eliminating the need for external components or MCU timer resources. The device provides eight open-drain outputs capable of sinking up to 25 mA per bit and 100 mA per package. It supports I²C clock frequencies from 0 Hz to 400 kHz and operates within a supply voltage range of 2.3 V to 5.5 V. Unused bits function as general-purpose I/O.

Feature Summary

• Internal dual programmable blink rate generators eliminate MCU timer dependency
• Eight open-drain outputs with independent on/off/blink control
• Low-power operation with low standby current consumption
• Hardware reset and power-on reset ensure defined initial states

Applications

• I²C bus applications requiring limited communication traffic
• SMBus systems needing LED status indication without MCU overhead
• Embedded designs releasing microcontroller timers for other tasks
• Portable devices utilizing low-voltage power supplies

Procurement Notes

Verify the specific suffix HP indicates the HVQFN16 reel pack orientation and standard product configuration. Confirm that the ordering code aligns with the required tape and reel specifications for automated assembly. Ensure compatibility with the target I²C address configuration using hardware pins A0, A1, and A2. Cross-reference the datasheet version to confirm electrical characteristics match the design requirements.

Selection Notes

Select this component when independent LED blinking is required without consuming processor resources. It is suitable for designs needing multiple LED indicators driven directly from the I²C bus. Consider the 25 mA sink capability for direct LED connection. Evaluate the HVQFN package size against available PCB space constraints.

Part Context

The PCA9551 series enhances standard I²C GPIO expanders by integrating dedicated LED driving functions. Unlike generic expanders like the PCF8574, it offloads blinking logic from the host controller. This reduces bus congestion and simplifies firmware architecture. The family includes variants with different pin counts and packages to suit various application densities.

Replacement Considerations

PCA9551BS (SO16), PCA9551BPW (TSSOP16), PCA9551BHV (HVQFN16). Verify package footprint and thermal performance differences before substitution.