PCA9551D,118

Overview

The PCA9551D,118 is an 8-bit I²C-bus and SMBus LED driver manufactured by NXP Semiconductors. It features an internal oscillator providing two fully programmable blink rates for frequency and duty cycle control. The device includes eight open-drain outputs capable of sourcing up to 25 mA per bit and 100 mA per package. It operates within a supply voltage range of 2.3 V to 5.5 V with a maximum clock frequency of 400 kHz. The component is housed in a 16-pin SO (SOT403) package.

Feature Summary

• Internal oscillator enables programmable LED blinking without external components
• I²C bus interface logic compatible with SMBus standards
• Low-level active hardware reset pin and internal power-on reset

Applications

• I²C bus applications requiring limited bus communication traffic
• Systems needing to release MCU timers for LED control
• General-purpose input/output expansion where bits are unused for LEDs

Procurement Notes

Verify the specific suffix '118' against official NXP documentation to confirm tape and reel packaging specifications. Ensure the SO-16 package variant matches the design requirements. Cross-reference the full part number with current datasheets to validate availability status and any potential obsolescence notices before finalizing procurement plans.

Selection Notes

Select this component when independent timer resources are constrained on the host microcontroller. It is suitable for applications requiring distinct blink patterns for status indication. Consider the 25 mA output capability for direct LED driving. Verify that the I²C address configuration via hardware pins meets the system topology requirements.

Part Context

This part belongs to the PCA95xx series of I/O expanders and LED controllers from NXP. It serves as a specialized solution for managing visual indicators in embedded systems. The device simplifies firmware complexity by offloading timing functions from the main processor to the dedicated hardware controller.

Replacement Considerations

PCA9551PW,118: Identical functionality in TSSOP-16 package.