PCA9955BTW/Q900J

PCA9955BTW/Q900J is NXP’s 16-channel constant-current LED driver with an I2C interface, designed to sink current from up to 16 LEDs or strings. The Q900J suffix usually indicates an automotive-grade variant/packaging.
Key points:
- 16 low-side current sinks with per-channel current programmable (via registers/IREF).
- I2C-bus control with configurable device addresses.
- PWM dimming: per-channel brightness control with global/group dimming options.
- Protections: short-circuit/overcurrent, thermal shutdown, and voltage protections.
- Separate logic voltage (VDD) from LED supply (VBAT), enabling flexible system design.
- Status reporting and fault flags available through registers.
Typical use cases:
- Automotive dashboards and backlighting, display backlights, signage, and architectural lighting.
Notes:
- Exact electrical specs (max per-channel current, voltage range, I2C speed, register map) depend on the specific revision and packaging; consult the PCA9955 datasheet for precise figures and the Q900J variant's environmental ratings.

The PCA9955BTW/Q900J uses a 28-pin TSSOP (plastic small-outline) package.

- Pin count: 28 pins (PCA9955BTW/Q900J in a 28‑pin package, e.g., TSSOP/SOIC)
- Function: I2C‑controlled, 16‑channel constant‑current LED sink driver. Provides 16 low‑side LED outputs (OUT0–OUT15) with per‑channel PWM/grayscale brightness control; includes I2C interface (SDA/SCL) and address pins (A0/A1) for bus addressing, plus power and ground pins.

Manufacturer: NXP Semiconductors.
What kind of company: A Dutch multinational semiconductor company that designs and manufactures integrated circuits and semiconductor solutions for automotive, industrial, IoT, and consumer electronics (formerly Philips Semiconductors).

Typical application areas for PCA9955BTW/Q900J include:
- Automotive lighting and instrument clusters
- LCD/LED display backlighting and signage
- Signage, architectural and decorative lighting
- LED matrices and signboards
- Keyboard/panel backlighting and other multi-channel LED driving in consumer electronics

Equivalent products (16-channel I2C LED drivers with similar function):
- NXP PCA9685 (16-channel I2C PWM LED driver)
- TI TLC59116 (16-channel I2C constant-current LED driver)
- ISSI IS31FL3731 (16-channel I2C LED driver for matrix/backlight)
If SPI is acceptable, consider TI TLC5940/TLC5949 (16-channel SPI, constant-current).