PCA9955BTW/Q900J

PCA9955BTW/Q900J is NXP’s 16‑channel I2C‑controlled constant‑current LED driver. It provides 16 low‑side current sinks to drive LED strings with uniform brightness. Key points:
- 16 programmable LED currents (via IREF/ISET) for multi‑string applications.
- Two dimming schemes: per‑channel grayscale PWM (fine brightness control) and a global group PWM for overall dimming.
- I2C interface with configurable address, plus fault/open/short detection and status flags.
- Suitable for LED displays, signage, backlighting, and automotive lighting.
- Lightweight power/voltage range (typical operation in a few volts, check datasheet for exact limits).
- “BTW” and “Q900J” specify the package/variant code used by distributors.
For exact pinout, register map, current‑setting equations, and timing details, refer to the PCA9955 family datasheet.

Possible equivalents (16-channel LED drivers with per-channel control):
- TI TLC5955 (16-channel constant-current sink, SPI interface, PWM)
- Macroblock MBI5168 (16-channel SPI-driven constant-current LED driver)
- NXP PCA9685 (16-channel I2C PWM LED driver; not constant-current—requires external current setting)
Note: interface, current-setting method, and voltages differ; verify current accuracy and pin compatibility for your design.

Concise features of PCA9955BTW/Q900J:
- 16-channel constant-current LED sink outputs
- I2C-bus controlled; programmable device address
- Per-channel brightness via grayscale/PWM dimming
- Global/group dimming capabilities (GSCLK, GRP registers)
- Adjustable LED current per channel (IREF/ILED with external resistor)
- Open/short LED protection and fault diagnostic reporting
- Software shutdown and hardware reset
- Wide supply voltage range with low standby current
- Suitable for automotive/industrial use; available in PCA9955BTW/Q900J packaging and lot code (Q900J) variant
Note: specific PWM resolution and exact current ranges are defined in the datasheet; this summarizes key capabilities.

- Pin count: 28 pins (28-pin package, e.g., TSSOP/SOIC).
- Function: 16-channel constant-current LED driver with I2C interface and 12-bit PWM per channel for dimming (sink outputs).

- Manufacturer: NXP Semiconductors
- Company type: Dutch multinational semiconductor company that designs, manufactures, and sells ICs and system solutions for automotive, industrial, and consumer electronics (one of the world’s largest chipmakers, with origins in Philips).

Applications include automotive instrument clusters and dashboards, automotive exterior lighting, LCD/backlight displays, LED signage and displays, LED matrix panels, architectural and decorative lighting, backlit keyboards and consumer/industrial indicators. The PCA9955BTW/Q900J provides 16 constant-current sink outputs with I2C control and PWM dimming, enabling independent current regulation for multi-channel LED systems.

28-pin HVQFN (leadless) package.