NXP Semiconductors PCA9633BS,118

Overview

PCA9633BS,118 from NXP Semiconductors is a 4-bit Fast-mode Plus (Fm+) I²C-bus LED driver optimized for RGBA color mixing, featuring four independent 8-bit PWM channels (97 kHz, 0–99.6% duty cycle), one group PWM controller (190 Hz fixed or 24 Hz–10.73 s programmable), 2.3–5.5 V supply range, and 5.5 V-tolerant outputs. It supports totem-pole (25 mA sink / 10 mA source) or open-drain (25 mA sink) output configuration and is used in keypad backlights and status indicators in handheld devices.

For engineers reviewing the PCA9633BS,118 datasheet, PCA9633BS,118 pinout, PCA9633BS,118 application, or PCA9633BS,118 equivalent, key selection considerations include I²C address flexibility (7 hardware pins → 126 addresses), software-reset capability via SWRST call, OE pin support for hardware-synchronized dimming/blinking, and HVQFN16 package compatibility with high-density PCB layouts.

Technical Context

The PCA9633BS,118 implements dual-layer PWM control: individual 97 kHz PWM per LED channel enables precise brightness tuning across 256 linear steps, while the group PWM operates at either fixed 190 Hz (dimming mode) or programmable frequency (24 Hz–10.73 s) for synchronized blinking. Its Fm+ interface supports up to 1 MHz clock rate and drives buses up to 4000 pF with 30 mA SDA drive strength.

Register-based configuration includes MODE1/MODE2 for sleep control, output polarity (INVRT), output structure (OUTDRV), and OE behavior (OUTNE[1:0]); LEDOUT register selects per-channel states (off/on/individual/group); and GRPFREQ/GRPPWM jointly define global blink timing and duty cycle when DMBLNK = 1.

Key Specifications

Pinout & Package

HVQFN16 package (4 × 4 × 0.85 mm, no leads, exposed thermal pad); VSS connected to both pin 7 and exposed center pad - requires soldering pad to PCB ground plane with thermal vias for reliable operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC59116IPWPR and IS31FL3728-QFLS4-TR, the PCA9633BS,118 uniquely balances 4-channel precision, Fm+ bus speed, 7-pin I²C address configurability, and hardware OE for deterministic multi-device timing - making it optimal for compact, cost-sensitive RGBA indicator systems.

Availability

PCA9633BS,118 is available at Aetrix Electronics and suitable for RGB status indicators, keypad backlights, LED display segments, and cellular phone UI lighting requiring stable component supply across industrial and consumer production cycles.

Supply support for PCA9633BS,118 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 focused on secure connectivity solutions for automotive, industrial, and IoT applications, with broad analog, digital, and mixed-signal product portfolios.

The PCA9633BS,118 belongs to NXP's Fm+ I²C LED driver family, designed specifically for space-constrained, low-power RGBA lighting systems requiring high bus density, precise brightness control, and hardware-synchronized effects.

FAQ

What is the function of the OE pin on the PCA9633BS,118?

The OE (Output Enable) pin on the PCA9633BS,118 is an active-low hardware control that globally enables or disables all four LED outputs. When OE is LOW, outputs follow the LEDOUT register settings; when HIGH, outputs assume a software-defined state (1, 0, or high-Z) per MODE2's OUTNE[1:0] bits. This enables synchronized dimming or blinking across multiple PCA9633BS,118 devices using a common external clock signal - a capability exclusive to the 16-pin versions like PCA9633BS,118.

How many I²C addresses can the PCA9633BS,118 support?

The PCA9633BS,118 supports up to 126 unique I²C slave addresses via seven hardware address pins (A0–A6). Two reserved addresses (Software Reset and LED All Call) are excluded from general use, leaving 126 configurable options. Additionally, it supports one LED All Call address (E0h) and three programmable Sub Call addresses (E2h, E4h, E8h), enabling grouped I²C commands - all accessible without modifying the PCA9633BS,118's physical address pins.

Does the PCA9633BS,118 support both totem-pole and open-drain output configurations?

Yes, the PCA9633BS,118 supports both output structures via the OUTDRV bit (bit 2) in the MODE2 register. When OUTDRV = 1 (default), outputs operate in totem-pole mode (25 mA sink / 10 mA source at 5 V); when OUTDRV = 0, they switch to open-drain mode (25 mA sink only). This flexibility allows direct driving of standard LEDs or interfacing with external high-current drivers - critical for applications requiring higher voltage or current than the PCA9633BS,118's native 25 mA limit.

What is the purpose of the GRPFREQ and GRPPWM registers in the PCA9633BS,118?

The GRPPWM and GRPFREQ registers in the PCA9633BS,118 jointly control global LED behavior. When DMBLNK = 0 (dimming mode), GRPPWM sets a 190 Hz group duty cycle (0–99.6%) applied uniformly across all four channels. When DMBLNK = 1 (blinking mode), GRPPWM defines the ON/OFF ratio while GRPFREQ programs the blink period from 41 ms (24 Hz) to 10.73 s - enabling precise, software-controlled synchronization of blinking effects across multiple PCA9633BS,118 devices without MCU intervention.

Can the PCA9633BS,118 be reset over the I²C bus?

Yes, the PCA9633BS,118 supports Software Reset (SWRST) via I²C address 06h with R/W = 0. This command resets all internal registers to their power-on default values - identical to a hardware power-on reset - restoring LED outputs to HIGH (off), MODE1/MODE2 to defaults, and PWM/GRPPWM registers to zero or full-scale values. This feature enables rapid reconfiguration of the PCA9633BS,118 during runtime without cycling VDD, simplifying firmware recovery and initialization sequences.