NXP Semiconductors PCA9634D,118

Overview

The PCA9634D,118 from NXP Semiconductors is an I²C-bus controlled 8-bit LED driver optimized for RGBA color mixing, featuring eight 25 mA totem-pole LED outputs, 97 kHz individual PWM (256-step), and 190 Hz/24 Hz–10.73 s group PWM control. It operates from 2.3 V to 5.5 V and supports Fast-mode Plus (1 MHz) I²C with 30 mA SDA drive strength - ideal for compact RGB status indicators and keypad backlights.

For engineers reviewing the PCA9634D,118 datasheet, PCA9634D,118 pinout, PCA9634D,118 application, or PCA9634D,118 equivalent, key selection criteria include I²C address flexibility (7 hardware + 4 software addresses), OE-driven hardware dimming/blinking synchronization, open-drain/totem-pole output configuration, group vs. individual PWM interaction, and SO20 package thermal and layout compatibility.

Technical Context

The PCA9634D,118 integrates a 25 MHz internal oscillator (no external components required) and dual PWM architecture: fixed 97 kHz individual channels per LED with 0–99.6% duty cycle control, plus a programmable group controller supporting either 190 Hz dimming or 24 Hz–10.73 s blinking via GRPFREQ/GRPPWM registers. Its MODE2 register configures output structure (totem-pole default) and output update timing (STOP-command synchronized by default).

I²C communication uses a 7-bit slave address with up to 126 devices supported via A0–A6 pins; additionally, four software-defined addresses (LED All Call E0h and three Sub Call addresses E2h/E4h/E8h) enable grouped command execution. The active-low OE pin provides asynchronous hardware-level output enable/disable and supports external PWM dimming independent of internal PWM engines.

Key Specifications

Pinout & Package

PCA9634D,118 is housed in a plastic small outline package (SO20) with 20 leads and 7.5 mm body width (SOT163-1). The package supports standard surface-mount reflow and offers adequate thermal dissipation for continuous 25 mA per channel operation at ambient temperatures up to +85 °C.

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 PCA9634D,118 uniquely balances 8-channel simplicity, hardware OE synchronization, programmable group blink timing, and SO20 manufacturability - making it optimal for cost-sensitive, medium-complexity RGBA UI lighting where deterministic timing and layout reuse matter.

Availability

PCA9634D,118 is available at Aetrix Electronics and suitable for RGB status indicators, keypad backlights, and LED display segments requiring stable component supply, long-term industrial temperature support (−40 °C to +85 °C), and SO20-compatible PCB layouts.

Supply support for PCA9634D,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 company specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with leadership in I²C peripheral IP and mixed-signal interface ICs.

The PCA9634D,118 belongs to NXP's Fm+ LED driver product line, designed specifically for low-pin-count, high-flexibility RGBA lighting control in space- and power-constrained user interfaces.

FAQ

What is the maximum I²C bus speed supported by the PCA9634D,118?

The PCA9634D,118 supports Fast-mode Plus (Fm+) I²C operation up to 1 MHz. Its SDA output features 30 mA drive capability, enabling reliable communication on heavily loaded buses with up to 4000 pF total capacitance - significantly exceeding standard Fast-mode (400 kHz) limits. This performance is confirmed in the NXP PCA9634 datasheet Rev. 7.1.

Can the PCA9634D,118 drive LEDs directly without external components?

Yes, the PCA9634D,118 can drive standard LEDs directly: its totem-pole outputs deliver 25 mA sink / 10 mA source at 5 V, and outputs are 5.5 V tolerant. For LEDs requiring >25 mA or >5.5 V, external drivers are needed - but no current-setting resistors or external oscillators are required for basic operation, thanks to its internal 25 MHz oscillator and programmable output structure.

How does the OE pin function in the PCA9634D,118?

The OE (Output Enable) pin on the PCA9634D,118 is active-low and provides hardware-level control over all eight LED outputs. When OE is LOW, outputs follow their programmed states (off/on/PWM). When OE is HIGH, outputs enter a defined state (1, 0, or high-Z) set by the OUTNE bits in MODE2. OE also supports external PWM dimming - but must not be used simultaneously with internal group blinking (DMBLNK = 1) to avoid undefined behavior.

What are the group PWM frequency options for the PCA9634D,118?

The PCA9634D,118 offers two group PWM modes: (1) fixed 190 Hz dimming when DMBLNK = 0 in MODE2, or (2) programmable blink frequency from 24 Hz to 10.73 s (i.e., ~0.093 Hz) when DMBLNK = 1. The GRPFREQ register selects the period in 256 linear steps - e.g., 0x00 = 41 ms (24 Hz), 0xFF = 10.73 s - enabling precise control of visual attention-grabbing effects without software intervention.

Is the PCA9634D,118 pin-compatible with other packages in the PCA9634 family?

No - the PCA9634D,118 (SO20) has identical pin functions but different physical layout versus PCA9634PW (TSSOP20) and PCA9634BS (HVQFN20). While electrical behavior and register mapping are identical across packages, the SO20 pin numbering (e.g., A0 = Pin 1, VDD = Pin 20) differs from TSSOP20 and HVQFN20 configurations. PCB layout must be package-specific; no mechanical interchangeability exists.