STMicroelectronics LED1642GWTTR

Overview

LED1642GWTTR from STMicroelectronics is a 16-channel constant-current LED driver IC with integrated error detection, 7-bit programmable current gain (dual-range), and 12/16-bit PWM grayscale control. It delivers 3–40 mA per channel, supports 3–5.5 V supply, features 30 MHz 4-wire serial interface, and drives LEDs up to 20 V output voltage-used in monochrome and full-color signage panels requiring precise brightness uniformity and fault resilience.

For engineers reviewing the LED1642GWTTR datasheet, LED1642GWTTR pinout, LED1642GWTTR application, or LED1642GWTTR equivalent, key selection criteria include channel-to-channel current matching (±3% typ.), programmable TON/TOFF timing (30–180 ns), open/short LED diagnostics, thermal shutdown at 170 °C, and daisy-chain SDO synchronization capability.

Technical Context

The LED1642GWTTR integrates a 16-bit shift register, 16 independent current-regulated output stages, and a configurable PWM counter synchronized to PWCLK. Its digital control logic uses LE-gated clock pulses to access configuration, brightness, and error registers via defined digital key sequences (e.g., 1–2 CLK edges for write switch, 7–8 for configuration read).

Current regulation relies on an external R-EXT resistor (100 Ω–100 kΩ) combined with a 7-bit gain register (CFG[0:5] + CFG[6] range select), enabling fine-tuned per-device current scaling across two subranges. Error detection operates in real time using programmable short-circuit thresholds and auto-flagging of open-load conditions during active drive cycles.

Key Specifications

Pinout & Package

TSSOP24 exposed pad package (RoHS-compliant, moisture sensitivity level 3), thermally enhanced with exposed die pad soldered to PCB ground plane for optimal thermal resistance (R_thj-amb = 37.5 °C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-channel constant-current LED driver applications.

Compared with LED1642GWTTR, TLC5947RTQT offers more channels but sacrifices fault resilience and output voltage headroom, while IS31FL3728-QFLS4-TR provides superior PWM resolution and smaller footprint but eliminates analog current tuning flexibility and serial daisy-chaining.

Availability

LED1642GWTTR is available at Aetrix Electronics and suitable for outdoor signage, indoor video walls, transportation information systems, and industrial indicator arrays requiring stable component supply, long-lifecycle support, and automotive-grade thermal robustness.

Supply support for LED1642GWTTR 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

STMicroelectronics is a global semiconductor leader specializing in power management, analog, and display interface solutions for industrial, automotive, and consumer markets.

The LED1642GWTTR belongs to ST's high-precision LED driver product line, engineered specifically for large-panel display systems demanding tight current matching, real-time fault visibility, and scalable multi-device synchronization.

FAQ

What is the maximum number of LED1642GWTTR devices that can be daisy-chained?

Up to 16 LED1642GWTTR devices can be cascaded using the SDO-to-SDI connection, limited by cumulative propagation delay and signal integrity at 30 MHz. Each device adds ~25 ns CLK-to-SDO delay (CFG-13 = '0'), requiring careful PCB layout and termination for reliable operation beyond 8 units.

How does the 7-bit current gain register interact with the external R-EXT resistor?

The R-EXT resistor sets the base current scale (e.g., 11 kΩ yields ~20 mA at mid-gain), while the 7-bit gain register (CFG[0:5] + CFG[6]) applies multiplicative scaling in two ranges: low-gain (0.25×–1×) and high-gain (1×–4×). This allows fine-grained per-device calibration without changing hardware.

Can the LED1642GWTTR drive RGB LEDs with independent color channel control?

Yes-the 16 independent current outputs and per-channel 12/16-bit PWM registers allow full RGB+white or RGB+amber configurations (e.g., 5 red + 5 green + 5 blue + 1 white). Each channel's brightness is controlled separately, enabling precise white-point tuning and color mixing without external transistors.

What happens during thermal shutdown, and how is recovery handled?

At 170 °C junction temperature, all 16 outputs disable immediately and the thermal flag (TFLG) asserts. Outputs remain off until junction cools below 155 °C (15 °C hysteresis); no reset or LE pulse is required. The device continues accepting commands and reporting status via SDO during thermal event.