STMicroelectronics LED7706

Overview

LED7706 from STMicroelectronics is a monolithic 6-channel LED backlight driver with integrated boost converter for LCD panel illumination. It delivers up to 30 mA per channel, supports 4.5–36 V input, regulates output up to 36 V, features ±2 % current matching between rows, and enables 1 % PWM dimming at 20 kHz in applications such as LCD TV and monitor backlighting.

For engineers reviewing the LED7706 datasheet, LED7706 pinout, LED7706 application, or LED7706 equivalent, key selection criteria include its six independent current-sink channels, programmable soft-start, OVP threshold setting via external divider, thermal shutdown, and fault detection for open/shorted LEDs - all critical for reliable LCD backlight design.

Technical Context

The LED7706 integrates two tightly coupled functional blocks: a constant-frequency peak-current-mode boost regulator (250 kHz–1 MHz, internal 280 mΩ MOSFET) and six precision current generators. The boost section regulates output voltage by sensing the minimum forward voltage across active LED rows and maintaining 400 mV feedback reference at the RILIM node.

Each row operates as a high-side current sink referenced to PGND, with dimming controlled via external PWM on the DIM pin (500 ns min on-time). Fault management uses MODE pin configuration to distinguish open-circuit (V_ROWx > 6.0 V) from short-circuit (V_ROWx < 3.4 V) conditions, triggering open-drain FAULT assertion.

Key Specifications

Pinout & Package

LED7706 is housed in a thermally enhanced VFQFPN-24 4×4 mm package with exposed pad for improved heat dissipation in high-current backlight applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX16832 and TPS61165, LED7706 uniquely combines six matched current sinks, integrated boost, programmable protections, and per-row fault reporting - making it the only single-package solution qualified for mid-size LCD panels demanding reliability, uniformity, and serviceability.

Availability

LED7706 is available at Aetrix Electronics and suitable for LCD monitor backlighting, industrial HMI displays, and automotive infotainment systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LED7706 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 headquartered in Geneva, Switzerland, specializing in power management, analog, and automotive ICs with broad manufacturing and quality certifications.

The LED7706 belongs to ST's LED backlight driver product line, engineered specifically for high-reliability LCD panel illumination - emphasizing current matching, fault resilience, and thermal robustness in space- and power-constrained displays.

FAQ

What is the minimum PWM dimming frequency supported by LED7706?

The LED7706 supports PWM dimming down to 20 kHz with guaranteed 1 % minimum duty cycle and 500 ns minimum on-time. This frequency avoids audible noise in display applications while maintaining full brightness control range. The DIM pin accepts standard logic-level PWM signals and does not require external level-shifting for microcontroller interfacing.

How is overvoltage protection configured on LED7706?

OVP is set using an external resistor divider from VOUT to SGND, feeding the OVSEL pin. The internal reference is 1.234 V (typ.), so a 30:1 divider sets OVP at ~37 V. The protection triggers when VOUT exceeds the programmed threshold, disabling the boost switch and asserting FAULT. No additional components beyond the divider resistors are required.

Can unused LED rows be left unconnected?

Yes - unused ROWx pins can be left floating. During soft-start, the device detects floating rows by monitoring for 0 V drop and activates floating-row management per MODE pin state. When MODE = SGND, floating rows are ignored; when MODE = AVCC, they trigger FAULT. This allows flexible configuration without external termination resistors.

What thermal considerations apply to VFQFPN-24 package operation?

The VFQFPN-24 package has R_thJA = 42 °C/W (on demo board). For continuous 30 mA per row at 36 V output, junction temperature rise is ~35 °C above ambient. To stay within –40 to +150 °C operating range, ensure ≥100 mm² exposed copper pad connected to internal ground plane and use ≥4 thermal vias under the pad for PCB-level heat extraction.