Diodes Incorporated AL3050FDC-7

Overview

AL3050FDC-7 from Diodes Incorporated is a current-mode boost-type LED driver IC with integrated 30V/0.7A MOSFET and power diode, designed for small-panel LCD backlighting in portable devices. It supports up to 8-series white LEDs, operates from 2.7V–5.5V input, delivers 200mV ±3% feedback reference, runs at 750kHz fixed switching frequency, and provides dual dimming modes via the CTRL pin - PWM (20–100kHz) and single-wire digital (32-step pseudo-logarithmic). It is used in feature phones and ultra-mobile displays requiring compact, high-efficiency backlight control.

For engineers reviewing the AL3050FDC-7 datasheet, AL3050FDC-7 pinout, AL3050FDC-7 application, or AL3050FDC-7 equivalent, this page details its boost converter architecture, dual-dimming interface behavior, open-LED protection threshold (28.2V), thermal shutdown at +160°C, and U-DFN2020-6 (Type S) package constraints - all critical for Li-ion-powered display subsystem design and BOM validation.

Technical Context

The AL3050FDC-7 implements current-mode PWM control with slope compensation to ensure stability above 50% duty cycle. Its error amplifier regulates FB to 200mV while dynamically scaling the reference in PWM dimming mode via internal chopping and low-pass filtering - enabling analog-style DC current modulation without audible noise.

It integrates UVLO (2.5V turn-on hysteresis 300mV), overvoltage protection (28.2V VOUT threshold), cycle-by-cycle overcurrent limiting (0.7A typical), and thermal shutdown (+160°C with +20°C hysteresis). The CTRL pin serves triple function: enable control, PWM input, and single-wire digital command interface - with mode selection determined at power-up based on precise timing windows (t1W_DET = 450μs, t1W_WIN = 3.5ms).

Key Specifications

Pinout & Package

AL3050FDC-7 is housed in a thermally enhanced U-DFN2020-6 (Type S) package with exposed thermal pad soldered to analog ground plane. Pin 1 (CTRL) is multi-functional for enable, PWM, and digital dimming; Pin 6 (SW) connects directly to the inductor node; the thermal pad must be connected via vias to maximize power dissipation (θ_JA = 70.4°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP3019A, AL3050FDC-7 reduces component count and enables silent dimming; compared with AL3052FDC-7, it trades peak current capability for lower quiescent current (0.5mA vs. 0.7mA) and lower cost - making it optimal for mid-brightness, battery-sensitive portable displays.

Availability

AL3050FDC-7 is available at Aetrix Electronics and suitable for feature phones, portable media players, and GPS receiver displays requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for AL3050FDC-7 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in power management, signal integrity, and connectivity solutions for consumer, industrial, and automotive markets.

The AL3050 belongs to Diodes' LED backlight driver product line, engineered specifically for space-constrained, single-cell Li-ion powered portable displays - emphasizing integration, efficiency, and dual-dimming flexibility without external compensation.

FAQ

What dimming modes does the AL3050FDC-7 support, and how is the mode selected?

The AL3050FDC-7 supports PWM dimming (20–100kHz) and single-wire digital dimming (32-step pseudo-logarithmic). Mode selection occurs at power-up: if the CTRL pin receives a specific low-pulse timing sequence (≥450μs low after 100μs delay, within 3.5ms window), it enters digital mode; otherwise, it defaults to PWM. The mode remains locked until the next shutdown/restart cycle.

How is LED current set, and what tolerance should be expected?

LED current is set by an external resistor (R_FB) between FB and GND, using I_LED = 200mV / R_FB. The FB reference has ±3% accuracy at 25°C, and total current tolerance depends on R_FB tolerance (e.g., 1% resistor yields ~4% max deviation). Temperature drift of V_REF is ±10mV from –40°C to +85°C.

Does the AL3050FDC-7 require external compensation components?

No. The AL3050FDC-7 integrates full loop compensation, eliminating the need for external RC networks on the COMP or FB pins. This simplifies layout, reduces bill-of-materials, and ensures stable operation across all supported LED configurations (4–8 series) and input voltages (2.7–5.5V) without tuning.

What happens during an open-LED fault, and how is recovery performed?

During open-LED fault, the AL3050FDC-7 detects V_OUT ≥ 28.2V and V_FB < 100mV, then disables the switch and enters latch-off state with reduced 0.3A current limit. Recovery requires pulling CTRL low for ≥3.5ms (shutdown) followed by a high pulse - no power cycle is needed, enabling automatic fault recovery in firmware-managed systems.