Texas Instruments LM36274YFFR

Overview

LM36274YFFR from Texas Instruments is a four-channel WLED backlight driver with integrated LCD bias power supply (±4 V to ±6.5 V), supporting up to 29-V boost output and 30 mA per LED string. It delivers 92% backlight and LCD bias efficiency, 0.2% LED current matching, and 11-bit dimming control via I²C or PWM. Used in smart phone and tablet LCD panels requiring compact, high-accuracy multi-rail power management.

For engineers reviewing the LM36274YFFR datasheet, LM36274YFFR pinout, LM36274YFFR application, or LM36274YFFR equivalent, this page provides verified technical context, package mapping, real-world application cards, and two validated alternative parts for LCD bias + backlight co-design scenarios.

Technical Context

The LM36274YFFR integrates three independent power blocks: an asynchronous backlight boost converter (500 kHz / 1 MHz selectable), a synchronous LCM bias boost (2.5 MHz), and a regulated inverting charge pump for VNEG generation. Its four current-sink LED drivers feature 310 mV headroom at 30 mA and support zone dimming via individual enable control (LED1–LED4).

It implements dual control paths - hardware PWM input (11-bit resolution, 50 Hz–50 kHz) and I²C interface (Fast Mode, 1 MHz) - with programmable auto-sequencing between VPOS and VNEG startup, slew-rate control, and fault flag reporting. All bias outputs are independently enabled via LCM_EN1/LCM_EN2 with internal 300-kΩ pulldowns.

Key Specifications

Pinout & Package

LM36274YFFR uses a 24-pin DSBGA (YFF) package, 2.44 mm × 1.67 mm, 0.4-mm pitch, designed for ultra-thin mobile applications. Thermal performance optimized via exposed die pad connected to AGND.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LCD backlight and bias power applications.

Compared with LM3633YFFR and TPS65136RGTR, LM36274YFFR uniquely combines four matched LED drivers, programmable bias sequencing, and dual-boost architecture in one DSBGA package - enabling true single-chip LCD power for mid-to-high-end mobile displays.

Availability

LM36274YFFR is available at Aetrix Electronics and suitable for smartphone displays, tablet HMIs, and home automation panels requiring stable component supply, long-term lifecycle support, and automotive-grade reliability validation.

Supply support for LM36274YFFR 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management ICs for industrial, automotive, and consumer applications.

The LM36274YFFR belongs to TI's display power management product line, engineered specifically for space-constrained mobile LCD systems needing integrated backlight and bias power with minimal external components.

FAQ

What is the maximum number of LEDs the LM36274YFFR can drive?

The LM36274YFFR supports up to four parallel white LED strings, with each string capable of driving up to six LEDs (typical 3.2 V VF × 6 = 19.2 V), constrained by its 29-V maximum boost output. Total power must remain ≤2.5 W. The LM36274YFFR achieves this with 30 mA per string and automatic headroom optimization.

Does the LM36274YFFR support both I²C and PWM dimming simultaneously?

Yes, the LM36274YFFR supports concurrent I²C and PWM dimming: I²C sets the base brightness level (11-bit exponential/linear), while PWM provides real-time modulation (e.g., for CABC). The LM36274YFFR internally blends both inputs without conflict or latency penalty.

What is the purpose of separate AGND, BL_GND, LCM_GND, and CP_GND pins on the LM36274YFFR?

These dedicated ground pins isolate analog reference (AGND), backlight boost return (BL_GND), LCM bias boost return (LCM_GND), and charge-pump return (CP_GND) to prevent noise coupling between high-switching and precision bias domains. This separation ensures <±1.5% VPOS/VNEG accuracy and stable LED current regulation in the LM36274YFFR.

Can the LM36274YFFR generate asymmetric bias voltages like +6.0 V and –4.5 V?

Yes - the LM36274YFFR independently programs VPOS from +4.0 V to +6.5 V and VNEG from –4.0 V to –6.5 V, both in 50-mV steps. So +6.0 V / –4.5 V is fully supported. The LM36274YFFR maintains ±1.5% output accuracy and 92% efficiency at these settings under 5–15 mA loads.

How does thermal shutdown work in the LM36274YFFR?

The LM36274YFFR triggers thermal shutdown at 140°C junction temperature, disabling all power blocks and asserting a flag in its I²C status register. Recovery occurs automatically after junction temperature falls below 125°C hysteresis. This protects the LM36274YFFR and host system during sustained high-load or poor-PCB thermal conditions.