Texas Instruments LM3632AYFFR

Overview

LM3632AYFFR from Texas Instruments is a single-chip integrated backlight, LCD bias (VPOS/VNEG), and flash LED driver IC for mobile displays. It delivers up to 25 mA per string across two WLED strings (up to 8 LEDs each), provides programmable ±4 V to ±6 V LCD bias rails with ≤1.5% accuracy, and supplies 1.5-A constant-current flash drive via synchronous boost. It targets smartphone and small tablet display power management.

For engineers reviewing the LM3632AYFFR datasheet, LM3632AYFFR pinout, LM3632AYFFR application, or LM3632AYFFR equivalent, key selection criteria include dual-boost architecture (backlight + LCM bias), I²C + PWM dimming control, thermal shutdown at 140°C, 30-pin DSBGA package, and support for CABC operation with 11-bit exponential/linear brightness scaling.

Technical Context

The LM3632AYFFR integrates three independent power conversion paths: an asynchronous backlight boost (selectable 500 kHz/1 MHz) driving two low-headroom current sinks (BLED1/BLED2); a synchronous LCM bias boost feeding both a post-regulated positive LDO (VPOS, 4–6 V) and a regulated inverting charge pump (VNEG, –4 to –6 V); and a synchronous flash boost with high-side 1.5-A current source (FLED). All outputs feature overvoltage, overcurrent, and thermal protection.

Control is implemented via I²C interface (400-kHz compliant), dedicated logic inputs (EN, PWM, STROBE, TX), and register-mapped enable bits for each output domain. Automatic voltage scaling minimizes headroom on BL_OUT and FL_OUT, while adaptive regulation maintains flash current accuracy across input voltage (2.7–5 V) and temperature (–40°C to 85°C).

Key Specifications

Pinout & Package

LM3632AYFFR is housed in a 30-pin DSBGA package (2.47 mm × 2.07 mm, 0.4-mm pitch) optimized for ultra-thin mobile PCBs. The package uses face-down ball grid array construction with solder bumps for minimal Z-height and high-density routing.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-rail display power management applications.

Compared with LM3632YFFR, the LM3632AYFFR adds verified flash current accuracy and tighter VNEG protection-critical for camera reliability. Versus TPS61165RTVR, LM3632AYFFR consolidates three power domains into one die, reducing total solution size by ~40% and eliminating inter-IC timing coordination.

Availability

LM3632AYFFR is available at Aetrix Electronics and suitable for smartphone display subsystems, small tablet LCD biasing, camera flash modules, content-adaptive backlight control systems, and portable medical display applications requiring stable component supply and long-term manufacturability.

Supply support for LM3632AYFFR 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 technologies with over 50 years of innovation in high-reliability, energy-efficient IC design.

The LM3632A product line was engineered specifically for space-constrained mobile displays requiring integrated backlight, LCD bias, and flash power-replacing 3–4 discrete ICs with a single, thermally optimized DSBGA solution.

FAQ

What is the maximum LED string configuration supported by the LM3632AYFFR?

The LM3632AYFFR supports up to two independent LED strings, each with up to eight series-connected WLEDs. Its backlight boost converter delivers up to 29 V output, enabling typical configurations like 2×7 or 2×8 LEDs at 25 mA per string. The device's automatic voltage scaling ensures optimal headroom and efficiency across varying forward voltage sums.

Does the LM3632AYFFR support both linear and exponential LED dimming curves?

Yes, the LM3632AYFFR supports both linear and exponential 11-bit brightness mapping via I²C register configuration. Exponential mode follows ILED = 50 µA × 1.00304^code, delivering perceptually uniform steps ideal for video playback. Linear mode uses ILED = 37.8 µA + 12.2 µA × code, simplifying calibration in UI-driven applications. Both modes are accessible in the LM3632AYFFR without hardware changes.

How does the LM3632AYFFR manage thermal safety during flash operation?

The LM3632AYFFR incorporates junction temperature monitoring with thermal shutdown activation at 140°C. During flash operation, its adaptive regulation maintains 1.5-A current accuracy while minimizing power dissipation. The 30-pin DSBGA package features low RθJA (58.6°C/W) and dedicated thermal vias to CP_GND/FL_GND/BL_GND planes-enabling sustained flash bursts without derating when properly laid out. This thermal behavior is fully characterized in the LM3632AYFFR datasheet.

Can the LM3632AYFFR generate both positive and negative LCD bias voltages simultaneously?

Yes, the LM3632AYFFR independently generates VPOS (4–6 V) and VNEG (–4 to –6 V) LCD bias rails using separate internal blocks: a synchronous LCM bias boost feeding a post-regulated LDO for VPOS, and the same boost output driving a regulated inverting charge pump for VNEG. Each rail has dedicated enable pins (LCM_EN1/LCM_EN2), ground returns (LCM_GND/CP_GND), and accuracy better than ±1.5%-all within the single LM3632AYFFR IC.

What protection features are built into the LM3632AYFFR for flash LED operation?

The LM3632AYFFR includes comprehensive flash protection: output overvoltage protection (VOVP) triggers at 4.9 V nominal, switch current limit set to 1.9 A/2.8 A (configurable), and thermal shutdown at 140°C. Fault conditions are reported via the open-drain TX pin and mirrored in I²C status registers. These protections are fully integrated and require no external components-ensuring robust flash operation in the LM3632AYFFR without design overhead.