Texas Instruments LM3648TTYFFR

Overview

LM3648TTYFFR from Texas Instruments is a synchronous boost LED flash driver IC with integrated 1.5-A high-side current source, 2-MHz/4-MHz fixed-frequency PWM converter, and I²C-compatible interface (address 0x63). It delivers programmable flash currents from 21.8 mA to 1.5 A and torch currents up to 357.2 mA (LM3648TT variant), operating from 2.5 V to 5.5 V input for smartphone camera flash applications.

For engineers reviewing the LM3648TTYFFR datasheet, LM3648TTYFFR pinout, LM3648TTYFFR application, or LM3648TTYFFR equivalent, key selection considerations include its DSBGA-12 (1.69 mm × 1.31 mm) package, hardware strobe (STROBE) and torch/temperature (TORCH/TEMP) inputs, adaptive IVFM low-battery current scaling, and NTC-based thermal monitoring capability.

Technical Context

The LM3648TTYFFR implements a current-mode synchronous boost converter with selectable 2-MHz or 4-MHz switching frequency, enabling use of compact 1-µH inductors and 10-µF ceramic capacitors. Its adaptive regulation maintains ≥290 mV headroom (VHR) across the high-side current source to ensure regulation over varying LED forward voltage and input conditions.

Three operational modes-Flash (64-step ramped current), Torch (128-step ramped current), and IR (instant on/off)-are controlled via I²C registers or hardware pins (STROBE, TORCH/TEMP, TX). The TX pin provides real-time PA synchronization by forcing flash-to-torch current reduction during RF transmit events without interrupting timing control.

Key Specifications

Pinout & Package

LM3648TTYFFR uses a 12-pin DSBGA (YFF) package measuring 1.69 mm × 1.31 mm with 0.4-mm pitch. The package supports grounded-cathode LED configuration for improved thermal dissipation and compact board area (<16 mm² solution size).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM3648YFFT, LM3648TTYFFR offers identical functionality and layout compatibility; compared with LM3648TT, it provides lower torch current and shorter flash timeout - making it better suited for cost-sensitive, battery-constrained smartphone flash where peak flash performance is prioritized over extended torch operation.

Availability

LM3648TTYFFR is available at Aetrix Electronics and suitable for smartphone camera modules, digital still cameras, emergency strobe lighting, and handheld barcode scanners requiring stable component supply and full lifecycle support.

Supply support for LM3648TTYFFR 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 company specializing in analog, embedded processing, and power management technologies, with leadership in precision analog and high-efficiency power conversion ICs.

The LM3648TTYFFR belongs to TI's LED flash driver product line, designed specifically for space-constrained, battery-powered imaging systems requiring high-current, thermally robust, and digitally controllable white LED illumination.

FAQ

What is the primary function of the LM3648TTYFFR?

The LM3648TTYFFR is a synchronous boost LED flash driver IC that delivers precisely regulated current-up to 1.5 A in flash mode and up to 357.2 mA in torch mode-to white LEDs in portable imaging devices. It integrates a 2-MHz/4-MHz PWM boost converter, high-side current source, I²C interface, and hardware control pins (STROBE, TORCH/TEMP, TX) to enable compact, efficient, and thermally managed flash solutions. The LM3648TTYFFR is optimized for smartphone camera modules where battery voltage varies and thermal headroom is limited.

Does the LM3648TTYFFR support thermal protection for the LED?

Yes, the LM3648TTYFFR supports LED thermal protection via its TORCH/TEMP pin, which functions as an analog input for an external NTC thermistor. When the thermistor resistance changes due to LED temperature rise, the internal comparator detects the voltage shift and triggers current foldback to prevent overheating. This feature is documented in the Electrical Characteristics table (VTRIP = 0.6 V ±5%, INTC = 50 µA ±6%) and is active in both flash and torch modes. The LM3648TTYFFR also includes junction thermal shutdown at 150°C (typical) as a secondary safeguard.

What are the key differences between LM3648TTYFFR and LM3648TT?

The LM3648TTYFFR and LM3648TT share identical silicon and pinout but differ in factory-programmed configuration: LM3648TT enables higher torch current (357.2 mA vs 178.6 mA) and longer flash timeout (1.6 seconds vs default 0.5–1.0 s). Both parts support the same 1.5-A flash current, 2/4-MHz switching, IVFM, and NTC monitoring. The LM3648TTYFFR is the base part number used for general flash applications, while LM3648TT targets designs needing sustained high-brightness torch mode. No hardware or firmware changes are needed to switch between them if the PCB supports both configurations.

Can the LM3648TTYFFR operate without I²C communication?

Yes, the LM3648TTYFFR supports full hardware-only operation using its dedicated control pins: STROBE (flash enable), TORCH/TEMP (torch enable or NTC input), and HWEN (standby/shutdown). Default flash and torch current levels are set at power-up, and hardware strobing initiates flash sequences without I²C interaction. However, I²C is required to configure non-default parameters-including custom current levels, flash timeout, IVFM thresholds, and current limit settings. The LM3648TTYFFR retains all register values across standby cycles but resets on HWEN low assertion.

What package type and dimensions does the LM3648TTYFFR use?

The LM3648TTYFFR uses a 12-pin DSBGA (Die Size Ball Grid Array) package designated YFF, with body dimensions of 1.69 mm × 1.31 mm and 0.4-mm ball pitch. It features a bottom-soldered micro-BGA footprint optimized for ultra-compact layouts, supporting <16 mm² total solution size when combined with 1-µH inductor and 10-µF ceramic capacitors. Thermal performance is characterized by RθJA = 90.2°C/W and RθJB = 40.0°C/W, enabling effective heat transfer to the PCB board layer. This package is not pin-compatible with QFN or WSON variants of other TI LED drivers.