Texas Instruments LM36923EVM

Overview

LM36923EVM from Texas Instruments is an evaluation module designed to characterize the LM36923 highly efficient triple-string white LED driver IC in backlight applications. It supports configurable 1–3 parallel LED strings with 2–8 series LEDs per string, operates from 2.5 V to 5.5 V input, and enables full register control via I²C-compatible interface using the included USB2ANY docking board and GUI software.

For engineers reviewing the LM36923EVM datasheet, LM36923EVM setup, LM36923EVM schematic, or LM36923EVM pinout, this module provides hands-on validation of LED current regulation accuracy (±5% typical), PWM dimming control (0–100% duty cycle), fault flag reporting (OVP, OCP, thermal shutdown), and I²C register read/write functionality across multiple string configurations.

Technical Context

The LM36923EVM implements the LM36923YFFR DSBGA-12 LED driver IC with integrated 10 µH shielded inductor, 24 white SMD LEDs (Rohm SML312WBCW1), and precision 10 Ω current-sense resistors (RL1–RL3) for per-string ILED measurement. It features configurable star-jumper connections (HL1/HL2/HL3) to set LED string count and series count (2–8 LEDs).

Power sequencing is managed via dedicated jumpers: VIO selects between VIN or USB2ANY 3.3 V for I²C pull-ups; HWEN enables hardware-driven driver activation; OUT toggles regulated output connection to LED strings; and BL_ADJ/PWM headers support analog or external PWM signal injection with 4.7 kΩ pull-downs.

Key Specifications

Availability

LM36923EVM is available at Aetrix Electronics and suitable for LCD backlight evaluation, LED driver qualification, and I²C-based lighting control prototyping requiring stable component supply and documented reference design validation.

Supply support for LM36923EVM 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 digital signal processing technologies, with over 90 years of innovation in power management and interface solutions.

The LM36923EVM belongs to TI's backlight LED driver evaluation platform family, engineered specifically to accelerate development of high-efficiency, multi-string LCD display lighting systems for portable and automotive infotainment displays.

FAQ

What is the primary function of the LM36923EVM?

The LM36923EVM is a Texas Instruments evaluation module built to validate the performance of the LM36923 triple-string white LED driver IC. It allows engineers to configure, measure, and debug LED current regulation, PWM dimming, I²C register access, and fault response under real-world backlight conditions. The LM36923EVM includes onboard LEDs, current-sense resistors, and jumper-based string configuration to replicate production use cases without custom PCB design.

Does the LM36923EVM require external power or can it be powered via USB?

The LM36923EVM requires an external DC power source (2.5 V–5.5 V) applied to the VL/GND terminal block for the LED driver and LED strings. While the USB2ANY interface board supplies 3.3 V to the I²C pull-up resistors (via VUSB VIO VL), it does not power the LED driver circuitry. The LM36923EVM documentation explicitly states that external VIN must be provided - USB alone cannot drive the backlight load.

How many LED strings can be evaluated simultaneously on the LM36923EVM?

The LM36923EVM supports evaluation of up to three independent LED strings simultaneously, each configurable for 2–8 series-connected white LEDs using the HL1, HL2, and HL3 star-jumper headers. Each string has dedicated current-sense resistors (RL1–RL3) and test points (ILED1–ILED3) for accurate per-string current measurement, enabling verification of channel-to-channel matching and load balancing behavior of the LM36923YFFR IC.

Can the LM36923EVM operate without the USB2ANY interface board?

Yes - the LM36923EVM can operate without the USB2ANY interface board. Hardware enable (HWEN), PWM input, and analog brightness control (BL_ADJ) are accessible via headers and jumpers, allowing standalone operation using external controllers or signal generators. However, full register-level configuration, fault flag monitoring, and GUI-based tuning require the USB2ANY board and TI's LM36923EVM software, as the I²C interface is not directly exposed without it.

What fault conditions does the LM36923EVM report, and how are they accessed?

The LM36923EVM reports overvoltage protection (OVP), overcurrent protection (OCP), and thermal shutdown faults via the LM36923's internal status register (address 0x0F). These flags are readable through the I²C interface using the GUI's "R 1F" button, and the register clears automatically upon read. The LM36923EVM User's Guide confirms fault detection is implemented in hardware and reflected in real time - no additional firmware or host-side logic is required to observe these events.