Texas Instruments LM3533TMX-40/NOPB

Overview

LM3533TMX-40/NOPB from Texas Instruments is a fully integrated LED power management IC for smartphone illumination systems, driving two parallel high-voltage LED strings (up to 40 V, 20.2 mA each) and five low-voltage indicator LEDs (up to 6 V, 20.2 mA each) via an internal boost converter and 2× charge pump. It supports I²C programming, ambient light sensing with 8-bit ADC, and PWM-based content-adjustable brightness control - deployed in display backlight, keypad, and RGB indicator subsystems.

For engineers reviewing the LM3533TMX-40/NOPB datasheet, LM3533TMX-40/NOPB pinout, LM3533TMX-40/NOPB application, or LM3533TMX-40/NOPB equivalent, key selection considerations include its dual-output topology (HVLED1/HVLED2 + LVLED1–LVLED5), programmable overvoltage protection thresholds (16/24/32/40 V), 14-bit equivalent exponential dimming, ALS zone-based current mapping, and DSBGA-20 package compatibility with space-constrained mobile PCB layouts.

Technical Context

The LM3533TMX-40/NOPB integrates a 500-kHz/1-MHz selectable inductive boost converter regulating HVLED1 and HVLED2 to a 400-mV current-sense headroom, while simultaneously operating a 2× charge pump (C+, C−, CPOUT) to bias five low-voltage current sinks. Its I²C interface configures four independent pattern generators, ALS mapper zones, and bank-assigned current control across six programmable control banks (A–F).

Functional modes include hardware enable (HWEN) shutdown (<5 µA), thermal shutdown at 140°C (15°C hysteresis), and adaptive OVP monitoring via the OVP pin tied to COUT. Current matching between HVLED1/HVLED2 is ±2% typical; LVLED matching across all five sinks is ±2% max - both validated under −40°C to +85°C operation with VIN = 2.7–5.5 V.

Key Specifications

Pinout & Package

LM3533TMX-40/NOPB uses a 20-pin DSBGA (YFQ) package measuring 2.04 mm × 1.78 mm with 0.5-mm pitch and bottom-side ball layout. Thermal resistance R_θJA = 55.3°C/W on standard 4-layer FR-4 board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM3532TMX-40/NOPB and TPS61165RTVR, the LM3533TMX-40/NOPB uniquely combines dual HVLED drive, five LVLED sinks with hardware pattern engines, on-chip ALS ADC, and integrated 2× charge pump - delivering a complete, programmable lighting solution in one DSBGA-20 package without external bias circuitry.

Availability

LM3533TMX-40/NOPB is available at Aetrix Electronics and suitable for smartphone display backlighting, keypad illumination, and RGB indicator subsystems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LM3533TMX-40/NOPB 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 decades of expertise in portable power solutions.

The LM3533 product line was designed specifically for space-constrained mobile devices requiring highly integrated, programmable LED lighting control - combining boost, charge pump, ALS processing, and pattern generation in a single chip.

FAQ

What is the maximum output voltage capability of the LM3533TMX-40/NOPB?

The LM3533TMX-40/NOPB supports a maximum output voltage of 40 V on its high-voltage boost converter, enabling it to drive up to 10-series white LEDs per string. This rating is confirmed in the Absolute Maximum Ratings table and reinforced by the selectable 40-V overvoltage protection threshold. The device regulates HVLED1 and HVLED2 to a 400-mV current-sense headroom, allowing efficient voltage headroom management across varying LED forward voltages.

How does the LM3533TMX-40/NOPB handle ambient light sensing?

The LM3533TMX-40/NOPB integrates a dedicated ALS input (pin D2) that accepts either analog voltage (0–2.1 V) or PWM signals from external sensors. It features an internal 8-bit ADC, programmable gain resistors (128 options), and five user-configurable brightness zones. Ambient light data is processed to map to target LED currents - enabling automatic, closed-loop brightness adjustment for both HVLED and LVLED channels without host MCU intervention.

Can the LM3533TMX-40/NOPB drive indicator LEDs independently from the backlight?

Yes. The LM3533TMX-40/NOPB provides five independent low-voltage current sinks (LVLED1–LVLED5), each assignable to one of four programmable control banks (C–F). Each bank supports independent brightness, dimming curve (linear/exponential), current ramping, and pattern generation - allowing LVLEDs to operate completely separately from HVLED1/HVLED2, including distinct blink sequences and ALS/PWM modulation.

What package type and thermal performance does the LM3533TMX-40/NOPB use?

The LM3533TMX-40/NOPB is housed in a 20-pin DSBGA (YFQ) package measuring 2.04 mm × 1.78 mm. Its junction-to-ambient thermal resistance (R_θJA) is 55.3°C/W on a standard 4-layer FR-4 evaluation board. Thermal shutdown activates at 140°C (typical) with 15°C hysteresis, protecting the IC during sustained high-power operation in compact smartphone modules.

Is I²C communication required to configure the LM3533TMX-40/NOPB?

Yes - the LM3533TMX-40/NOPB relies exclusively on its I²C-compatible interface (SCL/B1, SDA/B2) for full configuration: setting current levels, dimming curves, OVP thresholds, ALS zones, pattern parameters, and control bank assignments. Default power-on behavior is functional but minimal (e.g., HVLEDs disabled, LVLEDs off); all advanced features require register writes via I²C. No standalone analog or pin-strapping configuration is supported.