Texas Instruments TPS61183RTJT

Overview

TPS61183RTJT from Texas Instruments is a white-LED driver IC with integrated 2-A, 40-V boost MOSFET, six 30-mA current sinks, and programmable PWM dimming control. It operates from 4.5 V to 24 V input, delivers up to 38 V output, and supports both direct and frequency-programmable PWM dimming modes for notebook LCD backlighting.

For engineers reviewing the TPS61183RTJT datasheet, TPS61183RTJT pinout, TPS61183RTJT application, or TPS61183RTJT equivalent, key selection considerations include its 280 kHz–1 MHz adjustable switching frequency, 1.5% typical current matching across six channels, 100:1 dimming ratio at 20 kHz, adaptive boost output regulation, and QFN-20 (4 mm × 4 mm) thermal-enhanced package with PowerPAD™.

Technical Context

The TPS61183RTJT implements a current-mode fixed-frequency boost regulator with integrated loop compensation and automatic output voltage adaptation to WLED forward voltage. Its six independent current sinks regulate LED string currents with ±2% accuracy at 20 mA and ±1.5% typical matching between strings.

Dimming is implemented via two distinct modes: direct PWM mode synchronizes all six current sinks precisely to the external PWMIN signal's duty cycle and frequency; programmable PWM mode decodes the input duty cycle but drives outputs at a user-set frequency (100 Hz–22 kHz) determined by RFPWM/MODE pin resistor value.

Key Specifications

Pinout & Package

TPS61183RTJT is housed in a 20-pin QFN package (4.00 mm × 4.00 mm, 0.5 mm pitch) with exposed thermal pad (PowerPAD™) that must be soldered to PCB ground plane for thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS61183RTJT, TPS61185RTJT offers digital configurability at the cost of added software complexity, while LM3409QMYX/NOPB provides topology flexibility and higher voltage capability but demands more external components and design effort.

Availability

TPS61183RTJT is available at Aetrix Electronics and suitable for notebook backlighting, industrial HMI displays, ATM interfaces, and marine electronics requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for TPS61183RTJT 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 LED lighting and portable power solutions.

The TPS61183RTJT belongs to TI's white-LED driver product line, designed specifically for high-efficiency, multi-string LCD backlighting in space-constrained, thermally demanding applications such as ultrabooks and industrial displays.

FAQ

What is the maximum number of white LEDs the TPS61183RTJT can drive?

The TPS61183RTJT supports up to 60 white LEDs total - configured as six parallel strings, each with up to 10 LEDs in series (assuming typical 3.2–3.6 V forward voltage). The 38 V maximum output voltage and 30 mA per channel limit define this capacity. Each IFB pin corresponds to one string, and unused IFB pins should be shorted to AGND for optimal start-up behavior. The TPS61183RTJT automatically adjusts its boost output to match the highest-string forward voltage plus current sink headroom.

How does the TPS61183RTJT achieve adaptive output voltage regulation?

The TPS61183RTJT continuously monitors all six IFB pins and regulates the boost output to maintain the lowest IFB voltage at 350 mV (with 300 mV hysteresis). This ensures just enough voltage is generated to bias the string with the highest forward voltage, minimizing power dissipation in the current sinks. If input voltage exceeds the required output (e.g., at low dimming duty cycles), the device cannot regulate downward - in such cases, adding series ballast resistors or increasing LED count restores proper regulation. The TPS61183RTJT implements this via internal error amplifiers and a current-mode boost controller.

Can the TPS61183RTJT operate in both direct and programmable PWM dimming modes simultaneously?

No - the TPS61183RTJT operates exclusively in one mode at a time, selected by the RFPWM/MODE pin configuration. Tying RFPWM/MODE to VDDIO forces direct PWM mode, where all six current sinks switch exactly in phase with the PWMIN signal. Connecting a resistor from RFPWM/MODE to AGND selects programmable mode, where the internal decoder captures the PWMIN duty cycle and applies it at a fixed frequency set by that resistor (e.g., 9.09 kΩ → 20 kHz). The two modes are mutually exclusive; no hybrid operation is supported in the TPS61183RTJT.

What thermal design considerations apply to the TPS61183RTJT QFN package?

The TPS61183RTJT uses a 20-pin QFN with an exposed PowerPAD™ thermal pad that must be soldered to a solid copper ground plane for effective heat dissipation. With R_θJA = 39.9 °C/W, a 2-layer PCB with ≥2 in² of 2-oz copper under the pad achieves ~1.5 W usable power dissipation at 85 °C ambient. Thermal vias (≥6× 12-mil) from the pad to inner/ground layers are strongly recommended. Avoid routing signals under the pad, and ensure solder mask opening matches the pad geometry. The TPS61183RTJT triggers thermal shutdown at 150 °C with 15 °C hysteresis, protecting against sustained overload.

Does the TPS61183RTJT require external compensation components for stability?

No - the TPS61183RTJT integrates full loop compensation for its current-mode boost regulator, eliminating the need for external RC networks. Stability is guaranteed when using TI-recommended external components: 10 µH inductor (for 600 kHz–1 MHz operation), 1 µF input ceramic capacitor, and 4.7 µF output ceramic capacitor. Deviations - especially undersized output capacitance or excessive ESR - may cause oscillation or poor transient response. The integrated compensation is optimized for the specified L and C ranges; no user adjustment is possible or required for the TPS61183RTJT.