TI TPS92830-Q1 three-way high current linear LED control solution

TI's TPS92830-Q1 is a three-channel high-current linear LED controller that incorporates two stages of charge pumps, enabling low dropout operation. It meets AEC-Q100 standards, with an operating temperature range from â€“40Â°C to 125Â°C and an input voltage range of 4.5V to 40V. The device supports 20:1 analog dimming and PWM dimming through both PWM inputs and the power supply. It is commonly used in automotive lighting applications such as front position lights, daytime running lights, turn signals, low-beam headlights, and rear lighting like taillights, brake lights, turn indicators, fog lights, and reverse lights. This article provides an overview of the TPS92830-Q1, including its main features, block diagram, and typical application circuit. It also covers the TPS92830-Q1 EVM evaluation board, its circuit diagrams, bill of materials, and PCB layout design.

With the increasing demand for uniform lighting performance, high-current LEDs are frequently used in automotive front and rear lamps, often paired with light diffusers and light guides. To meet strict EMC and reliability requirements, linear LED drivers have become popular in automotive systems. However, managing high currents while maintaining efficiency remains a challenge. The TPS92830-Q1 is an advanced, automotive-grade high-side constant-current linear LED controller that uses external N-channel MOSFETs to deliver high current. It offers a comprehensive set of features suitable for various automotive applications and is compatible with a wide range of N-channel MOSFETs.

Each channel of the TPS92830-Q1 independently sets the current using a sense resistor. An internal precision constant-current regulation loop monitors the current by measuring the voltage across the sense resistor and adjusts the gate voltage of the N-channel MOSFET accordingly. Additionally, the device includes a two-stage charge pump to ensure low dropout operation, providing sufficient voltage to support a wide selection of N-channel MOSFETs. The device supports multiple dimming sources, including an internal PWM generator, external PWM inputs, or power supply dimming, offering flexibility in system design. Specialized diagnostics and protection features enhance system robustness and ease of use. A one-fails-all-fail fault bus allows the TPS92830-Q1 to operate alongside other devices in the TPS92630-Q1, TPS92638-Q1, and TPS9261x-Q1 family, meeting diverse fault-handling needs.

Key features of the TPS92830-Q1 include:

AEC-Q100 Qualified
Device Temperature Grade 1: â€“40Â°C to 125Â°C Operating Range
Device HBM ESD Classification Level H2
Device CDM ESD Classification Level C4B
Wide Input Voltage Range: 4.5 V to 40 V
Three-Channel High-Side Current Driving and Sensing
Independent Channel Current Setting
Independent PWM Inputs per Channel
PWM Dimming via PWM Inputs and Power Supply
Optimized Slew Rate for Improved EMC Performance
High-Precision LED Driving
Precision Current Regulation with External N-Channel MOSFET (2.5% Tolerance)
20:1 Analog Dimming Profile with Off-Board Bin Resistor Support
Precision PWM Generator with Full Duty-Cycle Mask (2% Tolerance)
Open-Drain PWM Output for Synchronization
Protection and Diagnostics Features
Adjustable Output Current Derating for External MOSFET Thermal Protection
Diagnostics for LED-String Open or Short Circuit with Auto Recovery
Diagnostic Enable with Adjustable Threshold for Low-Voltage Operation
Fault Bus Supporting Up to 15 Devices, Configurable as One-Fails-All-Fail or Only-Failed-Channel-Off
Low Quiescent Current in Fault Mode (<0.75mA per Device)
Operating Junction Temperature Range: â€“40Â°C to 150Â°C
TSSOP 28 Package (PW)

The TPS92830-Q1 is ideal for automotive exterior lighting applications, including rear lights such as tail and stop lights, rear turn indicators, fog lights, and reverse lights, as well as front lights like position lights, daytime running lights, front turn indicators, and low-beam headlights.

Figure 1. Functional block diagram of the TPS92830-Q1

Figure 2. TPS92830-Q1 automotive exterior lighting application circuit diagram

Figure 3. Master-slave configuration of the TPS92830-Q1 PWM generator

Evaluation Board TPS92830-Q1 EVM

The TPS92830-Q1 evaluation module (EVM) is designed to help engineers evaluate the functionality and performance of the TPS92830-Q1, a linear LED controller that uses external N-channel MOSFETs for automotive lighting applications. It provides a complete platform for testing and development, supporting various configurations and dimming methods.

Main features of the TPS92830-Q1 EVM include:

Channel current setting via separate high-side sensing resistors
LED short and open protection with fault reporting
Auto-recovery after fault clearance
One-fails-all-fail with configurable fault modes (fault floating or only failed channel off)
Stand-alone operation with full duty cycle or PWM dimming via internal PWM generator
Configurable PWM duty cycle and frequency via jumper
Optional PWM output for synchronized dimming
Analog dimming using a potentiometer on the LED board
Optional thermal protection via ICTRL
Current derating during overvoltage conditions
Open-fault detection mask during dropout mode
Compatibility with different types of N-channel MOSFETs

The TPS92830-Q1 EVM is suitable for a variety of automotive lighting applications, including DRLs, position lights, stop or tail lights, turn indicators, reverse lights, and fog lights.