SLUSE50 November 2023 TPS92642-Q1
PRODUCTION DATA
- 1
- 1 Features
- 2 Applications
- 3 Description
- 4 Pin Configuration and Functions
- 5 Specifications
-
6 Detailed Description
- 6.1 Overview
- 6.2 Functional Block Diagram
- 6.3
Feature Description
- 6.3.1 Internal Regulator
- 6.3.2 Buck Converter Switching Operation
- 6.3.3 Bootstrap Supply
- 6.3.4 Switching Frequency and Adaptive On-Time Control
- 6.3.5 Minimum On-Time, Off-Time, and Inductor Ripple
- 6.3.6 LED Current Regulation and Error Amplifier
- 6.3.7 Start-Up Sequence
- 6.3.8 Analog Dimming and Forced Continuous Conduction Mode
- 6.3.9 External PWM Dimming and Input Undervoltage Lockout (UVLO)
- 6.3.10 Pulse Duty Cycle Limit Circuit
- 6.3.11 Output Short and Open-Circuit Faults
- 6.3.12 Overcurrent Protection
- 6.3.13 Thermal Shutdown
- 6.3.14 Fault Indicator and Diagnostics Summary
- 6.4 Device Functional Modes
-
7 Application and Implementation
- 7.1
Application Information
- 7.1.1 Duty Cycle Considerations
- 7.1.2 Switching Frequency Selection
- 7.1.3 LED Current Programming
- 7.1.4 Inductor Selection
- 7.1.5 Output Capacitor Selection
- 7.1.6 Input Capacitor Selection
- 7.1.7 Bootstrap Capacitor Selection
- 7.1.8 Compensation Capacitor Selection
- 7.1.9 Input Dropout and Undervoltage Protection
- 7.1.10 Pulse Duty Cycle Limit Circuit
- 7.1.11 Protection Diodes
- 7.2
Typical Application
- 7.2.1 Design Requirements
- 7.2.2
Detailed Design Procedure
- 7.2.2.1 Calculating Duty Cycle
- 7.2.2.2 Calculating Minimum On-Time and Off-Time
- 7.2.2.3 Minimum Switching Frequency
- 7.2.2.4 LED Current Set Point
- 7.2.2.5 Inductor Selection
- 7.2.2.6 Output Capacitor Selection
- 7.2.2.7 Bootstrap Capacitor Selection
- 7.2.2.8 Compensation Capacitor Selection
- 7.2.2.9 VIN Dropout Protection and PWM Dimming
- 7.2.3 Application Curves
- 7.3 Power Supply Recommendations
- 7.4 Layout
- 7.1
Application Information
- 8 Device and Documentation Support
- 9 Revision History
- 10Mechanical, Packaging, and Orderable Information
3 Description
The TPS92642-Q1 is a monolithic, synchronous Buck LED driver with a wide 5.5-V to 36-V operating input voltage range and 40-V tolerance that supports load dump for duration of 400 ms. The TPS92642-Q1 implements an adaptive on-time average current mode control based on inductor valley current detection. The adaptive on-time control provides near constant switching frequency that can be set between 100 kHz and 2.2 MHz. Inductor current sensing and closed-loop feedback enables better than ±4% accuracy over wide input, output and ambient temperature.
The high-performance infrared LED driver can independently modulate LED current using both analog or PWM dimming techniques. Linear analog dimming range with over 15:1 range is obtained by setting the IADJ voltage. PWM dimming of LED current is achieved by directly modulating the UDIM input pin with desired duty cycle. The device incorporates an internal pulse monitoring circuit that limits the maximum pulse duty cycle.
The TPS92642-Q1 incorporates advanced diagnostic and fault protection featuring: cycle-by-cycle switch current limit, bootstrap undervoltage, LED open, LED short and thermal shutdown.
The TPS92642-Q1 is available in a 6.6-mm × 5.1-mm thermally-enhanced 16-pin HTSSOP package with 0.65-mm lead pitch.
| PART NUMBER | PACKAGE(1) | BODY SIZE (NOM) |
|---|---|---|
| TPS92642-Q1 | HTSSOP (16) | 6.60 mm × 5.10 mm |
Typical
Buck LED Driver Application Schematic
LED Pulse Limit| Ch1: UDIM input | Ch2: PLMT voltage | Ch4: LED current |