Synchronous High Voltage 4 Switch Buck Boost LED Controller

Description

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The MAX25600 is a synchronous 4-switch buck-boost LED driver controller. The controller regulates the LED current for LED string voltages from 0V to 60V. The MAX25600 can be used as a seamless buck-boost LED driver for applications that require an efficient buck-boost LED driver with synchronous rectification. The MAX25600 is ideal for high-power applications that require a current source with PWM dimming capability.

The device provides seamless transition between buck, boost, and buck-boost modes depending on the ratio of input to output voltage. The MAX25600 is ideal for LED driver applications in automotive, industrial, and other LED lighting applications. A fault flag indicates open LED, shorted LED, or thermal shutdown conditions. The device uses Maxim's proprietary average-current-mode control scheme and allows adjustable 200kHz to 700kHz fixed-frequency operation. In addition, ±6% triangular spread spectrum is added internally to the oscillator to improve EMI performance. The MAX25600 provides both analog and digital PWM dimming, and has built-in analog PWM dimming at a dimming frequency of 200Hz. The adjustable soft-start feature limits the current peaks and voltage overshoots at startup. The MAX25600 integrates a high-side p-channel dimming MOSFET driver for PWM dimming applications that require fast rising and falling edges of the LED current. It also features robust output open and short protection, is AEC qualified, and is suitable for automotive applications.

Design Solution: Improve Automotive Exterior LED Lighting with Buck-Boost Average Current Control ›

Key Features

• Automotive Ready: AEC-Q100 Qualified
• Integration Minimizes BOM for High-Brightness LED Driver, Saving Space and Reducing Cost
  • Wide Input-Voltage Range from 5V to 60V
  • H-Bridge Single Inductor Buck-Boost Architecture
  • Constant-Current and Constant-Voltage Regulation
  • 28-pin TSSOP with EP Pad and 28-pin(5mm x 5mm) TQFN with EP Pad Packages
• Wide Dimming Ratio allows High Contrast Ratio
  • Analog and PWM Dimming
  • Flicker-Free PWM Dimming with Spread Spectrum
  • Integrated pMOS Dimming FET Gate Driver
  • 200Hz On-Board Ramp Simplifies PWM Dimming
• Protection Features and Wide Temperature Range Increase System Reliability
  • Short Circuit,Overvoltage, and Thermal Protection
  • LED Current Monitor and Input Current Limiter
  • -40°C to +125°C Operating Junction-Temperature Range

Applications/Uses

• Automotive Exterior Lighting and General, Commercial, and Industrial Lighting