STMicroelectronics LED7708

Description

The LED7708 has been specifically designed to supply several LEDs starting from a single low-voltage rail. It integrates a boost controller, sixteen current generators and a 4-wire serial interface. The boost controller regulates the output voltage in an adaptive way, according to the LED requirements, resulting in an improved overall efficiency. All the current generators are 40 V-rated, allowing the LED7708 to drive several LEDs in series on each channel. The channels can be put in parallel for higher output current.

The brightness of the LEDs is controlled by using the serial interface. A selectable 12-bit or 16-bit grayscale brightness control allows independent PWM on each channel. A programmable on-chip dimming oscillator is provided for external circuitry simplification. The device has dedicated pins to lock to an external synchronization with other devices (master or slave) for noise reduction in multi-device applications. The LED7708 implements basic protection (OVP, OCP and thermal shutdown) as well as LED array protection. It can detect and manage open-LED and shorted-LED faults and different fault-management options are available in order to cover most application needs.

Features

• Boost controller section
• 3.6 V to 36 V input voltage range (LDO)
• Adaptive output voltage for high efficiency
• Internal +5 V LDO for gate driver supply
• Internal +3.3 V LDO for device supply
• High performance external MOSFET driver
• 250 kHz to 1 MHz switching frequency
• Programmable OV and OC protection
• Fixed frequency peak current-mode control
• External synchronization for multi-device application
• Overtemperature alert and thermal shutdown
• LED array driver section
• 16 channels with 85 mA/ch current capability
• ±2% channel current accuracy
• ±2% channel-to-channel current matching
• LED short-circuit and open channel fault detection and management
• 4-wire, 30 MHz serial interface
• 16 x16-bit, 1x256-bit or 1x192-bit serial data formats
• Grouped or independent channel PWM control
• Selectable 12/16-bit grayscale brightness control for local dimming
• Programmable internal dimming oscillator
• Programmable grayscale latency
• Master/slave chain configuration supported

Typical applications

• Medium and large size LCD panel backlights
• RGB/RGGB backlight solutions
• TV and monitor backlight units for LCD panels

More information

• Datasheet
• IC product information