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.
Feature
- Boostcontrollersection
- 3.6Vto36Vinputvoltagerange(LDO)
- Adaptiveoutputvoltageforhighefficiency
- Internal+5VLDOforgatedriversupply
- Internal+3.3VLDOfordevicesupply
- HighperformanceexternalMOSFETdriver
- 250kHzto1MHzswitchingfrequency
- ProgrammableOVandOCprotection
- Fixedfrequencypeakcurrent-modecontrol
- Externalsynchronizationformulti-deviceapplication
- Overtemperaturealertandthermalshutdown
- LEDarraydriversection
- 16channelswith85mA/chcurrentcapability
- ±2%channelcurrentaccuracy
- ±2%channel-to-channelcurrentmatching
- LEDshort-circuitandopenchannelfaultdetectionandmanagement
- 4-wire,30MHzserialinterface
- 16x16-bit,1x256-bitor1x192-bitserialdataformats
- GroupedorindependentchannelPWMcontrol
- Selectable12/16-bitgrayscalebrightnesscontrolforlocaldimming
- Programmableinternaldimmingoscillator
- Programmablegrayscalelatency
- Master/slavechainconfigurationsupported