A8502is a multi-output white light for small LCD backlightingLED drivers。 It combines a current-mode boost converter with an internal power switch and two current converters. The boost converter can drive up to 24 LEDs with 12 LEDs per string (120 mA per string). LED sinks can be paralleled to achieve higher LED currents up to 240 mA. The A8502 operates from a single power supply of 5 V to 40 V, allowing the part to withstand load dump conditions found in automotive systems.
In the event of a fault, the A8502 can drive an external P-FET to disconnect the system's input power. The A8502 provides protection including output short-circuit and overvoltage, open-circuit or short-circuit diodes, open- or short-circuit LED pins, short-circuit boost switches or inductors, short-circuit FSET or ISET resistors, and IC overtemperature protection. Two-stage wave-by-wave current limit provides soft-start and protection against high current overload in the internal current switch.
The A8502 synchronizes the PWM switching frequency from 580kHz to 2.3MHz through the sync pin. The high switching frequency allows the A8502 to operate above the AM radio band.
The A8502 is available in a 16-pin TSSOP package (suffix LP) with an exposed heatsink mounted for enhanced thermal functionality. The packages are lead-free and feature 100% matte tin plating.
apply
LCD backlighting or LED lighting is used to:
- Car infotainment
- Car battery pack
- Car center console
-
- Wide input voltage range from 5 to 40 volts to meet start/shutdown, cold crank and load dump requirements
- The LED sink and boost converters are fully integrated with the 60 volt DMOS
- The sync function synchronizes the boost converter switching frequency up to 2.3 MHz and operates above the AM band
- Excellent input voltage transient response
- Single resistor main overvoltage protection minimizes VOUT leak
- Internal secondary overvoltage protection for redundancy protection
- LED current of 120 mA per channel
- Drives up to 12 LEDs in series (split into 2 parallel strings)
- 0.7% to 0.8% LED-to-LED matching accuracy
- PWM and analog dimming inputs
- Provides a driver for an optional external PMOS input disconnect switch
- Extensive protection features:
- Short-circuit boost switch or inductor protection
- Short-circuit FSET or ISET resistor protection
- Short-circuit output protection
- Open or shorted LED pin protection
- Open circuit boost Schottky protection
- Over-Temperature Protection (OTP)