A8516 데이터 시트보기 (PDF) - Allegro MicroSystems

부품명

상세내역

제조사

A8516

LED Backlight Driver for LCD Monitors and Televisions

Allegro MicroSystems 

A8516

LED Backlight Driver for LCD Monitors and Televisions

Features and Benefits

▪ Six integrated high current sinks

▪ Fixed frequency current mode control with integrated gate driver

▪ 300 kHz to 1 MHz adjustable Boost switching frequency

▪ Controlled startup using options of Enable, PWM signal, or

battery voltage ramp

▪ Active current sharing between LED strings for ±0.6% accuracy

and matching

▪ No audible MLCC noise during PWM dimming

▪ Adjustable overvoltage protection (OVP)

▪ Open or shorted LED string protection

▪ Overtemperature, cycle-by-cycle current limit, and

undervoltage protection

▪ SOIC 24-pin package for easy single-side PCB manufacturing,

or TSSOP 24-pin package with exposed thermal pad for better

thermal performance

Packages:

24-pin SOICW

with internally fused pins

(LB package)

Not to scale

Description

The A8516 is a multi-output WLED/RGB driver for

backlighting LCD monitors and televisions. It integrates a boost

controller to drive external MOSFET, and six internal current-

sinks. The boost converter operates in constant frequency

(programmable) current mode control.

The LED sink current is set by an external R_ISET resistor

(see chart below). More than one LED sinks can be combined

together to achieve even higher current per LED string.

TheA8516 operates from a single supply of 8 to24V. It provides

protection against overvoltage, open or shorted LED string,

and overtemperature. A dual level cycle-by-cycle current limit

function provides soft start and protects against overloads.

The device is provided in a 24-pin SOICW package (LB), with

internally fused pins for enhanced thermal dissipation, and a

24-pin TSSOP package (LP), with an exposed thermal pad

for enhanced thermal dissipation. All packages are lead (Pb)

free, with 100% matte tin leadframe plating.

24-pin TSSOP

with exposed thermal pad

(LP package)

Typical Application Circuit

VOUT 18 LEDs per string

VBAT

8 to 24 V

C1 C2

L1

D1

Q1

RSC ROVP

C3 C4

P

P

P

R1

C5

R2

R3

RFSET

RISET

Rz1

DRIVER SENSE1 SENSE2 OVP

VIN

VBIAS

FAULT

EN

PWM

COMP

FSET

ISET

VREG7V

A8516

LED1

LED2

LED3

LED4

LED5

C6

Cz1

LED6

AGND AGND LGND LGND PGND

130

120

110

100

90

80

70

60

50

40

30

20

6

LED Current versus ISET Resistor Value

VREF = 1.24 V, Gain = 640

8 10 12 14 16 18 20 22 24 26 28 30

RISET (kΩ)

R2, R3 optional (A8516 has

internal pull-down resistors)

A8516, Rev. 1

P

Figure 1. Typical application circuit; VIN pin tied to VBAT .

Share Link: