Wide Input Voltage Range, High-Efficiency,

Fault-Tolerant LED Driver

A8519 and

A8519-1

9

Allegro MicroSystems, LLC

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

V> V

OUT

IN

C

IN

C

OUT1

C

OUT2

C

VDD

R

PU

C

P

L1

Q1

D1

R

ADJ

R

SC

Optional

C

Z

R

Z

R

ISET

V

IN

APWM

AGND

GND

PGND

VDD

R

OVP

V

C

PWM

LED4

LED1

OVP

VIN

GATE

SW

VOUT

FAULT

VSENSE

R

FSET

CLKOUT

ISET

FSET

A8519

LED2

LED3

COMP

C

IN

C

OUT

C

VDD

R

PU

C

P

L1

R1*

C

SW

L2

D2

D2*

C

Z

R

Z

R

ISET

V

IN

APWM

*Notes:

Input disconnect switch is not necessary in this

case to protect against VOUT-to-ground short.

R1 and D2 are used to provide a leakage path

so the OVPpin is above 100 mV during startup.

Otherwise, the IC would assume an VOUT-to-GND

short and not proceed with soft start.

AGND

GND

PGND

VDD

R

OVP

V

C

PWM

LED4

LED1

OVP

VIN

GATE

SW

VOUT

FAULT

VSENSE

Output: 3 WLED in series

(~10 V)

R

FSET

CLKOUT

ISET

FSET

LED2

LED3

COMP

A8519

Typical Application Showing Boost Configuration with Input Disconnect Switch to Protect Against VOUT-to-Ground Short

Typical Application Showing SEPIC Configuration for Flexible Input/Output Voltage Ratio