A8509 View Datasheet(PDF) - Allegro MicroSystems
Part Name
Description
MFG CO.
A8509
Allegro MicroSystems
'A8509' PDF : 28 Pages View PDF
A8509
Wide Input Voltage Range, High Efficiency
4-Channel Fault Tolerant LED Driver
Selection Guide
Part Number
Package
A8509GLPTR-T
24-pin TSSOP with exposed thermal pad
A8509GLBTR-T2
24-pin SOICW with internally-fused leads
1Contact Allegro® for additional packing options.
2Contact factory for availability.
Packing1
4000 pieces per 13-in. reel
Contact factory
Absolute Maximum Ratings*
Characteristic
Symbol
Notes
Rating
Unit
LEDx Pin Voltage
OVP Pin Voltage
VIN Pin Voltage
¯F¯¯A¯U¯¯L¯¯T¯ Pin Voltage
COMP, EN, FSET/SYNC, ISET,
MODE, PWM, SENN, SENP, and VDD
Pin Voltage
VLEDx
VOVP
VIN
VFAULT
–
–0.3 to 55
V
–0.3 to 60
V
–0.3 to 40
V
–0.3 to 40
V
–0.3 to 5.5
V
GATE, VDR Pin Voltage
–
–0.3 to 8
V
Operating Ambient Temperature
TA
G temperature range
–40 to 105
ºC
Maximum Junction Temperature
TJ(max)
150
ºC
Storage Temperature
Tstg
–55 to 150
ºC
*Stresses beyond those listed in this table may cause permanent damage to the device. The absolute maximum ratings are
stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the Electrical
Characteristics table is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
Thermal Characteristics may require derating at maximum conditions, see application information
Characteristic
Symbol
Test Conditions*
Package Thermal Resistance
Package LP, on 4-layer PCB based on JEDEC standard
RθJA
Package LB, on 4-layer PCB based on JEDEC standard
*Additional thermal information available on the Allegro website
Value Unit
28 ºC/W
35 ºC/W
Table of Contents
Specifications
2
Functional Block Diagram
3
Pin-out Diagram and Terminal List
4
Electrical Characteristics Table
5
Functional Description
8
Enabling the IC
8
Powering up: LED pin short-to-GND check
8
Soft start function
9
Frequency selection
10
Synchronization
10
LED current setting and LED dimming
11
PWM dimming
12
Analog dimming
12
Boost switch overcurrent protection
13
Setting the current sense resistor
13
Current sense resistor routing
13
Pulse-by-pulse current limit
14
Secondary boost switch limit
14
Output overvoltage and undervoltage protection 14
LED Open Detect
15
Undervoltage Protection (UVP)
15
LED short detect
16
Input UVLO
16
VDD and VDR
16
Shutdown
17
Fault protection during operation
17
Application Information
19
Paralleling more than one A8509
19
Design Example
21
Typical Applications
24
Typical Applications
25
Package Drawings
27
Allegro MicroSystems, Inc.
2
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
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