a8504 Allegro MicroSystems, Inc., a8504 Datasheet - Page 5

• Manufacturer Part Number: a8504
• Description: Wled/rgb Backlight Driver For Medium Size Lcds
• Manufacturer: Allegro MicroSystems, Inc.

A8504
ELECTRICAL CHARACTERISTICS (continued), valid at T
otherwise noted
LED Current Sinks
LEDx Regulation Voltage
I
Voltage on ISET Pin
I
LEDx Accuracy
LEDx Matching
LEDx Switch Leakage Current
LEDx Switch Leakage Current
Soft Start
Soft Start Boost Current Limit
Soft Start LEDx Current Limit
Thermal Shutdown Threshold
SET
SET
to I
Allowable Current Range
LEDx
Current Gain
Characteristics
WLED/RGB Backlight Driver for Medium Size LCDs
Symbol
I
Err
I
∆
∆
LSleak21
I
T
V
LSleak5
I
A
V
LEDSS
SWSS
I
LEDx1
LEDx2
SHDN
LEDx
SET
ISET
ISET
LEDx
I
R
measured as average of LED1 to LED8;
LED1 to LED8 = 0.8 V
LED1 to LED6; I
LED1 to LED6 = 0.8 V; SEL1=SEL3=V
SEL2=V
LED1 to LED8; I
LED1 to LED8 = 0.8 V; SEL1=SEL2=SEL3=V
V
V
Initial soft start current for boost switch
Current through enabled LEDx pins during soft
start, R
40°C hysteresis
SET
LEDx
LEDx
ISET
= 83 μA
= 5 V, PWM = 0, T
= 21 V, PWM =0
= 14.7 kΩ; 100% current ratio,
ISET
A
IL
= –40°C to 85°C, typical values at T
= 14.7 kΩ
SET
SET
Test Conditions
= 83 μA , 100% current ratio;
= 83 μA , 100% current ratio;
A
= 25°C
IH
;
IH
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
A
= 25°C, V
Min.
40
–
–
–
–
–
–
–
–
–
-
-
IN
to 2.5
Typ.
1.23
±1.2
±1.3
–1.7
800
460
165
1.2
–
–
1
3
= 5 V, unless
Max.
100
–
–
–
–
–
–
1
–
–
-
-
Units
mV
mA
μA
μA
μA
°C
%
%
%
V
–
A
5