A8500EECTR-T Allegro Microsystems Inc, A8500EECTR-T Datasheet - Page 5

• Manufacturer Part Number: A8500EECTR-T
• Description: IC,Laser Diode/LED Driver,LLCC,28PIN,PLASTIC
• Manufacturer: Allegro Microsystems Inc
• Type: Backlight, White LED, RGBr

Specifications of A8500EECTR-T

• Topology: PWM, Step-Up (Boost)
• Number Of Outputs: 8
• Internal Driver: Yes
• Type - Primary: Backlight
• Type - Secondary: RGB, White LED
• Frequency: 2MHz
• Voltage - Supply: 4.2 V ~ 5.5 V
• Voltage - Output: 28V
• Mounting Type: Surface Mount
• Package / Case: 26-WFQFN Exposed Pad
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 25mA
• Internal Switch(s): Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Efficiency: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 620-1204-2

A8500
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
Serial Pulse Timing (see figure 4 for further explanation)
EN Pulse Low Time
EN Pulse High Time
Initial EN or APWM Pulse High Time (rela-
tive to switching period)
Level Change Delay (relative to switching
period)
Shutdown Delay (relative to switching
period on EN or APWM)
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
Symbol
I
Err
I
LSleak21
I
T
V
∆
LSleak5
t
t
I
A
V
LEDSS
HI(init)
SWSS
SHDN
I
t
SHDN
LEDx
SET
LEDx
t
t
ISET
ISET
HID
LO
LEDx
HI
I
R
measured as average of LED1 to LED8;
LED1 to LED8 = 0.5 V
I
LED1 to LED8 = 0.5 V
V
V
First EN or APWM pulse after
shutdown
Falling edge of EN or APWM
pulse
Initial soft start current for boost switch
Current through enabled LEDx pins during soft
start, R
40°C hysteresis
SET
SET
LEDx
LEDx
ISET
= 100 μA
= 100 μA , 100% current ratio;
= 5 V, EN = PWM = APWM = 0, T
= 21 V, EN = PWM = APWM=0
= 12 kΩ; 100% current ratio,
ISET
A
= –40°C to 85°C, typical values at T
=12 kΩ
Flexible WLED/RGB Backlight Driver
Test Conditions
SKIP = Low
SKIP = High
SKIP = Low
SKIP = High
SKIP = Low
SKIP = High
A
= 25°C
for Medium Size LCDs
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
A
= 25°C, V
Min.
0.5
0.5
40
–
–
–
–
–
–
–
–
–
–
–
–
–
–
-
-
IN
Typ.
1.23
±1.2
±1.5
1.25
500
210
256
256
256
165
64
64
64
–
–
1
–
–
1
= 5 V, unless
Max.
120
100
100
–
–
–
–
–
1
–
–
–
–
–
–
–
–
-
-
Switching
Switching
Switching
Switching
Switching
Switching
Pulses
Pulses
Pulses
Pulses
Pulses
Pulses
Units
mV
mA
μA
μA
μA
°C
μs
μs
%
%
V
–
A
5