A8500EECTR-T Allegro Microsystems Inc, A8500EECTR-T Datasheet - Page 15

• 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
Terminal List Table
Number
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
1
2
3
4
5
6
7
8
9
–
APWM
PGND
COMP
PGND
AGND
LGND
Name
FSET
LED1
LED3
LED5
LED7
LED8
LED6
LED4
LED2
SEL1
SEL2
SEL3
PWM
SKIP
ISET
OVP
SW
SW
VIN
EN
EP
Power ground pin.
Reduces boost switching frequency in case of light load to improve frequency. Normally, this pin should be low; when
high, f
Compensation pin; connect external compensation network for boost converter.
Sets boost switching frequency. Connect RFSET from FSET to GND to set frequency. Range for RFSET is 13 to 40 kΩ.
Sets 100% current through LED string. Connect RISET from ISET to GND. Range for RISET is 10 to 30 kΩ.
On/off and analog LED current control with external PWM. Apply logic level PWM (1.2 V < V
dimming mode. When unused, connect to AGND.
LEDx capable of 25 mA.
Power ground pin for LED current sink.
LEDx capable of 25 mA.
SEL1, SEL2, and SEL3 decide active LED strings.
On/off and serial dimming control. EN high enables IC and EN low disables IC. This pin can also be used to program
LEDx current. When unused, connect to AGND.
On/off and on/off LED current control with external PWM. Apply logic level PWM for PWM controlled dimming mode.
When unused, connect to AGND.
Power ground pin.
Connect to this pin to output capacitor +Ve node through a resistor to enable OVP (overvoltage protection). Default OVP
level with 0 Ω resistor is 30 V, and it can be programmed up to 47 V.
DMOS drain node.
Input supply for the IC. Decouple with a 0.1 μF ceramic capacitor.
Circuit ground pin.
Exposed pad. Electrically connectred to PGND and LGND; connect to PCB copper plane for heat transfer.
SW
is divided by 4.
APWM
COMP
PGND
FSET
LED1
SKIP
ISET
Pin-out Diagram
1
2
3
4
5
6
7
(Top View)
Flexible WLED/RGB Backlight Driver
EP
Description
21
20
19
18
17
16
15
PGND
PWM
EN
SEL3
SEL2
SEL1
LED2
for Medium Size LCDs
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
IH
< 5 V) for PWM controlled
15