AL5812MP-13 Diodes Inc., AL5812MP-13 Datasheet - Page 7

• Manufacturer Part Number: AL5812MP-13
• Description: LED Lighting Drivers 60V 150mA ADJ Linear LED Driver
• Manufacturer: Diodes Inc.

Specifications of AL5812MP-13

• Rohs: yes
• Input Voltage: 3.5 V to 60 V
• Maximum Supply Current: 500 uA
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: MSOP-8EP
• Minimum Operating Temperature: - 40 C
• Power Dissipation: 366 mW

Application Information
Description
The AL5812 is a Linear LED driver and in normal operation has the LEDs connected to the same potential as its V
current by sinking current into to its LED pin see Figure 13.
The LED current is set by the use of an external resistor, R
AL5812 together with current regulator to set the LED current.
The nominal LED current is determined by this equation:
With R
The AL5812 with its 60V capability on its supply pin, V
drive LED chains up to 60V as shown in Figures 13 and 14. The voltage applied to the V
to the LED string. Figure 14 shows where you might control it from a 5-V rail but power the rails from a 12V rail.
High Voltage Operation
An extension of Figure 14 is to derive the power for the AL5812 from the LED chain itself see Figure 15. LED chains greater than 60V can be
driven in this manner as long PWM dimming is not utilized.
The AL5812 can also be used on the high side of the LEDs, see Figure 16. This is a simple way of extending the maximum LED chain voltage,
however, it does increase the minimum system input voltage to:
Where
AL5812
Document number: DS35616 Rev. 2 - 2
SET
C
C
IN
IN
= 7.5k
V
0.1µF
V
V
V
0.1µF
IN
IN(min)
LED_CHAIN
Figure 13 Low Side Current LED Setting
I
I
IN
LED
LED
Figure 15 Low Side LED String Tapping
= V
=
=
1500
1500
is the LED chain voltage.
LED_CHAIN
R
*
R
SET
*
. 7
SET
V
R
0
R
5 .
k 5
V
R
+ 3.5V.
CC
SET
0
= 7.5kΩ
AL5812
SET
CC
SET
5 .
= 7.5kΩ
AL5812
=
100
mA
where 1500 is the current ratio between the LED pin current and R
GND
LED
GND
LED
CC
, and its LED drive pin allows it to operate from supply rails up to 60V and/or directly
SET
, connected from the R
www.diodes.com
7 of 12
C
C
IN
SET
IN
Figure 14 Low Side Drive – Separate Supplies
0.1µF
V
V
pin to GND. This resistor supplies the bias current of the
0.1µF
IN
IN
CC
Figure 16 High Side Current LED String
pin can be greater or lower than the voltage applied
R
SET
V
V
R
LED
V
R
CC
SET
SET
= 4.99kΩ
AL5812
CC
SET
AL5812
pin current.
R
SET
CC
pin and regulates the LED
GND
= 4.99kΩ
LED
GND
LED
© Diodes Incorporated
December 2012
AL5812