AS1101_1 AMSCO [austriamicrosystems AG], AS1101_1 Datasheet - Page 9

• Manufacturer Part Number: AS1101_1
• Description: Low-Dropout LED Drivers
• Manufacturer: AMSCO [austriamicrosystems AG]

AS1101/AS1102/AS1103/AS1104
Data Sheet
8 Application Information
Figure 19. Typical Application Diagrams
Setting the LED Current
The current going into the LEDs is approximately OCMR times greater then the current I
by V
For V
Figure
Figure 3 on page
Note: LED brightness can also be adjusted by driving pin ENABLE or pin CTRL with a PWM signal.
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ENABLE
V
V
(3V)
(3V)
SET
SET
SET
SET
10, and
R
R
and R
I
I
SET
SET
SET
SET
= 3V and a specific LED current, the value of R
V
- A p p l i c a t i o n I n f o r m a t i o n
IN
CTRL
CTRL
V
SET
Figure 11
IN
ON
6.
2 Diode Control with Enable
I1/I2
(see
I1
V
V
SAT
Figure
SAT
4 Diode Control
on page 7. For any other option, the value of I
GND
I2
GND
AS1101
AS1103
19) according to the formula:
I3
I3/I4
I
LED
I4
= OCMR x (V
Revision 1.5
SET
SET
- V
can be determined using the graphs shown in
CTRL
ENABLE
ENABLE
V
V
(3V)
(3V)
SET
SET
)/R
R
R
SET
I
I
SET
SET
SET
SET
SET
V
IN
can be determined using the graph in
CTRL
CTRL
V
IN
ON
ON
4 Diode Control with Enable
I1
3 Diode Control with Enable
I1
V
SAT
V
SAT
SET
GND
I2
GND
AS1102
AS1104
. LED current is controlled
I2
I3
I3
I4
Figure
(EQ 1)
9 - 13
9,