ADM8845ACP-REEL Analog Devices Inc, ADM8845ACP-REEL Datasheet - Page 15

• Manufacturer Part Number: ADM8845ACP-REEL
• Description: IC,Laser Diode/LED Driver,LLCC,16PIN,PLASTIC
• Manufacturer: Analog Devices Inc
• Type: Backlight, White LEDr

Specifications of ADM8845ACP-REEL

• Constant Current: Yes
• Topology: PWM, Switched Capacitor (Charge Pump)
• Number Of Outputs: 6
• Internal Driver: Yes
• Type - Primary: Backlight, Flash/Torch
• Type - Secondary: White LED
• Frequency: 200kHz
• Voltage - Supply: 2.6 V ~ 5.5 V
• Voltage - Output: 4.81V
• Mounting Type: Surface Mount
• Package / Case: 16-LFCSP
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 30mA
• Internal Switch(s): Yes
• Efficiency: 88%
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With: ADM8845EB-EVALZ - BOARD EVALUATION FOR ADM8845
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

DRIVING FLASH LEDs
The ADM8845 can be operated with any two FBx pins used in
parallel to double the combined LED current supplied by the
ADM8845. For example, if three flash LEDs need to be driven
with 60 mA/LED, the ADM8845 can be configured as in
Figure 31 (see also Figure 21).
4.27kΩ
R
2.6V–5.5V
SET
CTRL1
CTRL2
9.44kΩ
V
4.7µF
R
CC
CTRL1
CTRL2
SET
C4
VCC
I
SET
Figure 31. Driving Three Flash LEDs
ADM8845
ADM8845
CURRENT
CONTROL
CIRCUIT
CONTROL
LED
LOGIC
GND
V
FB1
FB2
FB3
FB4
FB5
FB6
CURRENT CONTROLLED SINKS
OUT
V
1µF
1×/1.5×/2× MODE
C1
REF
CHARGE PUMP
GND
OSC
1µF
C2
60mA
Figure 32. Driving Camera Light, Two Main LEDs, and One Sub LED
60mA
60mA
Rev. C | Page 15 of 20
V
FB1
FB2
FB3
FB4
FB5
FB6
OUT
C3
2.2µF
DRIVING CAMERA LIGHT, MAIN, AND SUB LEDs
The ADM8845 can be configured to power a camera light that
is composed of four white LEDs in parallel, along with the main
and sub display bundled into one package. FB1 to FB4 now
power the camera light, and FB5 and FB6 power the main
display. The sub display LED is powered from the ADM8845 by
using an external current mirror to control the current flowing
through the sub white LED (see Figure 32
15 mA/LED. Total load on the ADM8845 charge pump is
therefore 105 mA, and the maximum load on the ADM8845
charge pump is 180 mA (see Figure 21).
15mA/LED
CAMERA
15mA/LED
MAIN
R
)
. All white LEDs have
CURRENT
CONTROL7
15mA/LED
ADM8845
SUB