ADP8860 Analog Devices, ADP8860 Datasheet - Page 12

• Manufacturer Part Number: ADP8860
• Description: Charge Pump, 7-Channel Smart LED Driver with I2C Interface
• Manufacturer: Analog Devices

Specifications of ADP8860

• Vin Range: 2.4V to 5.5V
• Vout (v): 4.3 to 5.5
• Synchronous: No
• Package: 20-Lead WLCSP
• Led Configuration: Parallel
• Topology: Capacitive
• I2c Support: Yes
• Max Iout (ma): 60mA
• Brightness Control: I2C
• Peak Efficiency (%): 89%
• Switching Frequency: 1MHz

ADP8860
THEORY OF OPERATION
The ADP8860 combines a programmable backlight LED charge
pump driver with automatic phototransistor control. This combi-
nation allows for significant power savings because it is able to
change the current intensity based on the lighting conditions. It
performs this function automatically thereby removing the
need for a processor to monitor the phototransistor. The light
intensity levels are fully programmable via the I
second phototransistor input, with dedicated comparators,
improves the ambient light detection abilities for various user-
operating conditions.
VBAT
VDDIO
nRST
nINT
SDA
SCL
C
IN
A3
C2
D2
E1
E2
ID1
VIN
NOISE FILTER
D3
LOGIC
STNDBY
RESET
I
50µs
2
D1
C
ID2
UVLO
E3
D2
ID3
STNDBY
SWITCH CONTROL
ILED CONTROL
E4
2
D3
C interface. A
ID4
SENSOR
D4
LOGIC
LIGHT
EN
D4
Figure 26. Detailed Block Diagram
ID5
VIN
C4
Rev. 0 | Page 12 of 52
D5
V
ID6
I
REFS
REFS
B4
GND1
A4
D6
CLK
ID7
B3
GND2
The ADP8860 allows up to seven LEDs to be independently
driven up to 30 mA (typical). The seventh LED can also be
driven to 60 mA (typical). All LEDs can be individually pro-
grammed or combined into a group to operate backlight LEDs.
A full set of safety features including short-circuit, overvoltage,
and overtemperature protection with input-to-output isolation
allow for a robust and safe design. The integrated soft start
limits inrush currents at startup, restart attempts, and gain
transitions.
D1
D7
PHOTOSENSOR
CHARGE
SELECT
LOGIC
LOGIC
PUMP
GAIN
OPTIONAL
PHOTOSENSOR
CONVERSION
V
C3
ALS
CMP_IN
SOFT START
(1×, 1.5×, 2×)
CHARGE
PUMP
I
SS
V
IN
A1
C1
B1
B2
A2
C1+
C1–
C2+
C2–
VOUT
C
C1
1µF
C2
1µF
OUT