
ADM8843
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
PIN 1
V OUT 1
C2+ 2
I SET 3
GND 4
INDICATOR
ADM8843
TOP VIEW
(Not to Scale)
12 CTRL2
11 C2–
10 GND
9 GND
NOTES
1. CONNECT THE EXPOSED PADDLE TO GND.
Figure 2. Pin Configuration
Table 3. Pin Function Descriptions
Pin No.
1
2
3
4, 9, 10
5 to 8
11
12
13
14
15
16
–
Mnemonic
V OUT
C2+
I SET
GND
FB1 to FB4
C2?
CTRL2
CTRL1
C1?
V CC
C1+
EP
Description
Charge Pump Output. A 2.2 μF capacitor to ground is required on this pin. Connect V OUT to the anodes of all the LEDs.
Flying Capacitor 2 Positive Connection.
Bias Current Set Input. The current flowing through the R SET resistor, I SET , is gained up by 120 to provide the I LED
current. Connect a resistor, R SET , to GND to set the bias current as V SET /R SET . Note that V SET = 1.18 V.
Device Ground Pins.
LED1 to LED4 Cathode Connection and Charge Pump Feedback. The current flowing in these LEDs is 120 times
the current flowing through R SET , I SET . When using fewer than four LEDs, this pin can be left unconnected or
connected to GND.
Flying Capacitor 2 Negative Connection.
Digital Input. 3 V CMOS Logic. Used with CTRL1 to control the shutdown operation of the main and sub LEDs.
Digital Input. 3 V CMOS Logic. Used with CTRL2 to control the shutdown operation of the main and sub LEDs.
Flying Capacitor 1 Negative Connection.
Positive Supply Voltage Input. Connect this pin to a 2.6 V to 5.5 V supply with a 4.7 μF decoupling capacitor.
Flying Capacitor 1 Positive Connection.
Expose Paddle. Connect the exposed paddle to GND.
Rev. C | Page 5 of 16