Data Sheet

ADP8140

Rev. B | Page 7 of 23

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

Figure 3. Pin Configuration

Table 4. Pin Function Descriptions

Pin No.

Mnemonic

Description

1

VIN

Supply Voltage Input (3.0 V to 30 V).

2

REG

Regulated 3.0 V (Typical) Source. Connect a 1.0 μF (or greater) capacitor from REG to ground.

3

MODE

Operation Mode. If MODE is connected to ground, the device is placed in dc EA operation. If MODE is connected to

REG, the device is placed in PWM EA operation. If MODE is connected via a 30.1 kΩ resistor to ground, the device is

placed in dc low gain buffer operation. If MODE is connected via a 52.3 kΩ resistor to ground, the device is placed

in PWM low gain buffer operation. The MODE pin is read only once at power-up (when VIN exceeds 3 V). Any

changes to the MODE pin after applying power are ignored. See the MODE Pin Operation section for more

information.

4

EN

resistor.

5

A

Fault Output. This pin must be connected to an external pull-up resistor. If using multiple ADP8140 ICs in parallel,

all

A

A

pins must be connected together.

6

FB_OUT

Feedback Output. The FB_OUT pin is a control signal for the external power stage. The action of this pin depends

on the MODE setting.

7

COMP

Compensation Pin for EA. The COMP pin is a control signal for the external power stage. COMP is a dual function

pin. The action of this pin depends on the MODE setting.

8

ISET

Output Current Setting. Connect a resistor to ground to set the output current. If left floating, the current sinks are

set to 15 mA.

9

VO_SNS

Overvoltage Protection Sensing Input. Connect the VO_SNS pin through a resistor divider to the top of the LED

strings, or connect it to ground to disable overvoltage sensing.

10

SINK4

Current Sink for LED Channel 4.

11

SINK3

Current Sink for LED Channel 3.

12

SINK2

Current Sink for LED Channel 2.

13

SINK1

Current Sink for LED Channel 1.

14

DIM

Dim Input. The DIM pin scales the LED current from the PWM signal or dc voltage. The action of this pin depends

on the MODE setting.

15

VT

Voltage Threshold. VT is a dual function pin. If MIN < 2.2 V at startup, VT is an analog current reduction pin. A

voltage on VT scales the LED current. If MIN is connected to REG at startup, a PWM signal applied to VT pulses the

LED current.

16

MIN

Minimum Voltage Threshold. If MIN < 2.2 V at startup, the MIN voltage sets the minimum voltage threshold for the

VT pin. VT voltages below the MIN voltage shuts down the power stage. If MIN is connected to REG at startup, a

PWM signal applied to VT pulses the LED current.

EPAD (GND)

Exposed Pad (Ground). Connect the exposed pad of the LFCSP to ground.

TOP VIEW

(Not to Scale)

PIN 1 INDICATOR

(LASER MARKING)

EXPOSED PAD

(GND)

ADP8140

15 VT

9

VO_SNS

14 DIM

13 SINK1

12 SINK2

11 SINK3

10 SINK4

REG 2

MODE 3

EN 4

FAULT 5

FB_OUT 6

COMP 7

ISET 8

16 MIN

VIN 1

NOTES

1. CONNECT THE EXPOSED PAD OF THE LFCSP TO GROUND.