ADP1071-1/ADP1071-2

Data Sheet

Rev. B | Page 10 of 27

AGND1

COMP

4

VREG1

5

MODE

6

EN

7

CS

8

RT

9

13

14

15

16

FB

17

OVP

18

VDD2

19

VREG2

20

AGND2

21

22

23

24

1

2

3

TOP VIEW

(TERMINAL SIDE DOWN)

Not to Scale

ADP1071-1

10

11

12

EPAD1

EPAD2

NOTES

1. NC = NO CONNECT.

2. EPAD1 AND EPAD2 ARE INTERNALLY TIED TO

AGND1 AND AGND2, RESPECTIVELY.

Figure 4. ADP1071-1 LGA Pin Configuration

AGND1

COMP

4

VREG1

5

VIN

6

EN

7

CS

8

RT

9

13

14

15

16

FB

17

OVP

18

VDD2

19

VREG2

20

AGND2

21

22

23

24

1

2

3

TOP VIEW

(TERMINAL SIDE DOWN)

Not to Scale

ADP1071-2

10

11

12

EPAD1

EPAD2

NOTES

1. NC = NO CONNECT.

2. EPAD1 AND EPAD2 ARE INTERNALLY TIED TO

AGND1 AND AGND2, RESPECTIVELY.

Figure 5. ADP1071-2 LGA Pin Configuration

Table 10. Pin Function Descriptions, LGA

Pin No.

Mnemonic

Description

ADP1071-1

ADP1071-2

1

1

GATE

Driver Output for the Main Power MOSFET on the Primary Side. GATE is a multifunction pin.

Connect a resistor from the GATE pin to AGND1 to set up the open loop soft start time.

2

2

NC

No Connect.

3

3

NC

No Connect.

4

4

AGND1

Ground for the Primary Side.

5

5

VREG1

8 V Regulated LDO Output for the MOSFET Driver. Connect 1 µF or greater from VREG1 to AGND1.

6

Not

applicable

MODE

Light Load Mode Pin (ADP1071-1 Only). This pin sets the light load mode threshold. Connect the

MODE pin to either AGND1 to enable forced continuous conduction mode (CCM), or to a high

logic (2.5 V or higher) to force an LLM operation, or to a resistor to set up an LLM threshold voltage.

Not

applicable

6

VIN

Input Voltage (ADP1071-2 Only). See the Primary Side Supply, Input Voltage, and LDO section.

Connect a 4.7 µF capacitor to the VIN pin. The size of this capacitor can be reduced if the

input voltage to the VIN pin is guaranteed stable. Reference the VIN pin to AGND1.

7

7

EN

Precision Enable Input. The controller is enabled when EN is above the EN threshold voltage.

The EN pin also has a programmable EN hysteresis. The EN pin is referenced to AGND1.

8

8

CS

Input Current Sensing. The CS pin senses the input PWM current. Place a current sense

resistor between the source terminal of the power MOSFET and AGND1.The current sense

resistor sets up the input current limit. This pin is also used for the external slope compensator.

Connect a resistor from the CS pin to the current sense resistor to generate a voltage ramp for

the slope compensation. Reference the CS pin to AGND1. Connect a 33 pF to 100 pF capacitor

at the CS pin to act as a resistor capacitor (RC) filter along with the slope compensation resistor in

noisy environments.

9

9

RT

Switching Period Resistor. Connect a resistor from the RT pin to AGND1 to set the oscillator

frequency.

10

10

SYNC

Frequency Synchronization. Connect an external clock to the SYNC pin to synchronize the internal

oscillator to this external clock frequency. Connect the SYNC pin to AGND1 if this feature is not

used. The SYNC frequency is recommended to be within 10% of the frequency set by the RT pin.

11

11

NC

No Connect.

12

12

NC

No Connect.

13

13

NC

No Connect.

14

14

NC

No Connect.

15

15

SS2

Soft Start on the Secondary Side. Connect a capacitor from SS2 to AGND2 to set up the soft

start time on the secondary side.

16

16

COMP

Compensation Node on the Secondary Side. This pin is the output of the transconductance

17

17

FB

Feedback Node on the Secondary Side. Set up the resistive divider from the output voltage

such that the nominal voltage, when the power supply is in regulation, is 1.2 V. Reference the

FB pin to AGND2.