ISL85014

FN8925 Rev.3.00

Page 2 of 21

Nov 11, 2021

Typical Application Schematic

FIGURE 3. TYPICAL APPLICATION SCHEMATIC FOR EXTERNAL COMPENSATION

12

3

4

5

6

15

14

13

12

11

10

9

8

7

SYNC MODE

FREQ

PG

VDD

BOOT

GND

PHASE

PVIN

FB

COMP

DNC

DNC

EN

VIN

CIN

VIN

4.5 TO 18V

CVDD

CBOOT

2.2µF

100nF

L1

COUT

C1

R1

R2

R3

CVIN

VOUT

C2

TABLE 1. DESIGN TABLE FOR DIFFERENT OUTPUT VOLTAGE USING INTERNAL COMPENSATION (SEE Figure 1)

VOUT (V)

1

1.2

1.8

3.3

5

VIN (V)

4.5 to 18

4.5 to 18

4.5 to 18

4.5 to 18

6.5 to 18

FREQ (kHz)

300

300

600

600

600

Compensation

Internal

Internal

Internal

Internal

Internal

CIN (µF)

3x22

3x22

3x22

3x22

3x22

COUT (µF)

1000 + 4x100

1000 + 3x100

4x100

4x100

4x100

L1 (µH)

0.68

1

0.68

1

1.5

R1 (kΩ)

200

300

200

365

365

R2 (kΩ)

300

300

100

80.6

49.9

C1 (pF)

DNP

DNP

DNP

4.7

8.2

NOTES:

1. The design table is referencing the schematic shown in Figure 1.

2. Ceramic capacitors are selected for 22µF and 100µF in the table.

3. 1000µF (5mΩ) are selected for low ESR conductive polymer aluminum solid capacitors.

4. Recommend to keep the inductor peak-to-peak current less than 6A.