ISL85009

FN8918 Rev.3.00

Page 2 of 20

Nov 11, 2021

Typical Application Schematic

FIGURE 3. TYPICAL APPLICATION SCHEMATIC FOR EXTERNAL COMPENSATION

CIN

VIN

4.5 TO

CVDD

CBOOT

2.2µF

100nF

L1

COUT

C1

R1

R2

R3

CVIN

VOUT

C2

1

2

34

56

15

14

13

12

11

10

9

8

7

SYNC MODE FREQ PG

VDD BOOT

GND

PHASE

PVIN

FB

COMP

DNC

DNC

EN

VIN

18V

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 to 18

FREQ (kHz)

300

300

600

600

600

Compensation

Internal

Internal

Internal

Internal

Internal

CIN (µF)

3x22

3x22

3x22

3x22

3x22

COUT (µF)

560 + 3x100

560 + 3x100

3x100

4x47

4x47

L1 (µH)

1

1

1

1.5

1.5

R1 (kΩ)

100

147

200

365

365

R2 (kΩ)

150

147

100

80.6

49.9

C1 (pF)

DNP

DNP

4.7

3.3

3.3

NOTES:

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

2. Ceramic capacitors are selected for 22µF, 47µF, and 100µF in the table.

3. 560µF (4.5mΩ) low ESR conductive polymer aluminum solid capacitors are selected.

4. Recommend to keep the inductor peak-to-peak current to less than 5A.

Ordering Information

PART NUMBER

(Notes 6, 7)

PART

MARKING

PACKAGE DESCRIPTION

(RoHS COMPLIANT)

PKG.

DWG. #

CARRIER TYPE

(Note 5)

TEMP. RANGE

ISL85009FRZ-T

5009

15 Ld 3.5mmx3.5mm TQFN

L15.3.5x3.5

Reel, 6k

-40 to +125°C

ISL85009FRZ-T7A

Reel, 250

ISL85009EVAL1Z

Evaluation Board

NOTES:

5. See TB347 for details on reel specifications.

6. These Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate

plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Pb-free products are

MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J-STD-020.

7. For Moisture Sensitivity Level (MSL), please see product information page for ISL85009. For more information on MSL, see TB363.