ISL85415

7. Application Guidelines

FN8373 Rev.5.01

Page 27 of 30

Jun.4.20

It is acceptable to use 150kΩ as the closest standard value for R6.

It is also acceptable to use the closest standard values for C6 and C7. There is approximately 3pF parasitic

capacitance from VCOMP to GND; therefore, C7 is optional. Use C6 = 1500pF and C7 = OPEN.

Use C3 = 68pF. Note: C3 can increase the loop bandwidth from previous estimated value. Figure 63 on page 27

shows the simulated voltage loop gain. It is shown that it has a 75kHz loop bandwidth with a 61° phase margin

and 6dB gain margin. It can be more desirable to achieve an increased gain margin, which can be accomplished

by lowering R6 by 20% to 30%. In practice, ceramic capacitors have significant derating on voltage and

temperature, depending on the type. See the ceramic capacitor datasheet for more details.

Figure 63. Simulated Loop Gain

(EQ. 15)

C6

5V 22

F

500mA 150k





------------------------------------------

1.46nF

=

=

(EQ. 16)

C7 max

5m

 22F



150k



--------------------------------

1

 500kHz 150k



----------------------------------------------------

(,

)

0.7pF 4.2pF

(,)

=

=

60

45

30

15

0

-15

-30

100

1k

10k

100k

1M

Frequency (Hz)

180

150

120

90

60

30

0

100

1k

10k

100k

1M

Frequency (Hz)