ADP1610

Rev. 0 | Page 13 of 16

Table 7. Recommended External Components for Popular Input/Output Voltage Conditions

L (µH)

3.3

5

0.700

4.7

10

10

30.9

10

50

520

600

5

1.23

2.7

10

10

30.9

10

90.9

150

600

9

0.700

10

10

10

63.4

10

71.5

820

350

9

1.23

4.7

10

10

63.4

10

150

180

350

12

0.700

10

10

10

88.7

10

130

420

250

12

1.23

4.7

10

10

88.7

10

280

100

250

5

9

0.700

10

10

10

63.4

10

84.5

390

450

9

1.23

4.7

10

10

63.4

10

178

100

450

12

0.700

10

10

10

88.7

10

140

220

350

12

1.23

4.7

10

10

88.7

10

300

100

350

REF

COMP

FB

C2

CC

RC

ERROR AMP

1

2

Figure 26. Compensation Components

The capacitor, C2, is chosen to cancel the zero introduced by

output capacitance ESR.

Solving for C2,

COMP

OUT

R

C

ESR

C2

×

=

(19)

For low ESR output capacitance such as with a ceramic capaci-

transient response of the ADP1610. For most applications, the

compensation resistor should be in the range of 30 kΩ to

400 kΩ, and the compensation capacitor should be in the range

of 100 pF to 1.2 nF. Table 7 shows external component values

for several applications.

SOFT START CAPACITOR

The voltage at SS ramps up slowly by charging the soft start

listed the values for the soft start period, based on maximum

output current and maximum switching frequency.

The soft start capacitor limits the rate of voltage rise on the

COMP pin, which in turn limits the peak switch current at

A 20 nF soft start capacitor results in negligible input current

overshoot at startup, and so is suitable for most applications.

However, if an unusually large output capacitor is used, a longer

soft start period is required to prevent input inrush current.

Table 8. Typical Soft Start Period

3.3

5

10

20

0.3

5

10

100

2

9

10

20

2.5

9

10

100

8.2

12

10

20

3.5

12

10

100

15

5

9

10

20

0.4

9

10

100

1.5

12

10

20

0.62

12

10

100

2

Conversely, if fast startup is a requirement, the soft start

capacitor can be reduced or even removed, allowing the

ADP1610 to start quickly, but allowing greater peak switch

current (see Figure 22 to Figure 25).

APPLICATION CIRCUITS

The circuit in Figure 27 shows the ADP1610 in a step-up

configuration. The ADP1610 is used here to generate a 10 V

IN

SD

SS

RT

SW

ON

FB

COMP

22nF

GND

L

4.7

µH

D1

ADP1610

5

6

3

2

7

8

1

4

10

µF

150pF

220k

Ω

10

µF

R1

71.3k

Ω

R2

10k

Ω

3.3V

10V

Figure 27. 3.3 V to 10 V Step-Up Regulator

The output can be set to the desired voltage using Equation 2.

Use Equation 16 and 17 to change the compensation network.