ADP1610

Rev. 0 | Page 11 of 16

Table 4. Inductor Manufacturers

Vendor

Part

L (µH)

Max DC Current

Max DCR (mΩ)

Height (mm)

CMD4D11-2R2MC

2.2

0.95

116

1.2

CMD4D11-4R7MC

4.7

0.75

216

1.2

CDRH4D28-100

10

1.00

128

3.0

CDRH5D18-220

22

0.80

290

2.0

CR43-4R7

4.7

1.15

109

3.5

Sumida

847-956-0666

www.sumida.com

CR43-100

10

1.04

182

3.5

DS1608-472

4.7

1.40

60

2.9

Coilcraft 847-639-6400

www.coilcraft.com

DS1608-103

10

1.00

75

2.9

D52LC-4R7M

4.7

1.14

87

2.0

Toko 847-297-0070

www.tokoam.com

D52LC-100M

10

0.76

150

2.0

on-time by the following equation:

SW

f

D

(4)

L

t

V

ON

(5)

Solving for the inductance value, L,

L =

L

ON

IN

I

t

V

∆

×

(6)

Make sure that the peak inductor current (the maximum input

current plus half the inductor ripple current) is below the rated

saturation current of the inductor. Likewise, make sure that the

maximum rated rms current of the inductor is greater than the

maximum dc input current to the regulator.

For duty cycles greater than 50%, which occur with input

voltages greater than one-half the output voltage, slope

compensation is required to maintain stability of the current-

mode regulator. For stable current-mode operation, ensure that

SW

IN

OUT

MIN

f

V

V

L

L

×

−

=

>

A

8

.

1

(7)

CHOOSING THE INPUT AND OUTPUT CAPACITORS

The ADP1610 requires input and output bypass capacitors to

supply transient currents while maintaining constant input and

output voltage. Use a low ESR (equivalent series resistance),

10 µF or greater input capacitor to prevent noise at the

ADP1610 input. Place the capacitor between IN and GND as

close to the ADP1610 as possible. Ceramic capacitors are

preferred because of their low ESR characteristics. Alternatively,

use a high value, medium ESR capacitor in parallel with a 0.1 µF

low ESR capacitor as close to the ADP1610 as possible.

The output capacitor maintains the output voltage and supplies

current to the load while the ADP1610 switch is on. The value

and characteristics of the output capacitor greatly affect the

output voltage ripple and stability of the regulator. Use a low

ESR output capacitor; ceramic dielectric capacitors are

preferred.

For very low ESR capacitors such as ceramic capacitors, the

ripple current due to the capacitance is calculated as follows.

multiplied by the on-time. Therefore, the output voltage ripple

OUT

ON

L

OUT

C

OUT

C

t

I

C

Q

V

×

=

=

∆

(8)

where:

SW

ON

f

D

t

=

(9)

and

OUT

IN

OUT

V

V

V

D

−

=

(10)

Choose the output capacitor based on the following equation:

OUT

OUT

SW

IN

OUT

L

OUT

V

V

f

V

V

I

C

∆

×

×

−

×

≥

)

(

(11)

Table 5. Capacitor Manufacturers

Vendor

Phone No.

Web Address

AVX

408-573-4150

www.avxcorp.com

Murata

714-852-2001

www.murata.com

Sanyo

408-749-9714

www.sanyovideo.com

Taiyo–Yuden

408-573-4150

www.t-yuden.com