ADP5003ACPZ-R7 datasheet(20/31 Pages) AD

20 / 31 page

ADP5003

Data Sheet

Rev. A | Page 20 of 31

Input Capacitor

The input current to the buck converter steps from zero to a

positive value that is dependent on inductor value, switching

frequency, and load current (typically between 1Aand 4A) and

then drops quickly to zero again every switching cycle. Because

these current pulses occur at relatively high frequencies (0.3 MHz

to 2.5 MHz), the input bypass capacitor provides most of the

high frequency current while the input power source supplies

only the average current. Higher value input capacitors reduce

the input voltage ripple and improve transient response.

To minimize supply noise, it is recommended to place a low

ESR capacitor as close as possible to the relevant supply pin.

Inductor

The high switching frequency of the ADP5003 buck allows the

selection of small chip inductors. Asmall inductor leads to larger

inductor current ripple that provides improved transient response

but degrades efficiency. The sizing of the inductor is a trade-off

between efficiency and transient response.As a guideline, the

inductor peak-to-peak current ripple is typically set to 1/3 of

the maximum load current for optimal transient response and

efficiency.

To calculate the inductor value, L, use the following equation:

L = ((VPVIN1 − VPVOUT1) × D)/(ΔIL × fSW)

(8)

where:

VPVIN1 is the input voltage.

VPVOUT1 is the output voltage.

D is the duty cycle (D = VVOUT1/VPVIN1).

ΔIL is the inductor ripple current.

fSW is the switching frequency.

The minimum dc current rating of the inductor must be greater

than the inductor peak current. Use the following equation to

calculate the inductor peak current:

IPEAK = ILOAD1 + (ΔIL/2)

(9)

where:

ILOAD1 is the output current.

ΔIL is the inductor ripple current.

Inductor conduction losses are minimized by using larger sized

inductors that have smaller dc resistance; this in turn improves

efficiency at the cost of solution size. Due to the high switching

frequency of the ADP5003, shielded ferrite core material is

recommended for its low core losses and low electromagnetic

interference (EMI).

Table 9. Recommended Inductors

Vendor

Part No.

Value (µH)

Saturation Current, ISAT (A)

RMS Current, IRMS (A)

DC Resistance (mΩ)

Size (mm)

Coilcraft

XAL4020-102

8.7

6.7

13.25

4 × 4

XAL4020-122

1.2

7.9

6.6

17.75

4 × 4

XAL4020-152

1.5

7.1

5.2

21.45

4 × 4

XAL4020-222

2.2

5.6

35.2

4 × 4

XAL5030-102

8.7

8.5

5 × 5

XAL5030-122

1.2

12.5

7.9

11.4

5 × 5

XAL5030-222

2.2

9.2

7.2

13.2

5 × 5

XAL5030-332

3.3

8.7

5.9

21.2

5 × 5

XAL5050-562

5.6

6.3

5.3

23.45

5 × 5

XAL5050-682

6.8

4.7

26.75

5 × 5

XEL6030-102

6.32

6 × 6

XEL6030-152

1.5

9.57

6 × 6

XEL6030-222

2.2

12.7

6 × 6

XEL6030-332

3.3

10.5

19.92

6 × 6

XEL6060-472

4.7

11.4

13.65

6 × 6

XAL6060-562

5.6

9.9

7.5

14.46

6 × 6

XEL6060-682

6.8

7.9

7.3

20.82

6 × 6

XEL6060-822

8.2

7.6

22.71

6 × 6

XAL6060-103

7.6

6 × 6

Wurth

744 383 570 10

9.6

7.4

11.6

4 × 4

744 383 570 12

1.2

8.8

13.4

4 × 4

744 383 570 15

1.5

8.5

6.2

17.1

4 × 4

744 383 570 18

1.8

5.8

4 × 4

744 383 570 22

2.2

5.2

4 × 4

ADP5003ACPZ-R7 数据表(PDF) 20 Page - Analog Devices

ADP5003ACPZ-R7 数据表(HTML) 20 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

数据表下载

链接网址

ADP5003ACPZ-R7 数据表(PDF) 20 Page - Analog Devices

ADP5003ACPZ-R7 数据表(HTML) 20 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

数据表 下载

链接网址

数据表下载