MAX20004 datasheet(17/20 Pages) MAXIM

17 / 20 page

PCB Layout Guidelines

Careful PCB layout is critical for stability, low-noise/

EMI and overall performance. Use a multilayer board

whenever possible for better noise immunity and power

dissipation. See Figure 4 for the following guidelines for

good PCB layout:

1) Use the correct footprint for the IC and place as

many copper planes as possible under the IC foot-

print to ensure efficient heat transfer.

2) Place the ceramic input bypass capacitors (CBP and

CIN) as close as possible to the SUPSW and PGND

pins on the same side as the IC. Use low-impedance

connections (no vias or other discontinuities) be-

tween the capacitors and IC pins. CBP should be

located closest to the IC and should have very good

high-frequency performance (small package size,

low inductance, and high. Use flexible terminations

or other technologies instead of series capacitors

for these functions if failure modes are a concern.

This approach provides the best EMI rejection and

minimizes internal noise on the device, which can

degrade performance.

3) Place the inductor (L), output capacitors (COUT),

boost capacitor (CBST) and BIAS capacitor (CB) on

the same side as the IC in such a way as to minimize

the area enclosed by the current loops. Place the

inductor (L) as close as possible to the IC LX pin and

minimize the area of the LX node. Place the output

capacitors (COUT) near the inductor and the ground

side of COUT near the CIN ground connection so as

to minimize the current the loop area. Place the BIAS

capacitor (CB) next to the BIAS pin.

4) Use a contiguous copper GND plane on the layer

next to the IC to provide an image plane and shield

the entire circuit. GND should also be poured around

the entire circuit on the top side. Use a single GND:

do not separate or isolate PGND and GND connec-

tions with separate planes or copper areas. Ensure

that all heat-dissipating components have adequate

connections to copper for cooling. Use multiple vias

to interconnect GND planes/areas for low impedance

and maximum heat dissipation. Place vias at the GND

terminals of the IC, input/output/bypass capacitors,

and other components.

5) Place the compensation network (CF, CC, RC) near

the COMP pin so that the ground connections are as

short as possible to the GND pin. Keep high frequency

signals away from these components.

6) Place the oscillator set resistor (RF) near the FSET

pin so that the ground connection is as short as

possible to the GND pin. Keep high-frequency signals

away from this component.

7) Place the feedback resistor-divider (if used) near

the IC and route the feedback and OUT connections

away from the inductor and LX node and other noisy

signals.

MAX20004/MAX20006/

MAX20008

36V, 220kHz to 2.2MHz, 4A/6A/8A

Fully Integrated Automotive

Step-Down Converters

www.maximintegrated.com

Maxim Integrated │ 17

MAX20004 Datasheet(PDF) 17 Page - Maxim Integrated Products

MAX20004 Datasheet(HTML) 17 Page - Maxim Integrated Products

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Datasheet Download

Link URL