MMPF0100 datasheet(124/136 Pages) NXP

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124

NXP Semiconductors

PF0100

TYPICAL APPLICATIONS

Figure 36. Recommended shielding for critical signals

•

These signals can be placed on an outer layer of the board to reduce their capacitance with respect to the ground plane.

•

Care must be taken with these signals not to contaminate analog signals, as they are high frequency signals. Another good

practice is to trace them perpendicularly on different layers, so there is a minimum area of proximity between signals.

7.2.5

Switching regulator layout recommendations

1. Per design, the switching regulators in PF0100 are designed to operate with only one input bulk capacitor. However, it is

recommended to add a high frequency filter input capacitor (CIN_hf), to filter out any noise at the regulator input. This capacitor

should be in the range of 100 nF and should be placed right next to or under the IC, closest to the IC pins.

2. Make high-current ripple traces low-inductance (short, high W/L ratio).

3. Make high-current traces wide or copper islands.

4. Make high-current traces symetrical for dual–phase regulators (SW1, SW3).

Figure 37. Generic buck regulator architecture

Driver Controller

SWxIN

SWxLX

SWxFB

COUT

CIN

SWx

VIN

Compensation

CIN_HF

MMPF0100 Datasheet(PDF) 124 Page - NXP Semiconductors