ADP1074ARWZ-R7 datasheet(27/32 Pages) AD

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Data Sheet

ADP1074

Rev. D | Page 27 of 32

LAYOUT GUIDELINES

The layout guidelines for the primary side are as follows:

Ground all the capacitors to their respective grounds. For

example, ground the SS1 capacitor to AGND1.

Use the CS pin and the AGND1 pin to differentially sense

the primary current measurement through the sense

resistor. Do not cross the CS and AGND1 traces for

current sensing across any switch nodes.

Place a capacitor (33 pF to 470 pF typical) close to the CS

pin, connected to AGND1.

Connect the ground plane on the primary side to PGND1.

Connect AGND1 to PGND1 using a 0 Ω resistor.

Place resistors (1 Ω to 5 Ω typical) in series with NGATE

and the main power MOSFET. These resistors aid in

eliminating any ringing on the drive voltages.

The layout guidelines for the secondary side are as follows:

Ground all the capacitors to their respective grounds. For

example, ground the SS2 capacitor to AGND2.

Place resistors (1 Ω to 5 Ω) in series with SRx and the

synchronous MOSFET. These resistors aid in eliminating

any ringing on the drive voltages.

Connect the ground plane on the secondary side to

PGND2. Connect the negative terminal of the output

voltage to the PGND2 plane.

Use the FB pin and the AGND2 pin to remotely

differentially sense the output voltage by connecting

AGND2 to the negative terminal of the output voltage

using a 0 Ω resistor.

Use a 100 nF capacitor on the MODE pin if light load

mode is used in noisy environments.

ADP1074ARWZ-R7 数据表(PDF) 27 Page - Analog Devices