MP1909

– 30V, HIGH-FREQUENCY HALF-BRIDGE GATE DRIVER

MP1909 Rev. 1.0

www.MonolithicPower.com

11

7/10/2020

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APPLICATION INFORMATION

It is not recommended to add a resistor (RGATE)

between DRVH/DRVL and the MOSFET gate. If

RGATE is required to slow down the MOSFET’s

turn-on speed, a turn-off diode must be placed

within the system. Figure 3 shows the turn-off

diode circuit. This circuit significantly reduces the

turn-off delay time, which reduces the risk of

shoot-through.

MP1909

DRVH

DRVL

Q1

Q2

RGATE

RGATE

DOFF

OFF

D

GND

Figure 3: Turn-Off Diode Circuit

PCB Layout Guidelines (10)

Proper PCB layout of the driver is very important.

For the best results, refer to Figure 4 and follow

the guidelines below:

1. Put the VCC capacitor close to VCC and GND

pins.

2. Use wide PCB traces to connect the MP1909

to the GND pin.

3. Place the BST capacitor close to the BST and

SW

pins.

A

4.7

Ω

BST

resistor

is

recommended to reduce the spike voltage.

4. Use wide and short PCB traces to connect

DRVH/DRVL to the MOSFET gate.

Note:

10) The recommended layout is based on the circuit on Figure 5.

VIN

VOUT

GND

GND

GND

Top Layer

GND

DRVL

Bottom Layer

Figure 4: Recommended PCB Layout