ACPL-P345 and ACPL-W345 Data Sheet

2.5-Amp Output Current Power, GaN, and SiC MOSFET Gate Drive Optocoupler with Rail-

to-Rail Output Voltage in Stretched SO6

Broadcom

AV02-4079EN

13

Application Information

Product Overview Description

The ACPL-P345/W345 is an optically isolated power output

stage capable of driving power, GaN, or SiC MOSFET.

Based on BCDMOS technology, this gate drive optocoupler

delivers higher peak output current, better rail-to-rail output

voltage performance and two times faster speed than the

previous generation products.

The high peak output current and short propagation delay

are needed for fast MOSFET switching to reduce dead time

and improve system overall efficiency. Rail-to-rail output

voltage ensures that the MOSFET’s gate voltage is driven to

the optimum intended level with no power loss across the

MOSFET. This helps the designer lower the system power

which is suitable for bootstrap power supply operation.

It has very high CMR (common mode rejection) rating that

allows the microcontroller and the MOSFET to operate at

very large common mode noise found in industrial motor

drives and other power switching applications. The input is

driven by direct LED current and has a hysteresis that

prevents output oscillation if insufficient LED driving current

is applied. This will eliminates the need of additional Schmitt

trigger circuit at the input LED.

The stretched SO6 package which is up to 50% smaller than

conventional DIP package facilitates smaller and more

compact design. These stretched packages are compliant

to many industrial safety standards such as IEC/EN/DIN EN

60747-5-5, UL 1577 and CSA.

The stretched SO6 package which is up to 50% smaller than

conventional DIP package facilitates smaller more compact

design. These stretched packages are compliant to many

industrial safety standards, such as IEC/EN/DIN EN

60747-5-5, UL 1577 and CSA.

Recommended Application Circuit

The recommended application circuit shown in Figure 16

illustrates a typical gate drive implementation using the

ACPL-P345.

The supply bypass capacitors (1 µF) provide the large

transient currents necessary during a switching transition.

Because of the transient nature of the charging currents, a

low current (4.0 mA) power supply will be enough to power

the device. The split resistors (in the ratio of 1.5:1) across

the LED will provide a high CMR response by providing a

balanced resistance network across the LED.

The gate resistor RG serves to limit gate charge current and

controls the MOSFET switching times.

In PC board design, care should be taken to avoid routing

the MOSFET drain or source traces close to the ACPL-P345

input as this can result in unwanted coupling of transient

signals into ACPL-P345 and degrade performance.

Figure 16: Recommended Application Circuit with Split Resistors LED

+

_

+

_

Rg

Q1

Q2

+HVDC

-HVDC

1 μF

1

2

3

6

5

4

CATHODE

NC

ANODE

232Ω

154Ω