ACPL-P343 View Datasheet(PDF) - Avago Technologies

Part Name

Description

Manufacturer

ACPL-P343

4.0 Amp Output Current IGBT Gate Drive Optocoupler with Rail-to-Rail Output Voltage in Stretched SO6

Avago Technologies 

Selecting the Gate Resistor (Rg)

Step 1: Calculate Rg minimum from the IOL peak specification. The IGBT and Rg in Figure 28 can be analyzed as a simple

RC circuit with a voltage supplied by ACPL-P343/W343.

Rg ≥ VCC – VEE – VOL

IOLPEAK

= 15 V + 5 V – 2.9 V

4A

= 4.3   5 

The VOL value of 2.9 V in the previous equation is the VOL at the peak current of 4.0 A (see Figure 7).

Step 1: Check the ACPL-P343/W343 power dissipation and increase Rg if necessary. The ACPL-P343/W343 total power

dissipation (PT) is equal to the sum of the emitter power (PE) and the output power (PO).

PT = PE + PO

PE = IF • VF • Duty Cycle

PO = PO(BIAS) + PO(SWITCHING)

= ICC • (VCC-VEE) + ESW(Rg;Cg) • f

Using IF(worst case) = 16 mA, Rg = 5 , Max Duty Cycle = 80%, Cg = 25 nF, f = 25 kHz and TA max = 85° C:

PE = 16 mA • 1.95 V • 0.8 = 25 mW

PO = 3 mA • 20 V + 5 J • 25 kHz

= 60 mW + 125 mW

= 185 mW < 700 mW (PO(MAX) @ 85° C)

The value of 3 mA for ICC in the previous equation is the maximum ICC over the entire operating temperature range.

Since PO is less than PO(MAX), Rg = 5  is alright for the power dissipation.

3.0E-05

2.5E-05

2.0E-05

VCC = 30 V

VCC = 20 V

VCC = 15 V

1.5E-05

1.0E-05

5.0E-06

0.0E+00

0

2

4

6

8

10

Rg - Gate Resistance - 7

Figure 31. Energy Dissipated in the ACPL-P343/W343 for each IGBT switching

cycle

17

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