BU323Z

3

Motorola Bipolar Power Transistor Device Data

Figure 1. IC = f(VCE) Curve Shape

IC

INOM = 6.5 A

Output transistor turns on: IC = 40 mA

High Voltage Circuit turns on: IC = 20 mA

Avalanche diode turns on: IC = 100 µA

Icer Leakage Current

250 V

300 V

340 V

VCE

VCLAMP NOMINAL

= 400 V

By design, the BU323Z has a built–in avalanche diode and

a special high voltage driving circuit. During an auto–protect

cycle, the transistor is turned on again as soon as a voltage,

determined by the zener threshold and the network, is

reached. This prevents the transistor from going into a

Reverse Bias Operating limit condition. Therefore, the device

will have an extended safe operating area and will always

appear to be in “FBSOA.” Because of the built–in zener and

associated network, the IC = f(VCE) curve exhibits an

unfamiliar shape compared to standard products as shown in

Figure 1.

Figure 2. Basic Energy Test Circuit

MERCURY CONTACTS

WETTED RELAY

VCE

MONITOR

(VGATE)

L INDUCTANCE

(8 mH)

IB CURRENT

SOURCE

VBEoff

IB2 SOURCE

IC CURRENT

SOURCE

0.1

Ω

NON

INDUCTIVE

IC

MONITOR

RBE = 100 Ω

The bias parameters, VCLAMP, IB1, VBE(off), IB2, IC, and

the inductance, are applied according to the Device Under

Test (DUT) specifications. VCE and IC are monitored by the

test system while making sure the load line remains within

the limits as described in Figure 4.

Note: All BU323Z ignition devices are 100% energy tested,

per the test circuit and criteria described in Figures 2 and 4,

to the minimum guaranteed repetitive energy, as specified in

the device parameter section. The device can sustain this

energy on a repetitive basis without degrading any of the

specified electrical characteristics of the devices. The units

under test are kept functional during the complete test se-

quence for the test conditions described:

IC(peak) = 7.0 A, ICH = 5.0 A, ICL = 100 mA, IB = 100 mA,

RBE = 100 Ω, Vgate = 280 V, L = 8.0 mH

Figure 3. Forward Bias Safe Operating Area

VCE, COLLECTOR–EMITTER VOLTAGE (VOLTS)

1000

340 V

100

10

0.001

0.01

0.1

1

10

TC = 25°C

250 ms

10 ms

1ms

300

µs

THERMAL LIMIT

SECOND BREAKDOWN LIMIT

CURVES APPLY BELOW

RATED VCEO