VB325 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

VB325

HIGH VOLTAGE IGNITION COIL DRIVER POWER I.C.

STMicroelectronics 

VB325SP

ELECTRICAL CHARACTERISTICS (continued)

Symbol

IEH

IEL

VBD(off)

VBD(on)

Parameter

High Level Enable Current

Low Level Enable Current

Base Darlington Voltage Off

Base Darlington Voltage On

Test Conditions

VE=5V

VE<0.4V

VE=VEH

VIN=VINH; VE=VEL; IC=6.5A

Min Typ Max Unit

500

µA

- 200

µA

1

V

1.8

V

PRINCIPLE OF OPERATION

The VB325SP is mainly intended as a high voltage

power switch device driven by a logic level input

and interfaces directly to a high energy electronic

ignition coil.

The input VIN of the VB325SP is fed from a low

power signal generated by an external controller

that determinesboth dwell time and ignition point.

During Vin high (≥ 4V) the VB325SP increases

current in the coil to the desired, internally set

current level.

After reaching this level, the coil current remains

constant until the ignition point, that corresponds

to the transition of Vin from high to low (typ. 1.9V

threshold).

During the coil current switch-off, the primary

voltage HVC is clamped at an internally set value

Vcl, typically 380V. The transition from saturation

to desaturation, coil current limiting phase, must

have the ability to accomodate an overvoltage.

A maximum overshoot of 20V is allowed.

FEEDBACK

When the collector current exceeds 4.5A, the

feedback signal is turned high and it remains so,

until the input voltage is turned-off.

OVERVOLTAGE

The VB325SP can withstand the following

transients of the battery line:

-100V/2msec(Ri =10 Ω)

+100V/0.2msec (Ri =10 Ω)

+50V/400msec (Ri = 4.2 Ω, with VIN= 3V)

Figure 1: Flag current Vs. temperature

4/9

Figure 2: Single pulse avalanche energy capability

700

650

600

550

500

450

400

350

300

250

200

150

100

50

0

0

Tc=25º

C

Tc=150º

10 20 30 40 50 60 70 80 90 100 110

L (mH)

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