VB326 Datasheet, PDF (4/9 Pages) STMicroelectronics – HIGH VOLTAGE IGNITION COIL DRIVER POWER I.C

VB326SP
ELECTRICAL CHARACTERISTICS (continued)
Symbol
I_EH
I_EL
V_BD(off)
V_BD(on)
Parameter
High Level Sinked Enable
Current
Low Level Sinked Enable
Current
Base Darlington Voltage Off
Base Darlington Voltage On
V_E=5V
Test Conditions
V_E<0.4V
V_E=V_EH
V_IN=V_INH; V_E=V_EL; I_C=6.5A
Min Typ Max Unit
500
µA
- 200
1.8
µA
1
V
V
PRINCIPLE OF OPERATION
The VB326SP 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 V_IN of the VB326SP is fed from a low
power signal generated by an external controller
that determinesboth dwell time and ignition point.
During Vin high (≥ 4V) the VB326SP 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 HV_C is clamped at an internally set value
V_cl, 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 6.5A, the
feedback signal is turned high and it remains so,
until the input voltage is turned-off.
OVERVOLTAGE
The VB326SP can withstand the following
transients of the battery line:
-100V/2msec(R_i =10 Ω)
+100V/0.2msec (R_i =10 Ω)
+50V/400msec (R_i = 4.2 Ω, with V_IN= 3V)
Figure 1: Flag current Vs. temperature
4/9
1
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)