VB526SP-E Datasheet, PDF (13/19 Pages) STMicroelectronics – High voltage ignition coil driver power integrated circuit

VB526SP-E
4
Application schematic
Application schematic
Figure 8. Application diagram
+5V
1μF
100nF
V_bat
μP
1K
1K
1K
1nF 18K
V_IN ^VCC
E
BD
HV_C
FLAG
LGND
GND
Note:
ENABLE pin can be alternatively connected to LGND.
4.1
Principle of operation
The VB526SP-E 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 VB526SP-E is fed from a low power signal generated by an external
controller that determines both dwell time and ignition point. During V_IN high (≥ 4 V) the
VB526SP-E 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 V_IN from high to low (typ. 1.9 V threshold).
During the coil current switch-off, the primary voltage HV_C is clamped at an internally set
value V_cl, typically 380 V. The transition from saturation to desaturation, coil current limiting
phase, must have the ability to accommodate an overvoltage.
A maximum overshoot of 20 V is allowed.
4.2
Feedback
When the collector current exceeds 6.5 A, the feedback signal is turned high and it remains
so, until the input voltage is turned-off.
Doc ID 18029 Rev 1
13/19