VB125 STMicroelectronics, VB125 Datasheet - Page 4

• Manufacturer Part Number: VB125
• Description: HIGH VOLTAGE IGNITION COIL DRIVER POWER IC
• Manufacturer: STMicroelectronics

150 C. For higher temperature, the thermal protection circuit will begin its action reducing the Icl limit according with the
VB125SP
NOTE 1 Parametric degradation are allowed with 6V < V
NOTE 2 In the high voltage clamping structure of this device a temperature compensation has been implemented. The
circuit schematic is shown in fig. 1. The KVbe cell takes care of the temperature compensation. The whole
electrical characteristic of the new circuit is shown in fig. 2. Up to V
leakage current of the power stage); for nV
NOTE 3 The saturation voltage of the Power stage includes the drop on the sensing resistor.
NOTE 4 Considering the different ways of operation of the device (with or without spark, etc...) there are some short
the possibility for the HV
in the pin V
NOTE 5 A zener protection of 16V (typical) is placed on the supply pin (V
For this reason, when the battery voltage exceedes that value, the current flowing into V
maximum current specified at V
NOTE 6 The primary coil current value Icl must be measured 1 ms after desaturation of the power stage.
NOTE 7 These limits apply with regard to the minimum battery voltage and resistive drop on the coil and cables that permit
to reach the limitation or diagnostic level.
NOTE 8 No internal Pull-Down.
NOTE 9 Tj
NOTE 10 Propagation Time measured from input voltage rising edge to 50% of output voltage falling edge.
NOTE 11 As soon as the input signal is switched low the stored charges in the base of the power transistor are removed
and the so called «Turn-off Delay Time of Coil Current» begins; after at the «Turn-off Fall Time of Coil Current» starts
and, at the same time, the HVC rises.
t
t
4/8
power dissipation. Chip temperature is a function of the Rth of the whole system in which the device will be operating
(See Fig.4).
compensation circuit (typical slope
protect the device against overvoltage (See Fig. 3).
periods of time in which the output terminal (HV
inductances and stray capacitances of the ignition coil.With VIPower devices, if no corrective action is taken, these
negative currents can cause parasitic glitches on the diagnostic output. To kill this potential problem, a circuit that avoids
implemented in the VB125SP.For this reason there are some short periods in which a current exceeding 220 mA flows
resistor.
dLH
fLH
is defined as the delay between the 90% and the 10% of the coil current.
is defined as the time between the negative edge of the input pulse to the point where the HVC reaches 100V.
min
D
.
= 150 C means that the behaviour of the device will not be affected for junction temperature lower than
C
to be pulled undeground, by sending the required negative current from the battery is
bat
=14V (both in power on and power off condictions) : it will be limited by an internal
20 K
Z
< V
) as soon as the Vcl is reached the dinamic resistance drop to ~ 4
CE
C
< V
) is pulled below ground by a negative current due to leakage
CL
bat
a current begins to flow across the resistances of the KVbe
< 10V and V
CE
=nV
bat
Z
CC
no current will flow into the collector (just the
> 24V.
) of the chip to protect the internal circuitry.
cc
pin can be greater than the
to