BTS7970B Infineon Technologies, BTS7970B Datasheet - Page 19

• Manufacturer Part Number: BTS7970B
• Manufacturer: Infineon Technologies

Specifications of BTS7970B

• Operating Current: 3mA
• Operating Temperature Classification: Automotive
• Package Type: TO-263
• Operating Supply Voltage (min): 5.5V
• Operating Supply Voltage (max): 28V
• Lead Free Status / Rohs Status: Not Compliant

4.4
4.4.1
The control inputs IN and INH consist of TTL/CMOS compatible schmitt triggers with
hysteresis which control the integrated gate drivers for the MOSFETs. Setting the INH
pin to high enables the device. In this condition one of the two power switches is switched
on depending on the status of the IN pin. To deactivate both switches, the INH pin has
to be set to low. No external driver is needed. The BTS 7970B can be interfaced directly
to a microcontroller.
4.4.2
In bridge applications it has to be assured that the highside and lowside MOSFET are
not conducting at the same time, connecting directly the battery voltage to GND. This is
assured by a circuit in the driver IC, generating a so called dead time between switching
off one MOSFET and switching on the other. The dead time generated in the driver IC is
automatically adjusted to the selected slew rate.
4.4.3
In order to optimize electromagnetic emission, the switching speed of the MOSFETs is
adjustable by an external resistor. The slew rate pin SR allows the user to optimize the
balance between emission and power dissipation within his own application by
connecting an external resistor
4.4.4
The status pin IS is used as a combined current sense and error flag output. In normal
operation (current sense mode), a current source is connected to the status pin, which
delivers a current proportional to the forward load current flowing through the active high
side switch. If the high side switch is inactive or the current is flowing in the reverse
direction no current will be driven except for a marginal leakage current
external resistor
value of
leads to
Due to the good long term stability and the low temperature coefficient it is possible to
improve the absolute current sense accuracy in the application by calibration. For best
results it is recommended to do a two-point calibration.
In case of a fault condition the status output is connected to a current source which is
independent of the load current and provides I
is determined by the choice of the external resistor and the supply voltage. In case of
current limitation the
Data Sheet
V
19500
IS
Control and Diagnostics
Input Circuit
Dead Time Generation
Adjustable Slew Rate
Status Flag Diagnosis With Current Sense Capability
= (
I
for the current sense ratio
L
R
/
IS
19.5
I
determines the voltage per output current. E.g. with the nominal
IS(lim)
A)V.
is activated for 2 *
R
SR
to GND.
18
k
ILIS
IS(lim)
Block Description and Characteristics
t
CLS
=
I
.
L
. The maximum voltage at the IS pin
/
High Current PN Half Bridge
I
IS
, a resistor value of
Rev. 2.0, 2006-05-09
BTS 7970B
I
IS(LK)
R
IS
= 1kΩ
. The