BTS 7811K Infineon Technologies, BTS 7811K Datasheet - Page 5

• Manufacturer Part Number: BTS 7811K
• Manufacturer: Infineon Technologies

Specifications of BTS 7811K

• Packages: P-TO263-15
• Operating Range: 5.0 - 42.0 V
• Rds (on) (typ): 40.0 mOhm
• Id(lim): 42.0 A
• Iq (typ): 4.0 µA
• Diagnosis: OT, OL Status Flag

BTS 7811K
1.6
Circuit Description
Input Circuit
The control inputs IH1,2 consist of TTL/CMOS compatible Schmitt-Triggers with
hysteresis. Buffer amplifiers are driven by these stages and convert the logic signal into
the necessary form for driving the power output stages. The inputs are protected by ESD
clamp-diodes. The inputs IL1 and IL2 are connected to the gates of the standard N-
channel vertical power-MOS-FETs.
Output Stages
R
The output stages consist of a low
Power-MOS H-bridge. In H-bridge
DS ON
configuration, the D-MOS body diodes can be used for freewheeling when commutating
inductive loads. If the high-side switches are used as single switches, positive and
negative voltage spikes which occur when driving inductive loads are limited by
integrated power clamp diodes.
Short Circuit Protection
The outputs are protected against
– output short circuit to ground
– overload (load short circuit).
An internal OP-amp controls the Drain-Source-voltage by comparing the DS-voltage-
drop with an internal reference voltage. Above this trippoint the OP-Amp reduces the
output current depending on the junction temperature and the drop voltage.
Overtemperature Protection
The high-side switches incorporate an overtemperature protection circuit with hysteresis
which switches off the output transistors and sets the status output to low.
Undervoltage-Lockout (UVLO)
V
V
When
reaches the switch-on voltage
the IC becomes active with a hysteresis.
S
UVON
V
The high-side output transistors are switched off if the supply voltage
drops below the
S
V
switch off value
UVOFF.
Open Load Detection
The open load detection of the BTS 7811K works in OFF condition and is based on a
voltage measurement at the source of the high side switch. In order to use the open load
detection a pull up resistor to 5V has to be connected to source of one of the high side
switches. Because in ON condition this pull up resistor would connect the bridge output
to the µC supply it needs to be disconnected by a transistor when the high side switch is
Data Sheet
5
Rev. 2.0, 2006-07-18