l99h01 STMicroelectronics, l99h01 Datasheet - Page 30

• Manufacturer Part Number: l99h01
• Description: Motor Bridge Driver For Automotive Applications
• Manufacturer: STMicroelectronics

3.8
3.9
3.10
3.11
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Temperature warning and thermal shutdown
If junction temperature rises above T
detectable via the SPI. If junction temperature increases above the second threshold
T
switched-off to protect the device. The gates of the H-bridge are discharged by the resistive
low mode (see
temperature must decrease below T
by the microcontroller.
Short-circuit detection / drain source monitoring
The drain - source voltage of each activated external MOSFET of the H-bridge is monitored
by comparators to detect shorts to ground or battery. If the voltage drop over the external
MOSFET exceeds the threshold voltage V
time t
corresponding drain source monitoring flag (DS_MON [3:0]) is set. Until this failure flag is
reseted the corresponding half bridge is in sink condition. The DS_MON bits have to be
cleared through a software reset to reactivate the gate drivers. The drain source monitoring
has a filter time of 6 µs. This monitoring is only active when the corresponding gate driver is
in source condition. The threshold voltage V
0.5 V and 2 V with the SPI.
Programmable cross current protection
The external Power MOSFET’s transistors in H-bridge (two halfbridges) configuration are
switched-on with an additional delay time t
cross current protection time t
Current sense amplifier (CSA)
The current sense amplifier (CSA) is specially designed for current shunt automotive
applications. It is a bidirectional, single-supply difference amplifier for amplifying small
differential voltages in a wide common mode voltage range (-4 V to (V
the current measurement at two shunts. The result of respective shunt can be multiplexed to
the microcontroller compatible output voltage by a SPI command.
A gain of 50, 20 or 10 is SPI programmable. The inputs (CSI1+ / CSI1- and CSI2+ / CSI2-)
are build as a transconductance stage. Therefore a series resistor (for filtering etc.) should
not exceed 50 Ω to keep the additional gain error below 1%.
The output works at half scale: V
measurement is in normal mode available with the "OFF_CAL" SPI-bit. If this bit is set to
logic "1" the input pins are disconnected from the amplifier and a virtual zero input
differential voltage is selected.
jSDON
SCd
, the thermal shutdown bit (TSD) is set. The gate drivers and the charge pump are
the corresponding gate driver switches the external MOSFET off and the
Section
3.4). In order to reactivate the output stages the junction
CCP
Doc ID 15567 Rev 3
CSO0
can be programmed with the SPI.
j SD OFF
jTWON
= (0,5 * V
CCP
SCd
the temperature warning flag TW is set and is
SCd
and the thermal shutdown bit has to be cleared
to prevent cross current in the halfbridge. The
for longer than the short current detection
CC
can be programmed in 4 steps between
) V for V
IDIFF
= 0 V. An internal offset
CP
- 8) V). It supports
L99H01