TLE6209R_07 Datasheet, PDF (10/30 Pages) Infineon Technologies AG – 7 A H-Bridge for DC-Motor Applications

TLE 6209 R
2.5
Protection and Diagnosis
2.5.1
Short of Output to Ground
The high-side switches are protected against a short of the output to ground by an over
current shutdown. If a high-side switch is turned on and the current rises above the high-
side shutdown threshold I_SDH for longer than the shutdown delay time t_dOC, all output
transistors are turned off and bit 4 the SPI diagnosis word is set. During the delay time,
the current is limited to I_SC (typically 20 A). The output stages stay off and the error bit
set until a status register reset (bit 7 of SPI control word) is received or a power-on reset
is performed.
2.5.2
Short of Output to V_S
Due to the chopper current regulation, the low-side switches are protected against a
short to the supply voltage. To detect the short, the first time the current limit is reached,
the off-command for the low-side switch is blanked out for 10 µs. If the current rises
above the low-side shutdown threshold I_SDL during this time, all output transistors are
turned off and bit 5 in the SPI diagnosis word is set. The value of the shutdown threshold
depends on the current limit that is set via the SPI. The shutdown threshold is 1 A higher
than the current limit. The output stages stay off and the error bit set until a status register
reset (bit 7 of SPI control word) is received or a power-on reset is performed.
2.5.3
Short Across the Load
The short circuit protection circuits of the high- and low-side switches work
independently of each other. In most cases, a short across the load will be detected as
a short to V_S because of the longer filter time in the high-side switches t_dOC and the higher
shutdown threshold I_SDH.
2.5.4
Open Load
If the current through the low side transistor is lower than the reference current I_dOL in
ON-state (PWM = H), a timer is started. After a filter time t_dOC an open load failure will be
recognized and the status bit 3 is set. If the current exceeds the reference current I_dOL
the open load timer is reset. If the H-bridge is switched to OFF-state (PWM = L) the timer
is stopped but not reset. The timer continues if the H-bridge is switched to ON-state
again. There is no reset of the open load timer if the direction is changed using the DIR
input in open load condition. The open load error bit is latched and can be reset by the
status register reset bit 7 of the SPI control word or a POR.
2.5.5
Temperature Monitoring
Temperature sensors are integrated in the power stages. The temperature monitoring
circuit compares the measured temperature to the prewarning, warning and shutdown
Data Sheet, Version 3.1
10
2007-08-01