ata6831c ATMEL Corporation, ata6831c Datasheet - Page 6

• Manufacturer Part Number: ata6831c
• Description: Triple Half-bridge Driver With Spi And Pwm
• Manufacturer: ATMEL Corporation

3.2
3.3
6
Power-supply Fail
Open-load Detection
Atmel ATA6831C Preliminary
If undervoltage is detected at pin VS, the power-supply fail bit (PSF) in the output register is set
and all outputs are disabled. To detect an undervoltage, its duration has to last longer than the
undervoltage detection delay time t
voltage returns to the normal operational value. The PSF bit stays high until it is reset by the
SRR bit in the input register.
If the open-load detection bit (OLD) is set to low, a pull-up current for each high-side switch and
a pull-down current for each low-side switch is turned on (open-load detection current I
The open load condition of all the outputs is indicated in the SPI output register bit 1-6. High-side
open load is detected in case of OUT1-3 voltage above maximum voltage VOUT1-3_OLD_HTh
while Low-side open load is detected in case of OUT1-3 voltage below minimum voltage
VOUT1-3_OLD_LTh, see
If the OUTx is not connected, a Low-side open load is indicated, because the low-side current
sink is higher than the high-side current source, see open load detection current ratio
I
Switching on an output stage with the OLD bit set to low disables the open-load function for this
output.
Figure 3-2.
Out1-3L
/I
Out1-3H
.
OLD Threshold Level
Figure
Open-load high-side
Threshold
Threshold
Open-load low-side
3-2.
dUV
. The outputs are enabled immediately when the supply
VS
VOUT1-3_OLD_HTh
VOUT1-3_OLD_LTh
0V
9215C–AUTO–06/11
Out1-3
).