Rainbow Electronics ATA6831 - Manual (Page 6)

6
4908D–AUTO–09/06
ATA6831
After power-on reset, the input register has the following status:
The following patterns are used to enable internal test modes of the IC. Do not use these pat-
terns during normal operation.
3.2 Power-supply Fail
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
dUV
. The outputs are enabled immediately when the supply
voltage returns to the normal operational value. The PSF bit stays high until it is reset by the
SRR bit in the input register.
3.3 Open-load Detection
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
OUT1-3
). If
the current through the external load does not reach the open-load detection current, the corre-
sponding bit of the output in the output register is set to high.
Switching on an output stage with the OLD bit set to low disables the open-load function for this
output.
Bit 15
SI
Bit 14
OCS
Bit 13
OLD
Bit 12
PH3
Bit 11
PL3
Bit 10
PH2
Bit 9
PL2
Bit 8
PH1
Bit 7
PL1
Bit 6
HS3
Bit 5
LS3
Bit 4
HS2
Bit 3
LS2
Bit 2
HS1
Bit 1
LS1
Bit 0
SRR
H H H L L L L L L L L L L L L L
Bit 15 Bit 14 Bit 13
(OCS)
Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 Bit 7 Bit 6
(HS3)
Bit 5
(LS3)
Bit 4
(HS2)
Bit 3
(LS2)
Bit 2
(HS1)
Bit 1
(LS1)
Bit 0
(SRR)
H H H H H L L L L L L L L L L L
H H H L L H H L L L L L L L L L
H H H L L L L H H L L L L L L L