Datasheet

RAILUV PULLDOWN
REF PULLDOWN PULLUP
1024 V R
Vraw
V R R
´
= ´
+
(4)
OverVoltageThresholds
89101112131415 01234567
Vraw
0 0 00 0
RAILOV
REF
1024 V
Vraw
V
´
=
(5)
RAILOV PULLDOWN
REF PULLDOWN PULLUP
1024 V R
Vraw
V R R
´
= ´
+
(6)
RampTime
89101112131415 01234567
RAMPTIME
RAMPTIME=RAILnRailTime(inunits ofms).
0 0 00
UCD9080
SLVS692E – SEPTEMBER 2006 – REVISED MAY 2008 ................................................................................................................................................... www.ti.com
With external rail voltage divider:
The OverVoltageThreholds field in the configuration parameters specifies each rail overvoltage threshold that is
used when monitoring this rail. The address map for these registers is as follows:
ADDRESS SIZE DEFAULT VALUE DESCRIPTION
0xE120 2 0x0400 Overvoltage threshold for rail 8
0xE122 2 0x0400 Overvoltage threshold for rail 7
0xE124 2 0x0400 Overvoltage threshold for rail 6
0xE126 2 0x0400 Overvoltage threshold for rail 5
0xE128 2 0x0400 Overvoltage threshold for rail 4
0xE12A 2 0x0400 Overvoltage threshold for rail 3
0xE12C 2 0x0400 Overvoltage threshold for rail 2
0xE12E 2 0x0400 Overvoltage threshold for rail 1
The format for each register is as follows:
The voltage conversion is dependent upon the configured voltage reference, and the pullup/pulldown resistors
used on the board for each rail. The voltage reference is selected as either 2.5 V (internal) or V
CC
(external). The
formula to convert the desired rail OverVoltageThreshold to Vraw follows:
Without external rail voltage divider:
With external voltage divider:
The RampTime field in the configuration parameters specifies the maximum amount of time for each rail to
achieve regulation. The address map for these registers is as follows:
ADDRESS SIZE DEFAULT VALUE DESCRIPTION
0xE130 2 0x0FA0 Maximum voltage ramp time for rail 1
0xE132 2 0x0FA0 Maximum voltage ramp time for rail 2
0xE134 2 0x0FA0 Maximum voltage ramp time for rail 3
0xE136 2 0x0FA0 Maximum voltage ramp time for rail 4
0xE138 2 0x0FA0 Maximum voltage ramp time for rail 5
0xE13A 2 0x0FA0 Maximum voltage ramp time for rail 6
0xE13C 2 0x0FA0 Maximum voltage ramp time for rail 7
0xE13E 2 0x0FA0 Maximum voltage ramp time for rail 8
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