ADM1032
outside the programmed limits. THERM output does not
need to be reset, unlike the ALERT output. Once the
measurements are within the limits, the corresponding status
register bits are reset and the THERM output goes high.
Table 8. STATUS REGISTER BIT ASSIGNMENTS
Bit
7
6
5
4
3
2
1
0
Name
BUSY
(Note 1)
(Note 1)
(Note 1)
(Note 1)
(Note 1)
Table 10. CONVERSION RATE REGISTER CODES
Data
00h
01h
02h
03h
04h
05h
06h
07h
08h
09h
0Ah
0B to FFh
Conversion/Sec
0.0625
0.125
0.25
0.5
1
2
4
8
16
32
64
Reserved
Average Supply Current
mA Typ at V
DD
= 5.5 V
0.17
0.20
0.21
0.24
0.29
0.40
0.61
1.1
1.9
0.73
1.23
Function
1 When ADC Converting
1 When Local High Temp Limit Tripped
1 When Local Low Temp Limit Tripped
1 When Remote High Temp Limit
Tripped
1 When Remote Low Temp Limit
Tripped
1 When Remote Sensor Open-Circuit
1 When Remote THERM Limit Tripped
1 When Local THERM Limit Tripped
LHIGH
LLOW
RHIGH
RLOW
OPEN
RTHRM
LTHRM1
Limit Registers
1. These flags stay high until the status register is read, or they are
reset by POR.
Configuration Register
Two bits of the configuration register are used. If Bit 6 is
0, which is the power-on default, the device is in operating
mode with the ADC converting. If Bit 6 is set to 1, the device
is in standby mode and the ADC does not convert. The
SMBus does, however, remain active in standby mode so
values can be read from or written to the SMBus. The
ALERT and THERM O/Ps are also active in standby mode.
Bit 7 of the configuration register is used to mask the alert
output. If Bit 7 is 0, which is the power-on default, the output
is enabled. If Bit 7 is set to 1, the output is disabled.
Table 9. CONFIGURATION REGISTER BIT
ASSIGNMENTS
Bit
7
6
5 to 0
Name
MASK1
RUN/STOP
Function
0 = ALERT Enabled
1 = ALERT Masked
0 = Run
1 = Standby
Reserved
Power-On
Default
0
0
0
The ADM1032 has nine limit registers to store local and
remote, high, low, and THERM temperature limits. These
registers can be written to and read back over the SMBus.
The high limit registers perform a > comparison, while the
low limit registers perform a < or = to comparison. For
example, if the high limit register is programmed with 80C,
measuring 81C results in an alarm condition. If the low
limit register is programmed with 0C, measuring 0C or
lower results in an alarm condition. Exceeding either the
local or remote THERM limit asserts THERM low. A
default hysteresis value of 10C is provided, which applies
to both channels. This hysteresis can be reprogrammed to
any value after powerup (Reg 0x21h).
One-Shot Register
Conversion Rate Register
The one-shot register is used to initiate a single conversion
and comparison cycle when the ADM1032 is in standby
mode, after which the device returns to standby. This is not
a data register as such, and it is the write operation that
causes the one-shot conversion. The data written to this
address is irrelevant and is not stored. The conversion time
on a single shot is 96 ms when the conversion rate is 16
conversions per second or less. At 32 conversions per
second, the conversion time is 15.3 ms. This is because
averaging is disabled at the faster conversion rates (32 and
64 conversions per second).
Consecutive ALERT Register
The lowest four bits of this register are used to program the
conversion rate by dividing the internal oscillator clock by
1, 2, 4, 8, 16, 32, 64, 128, 256, 512, or 1024 to give
conversion times from 15.5 ms (Code 0Ah) to 16 seconds
(Code 00h). This register can be written to and read back
over the SMBus. The higher four bits of this register are
unused and must be set to 0. Use of slower conversion times
greatly reduces the device power consumption, as shown in
Table 10.
This value written to this register determines how many
out-of limit measurements must occur before an ALERT is
generated. The default value is that one out-of-limit
measurement generates an ALERT. The maximum value
that can be chosen is four. The purpose of this register is to
allow the user to perform some filtering of the output. This
is particularly useful at the faster two conversion rates where
no averaging takes place.
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