ADM1033ARQZ-RL7 ON Semiconductor, ADM1033ARQZ-RL7 Datasheet - Page 16

• Manufacturer Part Number: ADM1033ARQZ-RL7
• Description: IC THERM/FAN SPEED CTLR 16-QSOP
• Manufacturer: ON Semiconductor

Specifications of ADM1033ARQZ-RL7

• Function: Fan Control, Temp Monitor
• Topology: ADC, Comparator, Multiplexer, Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: -40°C ~ 125°C, External Sensor
• Output Type: SMBus™
• Output Alarm: Yes
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

remote temperature sensor to operate in noisy environments.
Figure 29 shows a low−pass R−C−R filter with the following
values: R = 100 W and C = 1 nF. This filtering reduces both
common−mode noise and differential noise.
Limits, Status Registers, and Interrupts
channel on the ADM1033. These can form the basis of system
status monitoring. A status bit can be set for any out−of−limit
condition and detected by polling the device. Alternatively,
SMBusALERTs can be generated to flag a processor or
microcontroller of an out−of−limit condition.
8−Bit Limits
ADM1033:
Out−of−Limit Comparisons
format and sets the appropriate status bit for out−of limit
conditions. Comparisons are made differently, depending
on whether the measured value is compared to a high or low
limit.
Analog Monitoring Cycle Time
if monitoring has been disabled, by writing a 1 to the monitor/
STBY bit of Configuration Register 1, (Address 0x01). The
ADC measures each one of the analog inputs in turn; as each
measurement is completed, the result is automatically stored
in the appropriate value register. The round−robin monitoring
cycle continues unless it is disabled by writing a 0 to the
monitor/STBY bit (Bit 0) of Configuration Register 1
(Address 0x01).
Table 11. Temperature Limit Registers
Table 12. THERM Limit Registers
The construction of a filter allows the ADM1033 and the
High and low limits are associated with each measurement
The following is a list of all the 8−bit limits on the
The ADM1033 measures all parameters in a round−robin
The analog monitoring cycle time begins on powerup, or,
Register
Register
High Limit: ≥ Comparison Performed
Low Limit: < Comparison Performed
0x19
0x0C
0x0D
0x0B
0x0E
0x0F
0x10
Figure 29. Filter between Remote Sensor and
TEMPERATURE
REMOTE
SENSOR
Local High Limit
Local Low Limit
Local THERM Limit
Remote 1 High Limit
Remote 1 Low Limit
Remote 1 THERM Limit
THERM % Limit
Description
Description
ADM1033
100 Ω
100 Ω
1nF
0xFF default
0x8B (75°C)
0x8B (75°C)
0x54 (20°C)
0x95 (85°C)
0x54 (20°C)
0x95 (85°C)
Default
Default
D+
D–
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16
11 ms for the local temperature measurement and 32 ms for
each remote temperature measurement with averaging
enabled.
temperatures is therefore nominally.
again. For more information, refer to the Conversion Rate
Register section.
synchronized with the temperature measurements in any way.
Status Registers
registers. A 1 represents an out−of−limit measurement; a 0
represents an in−limit measurement. The status registers are
located at Addresses 0x4F to 0x51.
status register bit is set to 1. It remains set at 1 until the
measurement falls back within its limits and it is read or until
an ARA is completed.
status registers over the serial bus. If Bit 0 (ALERT low) of
Status Register 3 (Address 0x51) is set, this means that the
ALERT output has been pulled low by the ADM1033.
automatically notifies the system supervisor of an
out−of−limit condition. Reading the status register clears the
status bit as long as the error condition is gone.
due to an out−of−limit condition, it remains set even after the
triggering event has gone. The only way to clear the status
bit is to read the status register (after the event has gone).
Interrupt mask registers (Reg. 0x08, Reg. 0x09, Reg. 0x0A)
allow individual interrupt sources to be masked from
causing an ALERT. However, if one of these masked
interrupt sources goes out of limit, its associated status bit is
set in the status register.
Table 13. Interrupt Status Register 1 (Reg. 0x4F)
The ADC performs round−robin conversions and takes
The total monitoring cycle time for the average
Once the conversion time elapses, the round robin starts
Fan TACH measurements take place in parallel and are not
The results of limit comparisons are stored in the status
If the measurement is outside its limits, the corresponding
Poll the state of the various measurements by reading the
Pin 14 can be configured as a SMBusALERT output. This
Status register bits are sticky. Whenever a status bit is set
Bit #
7
6
5
4
3
2
1
0
Unused
Unused
Unused
Name
R1H
R1D
R1L
LH
LL
1 = Local high temperature limit has
been exceeded.
1 = Local low temperature limit has
been exceeded.
1 = Remote 1 high temperature limit has
been exceeded.
1 = Remote 1 low temperature limit has
been exceeded.
1 = Remote 1 diode error; indicates an
open or short on the D1+/D1− pins.
Reserved.
Reserved.
Reserved.
32 ) 11 + 43 ms
Description
(eq. 2)