ADT7462ACPZ-REEL ON Semiconductor, ADT7462ACPZ-REEL Datasheet - Page 24

• Manufacturer Part Number: ADT7462ACPZ-REEL
• Description: IC TEMP/VOLT MONITOR 32-LFCSP
• Manufacturer: ON Semiconductor

Specifications of ADT7462ACPZ-REEL

• 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: No
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 32-LFCSP
• Number Of Voltages Monitored: 1
• Monitored Voltage: 0.9 V to 12 V
• Manual Reset: Not Resettable
• Watchdog: No Watchdog
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 3 V
• Supply Current (typ): 4000 uA
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ADC Information
Round Robin
inputs that are digitized using the on−board ADC. An
internal multiplexer switches between the different analog
inputs and digitizes them, in turn, in a round−robin manner.
The total conversion time depends upon how the ADT7462
is configured. The conversion times for each measurement
channel are shown in Table 14. The complete conversion
time is the sum of the time for the voltage and temperature
measurements.
Configuration Option 1, the round−robin conversion time is
calculated as follows:
part of the round−robin monitoring cycle.
from their value registers, 16 readings have actually been
made internally and the results averaged before being placed
in the value register.
Bypass Voltage Attenuators
ADT7462. Each of these voltage measurement channels has
an input structure (see Figure 36 for input structures for each
of the voltage channels). Because the ADC has a voltage
input range from 0 V to 2.25 V, these input circuits attenuate
the voltage input using a resistor divider network to match
the input range of the ADC. However, the user may
occasionally want to remove the attenuators and directly
apply a voltage of between 0 V and 2.25 V to the ADC.
These attenuators can be disabled by setting relevant bits in
the voltage attenuator configuration registers (see Table 15).
This feature also allows the user to rescale the voltage inputs
using an external attenuator circuit. However, when the
Table 14. Measurement Channel Conversion Times
Figure 37. Equivalent V
Both temperature and voltage measurements are analog
For example, if the ADT7462 is configured as Easy
The TACH is not measured using the ADC and so is not
For each ADC temperature and voltage measurement read
There are up to 13 voltage measurement channels on the
Total Conversion Time =
1 × (Local Conversion Time) +
3 × (Remote Conversion Time) +
4 × (Voltage Measurement Time)
Remote Temperature
Local Temperature
4.5pF
Channel
Voltage
V
BATT
49.5kΩ
82.7kΩ
BATT
Input Protection Circuit
3kΩ
Conversion Time (ms)
3kΩ
ADC
38.36
DIGITAL
CONTROL
9.01
8.53
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24
attenuators are disabled, the user should ensure that the
voltage on the pin never exceeds 2.25 V.
Single−Channel ADC Conversions
ADT7462 into single−channel mode. In this mode, the
ADT7462 can be made to convert on a single voltage or
temperature channel only. The channel to be converted on is
selected by writing to Bits [7:3] of the EDO
(single−channel) Enable register (0x16). When the device is
in single−channel mode, the pin configuration option should
not be changed.
Note that when the Pin 26 voltage, which includes the
V
means that voltage measurements are continuously made in
this mode. If a battery is connected to this input, this results
in an excessive current drain on the battery. The
specification of >10 years of battery life is valid only when
the battery voltage is measured as part of the round robin and
not in single−channel mode.
Dynamic VID Functionality
VID Code
VID inputs. The VID code is output on seven lines from the
CPU to tell the power controller what input voltage it
requires. The ADT7462 can monitor the VID code and the
Table 15. Voltage Attenuator Configuration Registers
Table 16. Single−Channel Mode Options
BATT
Setting Bit 2 of the EDO Enable register (0x16) places the
The ADT7462 can be configured to monitor up to seven
Configuration Register 1
Configuration Register 2
Bits [7:3]
0000 0
0000 1
0001 0
0001 1
0010 0
0010 1
0100 0
0100 1
0101 0
0101 1
1000 0
1000 1
0011 0
0011 1
0110 0
0110 1
0111 0
Voltage Attenuator
Voltage Attenuator
option, is selected in single−channel mode, this
Register Name
+1.2V2 voltage, Pin 26
Remote 1 temperature
Remote 2 temperature
Remote 3 temperature
Local temperature
+12V1 voltage, Pin 7
+12V2 voltage, Pin 8
+12V3 voltage, Pin 22
+3.3V voltage, Pin 13
+2.5V/+1.8V voltage, Pin 15
+1.25V/+0.9V voltage, Pin 19
+5V voltage, Pin 21
+1.5V/+1.8V/+2.5V voltage, Pin 23
+1.5V/+1.8V/+2.5V voltage, Pin 24
+1.2V1/+3.3V voltage, Pin 25
+1.5V1 voltage, Pin 28
+1.5V2 voltage, Pin 29
ADC Channel Selected
Register Address
0x18
0x19