EVAL-ADT7463EB ON Semiconductor, EVAL-ADT7463EB Datasheet - Page 47

• Manufacturer Part Number: EVAL-ADT7463EB
• Manufacturer: ON Semiconductor

Specifications of EVAL-ADT7463EB

• Lead Free Status / RoHS Status: Supplier Unconfirmed

Bit
0
1
2
3
4
5
6
7
*This register becomes read-only when the Configuration Register 1 Lock bit is set to 1. Any further attempts to write to this register will have no effect.
REV. C
Name
AIN1
AIN2
AIN3
AIN4
AVG
ATTN
CONV
SHDN
Table XXXI. Register 0x73 – Configuration Register 2 (Power-On Default = 0x00)
R/W*
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Description
AIN1 = 0, Speed of 3-wire fans measured using the TACH output from the fan.
AIN1 = 1, Pin 11 is reconfigured to measure the speed of 2-wire fans using an external
sensing resistor and coupling capacitor. AIN voltage threshold is set via Configuration
Register 4 (Reg. 0x7D).
AIN2 = 0, Speed of 3-wire fans measured using the TACH output from the fan.
AIN2 = 1, Pin 12 is reconfigured to measure the speed of 2-wire fans using an external
sensing resistor and coupling capacitor. AIN voltage threshold is set via Configuration
Register 4 (Reg. 0x7D).
AIN3 = 0, Speed of 3-wire fans measured using the TACH output from the fan.
AIN3 = 1, Pin 9 is reconfigured to measure the speed of 2-wire fans using an external
sensing resistor and coupling capacitor. AIN voltage threshold is set via Configuration
Register 4 (Reg. 0x7D).
AIN4 = 0, Speed of 3-wire fans measured using the TACH output from the fan.
AIN4 = 1, Pin 14 is reconfigured to measure the speed of 2-wire fans using an external
sensing resistor and coupling capacitor. AIN voltage threshold is set via Configuration
Register 4 (Reg. 0x7D).
AVG = 1, Averaging on the temperature and voltage measurements is turned off. This
allows measurements on each channel to be made much faster.
ATTN = 1, the ADT7463 removes the attenuators from the 2.5 V, V
12 V inputs. The inputs can be used for other functions such as connecting up external
sensors.
CONV = 1, the ADT7463 is put into a single-channel ADC conversion mode. In this
mode, the ADT7463 can be made to read continuously from one input only, e.g.,
Remote 1 Temperature. It is also possible to start ADC conversions using an external
clock on Pin 11 by setting Bit 2 of Test Register 2 (Reg. 0x7F). This mode could be
useful if, for example, users wanted to characterize/profile CPU temperature quickly.
The appropriate ADC channel is selected by writing to Bits <7:5> of TACH1 Min High
Byte Register (0x55).
Bits <7:5> Reg 0x55
000
001
010
011
100
101
110
111
SHDN = 1, ADT7463 goes into shutdown mode. All PWM outputs assert low (or high
depending on state of INV bit) to switch off all fans. The PWM current duty cycle
registers read 0x00 to indicate that the fans are not being driven.
–47–
Channel Selected
2.5 V
V
V
5 V
12 V
Remote 1 Temperature
Local Temperature
Remote 2 Temperature
CCP
CC
(3.3 V)
CCP
ADT7463
, 5 V, and