ADT7482 データシートの表示（PDF） - ON Semiconductor
部品番号
コンポーネント説明
メーカー
ADT7482 Datasheet PDF : 20 Pages
| |||
ADT7482
The ADT7482 has two temperature data formats. When
the temperature measurement range is from 0°C to 127°C
(default), the temperature data format for both local and
remote temperature results is binary.
Table 3. Temperature Data Format
(Local and Remote Temperature High Byte)
Temperature
Binary
Offset Binary
(Note 1)
−55°C
0 000 0000
(Note 2)
0 000 1001
0°C
0 000 0000
0 100 0000
+1°C
0 000 0001
0 100 0001
+10°C
0 000 1010
0 100 1010
+25°C
0 001 1001
0 101 1001
+50°C
+75°C
+100°C
+125°C
0 011 0010
0 100 1011
0 110 0100
0 111 1101
0 111 0010
1 000 1011
1 010 0100
1 011 1101
+127°C
0 111 1111
1 011 1111
+150°C
0 111 1111
(Note 3)
1 101 0110
1. Offset binary scale temperature values are offset by +64.
2. Binary scale temperature measurement returns 0 for all
temperatures <0°C.
3. Binary scale temperature measurement returns 127 for all
temperatures >127°C.
Registers
The registers in the ADT7482 are 8−bits wide. These
registers are used to store the results of remote and local
temperature measurements and high and low temperature
limits and to configure and control the device. A description
of these registers follows.
Address Pointer Register
The address pointer register itself does not have, or
require, an address, as the first byte of every write operation
is automatically written to this register. The data in this first
byte always contains the address of another register on the
ADT7482, which is stored in the address pointer register. It
is to this register address that the second byte of a write
operation is written to or to which a subsequent read
operation is performed.
The power−on default value of the address pointer register
is 0x00. Therefore, if a read operation is performed
immediately after power−on, without first writing to the
address pointer, the value of the local temperature is
returned, since its register address is 0x00.
Configuration Registers
There are two configuration registers used to control the
operation of the ADT7482. Configuration 1 register is at
Address 0x03 for reads and Address 0x09 for writes. See
Table 4 for details regarding the operation of this register.
Configuration 2 Register is at Address 0x24 for both reads
and writes. Setting Bit 7 of this register locks all lockable
registers. The affected registers can only be modified if the
ADT7482 is powered down and powered up again. See
Table 11 for a list of the registers affected by the lock bit.
Temperature Value Registers
The ADT7482 has five registers to store the results of
local and remote temperature measurements. These
registers can only be written to by the ADC and can be read
over the SMBus.
• The local temperature value register is at Address 0x00.
• The Remote 1 temperature value high byte register is at
Address 0x01; the Remote 1 low byte register is at
Address 0x10.
• The Remote 2 temperature value high byte register is at
Address 0x30; the Remote 2 low byte register is at
Address 0x33.
• The Remote 2 temperature values can be read from
Addresses 0x01 for the high byte and Address 0x10 for
the low byte if Bit 3 of Configuration Register 1 is set
to 1.
• To read the Remote 1 temperature values, set Bit 3 of
Configuration Register 1 to 0.
• The power−on default for all five registers is 0x00.
Table 4. Configuration 1 Register (Read Address 0x03, Write Address 0x09)
Bit Mnemonic
Function
7
Mask
Setting this bit to 1 masks all ALERTs on the ALERT pin. Default = 0 = ALERT enabled. This applies only if Pin 8 is
configured as ALERT, otherwise it has no effect.
6 Mon/STBY Setting this bit to 1 places the ADT7482 in standby mode, that is, it suspends all temperature measurements
(ADC). The SMBus remains active and values can be written to, and read from, the registers. THERM and ALERT
are also active in standby mode. Changes made to the limit registers in standby mode that effect the THERM or
ALERT outputs cause these signals to be updated. Default = 0 = temperature monitoring enabled.
5
AL/TH
This bit selects the function of Pin 8. Default = 0 = ALERT. Setting this bit to 1 configures Pin 8 as the THERM2 pin.
4
Reserved Reserved for future use.
3
Remote 1 Setting this bit to 1 enables the user to read the Remote 2 values from the Remote 1 registers. When default = 0,
/Remote2 Remote 1 temperature values and limits are read from these registers.
2
Temp
Setting this bit to 1 enables the extended temperature measurement range of −50°C to +150°C.
Range
Default = 0 = 0°C to +127°C.
1
Mask R1 Setting this bit to 1 masks ALERTs due to the Remote 1 temperature exceeding a programmed limit. Default = 0.
0
Mask R2 Setting this bit to 1 masks ALERTs due to the Remote 2 temperature exceeding a programmed limit. Default = 0.
http://onsemi.com
9
Share Link: 