ADT7421ARMZ-RL7 ON Semiconductor, ADT7421ARMZ-RL7 Datasheet - Page 11

• Manufacturer Part Number: ADT7421ARMZ-RL7
• Description: IC TEMP MONITOR 8-MSOP
• Manufacturer: ON Semiconductor
• Type: Temperature Sensorr

Specifications of ADT7421ARMZ-RL7

• Input Type: Logic
• Output Type: Logic
• Interface: 2-Wire SMBus
• Current - Supply: 4mA
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Full Temp Accuracy: +/- 2.75 C, +/- 3.25 C
• Digital Output - Bus Interface: Serial (2-Wire)
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 8. List of Registers
Serial Bus Interface
The ADT7421 is connected to this bus as a slave device,
under the control of a master device.
is enabled, the SMBus times out after typically 25 ms of no
activity. However, this feature is not enabled by default.
Bits 6
(Address = 0x22) should be set to enable it.
Addressing the Device
address, except for some devices that have extended 10−bit
addresses. When the master device sends a device address
over the bus, the slave device with that address responds.
The ADT7421is available with one device address, 0x4C
(1001 100b). The ADT7421−2 is also available.
101b). This is to allow two ADT7421 devices on the same
bus, or if the default address conflicts with an existing device
on the SMBus. The serial bus protocol operates as follows:
condition, defined as a high−to−low transition on SDATA,
the serial data line, while SCLK, the serial clock line,
Read Address
Control of the ADT7421 is carried out via the serial bus.
The ADT7421 has an SMBus timeout feature. When this
In general, every SMBus device has a 7−bit device
The ADT7421−2 has an SMBus address of 0x4D (1001
The master initiates a data transfer by establishing a start
Not Applicable
Not Applicable
(Hex)
3D
FE
FF
00
01
02
03
04
05
06
07
08
10
11
12
13
14
19
20
21
22
and
7
of
Write Address
Not Applicable
Not Applicable
Not Applicable
Not Applicable
Not Applicable
Not Applicable
Not Applicable
Not Applicable
the
(Hex)
0A
0B
0C
0D
0E
0F
09
11
12
13
14
19
20
21
22
consecutive
Address Pointer
Local Temperature Value
External Temperature Value High Byte
Status
Configuration
Conversion Rate
Local Temperature High Limit
Local Temperature Low Limit
External Temperature High Limit High Byte
External Temperature Low Limit High Byte
One−Shot
External Temperature Value Low Byte
External Temperature Offset High Byte
External Temperature Offset Low Byte
External Temperature High Limit Low Byte
External Temperature Low Limit Low Byte
External THERM Limit
Local THERM Limit
THERM Hysteresis
Consecutive ALERT
Device ID
Manufacturer ID
Die Revision Code
alert
register
http://onsemi.com
Name
11
remains high. This indicates that an address/data stream
follows. All slave peripherals connected to the serial bus
respond to the start condition and shift in the next eight bits,
consisting of a 7−bit address (MSB first) plus an R/W bit,
which determines the direction of the data transfer, that is,
whether data is written to, or read from, the slave device. The
peripheral whose address corresponds to the transmitted
address responds by pulling the data line low during the low
period before the ninth clock pulse, known as the
acknowledge bit. All other devices on the bus remain idle
while the selected device waits for data to be read from or
written to it. If the R/W bit is a 0, the master writes to the
slave device. If the R/W bit is a 1, the master reads from the
slave device.
1. Data is sent over the serial bus in a sequence of
nine clock pulses, eight bits of data followed by an
acknowledge bit from the slave device. Transitions
on the data line must occur during the low period
of the clock signal and remain stable during the
high period, since a low−to−high transition when
the clock is high can be interpreted as a stop
signal. The number of data bytes that can be
transmitted over the serial bus in a single read or
0000 0000
0000 0000
0000 1000
0000 1000
0101 0101
0000 0000
0101 0101
0000 0000
0000 0000
0000 0000
0000 0000
0000 0000
0000 0000
0101 0101
0101 0101
0000 1010
0000 0001
0010 0001
0100 0001
Undefined
Undefined
Binary
Power−On Default
0x0A
0x00
0x00
0x08
0x06
0x55
0x00
0x55
0x00
0x00
0x00
0x00
0x00
0x00
0x55
0x55
0x01
0x21
0x41
Hex
Decimal
85°C
85°C
85°C
85°C
10°C
0°C
0°C