ADT7461AR-REEL7 ON Semiconductor, ADT7461AR-REEL7 Datasheet - Page 16

ADT7461AR-REEL7

Manufacturer Part Number

ADT7461AR-REEL7

Description

IC SENSOR TEMP 2-CH 8SOIC

Manufacturer

ON Semiconductor

Datasheet

1.ADT7461AR-REEL7.pdf (23 pages)

Specifications of ADT7461AR-REEL7

Rohs Status

RoHS non-compliant

Function

Temp Monitoring System (Sensor)

Topology

ADC, Comparator, Multiplexer, Register Bank

Sensor Type

External & Internal

Sensing Temperature

0°C ~ 127°C, External Sensor

Output Type

SMBus™

Output Alarm

Yes

Output Fan

Yes

Voltage - Supply

3 V ~ 5.5 V

Operating Temperature

-40°C ~ 120°C

Mounting Type

Surface Mount

Package / Case

8-SOIC (3.9mm Width)

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ADT7461

When reading data from a register there are two possibilities.

If the ADT7461’s address pointer register value is unknown

or not the desired value, it is necessary to set it to the

correct value before data can be read from the desired data

but only the data byte containing the register read address

is sent, since data is not to be written to the register. This is

shown in Figure 18.

A read operation is then performed consisting of the serial

bus address, R/W bit set to 1, followed by the data byte

read from the data register. This is shown in Figure 19.

If the address pointer register is known to be at the desired

address, data can be read from the corresponding data

SDATA

SCLK

START BY

MASTER

SDATA

SCLK

Figure 17. Writing a Register Address to the Address Pointer Register, then Writing Data to the Selected Register

START BY

MASTER

START BY

MASTER

SERIAL BUS ADDRESS BYTE

FRAME 1

SERIAL BUS ADDRESS BYTE

FRAME 1

Figure 18. Writing to the Address Pointer Register Only

Figure 19. Reading from a Previously Selected Register

SDATA (CONTINUED)

SCLK (CONTINUED)

Rev. 3 | Page 16 of 23 | www.onsemi.com

A0 R/W

R/W

ADT7461

ACK. BY

R/W

ACK. BY

ADT7461

ACK. BY

Although it is possible to read a data byte from a data register

without first writing to the address pointer register, if the

address pointer register is already at the correct value, it is not

possible to write data to a register without writing to the

address pointer register because the first data byte of a write is

always written to the address pointer register.

Also, some of the registers have different addresses for read and

write operations. The write address of a register must be written

to the address pointer if data is to be written to that register, but

it may not be possible to read data from that address. The read

address of a register must be written to the address pointer

before data can be read from that register.

ADDRESS POINTER REGISTER BYTE

and the bus transaction shown in Figure 18 can be omitted.

ADDRESS POINTER REGISTER BYTE

DATA BYTE FROM ADT7461

DATA BYTE

FRAME 3

FRAME 2

ADT7461

ACK. BY

ADT7461

ACK. BY

ADT7461

ACK. BY

NACK. BY

STOP BY

MASTER

STOP BY

MASTER

STOP BY

MASTER

ADT7461AR-REEL7 ON Semiconductor, ADT7461AR-REEL7 Datasheet - Page 16

ADT7461AR-REEL7

Specifications of ADT7461AR-REEL7

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