ADM1021A

http://onsemi.com

2

Figure 1. Functional Block Diagram

ON-CHIP

TEMPERATURE

SENSOR

ANALOG

MUX

BUSY

A-TO-D

CONVERTER

LOCAL TEMPERATURE

VALUE REGISTER

RUN/STANDBY

EXTERNAL DIODE OPEN-CIRCUIT

STATUS REGISTER

SMBus INTERFACE

INTERRUPT

MASKING

ADD0

ADD1

6

10

CONVERTION RATE

REGISTER

LOCAL TEMPERATURE

LOW LIMIT REGISTER

LOCAL TEMPERATURE

HIGH LIMIT REGISTER

REMOTE TEMPERATURE

LOW LIMIT REGISTER

REMOTE TEMPERATURE

HIGH LIMIT REGISTER

CONFIGURATION

REGISTER

GND

7

2

ADM1021A

D+

ALERT

3

D− 4

REMOTE TEMPERATURE

VALUE REGISTER

ONE-SHOT

REGISTER

SCLK

14

SDATA

12

15 STBY

ADDRESS POINTER

REGISTER

LOCAL TEMPERATURE

LOW LIMIT COMPARATOR

LOCAL TEMPERATURE

HIGH LIMIT COMPARATOR

REMOTE TEMPERATURE

LOW LIMIT COMPARATOR

REMOTE TEMPERATURE

HIGH LIMIT COMPARATOR

11

NC

1

NC

5

GND

8

NC

9

NC

13

NC

16

NC = NO CONNECT

Table 1. PIN ASSIGNMENT

Pin No.

Mnemonic

Description

1

NC

No Connect

2

Positive Supply, 3.0 V to 5.5 V

3

D+

Positive Connection to Remote Temperature Sensor

4

D−

Negative Connection to Remote Temperature Sensor

5

NC

No Connect

6

ADD1

Three-state Logic Input, Higher Bit of Device Address

7

GND

Supply 0 V Connection

8

GND

Supply 0 V Connection

9

NC

No Connect

10

ADD0

Three-state Logic Input, Lower Bit of Device Address

11

ALERT

Open-drain Logic Output Used as Interrupt or SMBus ALERT

12

SDATA

Logic Input/Output, SMBus Serial Data. Open-drain Output

13

NC

No Connect

14

SCLK

Logic Input, SMBus Serial Clock

15

STBY

Logic Input Selecting Normal Operation (High) or Standby Mode (Low)

16

NC

No Connect