ADM1021AARQ-REEL7

Manufacturer Part NumberADM1021AARQ-REEL7
DescriptionIC SENSOR TEMP DUAL3/5.5V 16QSOP
ManufacturerON Semiconductor
ADM1021AARQ-REEL7 datasheet
 


Specifications of ADM1021AARQ-REEL7

Rohs StatusRoHS non-compliantFunctionTemp Monitoring System (Sensor)
TopologyADC, Comparator, Multiplexer, Register BankSensor TypeExternal & Internal
Sensing Temperature0°C ~ 100°C, External SensorOutput TypeSMBus™
Output AlarmYesOutput FanNo
Voltage - Supply3 V ~ 5.5 VOperating Temperature0°C ~ 100°C
Mounting TypeSurface MountPackage / Case16-QSOP
1
Page 1
2
Page 2
3
Page 3
4
Page 4
5
Page 5
6
Page 6
7
Page 7
8
Page 8
9
Page 9
10
Page 10
11
12
13
14
15
Page 1/15

Download datasheet (153Kb)Embed
Next
ADM1021A
Low Cost Microprocessor
System Temperature
Monitor Microcomputer
The ADM1021A is a two−channel digital thermometer and
under/overtemperature alarm, intended for use in personal computers
and other systems requiring thermal monitoring and management. The
device can measure the temperature of a microprocessor using a
diode−connected PNP transistor, which can be provided on−chip with
the Pentium® III or similar processors, or can be a low cost discrete
NPN/PNP device, such as the 2N3904/2N3906. A novel measurement
technique cancels out the absolute value of the transistor’s base emitter
voltage so that no calibration is required. The second measurement
channel measures the output of an on−chip temperature sensor to
monitor the temperature of the device and its environment.
The ADM1021A communicates over a two−wire serial interface
compatible with SMBus standards. Under/overtemperature limits can
be programmed into the device over the serial bus, and an ALERT
output signals when the on−chip or remote temperature is out of range.
This output can be used as an interrupt or as an SMBus alert.
FEATURES
Alternative to the ADM1021
On−Chip and Remote Temperature Sensing
No Calibration Necessary
1°C Accuracy for On−Chip Sensor
3°C Accuracy for Remote Sensor
Programmable Over/Undertemperature Limits
Programmable Conversion rate
2−Wire SMBus Serial Interface
Supports System Management Bus (SMBus) Alert
200 mA Max Operating Current
1 mA Standby Current
3.0 V to 5.5 V Supply
Small 16−Lead QSOP Package
APPLICATIONS
Desktop Computers
Notebook Computers
Smart Batteries
Industrial Controllers
Telecom Equipment
Instrumentation
© Semiconductor Components Industries, LLC, 2010
June, 2010 − Rev. 8
http://onsemi.com
MARKING DIAGRAM
1
1021AA
RQZ
#YYWW
xxx
= Device Code
#
= Pb−Free Package
YYWW = Date Code
PIN ASSIGNMENT
NC
1
V
2
DD
D+
3
D–
4
ADM1021A
TOP VIEW
NC
5
ADD1
6
GND
7
GND
8
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 14 of this data sheet.
1
QSOP−16
CASE 492
NC
16
15
STBY
SCLK
14
NC
13
12
SDATA
11
ALERT
10
ADD0
NC
9
Publication Order Number:
ADM1021A/D

ADM1021AARQ-REEL7 Summary of contents

  • Page 1

    ADM1021A Low Cost Microprocessor System Temperature Monitor Microcomputer The ADM1021A is a two−channel digital thermometer and under/overtemperature alarm, intended for use in personal computers and other systems requiring thermal monitoring and management. The device can measure the temperature of a ...

  • Page 2

    ON−CHIP TEMPERATURE LOCAL TEMPERATURE SENSOR VALUE REGISTER D+ 3 A−TO−D ANALOG MUX D- CONVERTER 4 BUSY RUN/STANDBY REMOTE TEMPERATURE VALUE REGISTER EXTERNAL DIODE OPEN−CIRCUIT ADM1021A GND GND NC DD ABSOLUTE MAXIMUM ...

  • Page 3

    PIN ASSIGNMENT Pin No. Mnemonic D− ADD1 7 GND 8 GND ADD0 11 ALERT 12 SDATA SCLK 15 STBY 16 NC ELECTRICAL CHARACTERISTICS ...

  • Page 4

    ELECTRICAL CHARACTERISTICS Parameter SMBus Interface (See Figure 2) Logic Input High Voltage STBY, SCLK, SDATA Logic Input Low Voltage STBY, SCLK, SDATA SMBus Output Low Sink Current ALERT Output Low Sink Current Logic Input Current, I ...

  • Page 5

    TYPICAL PERFORMANCE CHARACTERISTICS GND –5 – –15 –20 –25 – LEAKAGE RESISTANCE (M ) Figure 3. Temperature Error vs. PC Board Track Resistance 9 100mV p−p ...

  • Page 6

    TYPICAL PERFORMANCE CHARACTERISTICS 4 3 10mV p− 100k 1M 10M 100M FREQUENCY (Hz) Figure 9. Temperature Error vs. Differential−Mode Noise Frequency 100 –20 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 SUPPLY ...

  • Page 7

    Functional Description The ADM1021A contains a two−channel A−to−D converter with special input−signal conditioning to enable operation with remote and on−chip diode temperature sensors. When the ADM1021A is operating normally, the A−to−D converter operates in free−running mode. The analog input multiplexer ...

  • Page 8

    To measure DV , the sensor is switched between BE operating currents of I and N × I. The resulting waveform is passed through a 65 kHz low−pass filter to remove noise, and then to a chopper−stabilized amplifier that performs ...

  • Page 9

    Bit flag that is set if the remote temperature sensor is open−circuit. These five flags are NOR’d together so that if any of them ...

  • Page 10

    Table 4. Configuration Register Bit Assignments Bit Name Function 7 MASK1 0 = ALERT Enabled 1 = ALERT Masked 6 RUN/STOP 0 = Run 1 = Standby Reserved Conversion Rate Register The lowest three bits of this ...

  • Page 11

    The serial bus protocol operates as follows: 1. The master initiates data transfer by establishing a start condition, defined as a high−to−low transition on the serial data line SDATA, while the serial clock line SCLK remains high. This indicates that ...

  • Page 12

    SCLK A6 SDATA A5 A4 START BY MASTER SERIAL BUS ADDRESS BYTE Figure 15. Writing to the Address Pointer Register Only 1 SCLK SDATA START BY MASTER SERIAL BUS ADDRESS BYTE Figure 16. Reading Data from ...

  • Page 13

    Once the ADM1021A has responded to the alert response address, it resets its ALERT output, provided that the error condition that caused the ALERT no longer exists. If the SMBALERT line remains low, the master sends the ARA again, ...

  • Page 14

    ... ADM1021AARQZ 0°C to +100°C ADM1021AARQZ−R 0°C to +100°C ADM1021AARQZ−R7 0°C to +100°C †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D. *The “Z’’ suffix indicates Pb−Free part. ...

  • Page 15

    ... Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner. PUBLICATION ORDERING INFORMATION LITERATURE FULFILLMENT: Literature Distribution Center for ON Semiconductor P.O. Box 5163, Denver, Colorado 80217 USA Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada Fax: 303− ...