Texas Instruments THMC10DBQR Datasheet

THMC10

REMOTE/LOCAL TEMPERATURE MONITOR

WITH SMBus INTERFACE

SLIS089 – DECEMBER 1999

1

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

D

T wo-Wire SMBus Serial Interface

D

On-Chip and External Diode-Connected
Transistor Temperature Monitoring
– ±2.5°C Accuracy for On-Die
– ±3°C Accuracy for External

D

Programmable Under/Overtemperature
Limits

D

Under/Overtemperature Interrupt Signal to
Host Controller

D

Low Operating Current ...35 µA (Average)

D

Low Standby Current ...3 µA

D

3-V to 3.6-V Supply Voltage Range

description

The THMC10 is a dual digital temperature monitor with under/overtemperature alerts intended for use in
personal computer systems or any other system requiring local as well as remote temperature monitoring and
management (e.g., servers and workstations). The device may be used in smart battery applications and
memory modules. The device is designed to measure the temperature on a microprocessor using a
diode-connected transistor on the microprocessor die, such as the one present on the Intel



Pentium II, III,
and the Sun UltraSP ARC. The device may also be used with a low-cost, diode-connected, discrete transistor,
such as a 2N3904 or 2N3906, for remote temperature sensing applications.

The THMC10 uses a two-current measurement technique on a single diode-connected transistor that cancels
the absolute value of the remote transistor’s VBE; therefore, no calibration is needed. The second channel
measures an on-chip temperature sensor which can be used to monitor the ambient temperature in the
THMC10’s operating environment.

The THMC10 uses a two-wire, SMBus interface to report temperature in an 8-bit, 2s complement format in °C.
Under/overtemperature limits for both the on-chip and remote temperature sensors are user programmable via
the SMBus interface. The ALERT

terminal can be used as an interrupt or SMBus alert function to indicate

under/overtemperature. The STBY terminal and the

start/stop

bit in the SMBus interface allow the device to

enter a low current standby mode (typically <10 µA).
The THMC10 also provides diagnostics via the ALERT terminal and the SMBus interface for an open remote

sensor connection or if the sensor connection is shorted to V

DD.

Copyright  1999, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

Intel and Pentium are registered trademarks of Intel Corporation.
Sun is a registered trademark and UltraSPARC is a trademark of Sun Microsystems.

1
2
3
4
5
6
7
8

16
15
14
13
12
11
10

9

N/C

V

DD

DXP
DXN

N/C

ADD1

GND
GND

N/C
STBY
SCLK
N/C
SDATA
ALERT
ADD0
N/C

SSOP DBQ Package

(TOP VIEW)

THMC10

THMC10
REMOTE/LOCAL TEMPERATURE MONITOR
WITH SMBus INTERFACE

SLIS089 – DECEMBER 1999

2

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

schematic/block diagram

Interrupt
Masking

GND

STBY

DXP

Configuration

Register

High Limit

Register

Low Limit

Register

High Limit

Register

Low Limit

Register

Auto-Acquire

Rate Register

ADDR Pointer

Register

One-Shot

Register

Low Limit

Comparator

High Limit

Comparator

Status

Register

8-Bit A/D

Converter

Power-up

Clear

On-Chip

Temp

Sensor

Analog

MUX

Local Temp

Register

Remote Temp

Register

Low Limit

Comparator

High Limit

Comparator

SDATA

SMBus Interface

DXN

ALERT

V

DD

To All Registers

SCLK ADD0 ADD1

THMC10

REMOTE/LOCAL TEMPERATURE MONITOR

WITH SMBus INTERFACE

SLIS089 – DECEMBER 1999

3

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

Terminal Functions

TERMINAL

NAME NO.

I/O

DESCRIPTION

ADD0 10 I SMBus address select terminal 0 (Note: Excess capacitance on this terminal may cause SMBus address

recognition problems.)

ADD1 6 I SMBus address select terminal 1 (Note: Excess capacitance on this terminal may cause SMBus address

recognition problems.)
ALERT 11 O Active low temperature interrupt signal
DXN 4 I/O Current sink for external diode connected transistor and A/D negative input (Do not leave floating if no external

diode is used – should be tied to GND.)
DXP 3 I/O Current source for external diode connected transistor and A/D positive input
GND 7, 8 I IC ground
N/C 1, 5, 9,

13, 16

N/C No connection

SCLK 14 I SMBus serial clock input terminal – clock signal for SMBus serial data
SDATA 12 I/O SMBus serial data I/O terminal – serial data I/O for SMBus
STBY 15 I Active low standby mode input
V

DD

2 I IC supply voltage – should be decoupled with external 0.1 µF capacitor

absolute maximum ratings over operating case temperature (see Note 1) (unless otherwise noted)

†

Input voltage on: VDD supply terminal, V

(DDIN)

–0.3 V to 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

I/O terminals, V

(IOIN)

–0.3 V to V

DD

+ 0.3 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SMBus terminals, V

(SMBIN)

–0.3 V to 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DXN terminal, V

(DXN)

–0.3 V to 0.8 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SMBus input/output current, I

(SMBIN)

–1 mA to 50 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DXN input current, I

(DXN)

–1 mA to 1 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Continuous power dissipation, P

D

330 mW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating case temperature range, TC –55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Storage temperature, T

stg

–65°C to 165°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Junction temperature, TJ 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lead temperature (soldering, 10 sec), T

(LEAD)

300°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

†

Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

NOTE 1: All voltage values are with respect to GND.

recommended operating conditions

MIN MAX UNITS

Supply voltage, V

DD

3 3.6 V

SMBus input high voltage, V

IH

2.2 V

SMBus input low voltage, V

IL

0.8 V

SMBus operating frequency, f

(SCLK)

10 100 kHz

Operating ambient temperature, T

A

0 85 °C

THMC10
REMOTE/LOCAL TEMPERATURE MONITOR
WITH SMBus INTERFACE

SLIS089 – DECEMBER 1999

4

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

dc electrical characteristics, VDD = 3.3 V, TA = 25°C (unless otherwise noted)

A/D and supply

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

T

(RES)

T emperature resolution No missed codes 1 °C
Initial temperature error from internal

TA = 60°C to 100°C –2 2

°

T

(ERR1)

diode

TA = full range

–3 3

°C

Initial temperature error from external

TA = 60°C to 100°C –2.5 2.5

°

T

(ERR2)

diode (see Note 2)

TA = full range

–3.5 3.5

°C

V

(UVLOCK)

Under voltage lockout voltage VDD input, disables acquisition, rising edge 2.65 2.8 2.95 V

V

(POR)

Power-up reset threshold On VDD input, falling edge 1 2.25 2.5 V

pp

Logic inputs forced to VDD or GND,
STBY

mode, SMBus is static

3 10 µA

I

(DD,STANDBY)VDD

standby supply current

Logic inputs forced to VDD or GND,
STBY

mode, SCLK = 10 kHz

4 µA

VDD operating supply current (aver-

Slow auto-aquire rate (0.25 samples/sec) 40 70

I

DD

aged over 4 seconds in auto-acquire
mode)

Fast auto-aquire rate (2 samples/sec)

45 180

µ

A

V

(D,SOURCE)

DXN source voltage 0.7 V

I

(DLEAK)

DXP and DXN leakage current STBY = 0, DXP = DXN = 0 2 µA

I

(ADD,BIAS)

Add {0:1} bias current Momentary on power up 35 100 µA

DXP = 1.5 V, high level 100

I

(DIODE)

Diode source current

DXP = 1.5 V , low level 10

µ

A

I

(RATIO)

Diode source current ratio

DXP+1.5 V,

high level

low level

9.7 10 10.2

BasedonT(°C)

+

q

ǒ

D

V

BE

Ǔ

nk[ln(10

)]

*

273

Where

q = 1.6 × 10

–19

(charge)
n = 1.0085 (diode ideality factor)
k = 1.38 × 10

–23

(Boltzman’s constant)

NOTE 2:

SMBus

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

V

IH

Input high voltage 2.2 V

V

IL

Input low voltage 0.8 V

I

OL1

SMBus output low current SDATA = 0.6 V 6 mA

I

OL2

ALERT output low current ALERT = 0.4 V 1 mA

I

I

SMBus input current –1 1 µA

THMC10

REMOTE/LOCAL TEMPERATURE MONITOR

WITH SMBus INTERFACE

SLIS089 – DECEMBER 1999

5

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

ac electrical characteristics, VDD = 3.3 V, TA = 25°C (unless otherwise noted)

A/D and supply

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

t

(CONV)

One-shot conversion time

One-shot mode from SMBus stop bit to temperature
conversion completed (both channels)

12 ms

Acquisition rate accuracy Auto-aquire mode –25% 25%

SMBus

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

f

(SCLK

) SCLK operating frequency See Figure 1 10 100 kHz

t

(BUF)

Bus free time between stop and start condition See Figure 1 4.7 µs

t

(HDSTA)

Hold time after (repeated) start condition. After this period, the
first clock is generated

See Figure 1 4 µs

t

(SUSTA)

Repeated start condition setup time See Figure 1 4.7 µs

t

(SUSTO)

Stop condition setup time See Figure 1 4 µs

t

(HDDAT)

Data hold time See Figure 1 300 ns

t

(SUDAT)

Data setup time See Figure 1 250 ns

t

(LOW)

SCLK clock low period See Figure 1 4.7 µs

t

(HIGH)

SCLK clock high period See Figure 1 4 50 µs

t

(LOWSEXT)

Cumulative clock low extend time (slave device) See Figure 1 25 ms

t

(LOWMEXT)

Cumulative clock low extend time (master device) See Figure 1 10 ms

t

F

Clock/data fall time See Figure 1 300 ns

t

R

Clock/data rise time See Figure 1 1000 ns

THMC10
REMOTE/LOCAL TEMPERATURE MONITOR
WITH SMBus INTERFACE

SLIS089 – DECEMBER 1999

6

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

PARAMETER MEASUREMENT INFORMATION

SMBus timing diagrams

PS

t

(HDSTA)

t

(HDDAT)

t

(HIGH)

t

(SUDAT)

t

(SUSTA)

t

(HDSTA)

t

(SUSTO)

SP

SCLK

SDATA

Start

Stop

SCLK

ACK

SCLK

ACK

t

(LOWMEXT)

SCLK

SDATA

t

(LOW)

t

(LOWSEXT)

t

F

t

R

t

(BUF)

t

(LOWMEXT)

t

(LOWMEXT)

Figure 1. SMBus Timing Diagram

Frame 3 Data Byte

Frame 1 SMBus Slave Address Byte

Frame 2 Address Pointer Register Byte

A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0R/W

SCLK

SDATA

Start By

Master

ACK By

THMC10

ACK By

THMC10

D7 D6 D5 D4 D3 D2 D1 D0

ACK By

THMC10

SCLK

(Continued)

SDATA

(Continued)

1

91 9

1

9

Stop By
Master

Figure 2. SMBus Timing Diagram for Write Byte Format