Rainbow Electronics MAX6659 User Manual

General Description

The MAX6657/MAX6658/MAX6659 are precise, two­channel digital temperature sensors. Each accurately
measures the temperature of its own die and one
remote PN junction, and reports the temperature in digi­tal form on a 2-wire serial interface. The remote junction
can be a diode-connected transistor like the low-cost
NPN type 2N3904 or 2N3906 PNP type. The remote
junction can also be a common-collector PNP, such as
a substrate PNP of a microprocessor.

The 2-wire serial interface accepts standard System
Management Bus (SMBus™) commands such as Write
Byte, Read Byte, Send Byte, and Receive Byte to read
the temperature data and program the alarm thresholds
and conversion rate. The MAX6657/MAX6658/
MAX6659 can function autonomously with a program­mable conversion rate, which allows the control of sup­ply current and temperature update rate to match
system needs. For conversion rates of 4Hz or less, the
temperature is represented in extended mode as 10
bits + sign with a resolution of 0.125°C. When the con­version rate is faster than 4Hz, output data is 7 bits +
sign with a resolution of 1°C. The MAX6657/
MAX6658/MAX6659 also include an SMBus timeout
feature to enhance system reliability.

Remote accuracy is ±1°C between +60°C and +100°C
with no calibration needed. The MAX6657 measures
temperatures from 0°C to +125°C and the MAX6658/
MAX6659 from -55°C to +125°C. The MAX6659 has the
added benefit of being able to select one of three
addresses through an address pin, and a second over­temperature alarm pin for greater system reliability.

Applications

Desktop Computers Workstations
Notebook Computers
Servers

Features

♦ Dual Channel: Measures Remote and Local

Temperature

♦ 11-Bit, 0.125°C Resolution

♦ High Accuracy ±1°C (max) from +60°C to +100°C

(Remote)

♦ No Calibration Required

♦ Programmable Under/Overtemperature Alarms

♦ Programmable Conversion Rate

(0.0625Hz to 16Hz)

♦ SMBus/I

2

C™-Compatible Interface

♦ Two Alarm Outputs: ALERT and OVERT1

(MAX6657 and MAX6658)

♦ Three Alarm Outputs: ALERT, OVERT1,

and OVERT2 (MAX6659)

MAX6657/MAX6658/MAX6659

±1°C, SMBus-Compatible Remote/Local Temperature

Sensors with Overtemperature Alarms

________________________________________________________________ Maxim Integrated Products 1

19-2034; Rev 1; 10/01

Ordering Information

SMBus is a trademark of Intel Corp.

I

2

C is a trademark of Philips Corp.

16

15

14

13

12

11

10

9

1

2

3

4

5

6

7

8

V

CC

N.C.

STBY

SMBCLK

N.C.

SMBDATA

N.C.

OVERT2

ALERT

TOP VIEW

MAX6659

QSOP

N.C.

DXP

OVERT1

DXN

ADD

GND

GND

ALERT

GNDOVERT1

1

2

87SMBCLK

SMBDATADXP

DXN

V

CC

SO

3

4

6

5

MAX6657
MAX6658

Pin Configurations

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Typical Operating Circuit appears at the end of the
data sheet.

PART

MAX6 657MSA -55°C to +125°C 8 SO 0°C to +125°C

MAX6 658MSA -55°C to +125°C 8 SO -55°C to +125°C

MAX6 659MEE -55°C to +125°C 16 QSOP -55°C to +125°C

TEMP.

RANGE

PIN­PACKAGE

MEASURED

TEMP. RANGE

MAX6657/MAX6658/MAX6659

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

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 in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

All Voltages Referenced to GND
V

CC

..........................................................................-0.3V to +6V

DXP ............................................................-0.3V to (V

CC

+ 0.3V)

DXN ......................................................................-0.3V to +0.8V

SMBCLK, SMBDATA, ALERT, OVERT1,

OVERT2 ..............................................................-0.3V to +6V

SMBDATA, ALERT, OVERT1, OVERT2

Current ..........................................................-1mA to +50mA

DXN Current ......................................................................±1mA

Continuous Power Dissipation (T

A

= +70°C)

8-Pin SO (derate 5.9mW/°C above +70°C) .................471mW

16-Pin QSOP (derate 8.3mW/°C above +70°C) ..........664mW

Junction Temperature .....................................................+150°C

Storage Temperature Range ............................-65°C to +150°C

Lead Temperature (soldering, 10s) ................................+300°C

ELECTRICAL CHARACTERISTICS

(Circuit of Typical Operating Circuit, VCC= +3.0V to +5.5V, TA= 0°C to +125°C, unless otherwise specified. Typical values are at
V

CC

= +3.3V and TA= +25°C.)

±1°C, SMBus-Compatible Remote/Local Temperature
Sensors with Overtemperature Alarms

Average Operating Current

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Temperature Resolution,
Legacy Mode

Temperature Resolution,
Extended Mode

TRJ = +60°C to +100°C, VCC = +3.3V

Remote Temperature Error
(MAX6657)

Local Temperature Error
(MAX6657)

Remote Temperature Error
(MAX6658/MAX6659)

Local Temperature Error
(MAX6658/MAX6659)

Line Regulation 3.0V ≤ VCC≤ 5.5V 0.2 0.6 m°C/V

Supply Voltage Range V

Undervoltage Lockout Threshold UVLO Falling edge of VCC disables ADC 2.60 2.80 2.95 V

Undervoltage Lockout Hysteresis 90 mV

Power-On Reset (POR) Threshold VCC, falling edge 1.5 2.0 2.5 V

POR Threshold Hysteresis 90 mV

Standby Supply Current SMBus static 3 10 µA

Operating Current During conversion 0.5 1.0 mA

(Note 1)

TRJ = 0°C to +100°C, VCC = +3.3V (Note 1) -3.0 +3.0

T

= 0°C to +125°C, VCC = +3.3V (Note 1) -5.0 +5.0

RJ

TA = +60°C to +100°C, VCC = +3.3V -2.0 +2.0

TA = 0°C to +100°C, VCC = +3.3V -3.0 +3.0

= 0°C to +125°C, VCC = +3.3V -5.0 +5.0

T

A

TRJ = +60°C to +100°C, VCC = +3.3V
(Note 1)

TRJ = 0°C to +100°C, VCC = +3.3V (Note 1) -3.0 3.0

= -55°C to +125°C, VCC = +3.3V (Note 1) -5.0 +5.0

T

RJ

TA = +60°C to +100°C, VCC = +3.3V -2.0 +2.0

TA = 0°C to +100°C, VCC = +3.3V -3.0 +3.0

= -55°C to +125°C, VCC = +3.3V (Note 2) -5.0 +5.0

T

A

CC

0.25 conversions/s 40 70

2 conversions/s 150 250

1°C

8 Bits

0.125 °C

11 Bits

-1.0 +1.0

-1.0 1.0

3.0 5.5 V

°C

°C

°C

°C

µA

MAX6657/MAX6658/MAX6659

_______________________________________________________________________________________ 3

Note 1: TA= +25°C to +85°C.
Note 2: If both the local and the remote junction are below T

A

= -20°C, then VCC> 3.15V.

Note 3: For conversion rates of 4Hz or slower, the conversion time doubles.
Note 4: Timing specifications guaranteed by design.
Note 5: The serial interface resets when SMBCLK is low for more than t

TIMEOUT

.

Note 6: A transition must internally provide at least a hold time to bridge the undefined region (300ns max) of SMBCLK's falling edge.

ELECTRICAL CHARACTERISTICS (continued)

(Circuit of Typical Operating Circuit, VCC= +3.0V to +5.5V, TA= 0°C to +125°C, unless otherwise specified. Typical values are at
V

CC

= +3.3V and TA= +25°C.)

±1°C, SMBus-Compatible Remote/Local Temperature

Sensors with Overtemperature Alarms

SMBus-COMPATIBLE INTERFACE (SMBCLK, SMBDATA, STBY)

SMBus-COMPATIBLE TIMING (Note 4)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Conversion Time t

Conversion Timing Error ±25 %

DXP and DXN Leakage Current In standby mode 100 nA

Remote-Diode Source Current I

(ALERT, OVERT)

Output Low Sink Current

Output High Leakage Current VOH = 5.5V 1 µA

Logic Input Low Voltage V

Logic Input High Voltage V

Input Leakage Current I

Output Low Sink Current I

Input Capacitance C

Serial Clock Frequency f

Bus Free Time Between STOP
and START Condition

START Condition Setup Time 4.7 µs

Repeat START Condition Setup
Time

START Condition Hold Time t

STOP Condition Setup Time t

Clock Low Period t

Clock High Period t

Data Setup Time t

Receive SCL/SDA Rise Time t

Receive SCL/SDA Fall Time t

Pulse Width of Spike Suppressed t

SMBus Timeout SMBDATA low period for interface reset 25 37 45 ms

CONV

LEAK

SCL

t

BUF

t

SU:STA

HD:STA

SU:STO

LOW

HIGH

HD:DAT

From stop bit to conversion completed
(Note 4)

High level 80 100 120

RJ

Low level 8 10 12

VOL = 0.4V 1

V

= 0.6V 6

OL

IL

VCC = +3.0V 2.2

IH

VCC = +5.5V 2.4

VIN = GND or V

VOL = 0.6V 6 mA

OL

IN

(Note 5) 100 kHz

90% to 90% 50 ns

10% of SMBDATA to 90% of SMBCLK 4 µs

90% of SMBCLK to 90% of SMBDATA 4 µs

10% to 10% 4.7 µs

90% to 90% 4 µs

(Note 6) 0 µs

R

F

SP

CC

95 125 156 ms

µA

mA

0.8 V

±1 µA

5pF

4.7 µs

1µs

300 ns

050ns

V

MAX6657/MAX6658/MAX6659

4 _______________________________________________________________________________________

Typical Operating Characteristics

(VCC= +3.3V, TA= +25°C, unless otherwise noted.)

4.5

4.0

3.5

3.0

2.5

3.0 4.03.5 4.5 5.0 5.5

STANDBY SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX6657 toc01

SUPPLY VOLTAGE (V)

STANDBY SUPPLY CURRENT (µA)

0.063 0.5 10.125 0.25 2 4 8 16

OPERATING SUPPLY CURRENT

vs. CONVERSION RATE

MAX6657 toc02

CONVERSION RATE (Hz)

OPERATING SUPPLY CURRENT (µA)

0

200

400

600

8Hz AND 16Hz ARE 1°C RESOLUTION

-3

-2

-1

0

1

2

3

-55 -5-30 20 45 70 95 120

MAX6659

REMOTE TEMPERATURE ERROR

vs. REMOTE-DIODE TEMPERATURE

MAX6657 toc03

TEMPERATURE (°C)

TEMPERATURE ERROR (°C)

FAIRCHILD 2N3906

-3

-2

-1

0

1

2

3

-55 -5-30 20 45 70 95 120

LOCAL TEMPERATURE ERROR

vs. DIE TEMPERATURE

MAX6657 toc04

TEMPERATURE (°C)

TEMPERATURE ERROR (°C)

1

0

-1

-2

-3
10k 1M100k 10M 100M

TEMPERATURE ERROR vs.

POWER-SUPPLY NOISE FREQUENCY

MAX6657 toc05

FREQUENCY (Hz)

TEMPERATURE ERROR (°C)

VIN = SQUARE WAVE APPLIED TO V

CC

WITH NO 0.1µF VCC CAPACITOR

1

0

-1

-2

-3

0.01k 100k1k 10M 1G

TEMPERATURE ERROR vs.

COMMON-MODE NOISE FREQUENCY

MAX6657 toc06

FREQUENCY (Hz)

TEMPERATURE ERROR (°C)

VIN = AC-COUPLED TO DXN
V

IN

= 100mVp-p

1

0

-1

-2

-3
10k 1M100k 10M 100M

TEMPERATURE ERROR vs.

DIFFERENTIAL-MODE NOISE FREQUENCY

MAX6657 toc07

FREQUENCY (Hz)

TEMPERATURE ERROR (°C)

VIN = 10mV

P-P

SQUARE WAVE

APPLIED TO DXP-DXN

-5

-4

-3

-2

-1

0

0405020 3010 60 70 80 90 100

TEMPERATURE ERROR vs.

DXP-DXN CAPACITANCE

MAX6657 toc08

DXP-DXN CAPACITANCE (nF)

TEMPERATURE ERROR (°C)

±1°C, SMBus-Compatible Remote/Local Temperature
Sensors with Overtemperature Alarms

MAX6657/MAX6658/MAX6659

_______________________________________________________________________________________ 5

Pin Description

±1°C, SMBus-Compatible Remote/Local Temperature

Sensors with Overtemperature Alarms

PIN

MAX6657
MAX6658

11V

2 3 DXP

3 4 DXN

46OVERT1

5 7, 8 GND Ground

69ALERT

7 12 SMBDATA SMBus Serial-Data Input/Output, Open-Drain

8 14 SMBCLK SMBus Serial-Clock Input

— 5 ADD

—10OVERT2

—15STBY

— 2, 11, 13, 16 N.C. Not internally connected. Do not make connections to these pins.

MAX6659

NAME FUNCTION

Supply Voltage Input, +3V to +5.5V. Bypass to GND with a 0.1µF capacitor. A 200Ω

CC

series resistor is recommended but not required for additional noise filtering. See
Typical Operating Circuit.

Combined Remote-Diode Current Source and A/D Positive Input for Remote-Diode
Channel. DO NOT LEAVE DXP FLOATING; connect DXP to DXN if no remote diode
is used. Place a 2200pF capacitor between DXP and DXN for noise filtering.

Combined Remote-Diode Current Sink and A/D Negative Input. DXN is internally
biased to one diode drop above ground.

Overtemperature Active-Low Output, Open-Drain. Output is logic low only when
temperature is above the software programmed threshold.

SMBus Alert (Interrupt) Active-Low Output, Open-Drain. Asserts when temperature
exceeds user-set limits (high or low temperature). Stays asserted until acknowledged
by either reading the Status register or by successfully responding to an Alert

ALERT

Response address. See

SMBus Address-Select Pin. The MAX6659 is set to one of three available addresses
(connect to V

Overtemperature Active-Low Output, Open-Drain. Output is logic low only when
temperature is above the software programmed threshold.

Hardware Standby Input. Temperature and comparison threshold data are retained in
standby mode. If STBY is low, the IC is put into standby mode.

, GND, or leave open). See Slave Addresses section.

CC

Interrupts.

MAX6657/MAX6658/MAX6659

Detailed Description

The MAX6657/MAX6658/MAX6659 are temperature
sensors designed to work in conjunction with a micro­processor or other intelligence in thermostatic,
process-control, or monitoring applications. Com­munication with the MAX6657/MAX6658/MAX6659
occurs through the SMBus serial interface and dedicat­ed alert pins. Two independent overtemperature alarms
(OVERT1 and OVERT2) are asserted if their software
programmed temperature thresholds are exceeded.
OVERT1 and OVERT2 can be connected to fans, a sys­tem shutdown, or other thermal management circuitry.

The MAX6657/MAX6658/MAX6659 convert tempera­tures to digital data either at a programmed rate or a
single conversion. Conversions have a 0.125°C resolu­tion (extended resolution) or 1°C resolution (legacy res­olution). Extended resolution represents temperature as

10 bits + sign bit and is available for autonomous con­versions that are 4Hz and slower and single-shot con­versions. Legacy resolution represents temperature as
7 bits + sign bit and allows for faster autonomous con­version rates of 8Hz and 16Hz.

ADC and Multiplexer

The averaging ADC integrates over a 60ms period
(each channel, typically, in the 7-bit + sign legacy
mode). Using an averaging ADC attains excellent noise
rejection.

The multiplexer automatically steers bias currents
through the remote and local diodes. The ADC and
associated circuitry measure each diode’s forward volt­age and compute the temperature based on this volt­age. If the remote channel is not used, connect DXP to
DXN. Do not leave DXP and DXN unconnected. When a
conversion is initiated, both channels are converted

6 _______________________________________________________________________________________

Functional Diagram

±1°C, SMBus-Compatible Remote/Local Temperature
Sensors with Overtemperature Alarms

V

CC

MAX6657
MAX6658
MAX6659

2

DXP

DXN

ALERT

Q

OVERT1

Q

(OVERT2)

Q

MUX

REMOTE

LOCAL

DIODE
FAULT

S

R

S

R

S

R

MAX6659 ONLY

ADC

REGISTER BANK

COMMAND BYTE

REMOTE TEMPERATURE

LOCAL TEMPERATURE

ALERT THRESHOLD

ALERT RESPONSE

ADDRESS

OVERT1 THRESHOLD

(OVERT2 THRESHOLD)

8

8

CONTROL

LOGIC

SMBus

READ

WRITE

7

ADDRESS
DECODER

( ) ARE FOR MAX6659 ONLY

(STBY)

SMBDATA

SMBCLK

(ADD)