Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsMAX6698EE38+

General Description

The MAX6698 precision multichannel temperature sen-

sor monitors its own temperature, the temperatures of

three external diode-connected transistors, and the

temperatures of three thermistors. All temperature

channels have programmable alert thresholds.

Channels 1, 4, 5, and 6 also have programmable over-

temperature thresholds. When the measured tempera-

ture of a channel exceeds the respective threshold, a

status bit is set in one of the status registers. Two open-

drain outputs, OVERT and ALERT, assert correspond-

ing to these bits in the status register.

The 2-wire serial interface supports the standard system

management bus (SMBus™) protocols: write byte, read

byte, send byte, and receive byte for reading the tem-

perature data and programming the alarm thresholds.

The MAX6698 is specified for an operating temperature

range of -40°C to +125°C and is available in 16-pin

QSOP and 16-pin TSSOP packages.

Applications

Desktop Computers Workstations

Notebook Computers Servers

Features

♦ Three Thermal-Diode Inputs and Three Thermistor

Inputs

♦ Local Temperature Sensor

♦ 1°C Remote Temperature Accuracy (+60°C to

+100°C)

♦ Temperature Monitoring Begins at POR for Fail-

Safe System Protection

♦ ALERT and OVERT Outputs for Interrupts,

Throttling, and Shutdown

♦ Small 16-Pin QSOP and 16-Pin TSSOP Packages

♦ 2-Wire SMBus Interface

MAX6698

7-Channel Precision Remote-Diode, Thermistor,

and Local Temperature Monitor

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

+3.3V

EX3

THER3

GND

SMBCLK

SMBDATA

DXN2

DXP2

DXN1

DXP1

THER1

THER2VREF

THER3

DXN3

DXP3

MAX6698

ALERT

OVERT

EX2

THER2

EX1

THER1

Typical Application Circuit

19-3476; Rev 3; 8/07

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

EVALUATION KIT

AVAILABLE

PART TEMP RANGE

PIN-

PACKAGE

PKG

CODE

MAX6698EE_ _

-40°C to +125°C

16 QSOP

E16-1

MAX6698UE_ _

-40°C to +125°C

16 TSSOP

U16-1

SMBus is a trademark of Intel Corp.

Pin Configuration appears at end of data sheet.

*See the Slave Address section.

Summary of content (24 pages)

PAGE 1
9-3476; Rev 3; 8/07 KIT ATION EVALU E L B AVAILA 7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor Features The MAX6698 precision multichannel temperature sensor monitors its own temperature, the temperatures of three external diode-connected transistors, and the temperatures of three thermistors. All temperature channels have programmable alert thresholds. Channels 1, 4, 5, and 6 also have programmable overtemperature thresholds.
PAGE 2
MAX6698 7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor ABSOLUTE MAXIMUM RATINGS VCC, SCL, SDA, ALERT, OVERT to GND ................-0.3V to +6V DXP_ to GND..............................................-0.3V to (VCC + 0.3V) DXN_ to GND ........................................................-0.3V to +0.8V THER_ to GND..........................................................-0.3V to +6V VREF to GND............................................................-0.
PAGE 3
7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor (VCC = +3.0V to +5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25°C.) (Note 1) PARAMETER SYMBOL Reference-Load Regulation CONDITIONS MIN TYP 0mA < IREF < 2mA Reference-Supply Rejection MAX UNITS 0.4 % 0.5 %/V ALERT, OVERT Output Low Voltage VOL ISINK = 1mA 0.3 ISINK = 6mA 0.5 Output Leakage Current V 1 µA 0.
PAGE 4
Typical Operating Characteristics (VCC = 3.3V, TA = +25°C, unless otherwise noted.) 350 345 340 335 330 3 2 1 0 0 -1 -2 -3 325 -4 320 4.8 3.3 5.3 3.8 2 1 0 -1 -2 -3 -4 100mVP-P 3 2 1 0 -1 -2 50 75 100 1 0 -1 -2 -5 0.001 0.01 0.1 FREQUENCY (MHz) REMOTE TEMPERATURE ERROR vs. COMMON-MODE NOISE FREQUENCY MAX6698 toc07 5 4 TEMPERATURE ERROR (°C) TEMPERATURE ERROR (°C) 100mVP-P FREQUENCY (MHz) 3 2 1 0 -1 -2 -3 100mVP-P 3 2 1 0 -1 -2 -3 -4 -4 -5 0.001 -5 0.001 0.01 0.
PAGE 5
7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor -1.5 -2.0 -2.5 -3.0 -3.5 -4.0 VOL = 0.3V 25 20 15 VOL = 0.1V 10 MAX6698 toc11 MAX6698 toc10 -1.0 5 100mVP-P 4 TEMPERATURE ERROR (°C) TEMPERATURE ERROR (°C) -0.5 30 ALERT SINK CURRENT (mA) MAX6698 toc09 0 THERMISTOR ADC ERROR vs. POWER-SUPPLY NOISE FREQUENCY ALERT, OVERT SINK CURRENT vs. TEMPERATURE TEMPERATURE ERROR vs. DXP-DXN CAPACITANCE 3 2 1 0 -1 -2 -3 5 -4 -4.5 -5 0 -5.
PAGE 6
7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor MAX6698 Pin Description (continued) PIN NAME FUNCTION 9 THER2 Thermistor Voltage Sense Input 2. Connect thermistor 2 between THER2 and ground and an external resistor REXT3 between THER2 and VREF. 10 THER1 Thermistor Voltage Sense Input 1. Connect thermistor 1 between THER1 and ground and an external resistor REXT3 between THER1 and VREF. 11 OVERT Overtemperature Active-Low, Open-Drain Output.
PAGE 7
-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor 10/100µA DXP1 OVERT MAX6698 DXN1 3-TO-1 MUX DXP3 INPUT BUFFER ALU DP ALERT DXN3 BUF1 VREF ADC CNT COMMAND BYTE COUNTER VREF1 REGISTER BANK REMOTE TEMPERATURES LOCAL TEMPERATURES REXT1 ALERT THRESHOLD OVERT THRESHOLD RTHER1 ALERT RESPONSE ADDRESS SMBus INTERFACE REXT2 3-TO-1 MUX BUF2 RTHER1 REXT1 RTHER1 SCL SDA Figure 1.
PAGE 8
MAX6698 7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor Write Byte Format S ADDRESS WR ACK COMMAND 7 bits ACK DATA 8 bits Slave Address: equivalent to chip-select line of a 3-wire interface ACK P 8 bits Command Byte: selects which register you are writing to 1 Data Byte: data goes into the register set by the command byte (to set thresholds, configuration masks, and sampling rate) Read Byte Format S ADDRESS WR ACK 7 bits COMMAND ACK ACK DATA /// P 8 bi
PAGE 9
7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor B tLOW C D E F G H tHIGH I J K L MAX6698 A M SMBCLK SMBDATA tSU:STA tHD:STA tSU:STO tSU:DAT A = START CONDITION B = MSB OF ADDRESS CLOCKED INTO SLAVE C = LSB OF ADDRESS CLOCKED INTO SLAVE D = R/W BIT CLOCKED INTO SLAVE E = SLAVE PULLS SMBDATA LINE LOW F = ACKNOWLEDGE BIT CLOCKED INTO MASTER G = MSB OF DATA CLOCKED INTO SLAVE H = LSB OF DATA CLOCKED INTO SLAVE tBUF I = MASTER PULLS DATA LINE LOW J = ACKNOWLEDGE
PAGE 10
MAX6698 7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor ALERT Interrupt Mode An ALERT interrupt occurs when the internal or external temperature reading exceeds a high-temperature limit (user programmable). The ALERT interrupt output signal can be cleared by reading the status register(s) associated with the fault(s) or by successfully responding to an alert response address transmission by the master.
PAGE 11
7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor MAX6698 Table 4.
PAGE 12
MAX6698 7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor Table 5. Configuration 1 Register BIT NAME POR STATE 7(MSB) STOP 0 Standby Mode Control Bit. If STOP is set to logic 1, the MAX6698 stops converting and enters standby mode. 6 POR 0 Reset Bit. Set to logic 1 to put the device into its power-on state. This bit is selfclearing. 5 TIMEOUT 0 Timeout Enable Bit. Set to logic 0 to enable SMBus timeout. FUNCTION 4 Fast remote 1 0 Channel 1 Fast Conversion Bit.
PAGE 13
7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor BIT NAME POR STATE FUNCTION 7(MSB) Reserved 0 — 6 Reserved 0 — 5 Mask Thermistor 3 OVERT 0 Thermistor 3 OVERT Mask Bit. Set to logic 1 to mask thermistor 3 OVERT. 4 Mask Thermistor 2 OVERT 0 Thermistor 2 OVERT Mask Bit. Set to logic 1 to mask thermistor 2 OVERT. 3 Mask Thermistor 1 OVERT 0 Thermistor 1 OVERT Mask Bit. Set to logic 1 to mask thermistor 1 OVERT.
PAGE 14
MAX6698 7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor Table 8. Status 1 Register BIT NAME POR STATE FUNCTION 7(MSB) Reserved 0 — 6 Local ALERT 0 Local Channel High-Alert Bit. This bit is set to logic 1 when the local temperature exceeds the temperature threshold limit in the local ALERT high-limit register. 5 Thermistor 3 ALERT 0 Thermistor 3 Alert Bit.
PAGE 15
7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor BIT NAME POR STATE 7(MSB) Reserved 0 — 6 Reserved 0 — MAX6698 Table 9. Status 2 Register FUNCTION 5 Thermistor 3 OVERT 0 Thermistor 3 Overtemperature Status Bit. This bit is set to logic 1 when the thermistor 3 voltage exceeds the threshold limit in the thermistor 3 OVERT high-limit register. 4 Thermistor 2 OVERT 0 Thermistor 2 Overtemperature Status Bit.
PAGE 16
MAX6698 7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor Table 11. Remote-Sensors Transistor Manufacturers MANUFACTURER MODEL NO. Central Semiconductor (USA) CMPT3904 Rohm Semiconductor (USA) SST3904 Samsung (Korea) KST3904-TF Siemens (Germany) SMBT3904 Zetex (England) FMMT3904CT-ND Note: Discrete transistors must be diode connected (base shorted to collector). Slave Addresses Table 12 lists the MAX6698 slave addresses. Table 12.
PAGE 17
7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor 5) Use wide traces when practical. 6) When the power supply is noisy, add a resistor (up to 47Ω) in series with VCC. Twisted-Pair and Shielded Cables Use a twisted-pair cable to connect the remote sensor for remote-sensor distances longer than 8in or in very noisy environments. Twisted-pair cable lengths can be between 6ft and 12ft before noise introduces excessive errors.
PAGE 18
MAX6698 7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor Table 13. Temperature vs. Thermistor Channel Data for a Betatherm 103A1 Thermistor and REXT = 1600Ω 18 T (OC) RTHERM VREXT CODE (DECIMAL) BINARY CODE HEX CODE -20 96974 0.016231 3 11000000 3 -19 91525 0.017181 3 11000000 3 -18 86415 0.018179 4 10000000 4 -17 81621 0.019226 4 10000000 4 -16 77121 0.020325 4 10000000 4 -15 72895 0.021478 4 10000000 4 -14 68927 0.
PAGE 19
7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor T (OC) RTHERM VREXT CODE (DECIMAL) BINARY CODE HEX CODE 19 13072.8 0.109045 22 10110000 16 20 12493.7 0.113526 23 10111000 17 21 11943.3 0.11814 24 11000000 18 22 11420 0.122888 25 11001000 19 23 10922.7 0.127768 26 11010000 1A 24 10449.9 0.132781 27 11011000 1B 25 10000 0.137931 28 11100000 1C 26 9572 0.143215 29 11101000 1D 27 9164.7 0.148634 30 11110000 1E 28 8777 0.
PAGE 20
MAX6698 7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor Table 13. Temperature vs. Thermistor Channel Data for a Betatherm 103A1 Thermistor and REXT = 1600Ω (continued) 20 T (OC) RTHERM VREXT CODE (DECIMAL) BINARY CODE 58 2673.9 0.374365 75 10010110 4B 59 2578.5 0.382913 77 10011010 4D 60 2487.1 0.391476 78 10011100 4E HEX CODE 61 2399.4 0.40006 80 10100000 50 62 2315.2 0.408664 82 10100100 52 63 2234.7 0.417243 83 10100110 53 64 2156.
PAGE 21
7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor T (OC) RTHERM VREXT CODE (DECIMAL) BINARY CODE HEX CODE 93 835.93 0.656833 131 10000011 83 94 811.03 0.663617 133 10000101 85 95 786.99 0.6703 134 10000110 86 96 763.79 0.676879 135 10000111 87 97 741.38 0.683358 137 10001001 89 98 719.74 0.689732 138 10001010 8A 99 698.82 0.696009 139 10001011 8B 100 678.63 0.702176 140 10001100 8C 101 659.1 0.
PAGE 22
7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor MAX6698 Pin Configuration Chip Information PROCESS: BiCMOS TOP VIEW DXP1 1 16 GND DXN1 2 15 SMBCLK 14 SMBDATA DXP2 3 DXN2 4 MAX6698 13 ALERT DXP3 5 12 VCC DXN3 6 11 OVERT THER3 7 10 THER1 9 VREF 8 THER2 QSOP 22 ______________________________________________________________________________________
PAGE 23
7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor QSOP.EPS PACKAGE OUTLINE, QSOP .150", .025" LEAD PITCH 21-0055 F 1 1 ______________________________________________________________________________________ 23 MAX6698 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.
PAGE 24
Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) TSSOP4.40mm.EPS MAX6698 7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor PACKAGE OUTLINE, TSSOP 4.