19-4096; Rev 0; 5/08
7-Channel Precision Temperature Monitor
with Beta Compensation
The MAX6693 precision multichannel temperature sensor monitors its own temperature and the temperatures
of up to six external diode-connected transistors. All
temperature channels have programmable alert thresholds. Channels 1, 4, 5, and 6 also have programmable
overtemperature thresholds. When the measured temperature 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 corresponding 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 temperature data and programming the alarm thresholds.
The MAX6693 is specified for an operating temperature
range of -40°C to +125°C and is available in a 20-pin
TSSOP package.
Features
o Six Thermal-Diode Inputs
o Beta Compensation (Channel 1)
o Local Temperature Sensor
o 1.5°C Remote Temperature Accuracy (+60°C to
+100°C)
o Temperature Monitoring Begins at POR for FailSafe System Protection
o ALERT and OVERT Outputs for Interrupts,
Throttling, and Shutdown
o STBY Input for Hardware Standby Mode
o Small, 20-Pin TSSOP Package
o 2-Wire SMBus Interface
Ordering Information
PART
Applications
TEMP RANGE
MAX6693UP9A+
Desktop Computers
Notebook Computers
Workstations
Servers
-40°C to +125°C
PIN-PACKAGE
20 TSSOP
+Denotes a lead-free package.
Note: Slave address is 1001 101.
SMBus is a trademark of Intel Corp.
Pin Configuration appears at end of data sheet.
Typical Application Circuit
+3.3V
CPU
1
DXP1
GND 20
4.7kΩ
EACH
2
DXN1
MAX6693 SMBCLK 19
CLK
3
DXP2
SMBDATA 18
4
DXN2
ALERT 17
5
DXP3
VCC 16
6
DXN3
OVERT 15
7
DXP4
N.C. 14
8
DXN4
STBY 13
9
DXP5
DXP6 12
10
DXN5
DXN6 11
100pF
DATA
100pF
INTERRUPT
TO μP
0.1μF
100pF
TO SYSTEM
SHUTDOWN
100pF
GPU
100pF
100pF
________________________________________________________________ Maxim Integrated Products
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.
1
MAX6693
General Description
MAX6693
7-Channel Precision Temperature Monitor
with Beta Compensation
ABSOLUTE MAXIMUM RATINGS
VCC, SMBCLK, SMBDATA, ALERT, OVERT,
STBY to GND ....................................................-0.3V to +6.0V
DXP_ to GND..............................................-0.3V to (VCC + 0.3V)
DXN_ to GND ........................................................-0.3V to +0.8V
SMBDATA, ALERT, OVERT Current....................-1mA to +50mA
DXN_ Current......................................................................±1mA
Continuous Power Dissipation (TA = +70°C)
20-Pin TSSOP
(derate 13.6mW/°C above +70°C) .............................1084mW
Junction-to-Case Thermal Resistance (θJC) (Note 1)
20-Pin TSSOP...............................................................20°C/W
Junction-to-Ambient Thermal Resistance (θJA) (Note 1)
20-Pin TSSOP............................................................73.8°C/W
ESD Protection (all pins, Human Body Model) ....................±2kV
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
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.
ELECTRICAL CHARACTERISTICS
(VCC = +3.0V to +3.6V, VSTBY = VCC, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = +3.3V and TA =
+25°C.) (Note 2)
PARAMETER
Supply Voltage
SYMBOL
CONDITIONS
VCC
MIN
TYP
3.0
MAX
UNITS
3.6
V
Software Standby Supply Current
ISS
SMBus static
3
10
µA
Operating Current
ICC
During conversion (Note 3)
500
2000
µA
Channel 1 only
11
Other diode channels
8
Temperature Resolution
3 σ Temperature Accuracy
(Remote Channel 1)
VCC = 3.3V,
ß = 0.5
3 σ Temperature Accuracy
(Remote Channels 2–6)
VCC = 3.3V
3 σ Temperature Accuracy
(Local)
VCC = 3.3V
6 σ Temperature Accuracy
(Remote Channel 1)
VCC = 3.3V,
ß = 0.5
6 σ Temperature Accuracy
(Remote Channels 2–6)
VCC = 3.3V
6 σ Temperature Accuracy
(Local)
VCC = 3.3V
TA = TRJ = +60°C to +100°C
TA = TRJ = 0°C to +125°C
TA = TRJ = +60°C to +100°C
Bits
-1.5
+1.5
-2.375
+2.375
-2
+2
-2.5
+2.5
-2
+2
-2.5
+2.5
TA = TRJ = +60°C to +100°C
-3
+3
TA = TRJ = 0°C to +125°C
-4
+4
TA = TRJ = 0°C to +125°C
TA = +60°C to +100°C
TA = 0°C to +125°C
-3
+3
TA = TRJ = 0°C to +125°C
TA = TRJ = +60°C to +100°C
-3.5
+3.5
TA = +60°C to +100°C
-2.5
+2.5
-3
+3
TA = 0°C to +125°C
Supply Sensitivity of Temperature
Accuracy
±0.2
°C
°C
°C
°C
°C
°C
o
C/V
Remote Channel 1 Conversion
Time
tCONV1
190
250
312
ms
Remote Channels 2–6
Conversion Time
tCONV_
95
125
156
ms
2
_______________________________________________________________________________________
7-Channel Precision Temperature Monitor
with Beta Compensation
(VCC = +3.0V to +3.6V, VSTBY = VCC, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = +3.3V and TA =
+25°C.) (Note 2)
PARAMETER
Remote-Diode Source Current
SYMBOL
IRJ
CONDITIONS
UVLO
TYP
500
Low level, channel 1
20
High level, channels 2–6
Low level, channels 2–6
Undervoltage-Lockout Threshold
MIN
High level, channel 1
80
100
MAX
120
8
10
12
Falling edge of VCC disables ADC
2.30
2.80
2.95
VCC falling edge
1.20
Undervoltage-Lockout Hysteresis
90
Power-On Reset (POR) Threshold
POR Threshold Hysteresis
2
UNITS
µA
V
mV
2.25
90
V
mV
ALERT, OVERT
Output Low Voltage
VOL
ISINK = 1mA
0.3
ISINK = 6mA
0.5
Output Leakage Current
1
V
µA
SMBus INTERFACE (SMBCLK, SMBDATA), STBY
Logic-Input Low Voltage
VIL
Logic-Input High Voltage
VIH
0.8
VCC = 3.0V
Input Leakage Current
2.2
-1
Output Low Voltage
VOL
Input Capacitance
CIN
V
V
+1
ISINK = 6mA
0.3
5
µA
V
pF
SMBus-COMPATIBLE TIMING (Figures 3 and 4) (Note 4)
Serial-Clock Frequency
Bus Free Time Between STOP
and START Condition
fSMBCLK
tBUF
START Condition Setup Time
Repeat START Condition Setup
Time
tSU:STA
START Condition Hold Time
tHD:STA
STOP Condition Setup Time
tSU:STO
(Note 5)
400
fSMBCLK = 100kHz
4.7
fSMBCLK = 400kHz
1.6
fSMBCLK = 100kHz
4.7
fSMBCLK = 400kHz
0.6
90% of SMBCLK to 90% of SMBDATA,
fSMBCLK = 100kHz
0.6
90% of SMBCLK to 90% of SMBDATA,
fSMBCLK = 400kHz
0.6
10% of SMBDATA to 90% of SMBCLK
0.6
90% of SMBCLK to 90% of SMBDATA,
fSMBCLK = 100kHz
4
90% of SMBCLK to 90% of SMBDATA,
fSMBCLK = 400kHz
0.6
kHz
µs
µs
µs
µs
µs
_______________________________________________________________________________________
3
MAX6693
ELECTRICAL CHARACTERISTICS (continued)
MAX6693
7-Channel Precision Temperature Monitor
with Beta Compensation
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +3.0V to +3.6V, VSTBY = VCC, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = +3.3V and TA =
+25°C.) (Note 2)
PARAMETER
SYMBOL
Clock-Low Period
tLOW
Clock-High Period
tHIGH
Data Hold Time
tHD:DAT
Data Setup Time
tSU:DAT
Receive SMBCLK/SMBDATA
Rise Time
tR
Receive SMBCLK/SMBDATA Fall
Time
tF
Pulse Width of Spike Suppressed
SMBus Timeout
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
4
CONDITIONS
1.3
10% to 10%, fSMBCLK = 400kHz
1.3
90% to 90%
0.6
fSMBCLK = 100kHz
300
TYP
MAX
µs
900
fSMBCLK = 100kHz
250
fSMBCLK = 400kHz
100
1
fSMBCLK = 400kHz
0.3
300
0
25
ns
ns
fSMBCLK = 100kHz
SMBDATA low period for interface reset
UNITS
µs
fSMBCLK = 400kHz (Note 6)
tSP
tTIMEOUT
MIN
10% to 10%, fSMBCLK = 100kHz
37
µs
ns
50
ns
45
ms
All parameters are tested at TA = +85°C. Specifications over temperature are guaranteed by design.
Beta = 0.5 for channel 1 remote transistor.
Timing specifications are guaranteed by design.
The serial interface resets when SMBCLK is low for more than tTIMEOUT.
A transition must internally provide at least a hold time to bridge the undefined region (300ns max) of SMBCLK’s falling edge.
_______________________________________________________________________________________
7-Channel Precision Temperature Monitor
with Beta Compensation
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
SOFTWARE STANDBY SUPPLY CURRENT
vs. SUPPLY VOLTAGE
3.7
LOW BETA DIODE CONNECTED TO
CHANNEL 1 WITH RESISTANCE
CANCELLATION AND LOW BETA
560
SUPPLY CURRENT (μA)
3.6
3.5
3.4
3.3
540
520
500
480
460
3.2
440
3.1
420
400
3.0
3.2
3.3
3.4
3.2
3.0
3.6
3.5
0
-1
-2
2
1
0
-1
CHANNEL 1
-3
-5
50
75
100
0
125
25
CHANNEL 2
1
0
-1
-2
CHANNEL 1
50
75
100
125
-5
0.001
DIE TEMPERATURE (°C)
REMOTE-DIODE TEMPERATURE (°C)
LOCAL TEMPERATURE ERROR
vs. POWER-SUPPLY NOISE FREQUENCY
100mVP-P
4
0.100
1.000
10.000
FREQUENCY (MHz)
4
2
1
0
-1
-2
100mVP-P
3
TEMPERATURE ERROR (°C)
3
0.010
CH 2 REMOTE-DIODE TEMPERATURE ERROR
vs. COMMON-MODE NOISE FREQUENCY
MAX6693 toc06
5
2
1
0
-1
-2
-3
-3
-4
-4
-5
0.001
2
-4
-3
25
3
-3
-2
-4
0
100mVP-P
4
TEMPERATURE ERROR (°C)
3
TEMPERATURE ERROR (°C)
CHANNEL 2
1
5
MAX6693 toc04
4
MAX6693 toc03
3
TEMPERATURE ERROR (°C)
TEMPERATURE ERROR (°C)
4
3.6
REMOTE-DIODE TEMPERATURE ERROR
vs. POWER-SUPPLY NOISE FREQUENCY
LOCAL TEMPERATURE ERROR
vs. DIE TEMPERATURE
REMOTE-DIODE TEMPERATURE ERROR
vs. REMOTE-DIODE TEMPERATURE
5
3.4
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
MAX6693 toc05
3.1
MAX6693 toc07
3.0
2
MAX6693 toc02
580
MAX6693 toc01
STANDBY SUPPLY CURRENT (μA)
3.8
-5
0.010
0.100
FREQUENCY (MHz)
1.000
10.000
0.1
1.0
10.0
FREQUENCY (MHz)
_______________________________________________________________________________________
5
MAX6693
Typical Operating Characteristics
(VCC = 3.3V, VSTBY = VCC, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(VCC = 3.3V, VSTBY = VCC, TA = +25°C, unless otherwise noted.)
CH 1 REMOTE-DIODE TEMPERATURE
ERROR vs. CAPACITANCE
CH 2 REMOTE-DIODE TEMPERATURE
ERROR vs. CAPACITANCE
4
4
TEMPERATURE ERROR (°C)
3
2
1
0
-1
-2
3
2
1
0
-1
-2
-3
-3
-4
-4
-5
MAX6693 toc09
5
MAX6693 toc08
5
TEMPERATURE ERROR (°C)
MAX6693
7-Channel Precision Temperature Monitor
with Beta Compensation
-5
1
10
100
1
CAPACITANCE (nF)
10
100
CAPACITANCE (nF)
Pin Description
6
PIN
NAME
FUNCTION
1
DXP1
Combined Current Source and A/D Positive Input for Channel 1 Remote Transistor. Connect to the
emitter of a low-beta transistor. Leave unconnected or connect to VCC if no remote transistor is used.
Place a 100pF capacitor between DXP1 and DXN1 for noise filtering.
2
DXN1
Base Input for Channel 1 Remote Diode. Connect to the base of a PNP temperature-sensing transistor.
3
DXP2
Combined Current Source and A/D Positive Input for Channel 2 Remote Diode. Connect to the anode
of a remote-diode-connected temperature-sensing transistor. Leave unconnected or connect to VCC
if no remote diode is used. Place a 100pF capacitor between DXP2 and DXN2 for noise filtering.
4
DXN2
Cathode Input for Channel 2 Remote Diode. Connect the cathode of the channel 2 remote-diodeconnected transistor to DXN2.
5
DXP3
Combined Current Source and A/D Positive Input for Channel 3 Remote Diode. Connect to the anode
of a remote-diode-connected temperature-sensing transistor. Leave unconnected or connect to VCC
if no remote diode is used. Place a 100pF capacitor between DXP3 and DXN3 for noise filtering.
6
DXN3
Cathode Input for Channel 3 Remote Diode. Connect the cathode of the channel 3 remote-diodeconnected transistor to DXN3.
7
DXP4
Combined Current Source and A/D Positive Input for Channel 4 Remote Diode. Connect to the anode
of a remote-diode-connected temperature-sensing transistor. Leave unconnected or connect to VCC
if no remote diode is used. Place a 100pF capacitor between DXP4 and DXN4 for noise filtering.
8
DXN4
Cathode Input for Channel 4 Remote Diode. Connect the cathode of the channel 4 remote-diodeconnected transistor to DXN4.
_______________________________________________________________________________________
7-Channel Precision Temperature Monitor
with Beta Compensation
PIN
NAME
FUNCTION
9
DXP5
Combined Current Source and A/D Positive Input for Channel 5 Remote Diode. Connect to the anode
of a remote-diode-connected temperature-sensing transistor. Leave unconnected or connect to VCC
if no remote diode is used. Place a 100pF capacitor between DXP5 and DXN5 for noise filtering.
10
DXN5
Cathode Input for Channel 5 Remote Diode. Connect the cathode of the channel 5 remote-diodeconnected transistor to DXN5.
11
DXN6
Cathode Input for Channel 6 Remote Diode. Connect the cathode of the channel 6 remote-diodeconnected transistor to DXN6.
12
DXP6
Combined Current Source and A/D Positive Input for Channel 6 Remote Diode. Connect to the anode
of a remote-diode-connected temperature-sensing transistor. Leave unconnected or connect to VCC
if no remote diode is used. Place a 100pF capacitor between DXP6 and DXN6 for noise filtering.
13
STBY
Active-Low Standby Input. Drive STBY logic-low to place the MAX6693 in standby mode, or logic-high
for operate mode. Temperature and threshold data are retained in standby mode.
14
N.C.
No Connection. Must be connected to ground.
15
OVERT
16
VCC
Overtemperature Active-Low, Open-Drain Output. OVERT asserts low when the temperature of
channels 1, 4, 5, and 6 exceeds the programmed threshold limit.
Supply Voltage Input. Bypass to GND with a 0.1µF capacitor.
17
ALERT
18
SMBDATA
19
SMBCLK
20
GND
SMBus Alert (Interrupt), Active-Low, Open-Drain Output. ALERT asserts low when the temperature of
any channel exceeds the programmed ALERT threshold.
SMBus Serial Data Input/Output. Connect to a pullup resistor.
SMBus Serial Clock Input. Connect to a pullup resistor.
Ground
Detailed Description
The MAX6693 is a precision multichannel temperature
monitor that features one local and six remote temperature-sensing channels with a programmable alert
threshold for each temperature channel and a programmable overtemperature threshold for channels 1, 4, 5,
and 6 (see Figure 1). Communication with the MAX6693
is achieved through the SMBus serial interface and a
dedicated alert pin. The alarm outputs, OVERT and
ALERT, assert if the software-programmed temperature
thresholds are exceeded. ALERT typically serves as an
interrupt, while OVERT can be connected to a fan, system shutdown, or other thermal-management circuitry.
ADC Conversion Sequence
In the default conversion mode, the MAX6693 starts the
conversion sequence by measuring the temperature on
channel 1, followed by 2, 3, local channel, 4, 5, and 6.
The conversion result for each active channel is stored
in the corresponding temperature data register.
Low-Power Standby Mode
Enter software standby mode by setting the STOP bit to
1 in the configuration 1 register. Enter hardware standby
by pulling STBY low. Software standby mode disables
the ADC and reduces the supply current to approximately 3µA. Hardware standby mode halts the ADC
clock, but the supply current is approximately 350µA.
During either software or hardware standby, data is
retained in memory. During hardware standby, the
SMBus interface is inactive. During software standby, the
SMBus interface is active and listening for commands.
The timeout is enabled if a start condition is recognized
on SMBus. Activity on the SMBus causes the supply current to increase. If a standby command is received while
a conversion is in progress, the conversion cycle is interrupted, and the temperature registers are not updated.
The previous data is not changed and remains available.
_______________________________________________________________________________________
7
MAX6693
Pin Description (continued)
MAX6693
7-Channel Precision Temperature Monitor
with Beta Compensation
VCC
DXP1
MAX6693
DXN1
DXP2
ALARM
ALU
DXN2
DXP3
DXN3
DXP4
CURRENT
SOURCES,
BETA
COMPENSATION
AND MUX
INPUT
BUFFER
ADC
OVERT
ALERT
REGISTER BANK
COMMAND BYTE
REMOTE TEMPERATURES
DXN4
DXP5
LOCAL TEMPERATURES
REF
ALERT THRESHOLD
OVERT THRESHOLD
DXN5
ALERT RESPONSE ADDRESS
DXP6
SMBus
INTERFACE
DXN6
STBY
SMBCLK
SMBDATA
Figure 1. Internal Block Diagram
Operating-Current Calculation
SMBus Digital Interface
The MAX6693 operates at different operating-current
levels depending on how many external channels are in
use. Assume that ICC1 is the operating current when
the MAX6693 is converting the remote channel 1 and
ICC2 is the operating current when the MAX6693 is converting the other channels. For the MAX6693 with
remote channel 1 and n other remote channels connected, the operating current is:
ICC = (2 x ICC1 + ICC2 + n x ICC2)/(n + 3)
From a software perspective, the MAX6693 appears as
a series of 8-bit registers that contain temperature measurement data, alarm threshold values, and control bits.
A standard SMBus-compatible, 2-wire serial interface is
used to read temperature data and write control bits
and alarm threshold data. The same SMBus slave
address also provides access to all functions.
8
_______________________________________________________________________________________
7-Channel Precision Temperature Monitor
with Beta Compensation
MAX6693
WRITE BYTE FORMAT
S
ADDRESS
WR
ACK
COMMAND
7 BITS
ACK
DATA
8 BITS
ACK
P
8 BITS
SLAVE ADDRESS: EQUIVALENT TO CHIP-SELECT LINE OF
A 3-WIRE INTERFACE
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
S
SLAVE ADDRESS: EQUIVALENT TO CHIP SELECT LINE
ADDRESS
RD
COMMAND BYTE: SELECTS
WHICH REGISTER YOU ARE
REDING FROM
DATA
///
P
8 BITS
SLAVE ADDRESS: REPEATED
DUE TO CHANGE IN DATAFLOW DIRECTION
DATA BYTE: READS FROM
THE REGISTER SET BY THE
COMMAND BYTE
RECEIVE BYTE FORMAT
WR
ACK
7 BITS
COMMAND
ACK
P
8 BITS
S
ADDRESS
RD
7 BITS
ACK
DATA
///
P
8 BITS
COMMAND BYTE: SENDS COMMAND WITH NO DATA, USUALLY
USED FOR ONE-SHOT COMMAND
S = START CONDITION.
P = STOP CONDITION.
ACK
7 BITS
SEND BYTE FORMAT
S
ADDRESS
8 BITS
DATA BYTE: READS DATA FROM
THE REGISTER COMMANDED
BY THE LAST READ BYTE OR
WRITE BYTE TRANSMISSION;
ALSO USED FOR SMBus ALERT
RESPONSE RETURN ADDRESS
SHADED = SLAVE TRANSMISSION.
/// = NOT ACKNOWLEDGED.
Figure 2. SMBus Protocols
Table 1. Main Temperature Register
(High-Byte) Data Format
Table 2. Extended Resolution Temperature
Register (Low-Byte) Data Format
TEMP (°C)
DIGITAL OUTPUT
TEMP (°C)
DIGITAL OUTPUT
> +127
0111 1111
0
000X XXXX
+127
0111 1111
+0.125
001X XXXX
+126
0111 1110
+0.250
010X XXXX
+25
0001 1001
+0.375
011X XXXX
0
0000 0000
+0.500
100X XXXX
工商网监
湘ICP备2023018690号
