EVALUATION
KIT
AVAILABLE
TCM1617
SMBus Thermal Sensor with External Diode Input
FEATURES
s
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Includes Internal External Sensing Capability
Outputs Temperature as 8-Bit Digital Word
Solid State Temperature Sensing; 1
°
C Resolution
3.0 – 5.5V Operating Range
Independent Internal and External Threshold
Set-Points With ALERT# Interrupt Output
SMBus 2-Wire Serial Interface
Up To Nine TCM1617s May Share the Same Bus
Standby Mode for Low Standby Power
Low Power ............................ 70
µ
A (max) Operating
...................................... 10
µ
A (max) Standby Mode
16-Pin Plastic QSOP Package
GENERAL DESCRIPTION
The TCM1617 is a serially programmable temperature
sensor optimized for monitoring modern high performance
CPUs with on-board integrated thermal diodes. Tempera-
ture data is converted from the CPU’s thermal diode outputs
and made available as an 8-Bit digital word.
Communication with the TCM1617 is accomplished via
the standard System Management Bus (SMBus) commonly
used in modern computer systems. This permits reading the
current internal/external temperature, programming the
threshold setpoints, and configuring the device. Addition-
ally, an interrupt is generated on the ALERT# pin when
temperature moves outside the preset threshold windows in
either direction.
A Standby command may be sent via the SMBus by
signaling the STBY# input to activate the low-power Standby
mode. Registers can be accessed while in Standby mode.
Address selection inputs allow up to nine TCM1617s to
share the same 2-wire SMBus for multi-zone monitoring.
All registers can be read by the host, and both polled and
interrupt driven systems are easily accommodated. Small
size, low installed cost, and ease of use make the TCM1617
an ideal choice for implementing sophisticated system man-
agement schemes, such as ACPI.
TYPICAL APPLICATIONS
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Thermal Protection For Intel “Deschutes”
Pentium II™ and Other High Performance CPUs
with Integrated On-Board Diode — No Sensor
Mounting Problems!
Accurate Thermal Sensing From Any Si Junction
Diode
Thermal Management in Electronic Systems:
Computers, Network Equipment, Power Supplies
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BLOCK DIAGRAM
Internal
Sensor
(Diode)
D
+
D
–
ORDERING INFORMATION
Part No.
TCM1617MQR
TCM1617EV
Control
Logic
Package
Temp. Range
QSOP-16
–55°C to +125°C
Evaluation Kit for TCM1617
∆∑
Modulator
Register Set
Int. Temp
Ext. Temp
Status Byte
Config. Byte
Conv. Rate
Ext. Hi Limit
Ext. Lo Limit
Int. Hi Limit
Int. Lo Limit
PIN CONFIGURATION
ALERT#
STBY#
NC
V
DD
D+
D–
1
2
3
4
5
6
7
8
TCM1617
16 NC
15 STBY#
14
13
12
11
10
9
SCL
NC
SDA
ALERT#
ADD0
NC
SCL
SDA
NC
ADD 1
GND
SMBus
Interface
ADD 0
ADD 1
GND
16-Pin Plastic QSOP
2001 Microchip Technology Inc.
DS21485A
1
TCM1617-1 2/5/99
SMBus Thermal Sensor with External Diode Input
TCM1617
ABSOLUTE MAXIMUM RATINGS*
Power Supply Voltage (V
DD
) .........................................6V
Voltage On Any Pin ............ (GND – 0.3V) to (V
DD
+ 0.3V)
Operating Temperature (T
A
) .................. –55°C to +125°C
Storage Temperature (T
STG
) .................. –65°C to +150°C
SMBus Input/Output Current ................. –1 mA to +50 mA
D– Input Current ......................................................±1 mA
Max. Power Dissipation ........................................330 mW
*Static-sensitive device. Unused devices must be stored in conductive
material. Protect devices from static discharge and static fields. Stresses
above those listed under Absolute Maximum Ratings may cause perma-
nent damage to the device. These are stress ratings only and functional
operation of the device at these or any other conditions above 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:
V
DD
= 3.3V, –55°C
≤
T
A
≤
125°C, unless otherwise noted.
Symbol
V
DD
V
UV-LOCK
V
POR
I
DD
I
DD
Parameter
Power Supply Voltage
V
DD
Undervoltage
Lockout Threshold
Power-On Reset Threshold
Operating Current
Operating Current
Test Conditions
–55
≤
T
A
≤
+125°C
Min
3.0
2.4
1.0
—
—
—
—
—
—
—
V
DD
x 0.7
—
V
DD
x 0.7
—
Typ
—
2.80
1.7
—
—
—
—
160
—
—
—
—
—
1
—
—
±3
—
—
±5
100
10
0.7
Max
5.5
2.95
2.3
70
180
100
10
—
0.4
V
DD
x 0.3
—
V
DD
x 0.3
—
—
+2
+3
—
+3
+5
—
—
—
—
Unit
V
V
V
µA
µA
µA
µA
µA
V
V
V
V
V
°C
°C
°C
°C
°C
°C
µA
µA
V
Power Supply
I
DD-STANDBY
Standby Supply Current
I
DD-STANDBY
Standby Supply Current
I
ADD-BIAS
ADD[1:0] Bias Current
V
DD
Falling Edge
0.25 Conv./Sec Rate
SMBus Inactive (Note 1)
2 Conv./Sec Rate
SMBus Inactive (Note 1)
V
DD
= 3.3V SMBus Active
V
DD
= 3.3V, SMBus Inactive
Power-Up Only
I
OL
= 1.0 mA (Note 3)
ALERT# Output
V
OL
V
IL
V
IH
Output Low Voltage
Logic Input Low
Logic Input High
Logic Input Low
Logic Input High
Basic Temperature Resolution
Internal Diode Temperature
+60°C
≤
T
A
≤
+100°C
0°C
≤
T
A
≤
+125°C
–55°C
≤
T
A
< 0°C
+60°C
≤
T
A
≤
+100°C
0°C
≤
T
A
≤
+125°C –3
–55°C
≤
T
A
< 0°C
(D+) – (D–) ~ 0.65V
(D+) – (D–) ~ 0.65V
ADD[1:0] Inputs
STBY# Input
V
IL
V
IH
T
RES
T
IERR1
Temp-to-Bits Converter
–2
–3
—
–3
–5
—
—
—
T
EERR
External Diode Temperature
(Note 4)
External Diode
High Source Current
External Diode
Low Source Current
D– Source Voltage
I
DIODE-HIGH
I
DIODE-LOW
V
D-SOURCE
TCM1617-1
2/5/99
2
2001 Microchip Technology Inc.
DS21485A
SMBus Thermal Sensor with External Diode Input
TCM1617
ELECTRICAL CHARACTERISTICS (CONT):
V
DD
= 3.3V, –55°C
≤
T
A
≤
125°C, unless otherwise noted.
Symbol
t
CONV
∆CR
V
IH
V
IL
V
OL
C
IN
I
LEAK
Parameter
Conversion Time
Conversion Rate Accuracy
Logic Input High
Logic Input Low
SDA Output Low
Input Capacitance SDA, SCL
I/O Leakage
I
OL
= 2 mA (Note 3)
I
OL
= 4 mA (Note 3)
Conditions
from CHIP STOP to Conv.
Complete (Note 2)
See Conversion Rate Register Desc.
Min
54
–35
2.2
—
—
—
—
–1
Typ
83
—
—
—
—
—
5
0.1
Max
112
+35
—
0.8
0.4
0.6
—
1
Unit
msec
%
V
V
V
V
pF
µA
2-Wire SMBus Interface
SMBus PORT AC TIMING:
V
DD
= 3.3V, –55
≤
(T
A
= T
J
)
≤
125°C; C
L
= 80 pF, unless otherwise noted.
Symbol
f
SMB
t
LOW
t
HIGH
t
R
t
F
t
SU(START)
t
H(START)
t
SU-DATA
t
H-DATA
t
SU(STOP)
t
IDLE
Parameter
SMBus Clock Frequency
Low Clock Period
High Clock Period
SMBus Rise Time
SMBus Fall Time
Start Condition Setup Time
(for Repeated Start Condition)
Start Condition Hold Time
Data in Set Up Time
Data in Hold Time
Stop Condition Setup Time
Bus Free Time Prior to
New Transition
Test Conditions
10% to 10%
90% to 90%
10% to 90%
90% to 10%
90% SCL to 10% SDA
Min
10
4.7
4
—
—
4
4
1000
1250
4
4.7
Typ
—
—
—
—
—
—
—
—
—
—
—
Max
100
—
—
1,000
300
—
—
—
—
—
—
Unit
KHz
µsec
µsec
nsec
nsec
µsec
µsec
nsec
nsec
µsec
µsec
NOTES:
1. Operating current is an average value (including external diode injection pulse current) integrated over multiple conversion cycles.
Transient current may exceed this specification.
2. For true reccurring conversion time see Conversion Rate register description.
3. Output current should be minimized for best temperature accuracy. Power dissipation within the TCM1617 will cause self-heating and
temperature drift error.
4. Refer to Application Note 64.
2001 Microchip Technology Inc.
DS21485A
3
TCM1617-1 2/5/99
SMBus Thermal Sensor with External Diode Input
TCM1617
SMBUS THERMAL S
SMBUS Write Timing Diagram
A
ILOW
B
IHIGH
C
D
E
F
G
H
I
J
K
L
M
SCL
SDA
tSU(START) tH(START)
tSU-DATA
tH-DATA
tSU(STOP)
tIDLE
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 SDA Line Low
F = Acknowledge Bit Clocked into Master
G = MSB of Data Clocked into Slave
H = LSB of Data Clocked into Slave
I = Slave Pulls SDA Line Low
J = Acknowledge Clocked into Master
K = Acknowledge Clock Pulse
L = Stop Condition, Data Executed by Slave
M = New Start Condition
SMBUS Read Timing Diagram
A
ILOW
B
IHIGH
C
D
E
F
G
H
I
J
K
SCL
SDA
tSU(START)
tH(START)
tSU-DATA
tSU(STOP)
tIDLE
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 SDA Line Low
F = Acknowledge Bit Clocked into Master
G = MSB of Data Clocked into Master
H = LSB of Data Clocked into Master
I = Acknowledge Clock Pulse
J = Stop Condition
K = New Start Condition
TCM1617-1
2/5/99
4
2001 Microchip Technology Inc.
DS21485A
SMBus Thermal Sensor with External Diode Input
TCM1617
PIN DESCRIPTION
Pin Number
2
3
4
6,10
7,8
11
12
14
15
1,5, 9, 13,16
Symbol
V
DD
D+
D–
ADD[1:0]
GND
ALERT#
SDA
SCL
STBY#
NC
Type
Power
Bi-Directional
Bi-Directional
Input
Power
Output
Bi-Directional
Input
Input
—
Description
Power Supply Input
Current Source and A/D Positive Input
Current Sink and A/D Negative Input
Address Select Pins (See Address Decode Table)
System Ground
SMBus Interrupt (SMBALERT#)
SMBus Serial Data
SMBus Serial Clock
Standby Enable
Not Connected
PIN DESCRIPTION
SCL
Input. SMBus serial clock. Clocks data into and out of
the TCM1617. See System Management Bus Specification,
rev. 1.0, for timing diagrams.
INT_TEMP equal to or exceeds INT_HLIM
INT_TEMP falls below INT_LLIM
EXT_TEMP equal to or exceeds EXT_HLIM
EXT_TEMP falls below EXT_LLIM
External Diode “Open”
The operation of the ALERT# output is controlled by the
MASK1 bit in the CONFIG register. If the MASK1 bit is set to
“1,” no interrupts will be generated on ALERT#. The ALERT#
output is cleared and re-armed by the Alert Response
Address (ARA). This output may be WIRE-ORed with simi-
lar outputs from other SMBus devices. If the alarm condition
persists after the ARA, the ALERT# output will be immedi-
ately re-asserted.
(NOTE: A pull-up resistor is necessary on ALERT#
since it is an open-drain output. Current sourced from the
pull-up resistor causes power dissipation and may cause
internal heating of the TCM1617. To avoid affecting the
accuracy of internal temperature readings, the pull-up resis-
tors should be made as large as possible.)
SDA
Bi-directional. Serial data is transferred on the SMBus
in both directions using this pin. See System Management
Bus Specification, rev. 1.0, for timing diagrams.
ADD1, ADD0
Inputs. Sets the 7-bit SMBus address. These pins are
“tri-state,” and the SMBus addresses are specified in the
Address Decode Table below.
(NOTE: The tri-state scheme allows up to nine
TCM1617s on a single bus. A match between the TCM1617’s
address and the address specified in the serial bit stream
must be made to initiate communication. Many SMBus-
compatible devices with other addresses may share the
same 2-wire bus (see System Management Bus Specifica-
tion rev. 1.0 for address allocations). These pins are only
active at power-on reset, and will latch into the appropriate
states.
ALERT#
Output, Open Collector, Active Low. The ALERT# out-
put corresponds to the general SMBALERT# signal and
indicates an interrupt event. The TCM1617 will respond to
the standard SMBus Alert Response Address (see SMBus
Specification 1.0) and associated protocol when ALERT# is
asserted. Normally, the ALERT# output will be asserted
when any of the following occurs:
2001 Microchip Technology Inc.
DS21485A
STBY#
Input. The activation of Standby mode may be achieved
using either the STBY# pin or the CHIP STOP bit (CONFIG
register). If STBY# is pulled low, the TCM1617 uncondition-
ally enters its low-power Standby mode (I
DD
= 10
µA,
max).
The temperature-to-digital conversion process is halted, but
ALERT remains functional. The TCM1617’s bus interface
5
TCM1617-1 2/5/99
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