MAX1617MEE-T Maxim Integrated Products, MAX1617MEE-T Datasheet - Page 15

• Manufacturer Part Number: MAX1617MEE-T
• Description: Board Mount Temperature Sensors
• Manufacturer: Maxim Integrated Products

Specifications of MAX1617MEE-T

• Full Temp Accuracy: +/- 3.5 C, +/- 5 C
• Package / Case: QSOP-16
• Digital Output - Bus Interface: Serial (2-Wire)
• Digital Output - Number Of Bits: 7 bit + Sign
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 55 C
• Output Type: Digital
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

An untested example of pseudocode for proportional
temperature control of Intel mobile CPUs via a power-
management microcontroller is given in Listing 1. This
program consists of two main parts: an initialization rou-
tine and an interrupt handler. The initialization routine
checks for SMBus communications problems and sets
up the MAX1617 configuration and conversion rate. The
interrupt handler responds to ALERT signals by reading
the current temperature and setting a CPU clock duty
Figure 4. SMBus Write Timing Diagram
Figure 5. SMBus Read Timing Diagram
SMBCLK
SMBDATA
SMBCLK
SMBDATA
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
A = START CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE
t
t
SU:STA
SU:STA
Clock-Throttling Control for CPUs
A
A
t
HD:STA
t
HD:STA
______________________________________________________________________________________
t
t
LOW
LOW
B
B
Programming Example:
t
t
HIGH
HIGH
Remote/Local Temperature Sensor
t
SU:DAT
t
SU:DAT
C
C
F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO SLAVE
H = LSB OF DATA CLOCKED INTO SLAVE
I = SLAVE PULLS SMBDATA LINE LOW
E = SLAVE PULLS SMBDATA LINE LOW
F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO MASTER
H = LSB OF DATA CLOCKED INTO MASTER
D
with SMBus Serial Interface
D
E
E
F
F
factor proportional to that temperature. The relationship
between clock duty and temperature is fixed in a look-
up table contained in the microcontroller code.
Note: Thermal management decisions should be made
based on the latest temperature obtained from the
MAX1617 rather than the value of the Status Byte. The
MAX1617 has a very quick response to changes in its
environment due to its sensitivity and its small thermal
mass. High and low alarm conditions can exist in the
Status Byte due to the MAX1617 correctly reporting
environmental changes around it.
t
HD:DAT
G
G
H
J = ACKNOWLEDGE CLOCKED INTO MASTER
K = ACKNOWLEDGE CLOCK PULSE
L = STOP CONDITION, DATA EXECUTED BY SLAVE
M = NEW START CONDITION
I = ACKNOWLEDGE CLOCK PULSE
J = STOP CONDITION
K = NEW START CONDITION
H
I
J
I
K
t
SU:STO
t
SU:STO
J
L
t
BUF
t
BUF
M
K
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