TCM1617 Datasheet, PDF (5/14 Pages) Microchip Technology – SMBus Thermal Sensor with External Diode Input

SMBus Thermal Sensor with External Diode Input
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
—
TCM1617
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
SDA
EXT_TEMP equal to or exceeds EXT_HLIM
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.
EXT_TEMP falls below EXT_LLIM
External Diode “Open”
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:
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.)
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
 2001 Microchip Technology Inc. DS21485A
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TCM1617-1 2/5/99