lm73cimkx-1 National Semiconductor Corporation, lm73cimkx-1 Datasheet - Page 14

• Manufacturer Part Number: lm73cimkx-1
• Description: 2.7v, Sot-23, 11-to-14 Bit Digital Temperature Sensor With 2-wire Interface
• Manufacturer: National Semiconductor Corporation

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2.0 LM73 Registers
2.2 TEMPERATURE DATA REGISTER
Pointer Address 00h (Read Only)
Reset State: 7FFCh (+255.96875˚C)
One-Shot State: 8000h (-256˚C)
2.3 CONFIGURATION REGISTER
Pointer Address 01h (R/W)
Reset State: 40h
2.4 T
Pointer Address 02h (R/W)
Reset State: 7FE0h (+255.75˚C)
Bits
15:2
1:0
Bits
7
6
5
4
3
2
1:0
Bits
15:5
4:0
HIGH
SIGN
SIGN
D15
D15
1˚C
1˚C
PD
D7
D7
D7
Name
Temperature Data
Not Used
Name
Full Power Down
reserved
ALERT Enable
ALERT Polarity
ALERT Reset
One Shot
Reserved
Name
Upper-Limit
Temperature
Reserved
UPPER-LIMIT REGISTER
reserved
128˚C
128˚C
0.5˚C
0.5˚C
D14
D14
D6
D6
D6
Description
Represents the temperature that was measured by the most recent temperature conversion.
On Power-up, this data is invalid until the Data Available (DAV) bit in the Control/Status
register is high (after the completion of the first temperature conversion). The resolution is
user-progammable from 11-bit resolution (0.25˚C/LSB) through 14-bit resolution
(0.03125˚C/LSB). The desired resolution is programmed with bits 5 and 6 of the
Control/Status register.
Return zeros upon read.
Description
Writing a 1 to this bit puts the LM73 in shutdown mode for power conservation. Writing a 0
puts the LM73 into normal mode.
User must write only a 1 to this bit
A 0 in this location enables the ALERT output. A 1 disables it. This bit also controls the
ALERT Status bit (the Control/Status Register, Bit 3) since that bit reflects the state of the
Alert pin.
When set to 1, the ALERT pin and ALERT Status bit are active-high. When 0, it is
active-low.
Writing a 1 to this bit resets the ALERT pin and the ALERT Status bit. It will always be 0
when read.
When in shutdown mode (Bit 7 is 1), initiates a single temperature conversion and update of
the temperature register with new temperature data. Has no effect when in continuous
conversion mode (i.e., when Bit 7 is 0). Always returns a 0 when read.
User must write only a 0 to these bits.
Description
If the measured temperature that is stored in this register exceeds this user-programmable
upper temperature limit, the ALERT pin will go active and the THIGH flag in the
Control/Status register will be set to 1. Two’s complement format.
Returns zeros upon read. Recommend writing zeros only in these bits.
(Continued)
ALRT EN
0.25˚C
0.25˚C
64˚C
64˚C
D13
D13
D5
D5
D5
ALRT POL
0.125˚C
32˚C
32˚C
D12
D12
D4
D4
D4
14
ALRT RST
0.0625˚C
16˚C
16˚C
D11
D11
D3
D3
D3
ONE SHOT
0.03125˚C
reserved
D10
D10
8˚C
8˚C
D2
D2
D2
reserved
4˚C
4˚C
D9
D1
D1
D9
D1
reserved
reserved
2˚C
2˚C
D8
D0
D0
D8
D0