Datasheet
TMP122, TMP124
9
SBOS272B
www.ti.com
CONVERSION TIME
R1 R0 RESOLUTION (typical)
0 0 9 Bits (0.5°C) plus sign 30ms
0 1 10 Bits (0.25°C) plus sign 60ms
1 0 11 Bits (0.125°C) plus sign 120ms
1 1 12 Bits (0.0625°C) plus sign 240ms
TABLE XI. Resolution of the TMP122 and TMP124.
CONVERTER RESOLUTION (R1/R0)
The Converter Resolution Bits control the resolution of the
internal Analog-to-Digital (A/D) converter. This allows the user
to maximize efficiency by programming for higher resolution or
faster conversion time. Table XI identifies the Resolution Bits
and the relationship between resolution and conversion time.
The TMP122/TMP124 have a default resolution of 12 bits.
DELAY TIME
The Delay Bits control the amount of time delay between each
conversion. This feature allows the user to maximize power
savings by eliminating unnecessary conversions, and minimiz-
ing current consumption. During active conversion the TMP122/
TMP124 typically requires 50µA of current for approximately
0.25s conversion time, and approximately 20µA for idle times
between conversions. Delay settings are identified in Table XII
as conversion time and period, and are shown in Figure 9.
Default power up is D1/D0 equal 0/0. Conversion time and
conversion periods scale with resolution. Conversion period
denotes time between conversion starts.
D1 D0 CONVERSION TIME CONVERSION PERIOD
0 0 0.25s 0.25s
0 1 0.25s 0.5s
1 0 0.25s 1s
1 1 0.25s 8s
TABLE XII. Conversion Delay for 12-Bit Resolution.
FIGURE 9. Conversion Time and Period Description.
PARAMETER MIN MAX UNITS
SCK Period t
1
100 ns
Data In to Rising Edge SCK Setup Time t
2
20 ns
SCK Falling Edge to Output Data Delay t
3
30 ns
SCK Rising Edge to Input Data Hold Time t
4
20 ns
CS to Rising Edge SCK Set-Up Time t
5
40 ns
CS to Output Data Delay t
6
30 ns
CS Rising Edge to Output High Impedance t
7
30 ns
TABLE XIII. Timing Description.
0.25s
D1/D0 = 0/1
D1/D0 = 1/0
D1/D0 = 1/1
12-Bit Resolution
0.25s
1s
8s
0.25s
0.5s
50µA (active)
20µA (idle)
Timing Diagrams
The TMP122/TMP124 are SPI compatible. Figures 10 to 12
describe the various timing parameters of the TMP122/
TMP124 with timing definitions in Table XIII.