ATA5773-DK1 Atmel, ATA5773-DK1 Datasheet - Page 151

• Manufacturer Part Number: ATA5773-DK1
• Description: BOARD XMITTER FOR ATA5773 315MHZ
• Manufacturer: Atmel
• Type: Transmitterr

Specifications of ATA5773-DK1

• Frequency: 315MHz
• Maximum Frequency: 315 MHz
• Supply Voltage (max): 4 V
• Supply Voltage (min): 2 V
• Supply Current: 9 mA
• Product: RF Development Tools
• For Use With/related Products: ATA5773
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4.20.8.2
4.20.8.3
4.20.9
9137E–RKE–12/10
Temperature Measurement
Unipolar Differential Conversion
Bipolar Differential Conversion
If differential channels and an unipolar input mode are used, the result is
where V
and V
than the voltage of the negative pin or otherwise the voltage difference is saturated to zero.
The result is presented in one-sided form, from 0x000 (0d) through 0x3FF (+1023d). The
GAIN is either 1x or 20x.
If differential channels and a bipolar input mode are used, the result is
where V
and V
from 0x200 (-512d) through 0x1FF (+511d). The GAIN is either 1x or 20x. Note that if the user
wants to perform a quick polarity check of the result, it is sufficient to read the MSB of the
result (ADC9 in ADCH). If the bit is one, the result is negative, and if this bit is zero, the result
is positive.
As default the ADC converter operates in the unipolar input mode, but the bipolar input mode
can be selected by writting the BIN bit in the ADCSRB to one. In the bipolar input mode
two-sided voltage differences are allowed and thus the voltage on the negative input pin can
also be larger than the voltage on the positive input pin.
The temperature measurement is based on an on-chip temperature sensor that is coupled to a
single ended ADC8 channel. Selecting the ADC8 channel by writing the MUX5:0 bits in
ADMUX register to “100010” enables the temperature sensor. The internal 1.1V reference
must also be selected for the ADC reference source in the temperature sensor measurement.
When the temperature sensor is enabled, the ADC converter can be used in single conversion
mode to measure the voltage over the temperature sensor. The measured voltage has a linear
relationship to the temperature as described in Table 51. The voltage sensitivity is approxi-
mately 1 mV /
calibration. Bandgap is always calibrated and its accuracy is only guaranteed between 1.0V
and 1.2V
Table 4-49.
Temperature / °C
Voltage / mV
REF
REF
POS
POS
the selected voltage reference. The voltage of the positive pin must always be larger
the selected voltage reference. The result is presented in two’s complement form,
is the voltage on the positive input pin, V
is the voltage on the positive input pin, V
Temperature vs. Sensor Output Voltage (Typical Case)
°
C and the accuracy of the temperature measurement is +/-
243 mV
-40°C
ADC
ADC
=
=
---------------------------------------------------------- -
-------------------------------------------------------
V
V
POS
POS
–
–
V
V
V
V
NEG
REF
REF
NEG
314 mv
+25°C
1024
512
Atmel ATA5771/73/74
NEG
NEG
the voltage on the negative input pin,
the voltage on the negative input pin,
GAIN
GAIN
380 mV
+85°C
10°
C after offset
+125°C
424 mV
151