ATMEGA128RFA1-ZU Atmel, ATMEGA128RFA1-ZU Datasheet - Page 425

• Manufacturer Part Number: ATMEGA128RFA1-ZU
• Description: IC AVR MCU 2.4GHZ XCEIVER 64QFN
• Manufacturer: Atmel
• Series: ATMEGAr

Specifications of ATMEGA128RFA1-ZU

• Frequency: 2.4GHz
• Data Rate - Maximum: 2Mbps
• Modulation Or Protocol: 802.15.4 Zigbee
• Applications: General Purpose
• Power - Output: 3.5dBm
• Sensitivity: -100dBm
• Voltage - Supply: 1.8 V ~ 3.6 V
• Current - Receiving: 12.5mA
• Current - Transmitting: 14.5mA
• Data Interface: PCB, Surface Mount
• Memory Size: 128kB Flash, 4kB EEPROM, 16kB RAM
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-VFQFN, Exposed Pad
• Rf Ic Case Style: QFN
• No. Of Pins: 64
• Supply Voltage Range: 1.8V To 3.6V
• Operating Temperature Range: -40°C To +85°C
• Svhc: No SVHC (15-Dec-2010)
• Rohs Compliant: Yes
• Processor Series: ATMEGA128x
• Core: AVR8
• Data Bus Width: 8 bit
• Program Memory Type: Flash
• Program Memory Size: 128 KB
• Data Ram Size: 16 KB
• Interface Type: JTAG
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 38
• Number Of Timers: 6
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVR128RFA1-EK1
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

27.9 Internal Temperature Measurement
8266A-MCU Wireless-12/09
Table 27-7. Correlation Between Input Voltage and Output Codes
Example:
ADMUX = 0xED (ADC3 - ADC2, 10x gain, 1.6V reference, left adjusted result)
The voltage on ADC3 is 300 mV; the voltage on ADC2 is 425 mV.
ADCR = 512 * 10 * (300 - 425) / 1600 = -400 = 0x270.
ADCL will thus read 0x00, and ADCH will read 0x9C. Writing zero to ADLAR right
adjusts the result: ADCL = 0x70, ADCH = 0x02.
The on-chip temperature can be measured using a special setup of the A/D converter
inputs. The integrated temperature sensor provides a linear, medium-accurate voltage
proportional to the absolute temperature (in Kelvin). This voltage is first amplified with
the programmable gain amplifier and then processed with the A/D converter. A low
frequency of the conversion clock must be selected due to the nature of the input
signal. The absolute accuracy of the temperature measurement is limited by
manufacturing tolerances, noise from supply and ground voltages and the exactness of
the reference voltage. The following table summarizes the preferred setup of the
temperature measurement:
Table 27-8. Recommended ADC Setup for Temperature Measurement
The A/D conversion result ADC
can be calculated when using the internal 1.6V reference voltage according to the
following equation:
Similar the Celsius-temperature θ can be extracted from the A/D conversion result with
this formula:
V
V
V
V
…
V
V
V
…
V
V
Parameter
ADC Channel
ADC Clock
V
Start-up time
Tracking time
ADCn
ADCm
ADCm
ADCm
ADCm
ADCm
ADCm
ADCm
ADCm
REF
+ V
+ 0.999 V
+ 0.998 V
+ 0.001 V
- 0.001 V
- 0.999 V
- V
REF
REF
/ GAIN
/ GAIN
REF
REF
REF
REF
REF
Register
ADMUX,
ADCSRB
ADCSRA
ADMUX
ADCSRC
ADCSRC
/ GAIN
/ GAIN
/ GAIN
/ GAIN
/ GAIN
ADC
Read Code
0x1FF
0x1FF
0x1FE
…
0x001
0x000
0x3FF
…
0x201
0x200
Recommended Setup
Select the Temperature Sensor, MUX4:0 = 01001;
MUX5 = 1;
Select a clock frequency of 500kHz or lower;
Select the internal 1.6V reference voltage;
Standard requirement of 20µs is sufficient;
Setting ADTHT = 0 is sufficient;
TEMP
TEMP
will always be a positive number. The ideal result
=
241
4 .
+
. 0
885
ATmega128RFA1
⋅
θ
Corresponding Decimal Value
/
°
C
-511
-512
511
511
510
…
…
-1
1
0
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