Features
Fully Integrated Low IF Receiver
Fully Integrated GFSK Modulator for 72, 144, 288, 576 and 1152 Kbits/s
High Sensitivity of Typically –93 dBm Due to Integrated LNA
High Output Power of Typically +4 dBm
Multi-channel Operation
95 Channels
Support Frequency Hopping (ETSI) and Digital Modulation (FCC)
Supply-voltage Range 2.9V to 3.6V (Unregulated)
Auxiliary Voltage Regulator on Chip (3.2V to 4.6V)
Low Current Consumption
Few Low-cost External Components
Integrated Ramp-signal Generator and Power Control for an Additional Power Amplifier
Low Profile Lead-free Plastic Package QFN32 (5 mm × 5 mm × 0.9 mm)
RoHs Compliant
Applications
High-tech Multi-user Toys
Wireless Game Controllers
Telemetry
Wireless Audio/Video
Electronic Point of Sales
Wireless Head Set
FCC CFR47, Part 15, ETSI EN 300 328, EN 300 440 and ARIB STD-T-66 Compliant Radio
Links
1. Description
The ATR2406 is a single chip RF transceiver intended for applications in the 2.4-GHz
ISM band. The QFN32-packaged IC is a complete transceiver including image rejec-
tion mixer, low IF filter, FM demodulator, RSSI, TX preamplifier, power-ramping
generator for external power amplifier, integrated synthesizer, and a fully integrated
VCO and TX filter. No mechanical adjustment is necessary in production.
The RF transceiver offers a clock recovery function on-chip.
Low-IF 2.4-GHz
ISM Transceiver
ATR2406
4779N–ISM–12/08
2
4779N–ISM–12/08
ATR2406
Figure 1-1. Block Diagram
2. Pin Configuration
Figure 2-1. Pinning QFN32 - 5 × 5
LNA IR-Mixer
VCO
REG
REG_DEC
RAMP_OUT
TX_OUT
RX_IN
VREG_VCO
REG_CTRL VS_REG
VS_SYN
VREG IREF
CP REF_CLK TX_DATA VTUNE
AUX
REG
AUX
REG
TEST2
PU_REG
PU_TRX
RX_ON
TX_ON
nOLE
CLOCK
DATA
ENABLE
LIMITER
RSSI
DEMOD
BP
RAMP
GEN PLL
GAUSSIAN
FILTER
PA
CTRL
LOGIC
BUS
VCO
VS_IFD
RX_DATA
RSSI
VS_IFA
VS_RX/TX
TEST1
Divider
by 2
32
1
2
3
4
5
6
7
8
RX_ON
IC
IC
RAMP_OUT
TX_OUT
RX_IN1
RX_IN2
VS_TRX
RX_ON
IC
IC
RAMP_OUT
TX_OUT
RX_IN1
RX_IN2
VS_TRX
PU_REG
PENABLE
DATA
CLOCK
TX_DATA
RX_DATA
PU_TRX
nOLE
TX_ON
REG_CTRL
VREG
VS_REG
REG_DEC
VREG_VCO
VTUNE
CP
VS_SYN
RSSI
VS_IFD
VS_IFA
RX-CLOCK
IC
IREF
REF_CLK
24
23
22
21
20
19
18
17
31 30 29 28 27 26 25
9 10111213141516
ATR2406
3
4779N–ISM–12/08
ATR2406
Table 2-1. Pin Description
Pin Symbol Function
1 PU_REG Power-up input for auxiliary regulator
2 REF_CLK Reference frequency input
3 RSSI Received signal strength indicator output
4 VS_IFD Digital supply voltage
5 VS_IFA Analog supply voltage for IF circuits
6 RX-CLOCK RX-CLOCK, if RX mode with clock recovery is active
7 IC Internally connected. Connect to VS if internal AUX regulator is not used
8 IREF External resistor for band-gap reference
9 REG_CTRL Auxiliary voltage regulator control output
10 VREG Auxiliary voltage regulator output
11 VS_REG Auxiliary voltage regulator supply voltage
12 REG_DEC Decoupling pin for VCO_REG
13 VREG_VCO VCO voltage regulator
14 VTUNE VCO tuning voltage input
15 CP Charge-pump output
16 VS_SYN Synchronous supply voltage
17 VS_TRX Transmitter receiver supply voltage
18 RX_IN2 Differential receiver input 2
19 RX_IN1 Differential receiver input 1
20 TX_OUT TX driver amplifier output
21 RAMP_OUT Ramp generator output for PA power ramping
22 IC Internally connected, do not connect on PCB
23 IC Internally connected, do not connect on PCB
24 RX_ON RX control input
25 TX_ON TX control input
26 nOLE Open loop enable input
27 PU_TRX RX/TX/PLL/VCO power-up input
28 RX_DATA RX data output
29 TX_DATA TX data input
30 CLOCK 3-wire-bus: Clock input
31 DATA 3-wire-bus: Data input
32 ENABLE 3-wire-bus: Enable input
Paddle GND Ground
4
4779N–ISM–12/08
ATR2406
3. Functional Description
3.1 Receiver
The RF signal at RF_IN is differentially fed through the LNA to the image rejection mixer
IR_MIXER, driving the integrated low-IF band-pass filter. The IF frequency is 864 kHz. The limit-
ing IF_AMP with an integrated RSSI function feeds the signal to the digital demodulator
DEMOD. No tuning is required. Data slicing is handled internally.
3.2 Clock Recovery
For a 1152-kBit/s data rate, the receiver has a clock recovery function on-chip.
The receiver includes a clock recovery circuit which regenerates the clock out of the received
data. The advantage is that this recovered clock is synchronous to the clock of the transmitting
device (and thus to the transmitted data), which significantly reduces the load of the processing
microcontroller.
The falling edge of the clock is the optimal sampling position for the RX_Data signal, so at this
event the data must be sampled by the microcontroller. The recovered clock is available at pin 6.
3.3 Transmitter
The transmit data at TX_DATA is filtered by an integrated Gaussian filter (GF) and fed to the
fully integrated VCO operating at twice the output frequency. After modulation, the signal is fre-
quency divided by 2 and fed to the internal preamplifier PA. This preamplifier supplies typically
+4 dBm output power at TX_OUT.
A ramp-signal generator RAMP_GEN, providing a ramp signal at RAMP_OUT for the external
power amplifier, is integrated. The slope of the ramp signal is controlled internally so that spuri-
ous requirements are fulfilled.
3.4 Synthesizer
The IR_MIXER, the PA, and the programmable counter (PC) are driven by the fully integrated
VCO, using on-chip inductors and varactors. The output signal is frequency divided to supply the
desired frequency to the TX_DRIVER, the 0/90 degree phase shifter for the IR_MIXER, and to
be used by the PC for the phase detector (PD) (fPD = 1.728 MHz). Open loop modulation is
supported.
3.5 Power Supply
An integrated band-gap–stabilized voltage regulator for use with an external low-cost PNP tran-
sistor is implemented. Multiple power-down and current saving modes are provided.
5
4779N–ISM–12/08
ATR2406
Electrostatic sensitive device.
Observe precautions for handling.
4. Absolute Maximum Ratings
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating
only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this
specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Parameters Symbol Min. Max. Unit
Supply voltage auxiliary regulator VS–0.3 +4.7 V
Supply voltage VS–0.3 +3.6 V
Control voltages Vcontr –0.3 VSV
Storage temperature Tstg –40 +125 °C
Input RF level PRF +10 dBm
ESD protection VESD_ana TBD V
VESD_dig TBD V
5. Operating Range
Parameters Symbol Min. Max. Unit
Supply voltage VS2.9 3.6 V
Auxiliary regulator supply voltage VS_BATT 3.2 4.6 V
Temperature ambient Tamb –10 +60 °C
Input frequency range fRX 2400 2483 MHz
6
4779N–ISM–12/08
ATR2406
6. Electrical Characteristics
VS = 3.6V with AUX regulator, Tamb = 25°C, unless otherwise specified
No. Parameters Test Conditions Symbol Min. Typ. Max. Unit
1 Supply
1.1 Supply voltage With AUX regulator VS3.2 3.6 4.6 V
1.2 Supply voltage Without AUX regulator VS2.9 3.0 3.6 V
1.3 RX supply current CW mode (peak current) IS57 mA
Burst mode at 10 Kbits/s(4) IS625 µA
1.4 TX supply current CW mode (peak current) IS42 mA
Burst mode at 10 Kbits/s(4) IS500 µA
1.5
Battery lifetime of a remote
control application using an
AVR®
See Section 10. “Appendix: Current
Calculations for a Remote Control”
on page 20
1.6 Supply current in power-down
mode
With AUX regulator
PU_TRX = 0; PU_REG = 0 IS< 1 µA
1.7 Supply current in power-down
mode
Without AUX regulator
PU_TRX = 0; PU_REG = 0 IS< 1 µA
2 Voltage Regulator
2.1 AUX regulator VREG 3.0 V
2.2 VCO regulator VREG_VCO 2.7 V
3 Transmitter Part
3.1 TX data rate 72/144/288/576/1152 kBits/s
3.2 Output power PTX 4 dBm
3.3 TX data filter clock 9 taps in filter fTXFCLK 10.368/13.824 MHz
3.4 Frequency deviation To be tuned by GFCS bits GFFM_nom ±400 kHz
3.5 Frequency deviation scaling(3) GFFM = GFFM_nom × GFCS
(Refer to bus protocol D9 to D11) GFCS 60 130 %
3.6 Frequency drift
With standard loop filter and slot
length of 1400 µs (Refer to the
application note “ATR2406 Loop
Filter and Data Rates”)
Δfo (drift) ±40 kHz
3.7 Harmonics BW = 100 kHz(1) –41.2 dBm
3.8
Spurious emissions
30 – 1000 MHz
1 – 12.75 GHz
1.8 – 1.9 GHz
5.15 – 5.3 GHz
BW = 100 kHz(1) –57
–57
–57
–57
dBm
dBm
dBm
dBm
4 Ramp Generator, Pin 21
4.1 Minimum output voltage TX_ON = low Vmin 0.7 V
4.2 Maximum output voltage Refer to bus protocol D12 to D13 Vmax 1.1 1.9 V
4.3 Rise time trs
4.4 Fall time tfs
Notes: 1. Measured and guaranteed only on the Atmel® evaluation board, including microstrip filter, balun, and Smart Radio Fre-
quency (Smart RF) firmware. Conducted measured.
2. Timing is determined by external loop filter characteristics. Faster timing can be achieved by modification of the loop filter.
For further information refer to the application notes.
3. The Gaussian filter control setting (GFCS) is used to compensate production tolerances by tuning the modulation deviation
in production to the nominal value of 400 kHz.
4. Burst mode with 0.9% duty cycle
7
4779N–ISM–12/08
ATR2406
5 Receiver Part
5.1 RX input impedance Differential Zin 170 + j0 Ω
5.2 Sensitivity At input for BER 10-3
at 1152 kBits/s(1) –93 dBm
5.3 Third order input intercept point IIP3 –15 dBm
5.4 Intermodulation rejection
BER < 10-3, wanted at -83 dBm,
level of interferers in channels
N + 2 and N + 4(1) IM332 dBc
5.5 Co-channel rejection BER < 10-3, wanted at –76 dBm(1) RCO –11 dBc
5.6 Adjacent channel rejection
±1.728 MHz
BER < 10-3, wanted at –76 dBm,
adjacent level referred to wanted
channel level(1) Ri (N – 1) 14 dBc
5.7 Bi-adjacent channel rejection
±3.456 MHz
BER < 10-3, wanted at –76 dBm,
bi-adjacent level referred to wanted
channel level(1) Ri (N – 2) 30 dBc
5.8
Rejection with 3 channels
separation
±5.128 MHz
BER < 10-3, wanted at –76 dBm,
n3 adjacent level referred to
wanted channel level(1) Ri (n 3) 40 dBc
5.9 Out of band rejection > 6 MHz BER < 10-3, wanted at –83 dBm at
2.45 GHz(1) Bldf>6MHz 38 dBc
5.10
Out of band rejection
2300 MHz to 2394 MHz
2506 MHz to 2600 GHz
BER < 10-3, wanted at –83 dBm at
2.45 GHz(1) Blnear 47 dBc
5.11
Out of band rejection
30 MHz to 2300 MHz
2600 MHz to 6 GHz
BER < 10-3, wanted at –83 dBm at
2.45 GHz(1) Blfar 57 dBc
6 RSSI Part
6.1 Maximum RSSI output voltage Under high RX input signal level VRSSImax 2.1 V
6.2 RSSI output voltage, monotonic
over range –96 dBm to –36 dBm
With –33 dBm at RF input
With –96 dBm at RF input VRSSI 1.9
0.1
V
V
7VCO
7.1 Oscillator frequency defined at
TX output Over full temperature range(1) 2400 2483 MHz
7.2 Frequency control voltage range VVTUNE 0.5 VCC – 0.5 V
7.3 VCO tuning input gain defined at
TX output GVCO 240 MHz/V
6. Electrical Characteristics (Continued)
VS = 3.6V with AUX regulator, Tamb = 25°C, unless otherwise specified
No. Parameters Test Conditions Symbol Min. Typ. Max. Unit
Notes: 1. Measured and guaranteed only on the Atmel® evaluation board, including microstrip filter, balun, and Smart Radio Fre-
quency (Smart RF) firmware. Conducted measured.
2. Timing is determined by external loop filter characteristics. Faster timing can be achieved by modification of the loop filter.
For further information refer to the application notes.
3. The Gaussian filter control setting (GFCS) is used to compensate production tolerances by tuning the modulation deviation
in production to the nominal value of 400 kHz.
4. Burst mode with 0.9% duty cycle
8
4779N–ISM–12/08
ATR2406
8 Synthesizer
8.1 External reference input
frequency
D7 = 0
D7 = 1 REF_CLK 10.368
13.824
MHz
MHz
8.2 Sinusoidal input signal level
(peak-to-peak value) AC-coupled sine wave REF_CLK 500 1000 mVPP
8.3 Scaling factor prescaler SPSC 32/33 -
8.4 Scaling factor main counter SMC 86/87/88/89 -
8.5 Scaling factor swallow counter SSC 031-
9 Phase Detector
9.1 Phase detector comparison
frequency fPD 1728 kHz
10 Charge-pump Output
10.1 Charge-pump output current VCP = 1/2 VCC ICP ±2 mA
10.2 Leakage current VCP = 1/2 VCC IL±100 1000 pA
11 Timing Conditions(1)(2)
11.1 Transmit to receive time Reference clock stable TX RX time 200 µs
11.2 Receive to transmit time Reference clock stable RX TX time 200 µs
11.3 Channel switch time Reference clock stable CS time 200 µs
11.4 Power down to transmit Reference clock stable PD TR time 250 µs
11.5 Power down to receive Reference clock stable PD RX time 200 µs
11.6 Programming register Reference clock stable PRR time 3 µs
11.7 PLL settling time Reference clock stable PLL set time 200 µs
12 Interface Logic Input and Output Signal Levels, Pin DATA, CLOCK, ENABLE
12.1 HIGH-level input voltage Logic 1 VIH 1.4 3.1 V
12.2 LOW-level input voltage Logic 0 VIL –0.3 +0.4 V
12.3 HIGH-level output voltage Logic 1 VOH 3.1 V
12.4 LOW-level output voltage Logic 0 VOL 0V
12.5 Input bias current Logic 1 or logic 0 Ibias –5 +5 µA
12.6 3-wire bus clock frequency fCLKmax 10 MHz
6. Electrical Characteristics (Continued)
VS = 3.6V with AUX regulator, Tamb = 25°C, unless otherwise specified
No. Parameters Test Conditions Symbol Min. Typ. Max. Unit
Notes: 1. Measured and guaranteed only on the Atmel® evaluation board, including microstrip filter, balun, and Smart Radio Fre-
quency (Smart RF) firmware. Conducted measured.
2. Timing is determined by external loop filter characteristics. Faster timing can be achieved by modification of the loop filter.
For further information refer to the application notes.
3. The Gaussian filter control setting (GFCS) is used to compensate production tolerances by tuning the modulation deviation
in production to the nominal value of 400 kHz.
4. Burst mode with 0.9% duty cycle
9
4779N–ISM–12/08
ATR2406
7. PLL Principle
Figure 7-1. PLL Principle
"- Main counter MC
"- Swallow counter SC
fCVO = 1728kHz x (SMC x 32 + SSC)
Programmable counter PC
VCO
TXDAT
Baseband controller
Reference counter (RC)
REF_CLK D7
13.824MHz 1
10.368MHz 0
Mixer
PA driver
Gaussian
filter (GF)
Divide
by 2
Charge
pump
External
loop filter
PLL reference frequency
REF_CLK
Phase frequency
detector (PD)
fPD = 1728kHz
10
4779N–ISM–12/08
ATR2406
Table 7-1 shows the LO frequencies for RX and TX in the 2.4-GHz ISM band. There are 95
channels available. Since the ATR2406 supports wideband modulation with 400-kHz deviation,
every second channel can be used without overlap in the spectrum.
7.1 TX Register Setting
The following 16-bit word has to be programmed for TX.
Note: D12 and D13 are only relevant if ramping generator in conjunction with external PA is used, otherwise it can be programmed 0
or 1.
The VRAMP voltage is used to control the output power of an external power amplifier. The volt-
age ramp is started with the TX_ON signal.
These bits are only relevant in TX mode.
Table 7-1. LO Frequencies
Mode fIF /kHz Channel f
ANT /MHz f
VCO / MHz divided by 2 SMC SSC N
TX
C0 2401.056 2401.056 86 27 2779
C1 2401.920 2401.920 86 28 2780
... ... ... ... ... ...
C93 2481.408 2481.408 89 24 2872
C94 2482.272 2482.272 89 25 2873
RX 864
C0 2401.056 2401.920 86 28 2780
C1 2401.920 2402.784 86 29 2781
... ... ... ... ... ...
C93 2481.408 2482.272 89 25 2873
C94 2482.272 2483.136 89 26 2874
MSB LSB
Data bits
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
01 PA GFCS 1RC MC SC
Table 7-2. Output Power Settings with Bits D12 - D13
PA (Output Power Settings)
D13 D12 RAMP_OUT (Pin 21)
0 0 1.3V
0 1 1.35V
1 0 1.4V
1 1 1.75V
11
4779N–ISM–12/08
ATR2406
7.2 RX Register Setting
There are two RX settings possible. For a data rate of 1152 kBits/s, an internal clock recovery
function is implemented.
7.3 Register Setting Without Clock Recovery
Must be used for data rates below 1.152 Mbits/s.
Note: X values are not relevant and can be set to 0 or 1.
7.4 RX Register Setting with Internal Clock Recovery
Recommended for 1.152-Mbit/s data rate.
The output pin of the recovered clock is pin 6. The falling edge of the recovered clock signal
samples the data signal.
Note: X values are not relevant and can be set to 0 or 1.
7.5 PLL Settings
RC, MC and SC bits control the synthesizer frequency as shown in Table 7-3, Table 7-4 on page
12 and Table 7-5 on page 12.
Formula for calculating the frequency:
TX frequency: fANT = 864 kHz × (32 × SMC + SSC)
RX frequency: fANT = 864 kHz × (32 × SMC + SSC – 1)
MSB LSB
Data bits
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
01XXXXX0RC MC SC
MSB
Data bits
D24 D23 D22 D21 D20 D19 D18 D17 D16
10100 0000
LSB
Data bits
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
00XXX XX0RC MC SC
Table 7-3. PLL Settings of the Reference Counter Bit D7
RC (Reference Counter)
D7 CLK Reference
0 10.368 MHz
1 13.824 MHz
12
4779N–ISM–12/08
ATR2406
7.6 GFCS Adjustment
The Gaussian filter control setting (GFCS) is used to compensate for production tolerances by
tuning the modulation deviation in production to the nominal value of 400 kHz. These bits are
only relevant in TX mode.
Table 7-4. PLL Settings of the Main Counter Bits D5 to D6
MC (Main Counter)
D6 D5 SMC
0086
0187
1088
1189
Table 7-5. PLL Settings of the Swallow Counter Bits D0 to D4
SC (Swallow Counter)
D4 D3 D2 D1 D0 SSC
000000
000011
000102
... ... ... ... ... ...
1110129
1111030
1111131
Table 7-6. GFCS Adjustment of Bits D9 - D11
GFCS
D11 D10 D9 GFCS
00 060%
00 170%
01 080%
01 190%
1 0 0 100%
1 0 1 110%
1 1 0 120%
1 1 1 130%
13
4779N–ISM–12/08
ATR2406
7.7 Control Signals
The various transceiver functions are activated by the following control signals. A timing pro-
posal is shown in Figure 7-3 on page 14
7.8 Serial Programming Bus
The transceiver is programmed by the SPI (CLOCK, DATA and ENABLE).
After setting the enable signal to low, the data is transferred bit by bit into the shift register on the
rising edge of the clock signal, starting with the MSBit. When the enable signal has returned to
high, the programmed information is active. Additional leading bits are ignored and there is no
check made of how many clock pulses arrived during enable low.
The programming of the transceiver is done by a 16-bit or 25-bit data word (for the RX clock
recovery mode).
7.9 3-wire Bus Timing
Figure 7-2. 3-wire Bus Protocol Timing Diagram
Table 7-7. Control Signals and Functions
Signal Functions
PU_REG Activates AUX voltage regulator and the VCO voltage regulator supplying the
complete transceiver
PU_TRX Activates RX/TX blocks
RX_ON Activates RX circuits: DEMOD, IF AMP, IR MIXER
TX_ON Activates TX circuits: PA, RAMP GEN, Starts RAMP SIGNAL at RAMP_OUT
nOLE Disables open loop mode of the PLL
TTTEC
TH
TS
ENABLE
CLOCK
DATA
TL TCTPER
Table 7-8. 3-wire Bus Protocol Table
Description Symbol Minimum Value Unit
Clock period TPER 100 ns
Set time data to clock TS 20 ns
Hold time data to clock TH 20 ns
Clock pulse width TC 60 ns
Set time enable to clock TL 100 ns
Hold time enable to data TEC 0 ns
Time between two protocols TT 250 ns
14
4779N–ISM–12/08
ATR2406
Figure 7-3. Example TX and RX Timing Diagram
Power up Programming Programming Active TX slotActive RX slot Power down
optional
Power up
optional
Power down
Power down
> 40μs
> 200μs
C2
C1
> 40μs
> 50μs
> 50μs
Data
Pin name
MODE
PU_REG
Pin 1
PU_TRX
Pin 27
TX_DATA
Pin 29
3W_CLK
Pin 30
3W_DATA
Pin 31
3W_ENA
Pin 32
nOLE
Pin 26
REF_CLK
Pin 2
RX_ON
TRX (Output)
Signals fromSignals to TRX (Input)
Pin 24
TX_ON
Pin 25
RX_DATA
Pin 28
RSSI
Pin 3
RAMP_OUT
Pin 21
connected to
RAMP_IN of
optional PA Note: 1. Keep input signals at low level during power-down state of TRX
C3 C4 C1
C1 C2 C5
C3
16/25 bits
> 200μs
Preamble
(1-0-1-0)
16 bits
REF_CLK
VS
0V
VS
0V
REF_CLK
Valid signal
15
4779N–ISM–12/08
ATR2406
7.10 Received Signal Strength Indication (RSSI)
The RSSI is given as an analog voltage at the RSSI pin. A typical plot of the RSSI value is
shown in Figure 7-4.
Figure 7-4. Typical RSSI Value versus Input Power
Table 7-9. Description of the Conditions/States
Condition Description
C1 Power down
ATR2406 is switched off and the supply current is lower than 1 µA.
C2
Power up
ATR2406 is powered up by toggling PU_REG and PU_TRX to high.
PU_REG enables the external AUX regulator transistor including VCO regulator.
PU_TRX enables internal blocks like the PLL and the VCO.
Depending on the value of the external capacitors (for example, at the AUX
regulator, if one is used), it is necessary to wait at least 40 µs until the different
supply voltages have settled.
C3
Programming
The internal register of the ATR2406 is programmed via the three-wire interface.
At TX, this is just the PLL (transmit channel) and the deviation (Gaussian filter).
At RX, this is just the PLL (receive channel) and, if the clock recovery is used, also
the bits to enable this option. At the start of the three-wire programming, the
enable signal is toggled from high to low to enable clocking the data into the
internal register. When the enable signal rises again to high, the programmed
data is latched. This is the time point at which the settling of the PLL starts. It is
necessary to wait the settling time of 200 µs so that the VCO frequency is stable.
The reference clock needs to be applied to ATR2406 for at least the time when the
PLL is in operation, which is the programming state (C3) and the active slot (C4,
C5). Out of the reference clock, several internal signals are also derived, for
example, the Gaussian filter circuitry and TX_DATA sampling.
C4 This is the receive slot where the transmit burst is received and data as well as
recovered clock are available.
C5
This is the active transmit slot. As soon as TX_DATA is applied to ATR2406, the
signal nOLE toggles to low which enables modulation in open-loop mode.
The preamble (1-0-1-0 pattern) should start being sent at the start of TX_ON.
-130 -110 -90 -70 -50 -30 -10 10
RF Level (dBm)
2.5
2.0
1.5
1.0
0.5
0
RSSI Level (V)
16
4779N–ISM–12/08
ATR2406
8. Application Circuit
The ATR2406 requires only a few low-cost external components for operation. A typical applica-
tion is shown in Figure 8-3 on page 17.
8.1 Typical Application Circuit
Figure 8-1. Microcontroller Interfacing with General Purpose MCU, Pin Connections between
Microcontroller and ATR2406
Figure 8-2. Example with AVR MCU
Note: 1. XTAL: for example, XRFBCC-NANL; 13.824 MHz, 10 ppm
Order at: Taitien Electronic, Taitien Specific No.: A009-x-B26-3, SMD
Microcontroller ATR2406
Configuration
and control
RF-DATA
Interface
TX_DATA
RX_DATA
RX-CLOCK
DATA
CLOCK
ENABLE
Ctrl_Lines
XTAL_OUT REF_CLK
XTAL(1)
ATR2406
RF_CTRL
RF_DATA
AVR_MCU
USART
GPIO
R
13.824MHz XTAL REF_CLK
nOLE
ENABLE
CLOCK
DATA
TX_ON
RX_ON
PU_TRX
PU_REG
GPIO1
GPIO2
TXD
RXD
XCK
GPIO3
GPIO4
GPIO5
TX_DATA
RX_DATA
RX-CLOCK
RSSI
17
4779N–ISM–12/08
ATR2406
Figure 8-3. Application Circuit for ATR2406-DEV-BOARD
R1
C3
C1
2.2pF
2.2pF
5.6pF
31
32
29
30
27
28
25 G
15
16
9
10
11
12
13
14
26
TP2TP1
24
23
22
20
19
18
17
21
1
3
5
9
11
13
15
17
19
23
27
25
21
7
2
4
6
10
12
14
16
18
20
24
28
26
22
8
8
7
3
2
1
4
5
6
RX_DATA
RSSI
RX_CLOCK
REF_CLK
PU_REG
ENABLE
DATA
CLOCK
nOLE
PU_TRX
RAMP_OUT
RX_ON
VBATT
TX_DATA
CLOCK
TX_DATA
ENABLE
VS_IFA
VS_IFD
RSSI
REF_CLK
IREF
IC
RX_CLOCK
PU_REG
TX_OUT
RAMP_OUT
IC
IC
VS_TRX
RX_IN2
RX_IN1
RX_ON
DATA
RX_DATA
PU_TRX
TX_ON
nOLE
REG_DEC
VREG_VCO
REG_CTRL
VS_REG
VREG
VTUNE
CP
GND
VS_SYN
TX_ON
1.5pF
1.8pF
C24
C13
J2
VS
4.7μF
C12
100nF
C15
100nF
C16
4.7pF
4.7μF
C4
C17
390pF
C29
4.7nF
C11
R3
T1
BC808
18pF
C6
C9
1.8pF
C10
C7
R2 NC
J2
J24
RSSI
RX_ON
CLOCK
PU_TRX
TX_DATA
TX_ON
VBATT
J10
J3
REF_CLK
J9
J8
J7
J6
J5
J4 J11
J12
J13
J14
J20
J19
J18
J17
J16
J15
VBATT
ENABLE
DATA
nOLE
RX_DATA
RX_CLOCK
PU_REG
NC
SMASI
GND
ANT2
ANT
F antenna
Select integrated F antenna or
SMA connector by setting the
0 resistor
ANT GND
Microstrip
Microstrip
balun
Microstrip
ATR2416
Microstrip
Low-passfilter
C14
GND5
GND4
GND9
GND8
GND7
GND2
GND3
GND1
GND6
IC2
RFOUT (Ant)
R4
1kΩ
R6
R5
1.5kΩ
1.5kΩ
62kΩ
NC
C21
J26
C20, C21, COG
dielectric
C18 2.2nF
68pF
C19
470nF
C20
IC2P
GND
Slug
22nF
RAMP
NC
J21
18
4779N–ISM–12/08
ATR2406
9. PCB Layout Design
Figure 9-1. PCB Layout ATR2406-DEV-BOARD
19
4779N–ISM–12/08
ATR2406
Table 9-1. Bill of Materials
Part Value Part Number Vendor Package Comment
C1 5.6 pF 0402
C3, C10 1.8 pF 0402
C4 390 pF 0402
C5 4.7 pF 0402 NC
C6, C7 2.2 pF 0402
C9 1.5 pF 0402
C11 18 pF 0402
C12, C15 100 nF 0402
C13, C16 4.7 µF B45196H2475M109 Epcos®3216 Optional(2)
C14 1 nF 0402 NC
C17 3.3 nF 0402 NC
C18 68 pF 0402
C19 470 nF 0402/0603
C20 22 nF, COG GRM21B5C1H223JA01 Murata 0805 COG, important for good
RF performance
C21 2.2 nF,
COG GRM1885C1H222JA01 Murata 0603 COG, important for good
RF performance
C23 4.7 nF 0402
C24 4.7 pF 0402
R3 62 kΩ62k, 5% 0402
R4 1.0 kΩ1k0, 5% 0402
R5 1.5 kΩ1k5, 5% 0402 Ref_Clk level, optional(1)
R6 1.5 kΩ1k5, 5% 0402 Ref_Clk level, optional(1)
IC2 ATR2406 ATR2406 Atmel MLF32
T1 BC808-40 BC808-40, any standard type can be used, but it is
important that be “–40”!
Vishay®, Philips®,
etc. SOT-23 Optional(2)
MSUB FR4 FR4, e_r = 4.4 at 2.45 GHz, H = 500 µm, T = 35 µm, tand = 0.02, surface, that is, chem. tin or chem. gold
Notes: 1. Not necessary if supplied RefClk level is within specification range
2. If no AUX regulator is used, then T1 and C16 can be removed and a jumper is needed from the collector to the emitter pad.
Additionally, pin 7 of the ATR2406 has to be connected to pin 4 or pin 5 to use the integrated F antenna, set jumper R2 (0R
resistor 0603)
Table 9-2. Parts Count Bill of Materials
Parts Count Required (Minimal BOM) Optional (Depending on Application)
Capacitors 0402 14 14
Capacitors >0402 2 4
Resistors 0402 2 2
Inductors 0402
Semiconductors 1 2
20
4779N–ISM–12/08
ATR2406
10. Appendix: Current Calculations for a Remote Control
Assumptions:
Basic Numbers:
Amount of Current Needed to Transmit One Packet:
Protocol
A data packet consists of 24 bytes.
24 bytes = 240 bits (USART connection)
Tpacket_length = 210 µs at 1.152 Mbits/s
Channel The system will use five predefined channels for frequency hopping spread
spectrum (FHSS) which gives improved immunity against interferers
Loop filter Loop filter settling time will be 110 µs
Handheld device
If not in use, the handheld device will be in power-down mode with the AVR’s
watchdog timer disabled. The AVR power-down current is typically 1.25 µA. If
an external voltage regulator is used, additional power-down current has to be
taken into account
Base station device
The base station will periodically scan all the channels of the used subset. The
base station will stay on one channel for 2 seconds. If the base station receives
a correct packet, an acknowledge will be returned to the handheld device. The
power consumption of the base station device is not power-sensitive, as this
part of the application is normally mains powered
Peak current ATR2406 in TX at 1.152 Kbits/s 42 mA
Peak current ATR2406 in RX at 1.152 Kbits/s 57 mA
Peak current ATR2406 with synthesizer running 26 mA
Current ATmega88 active 5 mA
Current ATmega88 power down (no WDT) 1.25 µA
Current ATmega88 power down (+ WDT) 5 µA
Loop settling time of ATR2406 110 µs
Configuration of ATR2406 30 µs
Time needed for exchanging a packet at 1.152 Kbits/s 210 µs
Q1 = (0.005A + 0.026A) ×5030 µs = 155 µAs (charge up time ATR2406 + AVR internal calculations)
Q2 = (0.005A + 0.026A) ×30 µs = 0.93 µAs (charge for configuring the ATR2406)
Q3 = (0.005A + 0.026A) ×110 µs = 3.41 µAs (charge for settling the loop filter)
Q4 = (0.005A + 0.042A) ×210 µs = 9.87 µAs (charge for transmitting the packet)
Q5 = (0.005A) ×250 µs = 1.25 µAs (charge for turn around (TX to RX, RX to TX, etc.))
Q6 = (0.005A + 0.026A) ×30 µs = 0.93 µAs (charge for configuring the ATR2406)
Q7 = (0.005A + 0.026A) ×60 µs = 1.86 µAs (charge for settling the loop filter)
Q8 = (0.005A + 0.057A) ×50 µs = 3.10 µAs (charge until valid data can be received)
Q9 = (0.005A + 0.057A) ×210 µs = 13.02 µAs (charge for receiving the packet)
Q10 = (0.005A + 0.057A) ×50 µs = 3.1 µAs (charge for latency before receiving)
21
4779N–ISM–12/08
ATR2406
A successful packet exchange needs the following charge
Q = Q1 + Q2 + Q3 + Q4 + Q5 + Q6 + Q7 + Q8 + Q9 + Q10 = 192.47 µAs
As the described system is a FHSS system with 5 different channels, the system has to do this
up to five times before the packet is acknowledged by the base station. The average will be 2.5
times. In the case of an interfered environment, some more retries may be required; therefore, it
is assumed the factor will be 3. The power-up time is included only once, as the cycle will be
completed without powering up and down the handheld in order to be as power efficient as
possible.
Average current needed for a packet exchange:
155 µAs + (37.5 µAs ×3) = 267.5 µAs
If the device will be used 1000 times a day 3.1 µA
Average current in active mode:
System Power Down current:
Current ATmega88: 1.25 µA
Current ATR2406: 1.0 µA
Current VREG (+ ShutDown): 2.75 µA
Assumed average power-down current is 5 µA.
Overall power consumption is 8.1 µA
It is assumed the system uses a small battery with a capacity of 100 mAh. This is 100.000 µAh.
Battery lifetime will be around: 12345 hours = 514 days = 1.4 years.
The most important factor is to get the power-down current as low as possible!
Example:
Assume a system where the handheld is used just 10 times per day.
Iactive = 0.031 µA
and assuming the power-down current of this device is just 4 µA.
I = 0.031 µA + 4 µA = 4.03 µA
Battery lifetime will be around 24807 hours = 1033 days = 2.83 years.
Power-down current is the main factor influencing the battery lifetime.
22
4779N–ISM–12/08
ATR2406
12. Package Information
11. Ordering Information
Extended Type Number Package Remarks MOQ
ATR2406-PNQG QFN32 - 5x5 Taped and reeled, Pb-free 4000
ATR2406-DEV-BOARD RF module 1
ATR2406-DEV-KIT2
Complete evaluation kit
and reference design
ATR2406 + ATmega88
1
32
5
1
916
3225
17
24
8
1
5
3.7
3.5
0.5 nom.
0.23
0.4
0.9±0.1
0.05-0.05
+0
specifications
according to DIN
technical drawings
Issue: 1; 22.01.03
Drawing-No.: 6.543-5096.01-4
Package: QFN 32 - 5 x 5
Exposed pad 3.7 x 3.7
Dimensions in mm
Not indicated tolerances ± 0.05
23
4779N–ISM–12/08
ATR2406
13. Recommended Footprint/Landing Pattern
Figure 13-1. Recommenced Footprint/Landing Pattern
Table 13-1. Recommended Footprint/Landing Pattern Signs
Sign Size
A 3.2 mm
B 1.2 mm
C 0.3 mm
a 1.1 mm
b 0.3 mm
c 0.2 mm
d0.55 mm
e 0.5 mm
24
4779N–ISM–12/08
ATR2406
14. Revision History
Please note that the following page numbers referred to in this section refer to the specific revision
mentioned, not to this document.
Revision No. History
4779N-ISM-12/08 Put datasheet in a new template
Section 12 “Package Information” on page 22 changed
4779M-ISM-02/07 Put datasheet in a new template
Table 9-1 “Bill of Materials” on page 19 changed
4779L-ISM-08/06
Table “Electrical Characteristics” on pages 6 to 8 changed
Section 10 “Appendix: Current Calculations for a Remote Control” on
pages 20 to 21 changed
Table “Ordering Information” on page 22 changed
Minor corrections to grammar and style throughout document
4779K-ISM-06/06
Put datasheet in a new template
Table “Electrical Characteristics” on pages 6 to 8 changed
Section 10 “Appendix: Current Calculations for a Remote Control” on
pages 20 to 21 added
Ordering Information on page 22 changed
4779N–ISM–12/08
Headquarters International
Atmel Corporation
2325 Orchard Parkway
San Jose, CA 95131
USA
Tel: 1(408) 441-0311
Fax: 1(408) 487-2600
Atmel Asia
Unit 1-5 & 16, 19/F
BEA Tower, Millennium City 5
418 Kwun Tong Road
Kwun Tong, Kowloon
Hong Kong
Tel: (852) 2245-6100
Fax: (852) 2722-1369
Atmel Europe
Le Krebs
8, Rue Jean-Pierre Timbaud
BP 309
78054
Saint-Quentin-en-Yvelines Cedex
France
Tel: (33) 1-30-60-70-00
Fax: (33) 1-30-60-71-11
Atmel Japan
9F, Tonetsu Shinkawa Bldg.
1-24-8 Shinkawa
Chuo-ku, Tokyo 104-0033
Japan
Tel: (81) 3-3523-3551
Fax: (81) 3-3523-7581
Product Contact
Web Site
www.atmel.com
Technical Support
cordless_phone@atmel.com
Sales Contact
www.atmel.com/contacts
Literature Requests
www.atmel.com/literature
Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any
intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN ATMEL’S TERMS AND CONDI-
TIONS OF SALE LOCATED ON ATMEL’S WEB SITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY
WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDEN-
TAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT OF
THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no
representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications
and product descriptions at any time without notice. Atmel does not make any commitment to update the information contained herein. Unless specifically provided
otherwise, Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel’s products are not intended, authorized, or warranted for use
as components in applications intended to support or sustain life.
© 2008 Atmel Corporation. All rights reserved. Atmel®, Atmel logo and combinations thereof, AVR® and others are registered trademarks or
trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others.