ATA5745C/ATA5746C
UHF ASK/FSK Receiver
DATASHEET
Features
● Transparent RF receiver ICs for 315MHz (Atmel® ATA5746C) and 433.92MHz
(Atmel ATA5745C) with high receiving sensitivity
● Fully integrated PLL with low phase noise VCO, PLL, and loop filter
● High FSK/ASK sensitivity:
●
●
●
●
–105dBm (Atmel ATA5746C, FSK, 9.6Kbits/s, Manchester, BER 10-3)
–114dBm (Atmel ATA5746C, ASK, 2.4Kbits/s, Manchester, BER 10-3)
–104dBm (Atmel ATA5745C, FSK, 9.6Kbits/s, Manchester, BER 10-3)
–113dBm (Atmel ATA5745C, ASK, 2.4Kbits/s, Manchester, BER 10-3)
● Supply current: 6.5mA in Active Mode (3V, 25°C, ASK Mode)
● Data rate: 1Kbit/s to 10Kbits/s Manchester ASK, 1Kbit/s to 20Kbits/s Manchester
FSK with four programmable bit rate ranges
● Switching between modulation types ASK/FSK and different data rates possible in
≤ 1ms typically, without hardware modification on board to allow different
modulation schemes for RKE, TPMS
● Low standby current: 50µA at 3V, 25°C
● ASK/FSK receiver uses a Low-IF architecture with high selectivity, blocking, and
Low intermodulation (typical 3-dB blocking 68.0dBC at ±3MHz/74.0dBC at
±20.0MHz, system I1dBCP = –31dBm/system IIP3 = –24dBm)
● Telegram pause up to 52ms supported in ASK Mode
● Wide bandwidth AGC to handle large out-of-band blockers above the system
I1dBCP
● 440-kHz IF frequency with 30-dB image rejection and 420-kHz IF bandwidth to
support PLL transmitters with standard crystals or SAW-based transmitters
● RSSI (Received Signal Strength Indicator) with output signal dynamic range of
65dB
● Low in-band sensitivity change of typically ±2.0dB within ±160-kHz center
frequency change in the complete temperature and supply voltage range
● Sophisticated threshold control and quasi-peak detector circuit in the data slicer
● Fast and stable XTO start-up circuit (> –1.4kΩ worst-case start impedance)
● Clock generation for microcontroller
9249C-RKE-10/14
● ESD protection at all pins (±4kV HBM, ±200V MM, ±500V FCDM)
● Dual supply voltage range: 2.7V to 3.3V or 4.5V to 5.5V
● Temperature range: –40°C to +105°C
● Small 5mm × 5mm QFN24 package
Applications
● Automotive keyless entry and tire pressure monitoring systems
● Alarm, telemetering and energy metering systems
Benefits
● Supports header and blanking periods of protocols common in RKE and TPM systems (up to 52ms in ASK Mode)
● All RF relevant functions are integrated. The single-ended RF input is suited for easy adaptation to λ / 4 or printed-loop
antennas
● Allows a low-cost application with only 8 passive components
● Suitable for use in a receiver for joint RKE and TPMS
● Optimal bandwidth maximizes sensitivity while maintaining SAW transmitter compatibility
● Clock output provides an external microcontroller crystal-precision time reference
● Well suited for use with Atmel® PLL transmitter ATA5756/ATA5757
2
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
1.
General Description
The Atmel® ATA5745C/ATA5746C is a UHF ASK/FSK transparent receiver IC with low power consumption supplied in a
small QFN24 package (body 5mm × 5mm, pitch 0.65mm). Atmel ATA5745C is used in the 433MHz to 435MHz band of
operation, and Atmel ATA5746C in 313MHz to 317MHz. The IC combines the functionality of remote keyless entry (RKE typically low bit rate ASK) and tire pressure monitoring (TPM - typically high bit rate FSK) into one receiver under the control
of an external microcontroller such as an Atmel ATmega48 (AVR®).
For improved image rejection and selectivity, the IF frequency is fixed to 440kHz. The IF block uses an 8th-order band pass
yielding a receive bandwidth of 420kHz. This enables the use of the receiver in both SAW- and PLL-based transmitter
systems utilizing various types of data-bit encoding such as pulse width modulation, Manchester modulation, variable pulse
modulation, pulse position modulation, and NRZ. Prevailing encryption protocols such as Keeloq® are easily supported due
to the receiver’s ability to hold the current data slicer threshold for up to 52ms when incoming RF telegrams contain a
blanking interval. This feature eliminates erroneous noise from appearing on the demodulated data output pin, and simplifies
software decoding algorithms. The decoding of the data stream must be carried out by a connected microcontroller device.
Because of the highly integrated design, the only required RF components are for the purpose of receiver antenna matching.
Atmel ATA5745C and Atmel ATA5746C support Manchester bit rates of 1Kbit/s to 10Kbits/s in ASK and 1Kbit/s to 20Kbits/s
in FSK mode. The four discrete bit rate passbands are selectable and cover 1.0Kbit/s to 2.5Kbits/s, 2.0Kbits/s to 5.0Kbits/s,
4.0Kbits/s to 10.0Kbits/s, and 8.0Kbits/s to 10.0Kbits/s or 20.0Kbits/s (for ASK or FSK, respectively). The receiver contains
an RSSI output to provide an indication of received signal strength and a SENSE input to allow the customer to select a
threshold below which the DATA signal is gated off. ASK/FSK and bit rate ranges are selected by the connected
microcontroller device via pins ASK_NFSK, BR0, and BR1.
Figure 1-1. System Block Diagram
ATA5745C/ATA5746C
Digital Control
Logic
Antenna
Power
Supply
RF Receiver
Microcontroller
4 ... 8
(LNA, Mixer,
VCO, PLL,
IF Filter,
RSSI Amp.,
Demodulator)
Microcontroller
Interface
XTO
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
3
Table 1-1.
RX
BR0
BR1
ASK_NFSK
TEST1
2
17
RSSI
CLK_OUT
3
16
SENSE_CTRL
CLK_OUT_CTRL1
4
15
SENSE
CLK_OUT_CTRL0
5
14
LNA_IN
ENABLE
6
TEST3
LNA_GND
GND
VS3V_AVCC
8
VS5V
7
13
9 10 11 12
DVCC
24 23 22 21 20 19
18
XTAL1
1
XTAL2
TEST2
Pin Description
Pin
Symbol
Function
1
TEST2
Test pin, during operation at GND
2
TEST1
Test pin, during operation at GND
3
CLK_OUT
4
CLK_OUT_CTRL1
Input to control CLK_OUT (MSB)
5
CLK_OUT_CTRL0
Input to control CLK_OUT (LSB)
6
ENABLE
7
XTAL2
Reference crystal
8
XTAL1
Reference crystal
9
DVCC
Digital voltage supply blocking
10
VS5V
Power supply input for voltage range 4.5V to 5.5V
Output to clock a connected microcontroller
Power supply input for voltage range 2.7V to 3.3V
Input to enable the XTO
11
VS3V_AVCC
12
GND
13
LNA_GND
14
LNA_IN
RF input
15
SENSE
Sensitivity control resistor
16
SENSE_CTRL
17
RSSI
18
TEST3
19
RX
Input to activate the receiver
20
BR0
Bit rate selection, LSB
21
BR1
Bit rate selection, MSB
22
ASK_NFSK
FSK/ASK selection
Low: FSK, High: ASK
23
CDEM
24
DATA_OUT
GND
4
CDEM
DATA_OUT
Figure 1-2. Pinning QFN24
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
Ground
RF ground
Sensitivity selection
Low: Normal sensitivity, High: Reduced sensitivity
Output of the RSSI amplifier
Test pin, during operation at GND
Capacitor to adjust the lower cut-off frequency data filter
Data output
Ground/backplane (exposed die pad)
Figure 1-3. Block Diagram
ASK/FSK
Demodulator
CDEM
ASK
Power
Supply
FSK
VS3V_AVCC
VS5V
ASK/FSK
Control
ASK_NFSK
Data
Slicer
DATA_OUT
IF Amp
SENSE
SENSE_CTRL
BR0
IF Filter
BR1
GND
Standby
Logic Control
LPF
XTO
Div. by 3, 6, 12
DVCC
IF Amp
RX
CLK_OUT_CTRL1
CLK_OUT_CTRL0
CLK_OUT
RSSI
LPF
LNA_IN
PLL
(/24, /32)
XTO
ENABLE
TEST1
LNA
VCO
TEST2
LNA_GND
TEST3
XTAL2
XTAL1
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
5
2.
RF Receiver
As seen in Figure 1-3 on page 5, the RF receiver consists of a low-noise amplifier (LNA), a local oscillator, and the signal
processing part with mixer, IF filter, IF amplifier with analog RSSI, FSK/ASK demodulator, data filter, and data slicer.
In receive mode, the LNA pre-amplifies the received signal which is converted down to a 440-kHz intermediate frequency
(IF), then filtered and amplified before it is fed into an FSK/ASK demodulator, data filter, and data slicer. The received signal
strength indicator (RSSI) signal is available at the pin RSSI.
2.1
Low-IF Receiver
The receive path consists of a fully integrated low-IF receiver. It fulfills the sensitivity, blocking, selectivity, supply voltage,
and supply current specification needed to design an automotive integrated receiver for RKE and TPM systems. A benefit of
the integrated receive filter is that no external components needed.
At 315MHz, the Atmel® ATA5745C receiver (433.92MHz for the Atmel ATA5746C receiver) has a typical system noise figure
of 6.0dB (7.0dB), a system I1dBCP of –31dBm (–30dBm), and a system IIP3 of –24dBm (–23dBm). The signal path is linear
for out-of-band disturbers up to the I1dBCP and hence there is no AGC or switching of the LNA needed, and a better
blocking performance is achieved. This receiver uses an IF (intermediate frequency) of 440kHz, the typical image rejection is
30dB and the typical 3-dB IF filter bandwidth is 420kHz (fIF = 440kHz ± 210kHz, flo_IF = 230kHz and fhi_IF = 650kHz). The
demodulator needs a signal-to-noise ratio of 8.5dB for 10Kbits/s Manchester with ±38kHz frequency deviation in FSK mode,
thus, the resulting sensitivity at 315MHz (433.92MHz) is typically –105dBm (–104dBm).
Due to the low phase noise and spurs of the synthesizer together with the 8th-order integrated IF filter, the receiver has a
better selectivity and blocking performance than more complex double superhet receivers, without using external
components and without numerous spurious receiving frequencies.
A low-IF architecture is also less sensitive to second-order intermodulation (IIP2) than direct conversion receivers where
every pulse or amplitude modulated signal (especially the signals from TDMA systems like GSM) demodulates to the
receiving signal band at second-order non-linearities.
2.2
Input Matching at LNA_IN
The measured input impedances as well as the values of a parallel equivalent circuit of these impedances can be seen in
Table 2-1. The highest sensitivity is achieved with power matching of these impedances to the source impedance.
Table 2-1.
Measured Input Impedances of the LNA_IN Pin
fRF [MHz]
ZIn(RF_IN) [Ω]
RIn_p//CIn_p [pF]
315
(72.4 – j298)
1300Ω//1.60
433.92
(55 – j216)
900Ω//1.60
The matching of the LNA input to 50Ω is done using the circuit shown in Figure 2-1 and the values of the matching elements
given in Table 2-2. The reflection coefficients were always ≤ –10dB. Note that value changes of C1 and L1 may be
necessary to compensate individual board layout parasitics. The measured typical FSK and ASK Manchester-code
sensitivities with a bit error rate (BER) of 10–3 are shown in Table 2-3 and Table 2-4 on page 7. These measurements were
done with wire-wound inductors having quality factors reported in Table 2-2, resulting in estimated matching losses of 0.8dB
at 315MHz and 433.92MHz. These losses can be estimated when calculating the parallel equivalent resistance of the
inductor with Rloss = 2 × π × f × L × QL and the matching loss with 10 log(1+RIn_p / Rloss).
Figure 2-1. Input Matching to 50Ω
RFIN
ATA5745C/ATA5746C
C1
14
LNA_IN
L1
6
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
Table 2-2.
Input Matching to 50Ω
fRF [MHz]
C1 [pF]
L1 [nH]
QL1
315
2.2
68
20
433.92
2.2
36
15
Table 2-3.
Measured Typical Sensitivity FSK, ±38 kHz, Manchester, BER = 10–3
RF Frequency
BR_Range_0
1.0Kbit/s
BR_Range_0
2.5Kbits/s
BR_Range_1
5Kbits/s
BR_Range_2
10Kbits/s
BR_Range_3
10Kbits/s
BR_Range_3
20Kbits/s
315MHz
–108dBm
–108dBm
–107dBm
–105dBm
–104dBm
–104dBm
433.92MHz
–107dBm
–107dBm
–106dBm
–104dBm
–103dBm
–103dBm
Table 2-4.
Measured Typical Sensitivity 100% ASK, Manchester, BER = 10–3
RF Frequency
BR_Range_0
1.0Kbit/s
BR_Range_0
2.5Kbits/s
BR_Range_1
5Kbits/s
BR_Range_2
10Kbits/s
BR_Range_3
10Kbits/s
315MHz
–114dBm
–114dBm
433.92MHz
–113dBm
–113dBm
–113dBm
–111dBm
–109dBm
–112dBm
–110dBm
–108dBm
Conditions for the sensitivity measurement:
The given sensitivity values are valid for Manchester-modulated signals. For the sensitivity measurement the distance from
edge to edge must be evaluated. As can be seen in Figure 6-1 on page 22, in a Manchester-modulated data stream, the time
segments TEE and 2 × TEE occur.
To reach the specified sensitivity for the evaluation of TEE and 2 × TEE in the data stream, the following limits should be used
(TEE min, TEE max, 2 × TEE min, 2 × TEE max).
Table 2-5.
2.3
Limits for Sensitivity Measurements
Bit Rate
TEE Min
TEE Typ
TEE Max
2 × TEE Min
2 × TEE Typ
2 × TEE Max
1.0Kbit/s
260µs
500µs
790µs
800µs
1000µs
1340µs
2.4Kbits/s
110µs
208µs
310µs
320µs
416µs
525µs
5.0Kbits/s
55µs
100µs
155µs
160µs
200µs
260µs
9.6Kbits/s
27µs
52µs
78µs
81µs
104µs
131µs
Sensitivity Versus Supply Voltage, Temperature and Frequency Offset
To calculate the behavior of a transmission system, it is important to know the reduction of the sensitivity due to several
influences. The most important are frequency offset due to crystal oscillator (XTO) and crystal frequency (XTAL) errors,
temperature and supply voltage dependency of the noise figure, and IF-filter bandwidth of the receiver. Figure 2-2 and
Figure 2-3 on page 8 show the typical sensitivity at 315MHz, ASK, 2.4Kbits/s and 9.6Kbits/s, Manchester, Figure 2-4 and
Figure 2-5 on page 9 show a typical sensitivity at 315MHz, FSK, 2.4Kbits/s and 9.6Kbits/s, ±38kHz, Manchester versus the
frequency offset between transmitter and receiver at Tamb = –40°C, +25°C, and +105°C and supply voltage
VS = VS3V_AVCC = VS5V = 2.7V, 3.0V and 3.3V.
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
7
Figure 2-2. Measured Sensitivity (315MHz, ASK, 2.4Kbits/s, Manchester) Versus Frequency Offset
Input Sensitivity (dBm)
Input Sensitivity (dBm) at BER < 1e-3, ATA5746C, ASK, 2.4Kbits/s (Manchester),
BR = 0
-118
-117
-116
-115
-114
-113
-112
-111
-110
-109
-108
-107
-106
-105
-104
-103
-300
2.7V / -40°C
3.0V / -40°C
3.3V / -40°C
2.7V / 27°C
3.0V / 27°C
3.3V / 27°C
2.7V / 105°C
3.0V / 105°C
3.3V / 105°C
-200
-100
0
100
200
300
delta RF (kHz) at 315MHz
Figure 2-3. Measured Sensitivity (315MHz, ASK, 9.6Kbits/s, Manchester) Versus Frequency Offset
Input Sensitivity (dBm) at BER < 1e-3, ATA5746C, ASK, 9.6Kbits/s (Manchester),
BR = 2
-115
-114
-113
Input Sensitivity (dBm)
-112
-111
-110
2.7V / -40°C
-109
3.0V / -40°C
-108
-107
3.3V / -40°C
-106
2.7V / 27°C
-105
3.0V / 27°C
-104
3.3V / 27°C
-103
2.7V / 105°C
-102
3.0V / 105°C
-101
3.3V / 105°C
-100
-300
-200
-100
0
100
delta RF (kHz) at 315MHz
8
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
200
300
Figure 2-4. Measured Sensitivity (315MHz, FSK, 2.4Kbits/s, ±38kHz, Manchester) Versus Frequency Offset
Input Sensitivity (dBm)
Input Sensitivity (dBm) at BER < 1e-3, ATA5746, FSK, 2.4Kbits/s
(Manchester), BR0
-112
-111
-110
-109
-108
-107
-106
-105
-104
-103
-102
-101
-100
-99
-98
-300
2.7V / -40°C
3.0V / -40°C
3.3V / -40°C
2.7V / 27°C
3.0V / 27°C
3.3V / 27°C
2.7V / 105°C
3.0V / 105°C
3.3V / 105°C
-200
-100
0
100
200
300
delta RF (kHz) at 315MHz
Figure 2-5. Measured Sensitivity (315MHz, FSK, 9.6Kbits/s, ±38kHz, Manchester) Versus Frequency Offset
Input Sensitivity (dBm)
Input Sensitivity (dBm) at BER < 1e-3, ATA5746C, FSK, 9.6Kbits/s (Manchester),
BR = 2
-110.00
-109.00
-108.00
-107.00
-106.00
-105.00
-104.00
-103.00
-102.00
-101.00
-100.00
-99.00
-98.00
-97.00
-96.00
-95.00
-300
2.7V / -40°C
3.0V / -40°C
3.3V / -40°C
2.7V / 27°C
3.0V / 27°C
3.3V / 27°C
2.7V / 105°C
3.0V / 105°C
3.3V / 105°C
-200
-100
0
100
200
300
delta RF (kHz) at 315MHz
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
9
As can be seen in Figure 2-5 on page 9, the supply voltage has almost no influence. The temperature has an influence of
about ±1.0dB, and a frequency offset of ±160kHz also influences by about ±1dB. All these influences, combined with the
sensitivity of a typical IC (–105dB), are then within a range of –103.0dBm and –107.0dBm over temperature, supply voltage,
and frequency offset. The integrated IF filter has an additional production tolerance of ±10kHz, hence, a frequency offset
between the receiver and the transmitter of ±160kHz can be accepted for XTAL and XTO tolerances.
Note:
For the demodulator used in the Atmel ATA5745C/ATA5746C, the tolerable frequency offset does not change
with the data frequency. Hence, the value of ±160kHz is valid for 1Kbit/s to 10Kbits/s.
This small sensitivity change over supply voltage, frequency offset, and temperature is very unusual in such a receiver. It is
achieved by an internal, very fast, and automatic frequency correction in the FSK demodulator after the IF filter, which leads
to a higher system margin. This frequency correction tracks the input frequency very quickly. If, however, the input frequency
makes a larger step (for example, if the system changes between different communication partners), the receiver has to be
restarted. This can be done by switching back to Standby mode and then again to Active mode (pin RX 1 −−> 0 → 1) or
by generating a positive pulse on pin ASK_NFSK (0 → 1 → 0).
2.4
Frequency Accuracy of the Crystals in a Combined RKE and TPM System
In a tire pressure measurement system working at 315MHz and using an Atmel® ATA5756 as transmitter and an Atmel
ATA5746C is receiver, the higher frequency tolerances and the tolerance of the frequency deviation of the transmitter has to
be considered.
In the TPM transmitter, the crystal has a frequency error over temperature –40°C to 125°C, aging, and tolerance of ±80ppm
(±25.2kHz at 315MHz). The tolerances of the XTO, the capacitors used for FSK modulation, and the stray capacitances
cause an additional frequency error of ±30 ppm (±9.45kHz at 315MHz). The frequency deviation of such a transmitter varies
between ±16kHz and ±24kHz, since a higher frequency deviation is equivalent to a frequency error this has to be considered
as an additional
±24kHz – ±19.5kHz = ±4.5kHz frequency tolerance (19.5kHz is constant). All tolerances added, these transmitters have a
worst-case frequency offset of ±39.15kHz.
For the receiver in the car, a tolerance of ±160kHz – ±39.15kHz = ±120.85kHz (±383.6ppm) remains. The needed frequency
stability of the crystals over temperature and aging is ±383.6ppm – ±5ppm = ±378.6ppm. The aging of such a crystal is
±10ppm, leaving a reasonable ±368.6 ppm for the temperature dependency of the crystal frequency in the car.
Since the receiver in the car is able to receive these TPM transmitter signals with high frequency offsets, the component
specification in the key can be largely relaxed.
This system calculation is based on worst-case tolerances of all the components; this leads in practice to a system with
margin.
For a 433.92MHz TPM system using Atmel ATA5757 as transmitter and Atmel ATA5745C as receiver, the same calculation
must be done, but since the RF frequency is higher, every ppm of crystal tolerances results in higher frequency offset and
either the system must have lower tolerances or a lower margin at this frequency.
2.5
RX Supply Current Versus Temperature and Supply Voltage
Table 2-7 shows the typical supply current of the receiver in Active mode versus supply voltage and temperature with VS =
VS3V_AVCC = VS5V.
Table 2-6.
VS = VS3V_AVCC = VS5V
2.7V
3.0V
3.3V
Tamb = –40°C
5.4mA
5.5mA
5.6mA
Tamb = 25°C
6.4mA
6.5mA
6.6mA
Tamb = 105°C
7.4mA
7.5mA
7.6mA
Table 2-7.
10
Measured Current in Active Mode ASK
Measured Current in Active Mode FSK
VS = VS3V_AVCC = VS5V
2.7V
3.0V
3.3V
Tamb = –40°C
5.6mA
5.7mA
5.8mA
Tamb = 25°C
6.6mA
6.7mA
6.8mA
Tamb = 105°C
7.6mA
7.7mA
7.8mA
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
Blocking, Selectivity
As can be seen in Figure 2-6 on page 11, and Figure 2-7 and Figure 2-8 on page 12, the receiver can receive signals 3dB
higher than the sensitivity level in the presence of large blockers of –34.5dBm or –28dBm with small frequency offsets of
±3MHz or ±20MHz.
Figure 2-6, and Figure 2-7 on page 11 show the narrow-band blocking, and Figure 2-8 on page 12 shows the wide-band
blocking characteristic. The measurements were done with a useful signal of 315MHz, FSK, 10Kbits/s, ±38kHz, Manchester,
BR_Range2 with a level of –105dBm + 3dB = –102dBm, which is 3dB above the sensitivity level. The figures show how
much larger than –102dBm a continuous wave signal can be, until the BER is higher than 10–3. The measurements were
done at the 50Ω input shown in Figure 2-1 on page 6. At 3MHz, for example, the blocker can be 67.5dBC higher than
–102dBm, or –102dBm + 67.5dBC = –34.5dBm.
Figure 2-6. Close-in 3-dB Blocking Characteristic and Image Response at 315MHz
70
Blocking Level (dBC)
60
50
40
30
20
10
0
-10
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
Distance from Interfering to Receiving Signal (MHz)
Figure 2-7. Narrow-band 3-dB Blocking Characteristic at 315MHz
80
70
Blocking Level (dBC)
2.6
60
50
40
30
20
10
0
-10
-5
-4
-3
-2
-1
0
1
2
3
4
5
Distance from Interfering to Receiving Signal (MHz)
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
11
Figure 2-8. Wide-band 3-dB Blocking Characteristic at 315MHz
80
Blocking Level (dBC)
70
60
50
40
30
20
10
0
-10
-50
-40
-30
-20
-10
0
10
20
30
40
50
Distance from Interfering to Receiving Signal (MHz)
Table 2-8 shows the blocking performance measured relative to –102dBm for some frequencies. Note that sometimes the
blocking is measured relative to the sensitivity level 104dBm (denoted dBS), instead of the carrier –102dBm (denoted dBC)
Table 2-8.
Blocking 3 dB Above Sensitivity Level With BER < 10–3
Frequency Offset
Blocking Level
Blocking
+1.5MHz
–44.5dBm
57.5dBC, 60.5dBS
–1.5MHz
–44.5dBm
57.5dBC, 60.5dBS
+2MHz
–39.0dBm
63dBC, 66dBS
–2MHz
–36.0dBm
66dBC, 69dBS
+3MHz
–34.5dBm
67.5dBC, 70.5dBS
–3MHz
–34.5dBm
67.5dBC, 70.5dBS
+20MHz
–28.0dBm
74dBC, 77dBS
–20MHz
–28.0dBm
74dBC, 77dBS
The Atmel® ATA5745C/ATA5746C can also receive FSK and ASK modulated signals if they are much higher than the
I1dBCP. It can typically receive useful signals at –10dBm. This is often referred to as the nonlinear dynamic range (that is,
the maximum to minimum receiving signal), and is 95dB for 10Kbits/s Manchester (FSK). This value is useful if the
transmitter and receiver are very close to each other.
2.7
In-band Disturbers, Data Filter, Quasi-peak Detector, Data Slicer
If a disturbing signal falls into the received band, or if a blocker is not a continuous wave, the performance of a receiver
strongly depends on the circuits after the IF filter. Hence, the demodulator, data filter, and data slicer are important.
The data filter of the Atmel ATA5745C/ATA5746C functions also as a quasi-peak detector. This results in a good suppression
of above mentioned disturbers and exhibits a good carrier-to-noise performance. The required useful-signal-to-disturbingsignal ratio, at a BER of 10–3, is less than 14dB in ASK mode and less than 3dB (BR_Range_0 to BR_Range_2) and 6dB
(BR_Range_3) in FSK mode. Due to the many different possible waveforms, these numbers are measured for the signal, as
well as for disturbers, with peak amplitude values. Note that these values are worst-case values and are valid for any type of
modulation and modulating frequency of the disturbing signal, as well as for the receiving signal. For many combinations,
lower carrier-to-disturbing-signal ratios are needed.
12
ATA5745C/ATA5746C [DATASHEET]
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2.8
RSSI Output
The output voltage of the pin RSSI is an analog voltage, proportional to the input power level. Using the RSSI output signal,
the signal strength of different transmitters can be distinguished. The usable dynamic range of the RSSI amplifier is 65 dB,
the input power range P(RFIN) is –110dBm to –45dBm, and the gain is 15mV/dB. Figure 2-9 shows the RSSI characteristic
of a typical device at 315MHz with VS3V_AVCC = VS5V = 2.7V to 3.3V and Tamb = –40°C to +105°C with a matched input
as shown in Table 2-2 and Figure 2-1 on page 6. At 433.92MHz, 1dB more signal level is needed for the same RSSI results.
Figure 2-9. Typical RSSI Characteristic at 315MHz Versus Temperature and Supply Voltage
1.7
1.6
1.5
1.4
min; -9dB
max; +9dB
2.7V, -40°C
3.0V, -40°C
3.3V, -40°C
2.7V, 27°C
3.0V, 27°C
3.3V, 27°C
2.7V, 105°C
3.0V, 105°C
3.3V, 105°C
V_RSSI (V)
1.3
1.2
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
-130 -120 -110 -100
-90
-80
-70
-60
-50
-40
-30
-20
-10
Pin (dBm)
As can be seen in Figure 2-9 on page 13, for single devices there is a variance over temperature and supply voltage range
of ±3dB. The total variance over production, temperature, and supply voltage range is ±9dB.
2.9
Frequency Synthesizer
The LO generates the carrier frequency for the mixer via a PLL synthesizer. The XTO (crystal oscillator) generates the
reference frequency fXTO. The VCO (voltage-controlled oscillator) generates the drive voltage frequency fLO for the mixer. fLO
is divided by the factor 24 (Atmel® ATA5746C) or 32 (Atmel ATA5745C). The divided frequency is compared to fXTO by the
phase frequency detector. The current output of the phase frequency detector is connected to the fully integrated loop filter,
and thereby generates the control voltage for the VCO. By means of that configuration, the VCO is controlled in a way, such
that fLO / 24 (fLO / 32) is equal to fXTO. If fLO is determined, fXTO can be calculated using the following formula: fXTO = fLO / 24
(fXTO = fLO / 32). The synthesizer has a phase noise of –130dBC/Hz at 3MHz and spurs of –75dBC.
Care must be taken with the harmonics of the CLK output signal, as well as with the harmonics produced by a
microprocessor clocked using the signal, as these harmonics can disturb the reception of signals.
ATA5745C/ATA5746C [DATASHEET]
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13
3.
XTO
The XTO is an amplitude-regulated Pierce oscillator type with external load capacitances (2 × 16pF). Due to additional
internal and board parasitics (CP) of approximately 2pF on each side, the load capacitance amounts to 2 × 18pF (9pF total).
The XTO oscillation frequency fXTO is the reference frequency for the integer-N synthesizer. When designing the system in
terms of receiving and transmitting frequency offset, the accuracy of the crystal and XTO have to be considered.
The XTO’s additional pulling (including the RM tolerance) is only ±5ppm. The XTAL versus temperature, aging, and
tolerances is then the main source of frequency error in the local oscillator.
The XTO frequency depends on XTAL properties and the load capacitances CL1,2 at pin XTAL1 and XTAL2. The pulling (p)
of fXTO from the nominal fXTAL is calculated using the following formula:
C LN – C L
Cm
-6
p = ------- × ------------------------------------------------------------- × 10 ppm
2 ( C O + C LN ) × ( C O + C L )
Cm, the crystal's motional capacitance; C0, the shunt capacitance; and CLN, the nominal load capacitance of the XTAL, are
found in the datasheet. CL is the total actual load capacitance of the crystal in the circuit, and consists of CL1 and CL2
connected in series.
Figure 3-1. Crystal Equivalent Circuit
Crystal Equivalent Circuit
C0
XTAL
Lm
CL1
CL2
Cm
Rm
CL = CL1 x CL2/(CL1 + CL2)
With Cm ≤ 10fF, C0 ≥ 1.0pF, CLN = 9pF and CL1,2 = 16pF ±1%, the pulling amounts to P ≤ ±1ppm.
The C0 of the XTAL has to be lower than CLmin / 2 = 7.9pF for a Pierce oscillator type in order to not enter the steep region of
pulling versus load capacitance where there is risk of an unstable oscillation.
To ensure proper start-up behavior, the small signal gain and the negative resistance provided by this XTO at start is very
large. For example, oscillation starts up even in the worst case with a crystal series resistance of 1.5kΩ at C0 ≤ 2.2pF with
this XTO. The negative resistance is approximately given by
Z 1 × Z 3 + Z 2 × Z 3 + Z 1 × Z 3 × gm
Re { Zxtocore } = Re -----------------------------------------------------------------------------------
Z 1 + Z 2 + Z 3 + Z 1 × Z 2 × gm
with Z1 and Z2 as complex impedances at pins XTAL1 and XTAL2, hence
Z1 = –j / (2 × p × fXTO × CL1) + 5Ω and Z2 = –j / (2 × p × fXTO × CL2) + 5Ω.
Z3 consists of crystal C0 in parallel with an internal 110-kΩ resistor, hence
Z3 = –j / (2 × p × fXTO × C0) / 110kΩ, gm is the internal transconductance between XTAL1 and XTAL2, with typically 20mS at
25°C.
With fXTO = 13.5MHz, gm = 20mS, CL = 9pF, and C0 = 2.2pF, this results in a negative resistance of about 2kΩ. The worst
case for technology, supply voltage, and temperature variations is then always higher than 1.4kΩ for C0 ≤ 2.2pF.
Due to the large gain at start, the XTO is able to meet a very low start-up time. The oscillation start-up time can be estimated
with the time constant τ.
2
τ = ----------------------------------------------------------------------------------------------------------2
2
4 × π × f XTAL × C m × ( Re ( Z xtocore ) + R m )
14
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
After 10τ to 20τ, an amplitude detector detects the oscillation amplitude and sets XTO_OK to High if the amplitude is large
enough; this activates the CLK_OUT output if it is enabled via the pins CLK_OUT_CTRL0 and CLK_OUT_CTRL1. Note that
the necessary conditions of the DVCC voltage also have to be fulfilled.
It is recommended to use a crystal with Cm = 3.0fF to 10fF, CLN = 9pF, Rm < 120Ω and C0 = 1.0pF to 2.2pF.
Lower values of Cm can be used, slightly increasing the start-up time. Lower values of C0 or higher values of Cm (up to 15fF)
can also be used, with only little influence on pulling.
Figure 3-2. XTO Block Diagram
CL1
XTAL1
CL2
XTAL2
CLK_OUT_CTRL0
CLK_OUT_CTRL1
CLK_OUT
&
fFXTO
Divider
/3, /6, /12
XTO_OK
Amplitude
Detector
Divider
/16
fDCLK
The relationship between fXTO and the fRF is shown in Table 3-1.
Table 3-1.
Calculation of fRF
Frequency [MHz]
fXTO [MHz]
fRF
433.92 (Atmel ATA5745C)
13.57375
fXTO x 32 – 440kHz
315.0 (Atmel ATA5746C)
13.1433
fXTO x 24 – 440kHz
Attention must be paid to the harmonics of the CLK_OUT output signal fCLK_OUT as well as to the harmonics produced by an
microprocessor clocked with it, since these harmonics can disturb the reception of signals if they get to the RF input. If the
CLK_OUT signal is used, it must be carefully laid out on the application PCB. The supply voltage of the microcontroller must
also be carefully blocked.
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
15
3.1
Pin CLK_OUT
Pin CLK_OUT is an output to clock a connected microcontroller. The clock is available in Standby and Active modes. The
frequency fCLK_OUT can be adjusted via the pins CLK_OUT_CTRL0 and CLK_OUT_CTRL1, and is calculated as follows:
Table 3-2.
Setting of fCLK_OUT
CLK_OUT_CTRL1
CLK_OUT_CTRL0
Function
0
0
Clock on pin CLK_OUT is switched off
(Low level on pin CLK_OUT)
0
1
fCLK_OUT = fXTO / 3
1
0
fCLK_OUT = fXTO / 6
1
1
fCLK_OUT = fXTO / 12
The signal at CLK_OUT output has a nominal 50% duty cycle. To save current, it is recommended that CLK_OUT be
switched off during Standby mode.
3.2
Basic Clock Cycle of the Digital Circuitry
The complete timing of the digital circuitry is derived from one clock. As seen in Figure 3-2 on page 15, this clock cycle,
TDCLK, is derived from the crystal oscillator (XTO) in combination with a divider.
f XTO
f DCLK = ----------16
TDCLK controls the following application relevant parameters:
- Debouncing of the data signal stream
- Start-up time of the RX signal path
The start-up time and the debounce characteristic depend on the selected bit rate range (BR_Range) which is defined by
pins BR0 and BR1. The clock cycle TXDCLK is defined by the following formulas for further reference:
BR_Range
16
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
BR_Range 0: TXDCLK = 8 × TDCLK
BR_Range 1: TXDCLK = 4 × TDCLK
BR_Range 2: TXDCLK = 2 × TDCLK
BR_Range 3: TXDCLK = 1 × TDCLK
4.
Sensitivity Reduction
The output voltage of the RSSI amplifier is internally compared to a threshold voltage VTh_red. VTh_red is determined by the
value of the external resistor RSense. RSense is connected between the pins SENSE and VS3V_AVCC (see Figure 10-1 on
page 26). The output of the comparator is fed into the digital control logic. By this means, it is possible to operate the receiver
at a lower sensitivity.
If the level on input pin SENSE_CTRL is low, the receiver operates at full sensitivity.
If the level on input pin SENSE_CTRL is high, the receiver operates at a lower sensitivity. The reduced sensitivity is defined
by the value of RSense, the maximum sensitivity by the signal-to-noise ratio of the LNA input. The reduced sensitivity depends
on the signal strength at the output of the RSSI amplifier.
Since different RF input networks may exhibit slightly different values for the LNA gain, the sensitivity values given in the
electrical characteristics refer to a specific input matching. This matching is illustrated in Figure 2-1 on page 6 and exhibits
the best possible sensitivity.
If the sensitivity reduction feature is not used, pin SENSE can be left open, pin SENSE_CTRL must be set to GND.
To operate with reduced sensitivity, pin SENSE_CTRL must be set to high before the RX signal path will be enabled by
setting pin RX to high (see Figure 4-1 on page 17). As long as the RSSI level is lower than VTh_red (defined by the external
resistor RSense) no data stream is available on pin DATA_OUT (low level on pin DATA_OUT). An internal RS flip-flop will be
set to high the first time the RSSI voltage crosses VTh_red, and from then on the data stream will be available on pin
DATA_OUT. From then on the receiver also works with full sensitivity. This makes sure that a telegram will not be interrupted
if the RSSI level varies during the transmission. The RS flip-flop can be set back, and thus the receiver switched back to
reduced sensitivity, by generating a positive pulse on pin ASK_NFSK (see Figure 4-2 on page 18). In FSK mode, operating
with reduced sensitivity follows the same way.
Figure 4-1. Reduced Sensitivity Active
ENABLE
ASK_NFSK
SENSE_CTRL
RX
VTh_red
RSSI
tStartup_PLL tStartup_Sig_Proc
DATA_OUT
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
17
Figure 4-2. Restart Reduced Sensitivity
ENABLE
ASK_NFSK
SENSE_CTRL
RX
VTh_red
RSSI
tStartup_Sig_Proc
DATA_OUT
5.
Power Supply
Figure 5-1. Power Supply
VS3V_AVCC
SW_DVCC
VS5V
IN
V_REG
3.0V typ.
OUT
DVCC
EN
RX
The supply voltage range of the Atmel® ATA5745C/ATA5746C is 2.7V to 3.3V or 4.5V to 5.5V.
Pin VS3V_AVCC is the supply voltage input for the range 2.7V to 3.3V, and is used in battery applications using a single
lithium 3V cell. Pin VS5V is the voltage input for the range 4.5V to 5.5V (car applications) in this case the voltage regulator
V_REG regulates VS3V_AVCC to typically 3.0V. If the voltage regulator is active, a blocking capacitor of 2.2µF has to be
connected to VS3V_AVCC (see Figure 10-1 on page 26).
DVCC is the internal operating voltage of the digital control logic and is fed via the switch SW_DVCC by VS3V_AVCC.
DVCC must be blocked on pin DVCC with 68nF (see Figure 9-1 on page 25 and Figure 10-1 on page 26).
Pin RX is the input to activate the RX signal processing and set the receiver to Active mode.
18
ATA5745C/ATA5746C [DATASHEET]
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5.1
OFF Mode
A low level on pin RX and ENABLE will set the receiver to OFF mode (low power mode). In this mode, the crystal oscillator is
shut down and no clock is available on pin CLK_OUT. The receiver is not sensitive to a transmitter signal in this mode.
Table 5-1.
5.2
Standby Mode
RX
ENABLE
Function
0
0
OFF mode
Standby Mode
The receiver activates the Standby mode if pin ENABLE is set to “1”.
In Standby mode, the XTO is running and the clock on pin CLK_OUT is available after the start-up time of the XTO has
elapsed (dependent on pin CLK_OUT_CTRL0 and CLK_OUT_CTRL1). During Standby mode, the receiver is not sensitive
to a transmitter signal.
In Standby mode, the RX signal path is disabled and the power consumption IStandby is typically 50µA (CLK_OUT output off,
VS3V_AVCC = VS5V = 3V). The exact value of this current is strongly dependent on the application and the exact operation
mode, therefore check the section “Electrical Characteristics: General” on page 27 for the appropriate application case.
Table 5-2.
Standby Mode
RX
ENABLE
Function
0
1
Standby mode
Figure 5-2. Standby Mode (CLK_OUT_CTRL0 or CLK_OUT_CTRL1 = 1)
CLK_OUT
tXTO_Startup
ENABLE
Standby Mode
5.3
Active Mode
The Active mode is enabled by setting the level on pin RX to high. In Active mode, the RX signal path is enabled and if a
valid signal is present it will be transferred to the connected microcontroller.
Table 5-3.
Active Mode
RX
ENABLE
Function
1
1
Active mode
During TStartup_PLL the PLL is enabled and starts up. If the PLL is locked, the signal processing circuit starts up
(TStartup_Sig_Proc). After the start-up time, all circuits are in stable condition and ready to receive. The duration of the start-up
sequence depends on the selected bit rate range.
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
19
Figure 5-3. Active Mode
CLK_OUT
ENABLE
RX
DATA_OUT
DATA_OUT valid
IStandby
tStartup_PLL
tStartup_Sig_Proc
IStartup_PLL
IActive
Standby Mode
Table 5-4.
Startup
Atmel ATA5745C (433.92MHz)
BR0
0
0
0
1
1
0
1
1
TStartup_PLL
TStartup_Sig_Proc
Atmel ATA5746C (315MHz)
TStartup_PLL
TStartup_Sig_Proc
1096µs
644µs
261µs
417µs
1132µs
665µs
269µs
431µs
304µs
324µs
Modulation Scheme
ASK_NFSK
RFIN at Pin LNA_IN
Level at Pin DATA_OUT
fFSK_H
1
fFSK_L
0
fASK on
1
fASK off
0
0
1
20
Active Mode
Start-up Time
BR1
Table 5-5.
IActive
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
6.
Bit Rate Ranges
Configuration of the bit rate ranges is carried out via the two pins BR0 and BR1. The microcontroller uses these two interface
lines to set the corner frequencies of the band-pass data filter. Switching the bit rate ranges while the RF front end is in
Active mode can be done on the fly and will not take longer than 100 µs if done while remaining in either ASK or FSK mode.
If the modulation scheme is changed at the same time, the switching time is (TStartup_Sig_Proc, see Figure 7-1 on page 23).
Each BR_Range is defined by a minimum edge-to-edge time. To maintain full sensitivity of the receiver, edge-to-edge
transition times of incoming data should not be less than the minimum for the selected BR_Range.
Table 6-1.
BR Ranges ASK
Recommended Bit Rate
(Manchester)(2)
Minimum Edge-to-edge
Time Period TEE of the
Data Signal(3)
Edge-to-edge Time Period TEE
of the Data Signal During the
Start-up Period(4)
BR1
BR0
BR_Range
0
0
BR_Range0
1.0Kbit/s to 2.5Kbits/s
200µs
200µs to 500µs
0
1
BR_Range1
2.0Kbits/s to 5.0Kbits/s
100µs
100µs to 250µs
1
0
BR_Range2
4.0Kbits/s to 10.0Kbits/s
50µs
50µs to 125µs
1
1
BR_Range3
8.0Kbits/s to 10.0Kbits/s
50µs
50µs to 62.5µs
Minimum Edge-to-edge
Time Period TEE of the
Data Signal(3)
Edge-to-edge Time Period TEE
of the Data Signal During the
Start-up Period(4)
Table 6-2.
BR Ranges FSK
BR1
BR0
BR_Range
Recommended Bit Rate
(Manchester)(2)
0
0
BR_Range0
1.0Kbit/s to 2.5Kbits/s
200µs
200µs to 500µs
0
1
BR_Range1
2.0Kbits/s to 5.0Kbits/s
100µs
100µs to 250µs
1
0
BR_Range2
4.0Kbits/s to 10.0Kbits/s
50µs
50µs to 125µs
1
Notes:
1
1.
BR_Range3
8.0Kbits/s to 20.0Kbits/s
25µs
25µs to 62.5µs
If during the start-up period (TStartup_PLL + TStartup_Sig_Proc) there is no RF signal, the data filter settles to the
noise floor, leading to noise on pin DATA_OUT.
2.
As can be seen, a bit stream of, for example, 2.5Kbits/s can be received in BR_Range0 and BR_Range1
(overlapping BR_Ranges). To get the full sensitivity, always use the lowest possible BR_Range (here,
BR_Range0). The advantage in the next higher BR_Range (BR_Range1) is the shorter start-up period,
meaning lower current consumption during Polling mode. Thus, it is a decision between sensitivity and current consumption.
3. The receiver is also capable of receiving non-Manchester-modulated signals, such as PWM, PPM, VPWM,
NRZ. In ASK mode, the header and blanking periods occurring in Keeloq-like protocols (up to 52ms) are
supported.
4. To ensure an accurate settling of the data filter during the start-up period (TStartup_PLL + TStartup_Sig_Proc), the
edge-to-edge time TEE of the data signal (preamble) must be inside the given limits during this period.
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
21
Figure 6-1. Examples of Supported Modulation Formats
TEE
MAN:
Logic 0
TEE
TEE
TEE
TEE
Logic 1
TEE
PWM:
TEE
TEE
TEE
Logic 0
TEE
Logic 1
Logic 0
TEE
VPWM:
Logic 1
TEE
TEE
On Transition Low to High
Logic 0
Logic 1
TEE
TEE
TEE
On Transition High to Low
TEE
PPM:
TEE
TEE
Logic 0
TEE
TEE
Logic 1
TEE
TEE
NRZ:
TEE
Logic 0
Logic 1
Figure 6-2. Supported Header and Blanking Periods
Preamble
22
Header
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
Data Burst
Guard Time
Data Burst
7.
ASK_NFSK
The ASK_NFSK pin allows the microcontroller to rapidly switch the RF front end between demodulation modes. A logic 1 on
this pin selects ASK mode, and a logic 0 FSK mode. The time to change modes (TStartup_Sig_Proc) depends on the bit rate
range being selected (not current bit rate range) and is given in Table 5-4 on page 20. This response time is specified for
applications that require an ASK preamble followed by FSK data (for typical TPM applications). During TStartup_Sig_Proc, the
level on pin DATA_OUT is low.
Figure 7-1. ASK Preamble 2.4Kbits/s followed by FSK Data 9.6Kbits/s
ENABLE
RX
BR1
BR0
ASK_NFSK
DATA_OUT
Data valid BR0
Data valid BR3
TStartup_Sig_Proc
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
23
8.
Polling Current Calculation
Figure 8-1. Polling Cycle
ENABLE
IStartup_PLL
IStartup_PLL
RX
IActive
ISupply
IStandby
IActive
IStandby
TBitcheck (= 1 / Signal_Bitrate (average)
TStartup_Sig_Proc (Startup Signal Processing)
TStartup_PLL (Startup RF-PLL)
In an RKE and TPM system, the average chip current in Polling mode, IPolling, is an important parameter. The polling period
must be controlled by the connected microcontroller via the pins ENABLE and RX. The polling current can be calculated as
follows:
IPolling = (TStartup_PLL / TPolling_Period) × IStartup_PLL + (TStartup_Sig_Proc / TPolling_Period) × IActive +
(TBitcheck / TPolling_Period) × IActive + (TPolling_Period – TStartup_PLL – TStartup_Sig_Proc – TBitcheck) / TPolling_Period × IStandby
TStartup_PLL:
TStartup_Sig_Proc:
TBitcheck:
TPolling_Period:
IStartup_PLL:
IActive:
IStandby:
Example:-
depends on 315MHz/433.92MHz application.
depends on 315MHz/433.92MHz application and the selected bit
rate range.
depends on the signal bit rate (1 / Signal_Bit_Rate).
depends on the transmitter telegram (preburst).
depends on 3V or 5V application and the setting of pin CLK_OUT.
depends on 3V or 5V application, ASK or FSK mode and the setting of
pin CLK_OUT.
depends on 3V or 5V application and the setting of pin CLK_OUT.
315-MHz application (Atmel ATA5746C), bit rate: 9.6Kbits/s,
TPolling_Period = 8ms
--> TStartup_PLL
=
269µs
--> TStartup_Sig_Proc
=
324µs (Bit Rate Range 3)
--> TBitcheck
=
104µs
3V application; ASK mode, CLK_OUT disabled
--> IStartup_PLL
=
4.5mA
--> IActive
=
6.5mA
--> IStandby
=
0.05mA
--> IPolling = 0.545mA
24
ATA5745C/ATA5746C [DATASHEET]
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3V Application
Figure 9-1. 3V Application
RX
BR0
BR1
ASK_NFSK
CDEM
TEST3
output
TEST2
output
TEST1
output
CLK_OUT
output
CLK_OUT_CTRL1
SENSE
input
CLK_OUT_CTRL0
LNA_IN
RSSI
ATA5745C/
ATA5746C
SENSE_CTRL
LNA_GND
GND
VS5V
DVCC
VCC
XTAL1
XTAL2
ENABLE
VS3V_AVCC
2.2pF
output
VSS
DATA_OUT
15nF
Microcontroller
9.
RFIN
68nH/36nH
315MHz/433.92MHz
68nF
18pF
18pF
68nF
VCC = 2.7V to 3.3V
Note:
Paddle (backplane) must be connected to GND
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
25
10.
5V Application
Figure 10-1. 5V Application with Reduced/Full Sensitivity
RX
BR0
BR1
ASK_NFSK
CDEM
TEST2
output
TEST1
output
CLK_OUT
output
CLK_OUT_CTRL1
SENSE
input
CLK_OUT_CTRL0
LNA_IN
RSSI
ATA5745C/
ATA5746C
SENSE_CTRL
RSense
LNA_GND
GND
VS5V
DVCC
VCC
XTAL1
ENABLE
VS3V_AVCC
2.2pF
output
VSS
TEST3
output
XTAL2
Microcontroller
output
DATA_OUT
15 nF
68nH/36nH
315MHz/433.92MHz
68nF
18pF
18pF
2.2µF
68nF
VCC = 4.5V to 5.5V
Note:
26
Paddle (backplane) must be connected to GND.
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
RFIN
11.
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
Junction temperature
Min.
Tj
Max.
Unit
+150
°C
Storage temperature
Tstg
–55
+125
°C
Ambient temperature
Tamb
–40
+105
°C
Supply voltage VS5V
VS
+6
V
ESD (Human Body Model ESD S 5.1)
every pin
HBM
–4
+4
kV
ESD (Machine Model JEDEC A115A)
every pin
MM
–200
+200
V
ESD (Field Induced Charge Device Model ESD
STM 5.3.1-1999) every pin
FCDM
–500
+500
V
Maximum input level, input matched to 50Ω
Pin_max
0
dBm
12.
Thermal Resistance
Parameters
Junction ambient
13.
Symbol
Value
Unit
RthJA
35
K/W
Electrical Characteristics: General
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 315MHz unless otherwise specified. Details about current
consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.
No. Parameters
1
1.1
2
Test Conditions
Pin(1)
Symbol
VVS3V_AVCC = VVS5V ≤ 3V
VVS5V = 5V
CLK_OUT disabled
10, 11
10
ISOFF
XTO running
VVS3V_AVCC = VVS5V ≤ 3V
CLK_OUT disabled
10, 11
IStandby
XTO running
VVS5V = 5V
CLK_OUT disabled
10, 11
Min.
Typ.
Max.
Unit
Type*
2
2
µA
µA
A
A
50
80
µA
A
IStandby
50
80
µA
A
TXTO_Startup
0.3
0.8
ms
A
OFF Mode
Supply current in OFF
mode
Standby Mode
Supply current
2.1
Standby mode
2.2 System start-up time
XTO startup
XTAL: Cm = 5fF,
C0 = 1.8pF, Rm = 15Ω
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
Note:
1. Pin numbers in parenthesis were measured with RF_IN matched to 50Ω according to Figure 2-1 on page 6 with component values as in Table 2-2 on page 7 (RFIN).
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13.
Electrical Characteristics: General (Continued)
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 315MHz unless otherwise specified. Details about current
consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.
No. Parameters
2.3
3
3.1
3.2
3.3
Active mode start-up
time
Test Conditions
Pin(1)
From Standby mode to
Active mode
BR_Range_3
Atmel ATA5745C
Atmel ATA5746C
Symbol
Min.
Typ.
TStartup_PLL +
TStartup_Sig_Proc
Max.
Unit
565
593
µs
µs
Type*
A
Active Mode
RF operating frequency
range
Supply current Active
mode
Supply current Polling
mode
Atmel ATA5746C
14
fRF
313
317
MHz
A
Atmel ATA5745C
433
435
MHz
A
14
fRF
VVS3V_AVCC = VVS5V = 3V
ASK mode
CLK_OUT disabled
SENSE_CTRL = 0
10, 11
IActive
6.5
9.6
mA
A
VVS3V_AVCC = VVS5V = 3V
FSK mode
CLK_OUT disabled
SENSE_CTRL = 0
10, 11
IActive
6.7
9.8
mA
A
VVS5V = 5V
ASK mode
CLK_OUT disabled
SENSE_CTRL = 0
10
IActive
6.7
9.8
mA
A
VVS5V = 5V
FSK mode
CLK_OUT disabled
SENSE_CTRL = 0
10
IActive
6.9
10
mA
A
10, 11
IPolling
545
µA
C
Bit rate 9.6Kbits/s BR2
(14)
PREF_FSK
–103
–105
–106.5
dBm
B
Bit rate 2.4Kbits/s BR0
(14)
PREF_FSK
–106
–108
–109.5
dBm
B
Bit rate 9.6Kbits/s BR2
(14)
PREF_FSK
–101
dBm
B
Bit rate 2.4Kbits/s BR0
(14)
PREF_FSK
–104
dBm
B
VVS3V_AVCC = VVS5V = 3V
TPolling_Period = 8ms
BR_Range_3, ASK
mode, CLK_OUT
disabled
Data rate = 9.6Kbits/s
FSK deviation
fDEV = ±38kHz
BER = 10–3
Tamb = 25°C
3.4
Input sensitivity FSK
fRF = 315MHz
FSK deviation ±18kHz to
±50kHz
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
Note:
1. Pin numbers in parenthesis were measured with RF_IN matched to 50Ω according to Figure 2-1 on page 6 with component values as in Table 2-2 on page 7 (RFIN).
28
ATA5745C/ATA5746C [DATASHEET]
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13.
Electrical Characteristics: General (Continued)
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 315MHz unless otherwise specified. Details about current
consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.
Pin(1)
Symbol
Min.
Bit rate 9.6Kbits/s BR2
(14)
PREF_ASK
Bit rate 2.4Kbits/s BR0
(14)
PREF_ASK
Sensitivity change at
f = 433.92MHz
3.6 RF
compared to
fRF = 315MHz
fRF = 315MHz to
fRF = 433.92MHz
P = PREF_ASK + ΔPREF1
P = PREF_FSK + ΔPREF1
(14)
ΔPREF1
Sensitivity change
versus temperature,
3.7
supply voltage and
frequency offset
FSK fDEV = ±38kHz
ΔfOFFSET ≤ ±160kHz
ASK 100%
ΔfOFFSET ≤ ±160kHz
P = PREF_ASK + ΔPREF1 +
ΔPREF2
(14)
ΔPREF2
No. Parameters
Test Conditions
Typ.
Max.
Unit
Type*
–109
–111
–112.5
dBm
B
–112
–114
–115.5
dBm
B
dB
B
ASK 100% level of
carrier, BER = 10–3
3.5
Input sensitivity ASK
fRF = 315MHz
Tamb = 25°C
+1
+4.5
–1.5
B
P = PREF_FSK + ΔPREF1 +
ΔPREF2
RSense connected from
pin SENSE to
pin VS3V_AVCC
Reduced sensitivity
3.8
3.9
dBm
(peak
level)
PRef_Red
RSense = 62kΩ
fin = 433.92MHz
–76
dBm
C
RSense = 82kΩ
fin = 433.92MHz
–88
dBm
C
RSense = 62kΩ
fin = 315MHz
–76
dBm
C
RSense = 82 kΩ
fin = 315 MHz
–88
dBm
C
Reduced sensitivity
variation over full
operating range
RSense = 62kΩ
RSense = 82kΩ
PRed = PRef_Red + PΔRed
Maximum frequency
offset in FSK mode
Maximum frequency
difference of fRF between
receiver and transmitter
in FSK mode (fRF is the
center frequency of the
FSK signal with
fBIT = 10Kbits/s
fDEV = ±38kHz
(14)
ΔPRed
–10
+10
dB
ΔfOFFSET
–160
+160
kHz
B
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
Note:
1. Pin numbers in parenthesis were measured with RF_IN matched to 50Ω according to Figure 2-1 on page 6 with component values as in Table 2-2 on page 7 (RFIN).
ATA5745C/ATA5746C [DATASHEET]
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13.
Electrical Characteristics: General (Continued)
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 315MHz unless otherwise specified. Details about current
consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.
No. Parameters
3.10
Supported FSK
frequency deviation
3.11 System noise figure
3.12 Intermediate frequency
3.13 System bandwidth
Pin(1)
Symbol
Min.
Typ.
Max.
Unit
Type*
With up to 2dB
loss of sensitivity.
Note that the tolerable
frequency offset is 12kHz
lower for fDEV = ±50kHz
than for fDEV = ±38kHz,
hence,
ΔfOFFSET ≤ ±148kHz
(14)
fDEV
±18
±38
±50
kHz
B
fRF = 315MHz
(14)
NF
6.0
9
dB
B
fRF = 433.92MHz
(14)
NF
7.0
10
dB
B
fRF = 433.92MHz
fIF
440
kHz
A
fRF = 315MHz
fIF
440
kHz
A
(14)
SBW
435
kHz
A
(14)
IIP3
–24
dBm
C
(14)
IIP3
–23
dBm
C
(14)
I1dBCP
–31
–36
dBm
C
(14)
I1dBCP
–30
–35
dBm
C
14
Zin_LNA
(72.4 – j298)
Ω
C
Test Conditions
3dB bandwidth
This value is for
information only!
Note that for crystal and
system frequency offset
calculations, ΔfOFFSET
must be used.
Δfmeas1 = 1.8MHz
System out-band
Δfmeas2 = 3.6MHz
3.14 3rd-order input intercept f = 315MHz
RF
point
fRF = 433.92MHz
3.15
Δfmeas1 = 1MHz
System outband input 1- f = 315MHz
RF
dB compression point
fRF = 433.92MHz
3.16 LNA input impedance
fRF = 315MHz
fRF = 433.92MHz
–3
Maximum peak RF input BER < 10 , ASK: 100%
3.17
level, ASK and FSK
FSK: fDEV = ±38kHz
3.18 LO spurs at LNA_IN
3.19 Image rejection
14
Zin_LNA
(55 – j216)
Ω
C
(14)
PIN_max
+5
–10
dBm
C
(14)
PIN_max
+5
–10
dBm
C
–57
dBm
C
–47
f < 1GHz
(14)
f >1GHz
(14)
fLO = 315.44MHz
2 × fLO
4 × fLO
fLO = 434.36MHz
2 × fLO
4 × fLO
dBm
C
(14)
–90
–94
–68
dBm
C
(14)
–92
–88
–58
dBm
C
With the complete image
band
fRF = 315MHz
(14)
24
30
dB
fRF = 433.92MHz
(14)
24
30
dB
A
A
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
Note:
1. Pin numbers in parenthesis were measured with RF_IN matched to 50Ω according to Figure 2-1 on page 6 with component values as in Table 2-2 on page 7 (RFIN).
30
ATA5745C/ATA5746C [DATASHEET]
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13.
Electrical Characteristics: General (Continued)
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 315MHz unless otherwise specified. Details about current
consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.
No. Parameters
Test Conditions
Peak level of useful
signal to peak level of
interferer for BER < 10–3
with any modulation
Useful signal to interferer
scheme of interferer
3.20
ratio
FSK BR_Ranges 0, 1, 2
FSK BR_Range_3
ASK (PRF < PRFIN_High)
3.21 RSSI output
3.22
Pin(1)
Symbol
(14)
Min.
Typ.
Max.
Unit
Type*
SNRFSK0-2
2
3
dB
B
(14)
SNRFSK3
4
6
dB
B
14
(14)
SNRASK
10
dB
B
Dynamic range
(14),17
DRSSI
65
dB
A
Lower level of range
fRF = 315MHz
fRF = 433.92MHz
(14),17
PRFIN_Low
–110
dBm
A
Upper level of range
fRF = 315MHz
fRF = 433.92MHz
(14),17
PRFIN_High
–45
dBm
A
Gain
(14),17
Output voltage range
(14),17
VRSSI
350
17
RRSSI
8
Output resistance
RSSI pin
15
10
mV/dB
A
1675
mV
A
12.5
kΩ
C
dBC
C
dBC
C
nF
D
Sensitivity (BER = 10–3)
is reduced by 3dB if a
continuous wave blocking
signal at ±Δf is ΔPBlock
higher than the useful
signal level
(Bit rate = 10Kbits/s,
FSK, fDEV ±38kHz,
Manchester code,
BR_Range2)
3.23 Blocking
fRF = 315MHz
Δf ±1.5MHz
Δf ±2MHz
Δf ±3MHz
Δf ±10MHz
Δf ±20MHz
fRF = 433.92MHz
Δf ±1.5MHz
Δf ±2MHz
Δf ±3MHz
Δf ±10MHz
Δf ±20MHz
3.24 CDEM
Capacitor connected to
pin 23 (CDEM)
(14)
(14)
23
57.5
63.0
67.5
72.0
74.0
ΔPBlock
56.5
62.0
66.5
71.0
73.0
ΔPBlock
–5%
15
+5%
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
Note:
1. Pin numbers in parenthesis were measured with RF_IN matched to 50Ω according to Figure 2-1 on page 6 with component values as in Table 2-2 on page 7 (RFIN).
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13.
Electrical Characteristics: General (Continued)
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 315MHz unless otherwise specified. Details about current
consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.
Pin(1)
Symbol
At startup; after startup
the amplitude is regulated
to VPPXTAL
7, 8
gm, XTO
20
C0 ≤ 2.2pF
Cm < 14fF
Rm ≤ 120Ω
7, 8
TXTO_Startup
300
7, 8
C0max
3
ΔfXTO
V(XTAL1, XTAL2)
peak-to-peak value
7, 8
VPPXTAL
V(XTAL1)
peak-to-peak value
7, 8
VPPXTAL
C0 ≤ 2.2pF, small signal
Maximum series
start impedance, this
4.6 resistance Rm of XTAL at
value is important for
startup
crystal oscillator startup
7, 8
ZXTAL12_START
Maximum series
4.7 resistance Rm of XTAL
after startup
C0 ≤ 2.2pF
Cm < 14fF
7, 8
Rm_max
15
fRF = 433.92MHz
fRF = 315MHz
7, 8
fXTAL
13.57375
13.1433
No. Parameters
4
4.1
Test Conditions
Min.
Typ.
Max.
Unit
Type*
mS
B
800
µs
A
3.8
pF
D
+5
ppm
C
700
mVpp
C
350
mVpp
C
–2000
Ω
B
Ω
B
MHz
D
MHz
A
XTO
Transconductance XTO
at start
4.2 XTO start-up time
4.3 Maximum C0 of XTAL
Pulling of LO frequency
f due to XTO, CL1 and
4.4 LO
CL2 versus temperature
and supply changes
1.0pF ≤ C0 ≤ 2.2pF
Cm = 4.0fF to 7.0fF
Rm ≤ 120Ω
–5
Cm = 5fF, C0 = 1.8pF
Rm = 15Ω
4.5
4.8
4.9
Amplitude XTAL after
startup
Nominal XTAL load
resonant frequency
External CLK_OUT
frequency
–1400
120
CLK_OUT_CRTL1 = 0
CLK_OUT_CTRL0 = 0
--> CLK_OUT disabled
fCLK disabled (low level on pin
CLK_OUT)
CLK_OUT_CRTL1 = 0
CLK_OUT_CTRL0 = 1
--> division ratio = 3
f XTO
f CLK = ----------3
CLK_OUT_CRTL1 = 1
CLK_OUT_CTRL0 = 0
--> division ratio = 6
CLK_OUT_CRTL1 = 1
CLK_OUT_CTRL0 = 1
--> division ratio = 12
3
fCLK_OUT
f CLK
f XTO
= ----------6
f XTO
f CLK = ----------12
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
Note:
1. Pin numbers in parenthesis were measured with RF_IN matched to 50Ω according to Figure 2-1 on page 6 with component values as in Table 2-2 on page 7 (RFIN).
32
ATA5745C/ATA5746C [DATASHEET]
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13.
Electrical Characteristics: General (Continued)
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 315MHz unless otherwise specified. Details about current
consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.
No. Parameters
4.10 DC voltage after startup
5
Pin(1)
Symbol
fRF = 433.92MHz
CLK_OUT division ratio
=3
=6
= 12
CLK_OUT has nominal
50% duty cycle
3
fCLK_OUT
fRF = 315MHz
CLK_OUT division ratio
=3
=6
= 12
CLK_OUT has nominal
50% duty cycle
3
fCLK_OUT
VDC (XTAL1, XTAL2)
XTO running (Standby
mode, Active mode)
7,8
VDCXTO
Test Conditions
Min.
–250
Typ.
Max.
Unit
Type*
4.52458
2.26229
1.13114
MHz
D
4.3811
2.190
1.0952
MHz
D
–45
mV
C
Synthesizer
5.1 Spurs in Active mode
At ±fCLK_OUT,
CLK_OUT enabled
(division ratio = 3)
fRF = 315MHz
fRF = 433.92MHz
SPRX
–75
–70
dBC
C
at ±fXTO
fRF = 315MHz
fRF = 433.92MHz
SPRX
–75
–70
dBC
A
5.2
Phase noise at 3MHz
Active mode
fRF = 315MHz
fRF = 433.92MHz
LRX3M
–130
–127
dBC/Hz
A
5.3
Phase noise at 20MHz
Active mode
Noise floor
LRX20M
–135
–132
dBC/Hz
B
trise
20
30
ns
tfall
20
30
ns
CCLK_OUT
8
6
Microcontroller Interface
CLK_OUT output rise
6.1
and fall time
6.2
Internal equivalent
capacitance
fCLK_OUT < 4.5MHz
CL = 10pF
CL = Load capacitance
on pin CLK_OUT
2.7V ≤ VVS5V ≤ 3.3V or
4.5V ≤ VVS5V ≤ 5.5V
20% to 80% VVS5V
3
Used for current
calculation
3
pF
C
C
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
Note:
1. Pin numbers in parenthesis were measured with RF_IN matched to 50Ω according to Figure 2-1 on page 6 with component values as in Table 2-2 on page 7 (RFIN).
ATA5745C/ATA5746C [DATASHEET]
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14.
Electrical Characteristic: 3V Application
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 433.92MHz unless otherwise specified. Details about
current consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.
No.
7
Parameters
Test Conditions
Pin
Symbol
10, 11
ISOFF
Min.
Typ.
Max.
Unit
Type*
2
µA
A
3V Application
7.1
Supply current in OFF
mode
7.2
VVS3V_AVCC =
VVS5V ≤ 3V
external load C on pin
CLK_OUT = 12pF
CLK enabled
Current in Standby
(division ratio 3)
mode (XTO is running)
CLK enabled
(division ratio 6)
CLK enabled
(division ratio 12)
CLK disabled
7.3
Current during
TStartup_PLL
VVS3V_AVCC = VVS5V ≤ 3V
CLK_OUT disabled
VVS3V_AVCC =
VVS5V ≤ 3V
CLK disabled
10, 11
IStandby
420
670
290
460
220
350
50
80
µA
10, 11
IStartup_PLL
4.5
7.4
VVS3V_AVCC =
Current in Active mode VVS5V ≤ 3V
ASK
CLK disabled
SENSE_CTRL = 0
10, 11
IActive
6.5
7.5
VVS3V_AVCC =
Current in Active mode VVS5V ≤ 3V
FSK
CLK disabled
SENSE_CTRL = 0
10, 11
IActive
6.7
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
C
C
A
mA
C
9.6
mA
A
9.8
mA
A
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
34
C
15.
Electrical Characteristics: 5V Application
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 433.92MHz unless otherwise specified. Details about
current consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”.
No.
8
Parameters
Test Conditions
Pin
Symbol
VVS5V = 5V
CLK_OUT disabled
10
ISOFF
Min.
Typ.
Max.
Unit
Type*
2
µA
A
5V Application
8.1
Supply current in OFF
mode
8.2
VVS5V ≤ 5V
external load C on pin
CLK_OUT = 12pF
CLK enabled
Current in Standby
(division ratio 3)
mode (XTO is running) CLK enabled
(division ratio 6)
CLK enabled
(division ratio 12)
CLK disabled
10
8.3
Current during
TStartup_PLL
10
IStartup_PLL
4.7
8.4
V
= 5V
Current in Active mode VS5V
CLK disabled
ASK
SENSE_CTRL = 0
10
IActive
6.7
8.5
V
= 5V
Current in Active mode VS5V
CLK disabled
FSK
SENSE_CTRL = 0
10
IActive
6.9
VVS5V = 5V
CLK disabled
IStandby
700
1120
C
490
780
370
590
C
50
80
A
µA
C
mA
C
9.8
mA
A
10
mA
A
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
ATA5745C/ATA5746C [DATASHEET]
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35
16.
Digital Timing Characteristics
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 433.92MHz unless otherwise specified. Details about
current consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”
No.
9
9.1
Parameters
Basic clock cycle
Extended basic clock
cycle
10
Active Mode
10.1
Startup PLL
10.3
Pin
Symbol
Min.
TDCLK
TXDCLK
Typ.
Max.
Unit
Type*
16 / fXTO
16 / fXTO
µs
A
8
4
2
1
× TDCLK
8
4
2
1
× TDCLK
µs
A
15 µs +
208 ×
TDCLK
µs
A
Basic Clock Cycle of the Digital Circuitry
9.2
10.2
Test Conditions
Startup signal
processing
Bit rate range
BR_Range_0
BR_Range_1
BR_Range_2
BR_Range_3
TStartup_PLL
BR_Range_0
BR_Range_1
BR_Range_2
BR_Range_3
TStartup_Sig_Proc
ASK
BR_Range =
BR_Range0
BR_Range1
BR_Range2
BR_Range3
FSK
BR_Range =
BR_Range0
BR_Range1
BR_Range2
BR_Range3
10.4
Minimum time period
between edges at pin
DATA_OUT
BR_Range_0
BR_Range_1
BR_Range_2
BR_Range_3
10.5
Edge-to-edge time
period of the data
signal for full sensitivity
in Active mode
BR_Range_0
BR_Range_1
BR_Range_2
BR_Range_3
BR_Range
24
929.5
545.5
353.5
257.5
× TDCLK
929.5
545.5
353.5
257.5
× TDCLK
1.0
2.0
4.0
8.0
2.5
5.0
10.0
10.0
1.0
2.0
4.0
8.0
2.5
5.0
10.0
20.0
TDATA_OUT_min
10 ×
TXDCLK
TDATA_OUT
200
100
50
25
500
250
125
62.5
A
Kbits/s
A
µs
A
µs
B
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
36
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
17.
Digital Port Characteristics
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 433.92MHz unless otherwise specified. Details about
current consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”
No.
Parameters
11
Digital Ports
ENABLE input
- Low level input
voltage
11.1
- High level input
voltage
RX input
- Low level input
voltage
11.2
- High level input
voltage
BR0 input
- Low level input
voltage
11.3
- High level input
voltage
BR1 input
- Low level input
voltage
11.4
- High level input
voltage
ASK_NFSK input
- Low level input
voltage
11.5
- High level input
voltage
Test Conditions
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V = 4.5V to
5.5V
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
Pin
Symbol
6
VIl
Min.
Typ.
Max.
Unit
Type*
V
A
V
A
V
A
V
A
V
A
V
A
V
A
V
A
V
A
V
A
0.2 × VS
0.12 × VS
6
VIh
19
VIl
0.8 × VS
0.2 × VS
0.12 × VS
19
VIh
20
VIl
0.8 × VS
0.2 × VS
0.12 × VS
20
VIh
21
VIl
21
VIh
22
VIl
22
VIh
0.8 × VS
0.2 × VS
0.12 × VS
0.8 × VS
0.2 × VS
0.12 × VS
0.8 × VS
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
ATA5745C/ATA5746C [DATASHEET]
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37
17.
Digital Port Characteristics (Continued)
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 433.92MHz unless otherwise specified. Details about
current consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”
No.
Parameters
SENSE_CTRL input
- Low level input
voltage
11.6
- High level input
voltage
11.7
CLK_OUT_CTRL0
input
- Low level input
voltage
- High level input
voltage
11.8
CLK_OUT_CTRL1
input
- Low level input
voltage
- High level input
voltage
Test Conditions
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
Pin
Symbol
16
VIl
Min.
Typ.
Max.
Unit
Type*
V
A
V
A
V
A
V
A
V
A
V
A
0.2 × VS
0.12 × VS
16
VIh
5
VIl
0.8 × VS
0.2 × VS
0.12 × VS
5
VIh
4
VIl
0.8 × VS
0.2 × VS
0.12 × VS
4
VIh
0.8 × VS
11.9
TEST1 input
TEST1 input must
always be connected
directly to GND
2
0
0
V
D
11.10
TEST2 output
TEST2 output must
always be connected
directly to GND
1
0
0
V
D
11.11
TEST3 input
TEST3 input must
always be connected
directly to GND
18
0
0
V
D
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
38
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
17.
Digital Port Characteristics (Continued)
All parameters refer to GND and are valid for Tamb = –40°C to +105°C, VVS3V_AVCC = VVS5V = 2.7V to 3.3V, and VVS5V = 4.5V to 5.5V.
Typical values are given at VVS3V_AVCC = VVS5V = 3V, Tamb = 25°C, and fRF = 433.92MHz unless otherwise specified. Details about
current consumption, timing, and digital pin properties can be found in the specific sections of the “Electrical Characteristics”
No.
Parameters
Test Conditions
Pin
Symbol
24
Vol
24
Voh
3
Vol
3
Voh
Min.
Typ.
Max.
Unit
Type*
0.15
0.4
V
B
V
B
V
B
V
B
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
DATA_OUT output
V = VVS5V =
- Saturation voltage low S
4.5V to 5.5V
IDATA_OUT = 250µA
11.12
- Saturation voltage
high
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VVS – 0.4
VVS –
0.15
IDATA_OUT = –250µA
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
CLK_OUT output
V = VVS5V =
- Saturation voltage low S
4.5V to 5.5V
0.15
0.4
IDATA_OUT = 100µA
11.13
- Saturation voltage
high
VS = VVS3V_AVCC =
VVS5V = 2.7V to 3.3V
VS = VVS5V =
4.5V to 5.5V
VVS – 0.4
VVS –
0.15
IDATA_OUT = –100µA
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
ATA5745C/ATA5746C [DATASHEET]
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39
18.
Ordering Information
Extended Type Number
Package
MOQ
ATA5745C-PXQW-1
QFN24
6000pcs
5mm × 5mm, Pb-free, 433.92MHz
ATA5746C-PXQW-1
QFN24
6000pcs
5mm × 5mm, Pb-free, 315MHz
19.
Remarks
Package Information
Top View
D
24
1
E
PIN 1 ID
technical drawings
according to DIN
specifications
6
A
Side View
A3
A1
Dimensions in mm
Bottom View
D2
7
12
13
COMMON DIMENSIONS
E2
6
1
Z
18
24
19
Z 10:1
L
e
b
(Unit of Measure = mm)
Symbol
MIN
NOM
MAX
A
0.8
0.85
0.9
A1
A3
0.0
0.16
0.035
0.21
0.05
0.26
D
4.9
5
5.1
D2
3.5
3.6
3.7
E
4.9
5
5.1
E2
3.5
3.6
3.7
L
0.35
0.4
0.45
b
e
0.2
0.25
0.65
0.3
NOTE
10/18/13
TITLE
Package Drawing Contact:
packagedrawings@atmel.com
40
Package: VQFN_5x5_24L
Exposed pad 3.6x3.6
ATA5745C/ATA5746C [DATASHEET]
9249C–RKE–10/14
GPC
DRAWING NO.
REV.
6.543-5132.02-4
1
20.
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.
9249C-RKE-10/14
History
• Section 18 “Ordering Information” on page 40 updated
• Section 19 “Package Information” on page 40 updated
• Section 13 “Electrical Characteristics: General” on pages 27 to 33 changed
9249B-RKE-08/12
• Section 14 “Electrical Characteristic: 3V Application” on page 34 changed
• Section 15 “Electrical Characteristic: 5V Application” on page 35 changed
ATA5745C/ATA5746C [DATASHEET]
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41
XXXXXX
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© 2014 Atmel Corporation. / Rev.: 9249C–RKE–10/14
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