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TH72011
Transmitter - 433MHz, FSK (SOIC8)
 Download TH72011 Datasheet (PDF)
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TH72011 General Description
The TH72011 FSK transmitter IC is designed for applications in the European 433MHz industrial-scientific-medical (ISM) band, according to the EN 300 220 telecommunications standard; but it can also be used in other counties with similar standards, e.g. FCC part 15.231.
The transmitter's carrier frequency fc is determined by the frequency of the reference crystal fref. The integrated PLL synthesizer ensures that carrier frequencies, ranging from 380MHz to 450MHz, can be achieved. This is done by using a crystal with a reference frequency according to: fref = fc/N, where N = 32 is the PLL feedback divider ratio.
TH72011 Features and Benefits
- Fully integrated PLL-stabilized VCO
- Frequency range from 380 MHz to 450 MHz
- Single-ended RF output
- FSK through crystal pulling allows modulation from DC to 40 kbit/s
- High FSK deviation possible for wideband data transmission
- Wide power supply range from 1.95 V to 5.5 V
- Operating temperature range -40°C to +125°C
- Very low standby current
- On-chip low voltage detector
- High over-all frequency accuracy
- FSK deviation and center frequency independently adjustable
- Adjustable output power range from -11 dBm to +10 dBm
- Adjustable current consumption from 3.4 mA to 10.6 mA
- Conforms to EN 300 220 and similar standards
- 8-pin Small Outline Integrated Circuit (SOIC)
TH72011 Environmental Information
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TH72011 Frequently asked Questions
RF ICs
Question
TH71071 vs TH72011
I am doing FSK transmission at 433MHz.
Which transmitter gives longer range: the TH7101 (monopole antenna) or TH72011 (loop antenna) ??
Answer
You will be limited by the regulations. The monopole antenna is the most efficient and so would give the longest range. The TH72011 can be used with a loop antenna or monopole antenna.
crystal for TH72011
Answer
In my FSK application I use a TH72011 with a 13,5600MHz
crystal series CM6035 from comtec crystal. The data for
this crystal are according your specification for TH72011.
At factory test the all units worked well but after a few weeks some units returned from the custumer with the crystal not oscillating. Do you have an idea what happens ?
Answer
under normal operating conditions the TH72011 should operate without any problems. If the shunt capacitance C0 of the quartz crystal is below 7pF (today, most of the xtal designs have less than 3pF) the crystal's ESR could also be higher. The oscillation margin is > 600ohms measured on our EVB. Nevertheless pls. reply if the phenomenon exists over the whole supply range (2..5.5V). In addition to that pls. also reply all the numbers marked on top & button of the IC.
Answer
From the crystals datasheet C0 is <5pF and ESRmax is 60Ohm.
The phenomenon exist over the whole supply voltage range.
The marking of the IC :
on top : TH72011.2 - 0240:
on bottom : 3B319 9901
Answer
The IC is powered by a Lithium Cell, so the max. Voltage 3.2 Volt and they did function at delivery to the customer.
We have 580 parts on stock with the following marking
on top : TH72011.2 0441
on bottom : B3920 2A
Is this design version .26 ? We got them on in july 2005.
I replaced the IC with one from our stock and the crystal also does not oscillate.
TH7122EVB Antenna
Question
We are designning the remote meter reading system.I want to know how long the distance that measured by using your EVB is.And give me a parameter of antenna according your EVB(7122-FSK-433.92MHz) Please.We need it can work in 350 meter distance,how can we do?
Another question.You know,the MC33593 and MC33594 are the freescale company chips.We transmit the signal using the TH72011 and receive it using the MC33594, the signal can't be received,but it can be received transmiting the signal using the MC33593 and receving the signal using the MC33594.The signal intensity using TH72011 is higher than using the MC33593. Make the distance short,The signal can be received by the MC33594 when transmit it by using the TH72011.
Answer
1) The EVB7122 contains a 50ohm SMA connector for RF in/output which can be used for a lambda/4 monopole antenna. This antenna is more efficient than a PCB loop antenna. A distance of 350m line-of-sight should be achievable, but it depends on several environmental conditions.
2) It should be ensured that the TX center frequency is equal to the RX center frequency. Of course also RX and TX should operate on the modulation scheme. Pls. also check the output power of the TH72011 in comparison to the MC33593. If the TH72011 antenna network is properly tuned there should be an improvement of approx. 3dB in comparison to the MC33593.
It is also important that the data rate selection bits (DR0,DR1) of the MC33593 are set according to the TX data rate. I don't know if it's necessary to send a kind of sync word to the RX in order to start-up data decoding - this should be checked by your side.
FM with all TH71xxx /TH72xxx
Question
I've bought some of your RF IC's -> TH72011
I have another little question to the topic below, can you tell me the function of the capacitor "CX1" in the circuit example for analog FM transmission found in the TH7122x Cookbook pg.6?
Is it possible to use this capacitor for fine tuning the transmission frequency of the IC (by replacing it with a variable capacitor for example)? Which values can be used?
And what about the varactor diode? Which one can I take (for audio transmission)? BB535 or perhaps another one?
Answer
I've bought some of your RF IC's -> TH72011
I have another little question to the topic below, can you tell me the function of the capacitor "CX1" in the circuit example for analog FM transmission found in the TH7122x Cookbook pg.6?
Is it possible to use this capacitor for fine tuning the transmission frequency of the IC (by replacing it with a variable capacitor for example)? Which values can be used?
And what about the varactor diode? Which one can I take (for audio transmission)? BB535 or perhaps another one?
TH72011 matching network
Answer
Sorry, now I realized it's the TH72011 you want to match. I guess the freq. is 433MHz? If your antenna is shorter than quarter wavelength (which would be about 18cm for 433MHz) then you can electronically increase the length of the antenna. Just add an inductor in series to the circuit diagram shown in the DS. You may play with values of 12 to 33nH.
TH72011
Question
I started some design with TH72011 and found it pretty - easy to be done and with very clean spectrum. But since I'd like to use it in different applications ( mainly alarm systems), I'll need to know the output impedance to mutch the device in the right way. I don't see in the data sheet any information about. Is somewhere data for S22 parameters or/and Smith chart for the output impedance of TH72011?
Next will be TH72031, for it also :)
Question
So, seems, a should accept , that there is a Reqw of a 300 ohms( or 250 for '..03serias) in paralel with 2-3 pf.
I throw a look to TH7122 datasheet and find there the well known formula for the equivalent load. But for TH72011 at 10mW output I found (5-0.6)^2/2*0.010=1232 ohms.You wrote 250 - 300. Which is the thrue walue?
Do I make some mistake somewhere?
Question
After some pause I started again work woth TH72011 and I have not bad resulults. I use it as a stabilizated oscilator for a transmitter in 450-470 MHz band, with analog FM directly at the crystal by a varicap diode. A small ( 1-5pF) trimmer - capacitor from the output to GND adjusts the matching circuit well. The spectrum is pretty clean , but the phase noise is a little bit loudy.
Very important was to use exact cystals- 12 pf paralel resonant.
The output is about 6-7 mW at 50 ohnm, mesured with HP8920A RFcommunication test set.
Answer
Thank you for the advice, I'll try with battery. :)
I'd like to share with others my experiance with the output matching of TH72011. As wroten above, the equivalent resistance Req is about 700 ohms. The capacitance of 3 pf means Xc=122 ohm at 433 MHz. Transfering the impedances in serial mode will result Z=20.64-118.4 ohm. The inductor to Vcc( in fact-shunt) is 33 nH, to make a tank at 433 MHz with the output capacitance of TH72011 is nessesery to add 1-3 pf; a small SMD trimmer-capacitor 0.6-5 pf allows to match exactly the thank frequecy. Thus the output impedance becomes only active 720 ohms and a serial inductor between 33 and 56 nH( depending of the PCB layering) matches to 50 ohm active impedance. The tolerances are matched by the trimer pretty well. If the antenna is 1/4 lambda, the impedance should be matched to 37.5 ohm; then the output serial inductor should be increased to 68-75 nH .
EBV72011 & TH71102 ETSI certification
Answer
Comment from customer: My TH72011 board already pass FCC certification.
how to change the center frequency fc
Question
about th72011 ,i want to ask how to change the center frequency fc,and how to select the value of cx1 and cx2 according to crystal parameters,
SOS! somebody help me, pls ! thank you!
Question
i use the th72011,we find a abnormity signal with spectrum analyser.
i have three pictures, but i don't know how to post them.i will send them to you if somebody can help me. thank you!
PS:
1st picture: circuit diagram
2nd picture: copy screen of spectrum analyser
3rd pciture: Frequency Sweep of the crystal(13.56MHz 20ppm)
TH71102 for ARIB STD67
Question
I'm currently working on receiver for japanesse standard. I chose a frequency to have 10mW (429.2MHz) power. Unfortunatly the receiver does not meet the ACP power 40dB limit (i'm near 35dB).
Can somebody confirm me if there is an issue to reach or surpass the 40dB or if as i think the max value i obtain is inherent of the TH71102.
Sorry for my mistake. It's on the transmiter TH72011 that the ACP for 12.5kHz BW doesn't complies the -40dB level needed for ARIB STD67. The receiver TH71102 work fine at the chosen fréquency.
Buy TH72011
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