Features: Single chip solution with only a few external components
Stand-alone fixed-frequency transceiver operation modes
Programmable multi-channel transceiver operation modes
Low current consumption in active mode and very low standby current
PLL-stabilized RF VCO (LO) with external varactor diode
Lock detection in programmable channel applications
3wire bus serial control interface
FSK/ASK modulation selection
FSK for digital data and FM for analog signal reception
RSSI allows signal strength indication and ASK detection
Switchable LNA gain for improved dynamic range
Automatic PA turn-on after PLL lock
FM possible with external varactor
ASK modulation achieved by on/off keying
AFC option for extended input frequency acceptance range
Surface mount package LQFP32
Application General bi-directional half duplex digital data transmission or analog signal transmission
Low-power telemetry
Alarm and security systems
Keyless car and central locking
Domotics
Model control
Pinout
Specifications
| Parameter |
Symbol |
Condition / Note |
Min |
Max |
Unit |
| Supply voltage |
Vcc |
|
0 |
7.0 |
V |
| Input voltage |
Vin |
|
-0.3 |
VCC+0.3 |
V |
| Input current |
Iin |
|
-1 |
1 |
mA |
| Input RF level |
Pimax |
no damage |
|
10 |
dBm |
| Storage temperature |
TSTG |
|
-40 |
+125 |
°C |
| Electrostatic discharge |
VESD1 |
human body model, 1) |
-1.0 |
+1.0 |
kV |
| Electrostatic discharge |
VESD2 |
human body model, 2) |
TBD |
TBD |
kV |
1) pins IN_DTA, ASK/FSK, RE/SCLK; TE/SDTA, FS0/SDEN, FS1/LD
2) all pins, exept IN_DTA, ASK/FSK, RE/SCLK; TE/SDTA, FS0/SDEN, FS1/LD
DescriptionThe TH7121 is a single chip FSK/FM/ASK transceiver IC. TH7121 is designed to operate in low-power multi-channel programmable or single-channel stand-alone, half-duplex data transmission systems. It can be used for ISM, SRD or any other application operating in the frequency ranging of 300 MHz to 930 MHz.
The TH7121 transceiver IC consists of the following building blocks:
Low-noise amplifier (LNA) for high-sensitivity RF signal reception with switchable gain
Mixer (MIX) for RF-to-IF down-conversion
IF amplifier (IFA) to amplify and limit the IF signal and for RSSI generation
Phase-coincidence demodulator with external ceramic discriminator (FSK Demodulator)
Operational amplifier, connected to demodulator output (OA1)
Operational amplifier, integrator circuit at FSK-AFC mode (OA2)
Control logic with 3wire bus serial control interface (SCI)
Reference oscillator (RO) with external crystal
Reference divider (R counter)
Programmable divider (N/A counter)
Phase-frequency detector (PFD)
Charge pump (CP)
Voltage control oscillator (VCO) with internal varactor
Power amplifier (PA) with adjustable output power
The transceiver TH7121 can be used either as a 3wire-bus-controlled programmable or as a stand-alone fixedfrequency device. After power up, the transceiver is set to fixed-frequency mode. In this mode, pins FS0/SDEN and FS1/LD must be connected to VEE or VCC in order to set the desired frequency of operation. The logic levels at pins FS0/SDEN and FS1/LD must not be changed after power up in order to remain in fixed-frequency mode.
TH7121 Data Sheet
