TDA5150 Datasheet, PDF (17/106 Pages) Infineon Technologies AG – On-chip, high resolution fractional-N synthesizer and Sigma-Delta modulator with ASK, FSK, GFSK options

2.3
Functional Block Diagram
TDA 5150
TDA 5150 Functional Description
VREG
VBAT
Voltage
Regulator
Internal
Supply
EN
SDIO
SCK
XTAL
Digital
Control
Crystal
Oscillator
Data
Encoder
ΣΔ / Fractional N PLL
Digital ASK/FSK
Modulator
Power
Amplifier
Clock
Divider
Antenna
Tuning
PAOUT
GNDPA
GND
CLKOUT
Figure 4 TDA 5150 Block Diagram
TDA 5150 is an SPI configurable fully integrated ASK/FSK/GFSK RF transmitter for the
300-320 MHz, 425-450 MHz and 863-928 MHz frequency bands. The input datastream,
applied to the digital SDIO line is transposed and appears as modulated RF-signal, at
the output of the integrated RF power amplifier. Signal encoding and spectrum is in
accordance with the chosen modulation type (i.e ASK, FSK or GFSK) and encoding
scheme.
TDA 5150 contains following major blocks which extend the functionality compared to
legacy RF transmitters:
• An on-chip voltage regulator is delivering 2.1 V nominal supply voltage for the
transmitter’s functional units. In addition, the battery voltage is monitored and battery
low and brown out flags are set, if a critical supply voltage drop event occurs.
• For avoidance of erroneous transmissions, the brownout flag is coupled with the RF
Power Amplifier state control. If a brownout or critical voltage drop event occurs, the
RF Power Amplifier is automatically switched off, as part of the Fail-Safe philosophy.
The mechanism is explained in detail in Chapter 2.4.8.5
• The crystal oscillator and the associated clock divider(s) generate the required clock
signals. There is an output line (CLKOUT) which may be used to clock a host µC, or
for bit rate generation.
• A digital control logic, accessible for user via the SPI bus allows flexible and fast
(re)configuration. At the same time it offers a simple but powerful Fail-Safe
mechanism, which enhances the reliability of transmissions
Data Sheet
17
V 1.0, July 2009