CYW20736
1.6.4 External Reset
The CYW20736 has an integrated power-on reset circuit that completely resets all circuits to a known power-on state. An external
active low reset signal, RESET_N, can be used to put the CYW20736 in the reset state. The RESET_N pin has an internal pull-up
resistor and, in most applications, it does not require that anything be connected to it. RESET_N should only be released after the
VDDO supply voltage level has been stabilized.
Figure 5. External Reset Timing
Pulse width
>20 µs
RESET_N
Crystal
warm‐up
delay:
~ 5 ms
Baseband Reset
Start reading EEPROM and
firmware boot
Crystal Enable
1.7 Integrated Radio Transceiver
The CYW20736 has an integrated radio transceiver that is optimized for 2.4 GHz Bluetooth wireless systems. It has been designed
to provide low power, low cost, and robust communications for applications operating in the globally available 2.4 GHz unlicensed
ISM band. It is fully compliant with Bluetooth Radio Specification 4.0 and meets or exceeds the requirements to provide the highest
communication link quality of service.
1.7.1 Transmitter Path
The CYW20736 features a fully integrated transmitter. The baseband transmit data is GFSK modulated in the 2.4 GHz ISM band.
Digital Modulator
The digital modulator performs the data modulation and filtering required for the GFSK signal. The fully digital modulator minimizes
any frequency drift or anomalies in the modulation characteristics of the transmitted signal.
Power Amplifier
The CYW20736 has an integrated power amplifier (PA) that can transmit up to +4 dBm for class 2 operation.
1.7.2 Receiver Path
The receiver path uses a low IF scheme to downconvert the received signal for demodulation in the digital demodulator and bit syn-
chronizer. The receiver path provides a high degree of linearity, an extended dynamic range, and high-order, on-chip channel filter-
ing to ensure reliable operation in the noisy 2.4 GHz ISM band. The front-end topology, which has built-in out-of-band attenuation,
enables the CYW20736 to be used in most applications without off-chip filtering.
Digital Demodulator and Bit Synchronizer
The digital demodulator and bit synchronizer take the low-IF received signal and perform an optimal frequency tracking and bit syn-
chronization algorithm.
Receiver Signal Strength Indicator
The radio portion of the CYW20736 provides a receiver signal strength indicator (RSSI) to the baseband. This enables the controller
to take part in a Bluetooth power-controlled link by providing a metric of its own receiver signal strength to determine whether the
transmitter should increase or decrease its output power.
Document Number: 002-14883 Rev. *I
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