CYW20736
1.7.3 Local Oscillator
The local oscillator (LO) provides fast frequency hopping (1600 hops/second) across the 79 maximum available channels. The
CYW20736 uses an internal loop filter.
1.7.4 Calibration
The CYW20736 radio transceiver features a self-contained automated calibration scheme. No user interaction is required during
normal operation or during manufacturing to provide optimal performance. Calibration compensates for filter, matching network, and
amplifier gain and phase characteristics to yield radio performance within 2% of what is optimal. Calibration takes process and tem-
perature variations into account, and it takes place transparently during normal operation and hop setting times.
1.7.5 Internal LDO Regulator
The CYW20736 has an integrated 1.2V LDO regulator that provides power to the digital and RF circuits. The 1.2V LDO regulator
operates from a 1.425V to 3.63V input supply with a 30 mA maximum load current.
Note: Always place the decoupling capacitors near the pins as closely together as possible.
1.8 Peripheral Transport Unit
1.8.1 Broadcom Serial Communications Interface
The CYW20736 provides a 2-pin master BSC interface, which can be used to retrieve configuration information from an external
EEPROM or to communicate with peripherals such as track-ball or touch-pad modules, and motion tracking ICs used in mouse
devices. The BSC interface is compatible with I2C slave devices. The BSC does not support multimaster capability or flexible
wait-state insertion by either master or slave devices.
The following transfer clock rates are supported by the BSC:
■ 100 kHz
■ 400 kHz
■ 800 kHz (not a standard I2C-compatible speed.)
■ 1 MHz (Compatibility with high-speed I2C-compatible devices is not guaranteed.)
The following transfer types are supported by the BSC:
■ Read (Up to 16 bytes can be read.)
■ Write (Up to 16 bytes can be written.)
■ Read-then-Write (Up to 16 bytes can be read and up to 16 bytes can be written.)
■ Write-then-Read (Up to 16 bytes can be written and up to 16 bytes can be read.)
Hardware controls the transfers, requiring minimal firmware setup and supervision.
The clock pin (SCL) and data pin (SDA) are both open-drain I/O pins. Pull-up resistors external to the CYW20736 are required on
both the SCL and SDA pins for proper operation.
1.8.2 UART Interface
The UART is a standard 2-wire interface (RX and TX) and has adjustable baud rates from 9600 bps to 1.5 Mbps. The baud rate can
be selected via a vendor-specific UART HCI command. The interface supports the Bluetooth 3.0 UART HCI (H5) specification. The
default baud rate for H5 is 115.2 kbaud.
Both high and low baud rates can be supported by running the UART clock at 24 MHz.
The CYW20736 UART operates correctly with the host UART as long as the combined baud rate error of the two devices is within
±5%.
Document Number: 002-14883 Rev. *I
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