AS3977-BQFT austriamicrosystems, AS3977-BQFT Datasheet - Page 18

• Manufacturer Part Number: AS3977-BQFT
• Description: IC RF TRANSMITTER FSK 16-QFN
• Manufacturer: austriamicrosystems

Specifications of AS3977-BQFT

• Frequency: 300MHz ~ 928MHz
• Applications: ISM
• Modulation Or Protocol: FSK
• Data Rate - Maximum: 100 kbps
• Power - Output: 10dBm
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 2 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 16-VQFN Exposed Pad, 16-HVQFN, 16-SQFN, 16-DHVQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Memory Size: -
• Current - Transmitting: -

AS3977
Data Sheet - D e t a i l e d S y s t e m D e s c r i p t i o n
SDI / Control Interface
This interface enables a serial and synchronous communication between external microcontroller and AS3977. Data
can be written to and read out from AS3977. Additionally, it facilitates the transmission of TX-data. The rising edge on
the SDI enable signal (transition to the active state), while the device is in Power Down Mode has various effects on
the circuit:
Thus, the wakeup event through the SDI interface determines the basic communication between AS3977 and the
microcontroller. In addition it takes some time to have a stable crystal oscillator clock available. Therefore all functions
that require a stable crystal oscillator clock are not immediately available after the wakeup.
Baud Rate Generator
This module generates two clocks; one used for the microcontroller (MCCLK) and one as baud rate clock with 50%
duty cycle. The baud rate clock is used by the microcontroller to properly synchronize the provided data during
transmission with the internal Manchester coder.
The baud rate generator maintains the behavior of MCCLK and keeps it properly synchronized to the TX data clock.
For example, a missing synchronization can occur when clock settings are changed by an asynchronous event like
SDI programming or when a new transmission starts.
The Baud rate generator offers different types of data outputs: one fully asynchronous, one synchronous and one
synchronous but Manchester coded. By means of AS3977 command control Byte, any of the three different output
data types can be selected.
www.austriamicrosystems.com
- It wakes up the crystal oscillator (this takes maximum 1.5 ms with the specified Crystal parameters)
- It sets the transfer and sampling edge of the AS3977 SDI data signal.
- It activates the Micro Controller clock output depending on the register setting and the value of the data signal.
Revision 3.5
18 - 45