AMIS-50051: Digital Demodulator
The AMIS-50051 is a small digital demodulator, specially developed to work with the AMIS-50050 spread spectrum baseband
controller. It simplifies the design of the receiver in a direct sequence spread spectrum wireless communication link.
2.0 Key Features
• 1Mbit/s demodulation (QPSK)
• PN code tracking output to AMIS-50050 (Please refer to the AMIS-50050 spread spectrum baseband controller.)
• Fully programmable
• CMOS technology
• Power-down mode
• Wireless local area networks
• Portable wireless communication
• Digital cellular telephones
• Wireless ISDN modems
The AMIS-50051 simplifies the design of the receiver in a direct sequence spread spectrum wireless communication link. The AMIS-
50051 uses advanced DSP technology to demodulate the data from a BPSK/DBPSK/QPSK/DQPSK modulated signal. This technique
also provides a PN code tracking signal output, a carrier tracking signal and an automatic gain control (AGC) output signal. The power
of the AMIS-50051 reduces the complexity and component count of a DSSS receiver. The AMIS-50051 is designed to demodulate
QPSK or BPSK data from a carrier whose frequency is11MHz or less. Data rates can be as high as 1Mbit/s for QPSK signals or
500Kbit/s for BPSK signals. An error signal is produced, which can be used to acquire and track the PN code of a direct sequence
This output is a
the phase of the
voltage, which the
receiver’s PN code.
AMIS-50050 (please refer to AMIS-50050
An external despreading device is required
to remove the PN
the received signal. This reduces the chance of false acquisition over other methods. The AMIS-50051’s internal NCO oscillator is
adjusted by a signal produced from the data demodulation process. This is used to track variations in the carrier frequency of the
The AMIS-50051 produces a level error output. This output is pulsed high or low depending on the level of the received signal. This can
be used to form an AGC circuit.
The AMIS-50051 requires few external components. The AMIS-50051 is designed to work directly with the AMIS-50050 to simplify the
design effort of a wireless communication link.
AMI Semiconductor – Sept. 06