Z87200

· Complete Direct Sequence Spread-Spectrum Transceiver in a Single CMOS IC
·Programmable Functionality Supports Many Different Operational Modes
· Acquires Within One Symbol Duration Using Digital PN Matched Filter
· Two Independent PN Sequences, Each up to 64 Chips Long for Distinct Processing of the Acquisition/Preamble Symbol and Subsequent Data Symbols
· Power Management Features
· Optional Spectral Whitening Code Generation
· Full- or Half-Duplex Operation n High Performance and High Reliability for Reduced Manufacturing Costs
· Ideal for a Wide Range of Wireless Applications Including Data Acquisition Systems, Transaction Systems, and Wireless Local Area Networks (WLANs)
· Fast Response and Very Low Overhead when Operating in Burst Modes
· Allows High Processing Gain to Maximize the Acquisition Probability, then Reduced Code Length for Increased Data Rate
· Reduced Power Consumption
· Randomizes Data to Meet Regulatory Requirements
· Permits Dual Frequency (Frequency Division Duplex) or Single Frequency (Time Division Duplex) Operation
· Small Footprint, Surface Mount

The Z87200 is a programmable single-chip, spread-spectrum, direct-sequence transceiver. The Z87200 incorporates Stanford Telecom spread-spectrum and wireless technology and is identical to Stanford Telecom's STEL- 2000A. By virtue of its fast acquisition capabilities and its ability to support a wide range of data rates and spreadspectrum parameters, the Z87200 spread-spectrum transceiver supports the implementation of a wide range of burst data communications applications.

Available in both 45- and 20-MHz versions, the Z87200 performs all the digital processing required to implement a fast-acquisition direct sequence (such as pseudonoise- or PN-modulated), spread-spectrum full- or half-duplex system. Differentially encoded BPSK and QPSK are fully supported.

The receiver section can also handle differentially encoded pi/4 QPSK. A block diagram of the Z87200 is shown in Figure 1; its pin configuration is shown in Z87200 receive functions integrate the capabilities of a digital downconverter, PN matched filter, and DPSK demodulator, where the input signal is an analog-to-digital converted  I.F. signal. Z87200 transmit functions include a differential BPSK/QPSK encoder, PN modulator (spreader), and BPSK/QPK modulator, where the transmitter output is a sampled digitally modulated signal ready for external digi- tal-to-analog conversion (or, if preferred, the spread basebnd signal may be output to an external modulator).

These transceiver functions have been designed and integrated for the transmission and reception of bursts of spread data. In particular, the PN Matched Filter has two distinct PN coefficient registers (rather than a single one) in order to speed and improve signal acquisition performance by automatically switching from one to the other upon signal acquisition. The Z87200 is thus optimized to provide reliable, high-speed wireless data communications.