InsideShowcase (Volume 27) is available in HTML and PDF format. - 179KBPowerFLEX™, a low-cost alternative to TO-220 High performance PLL clock drivers Digital control loop for 3-phase brushless dc motor Cost-effective gigabit ethernet transceiver SN75LVDM976, industry's first discrete dual mode LVDS SCSI transceiver TRF2050, a 1.2 GHz fractional-N/integrator-N syntheszier New external memory interface provides 8 hour speech duration |
1.2 GHz fractional-N/integer-N synthesizerProduct Features
The TRF2050 is a low-voltage, low-power consumption 1.2 GHz fractional-N/integer-N frequency synthesizer component for wireless applications. Along with external loops, the TRF2050 provides all functions necessary for voltage-control oscillator (VCO) control in dual phase-locked loop (PLL) frequency synthesizer systems. The main channel operates up to 1.2 GHz in support of cellular radio frequency (RF) channels. An auxiliary channel, which operates up to 125 MHz, supports most intermediate frequency (IF) channels within the RF transceiver. The operating current is typically 7.5 mA. The TRF2050 internal registers are programmed using a three-wire (Clock, Data, and Strobe) serial interface. The current-output charge pumps directly drive passive resistance-capacitance (RC) filter networks to generate VCO control voltages. When operated in the integer-N mode, rapid main-channel frequency switching is achieved with a charge pump arrangement which enables an increased current drive and also alters the loop-filter bandwidth during the "speed-up" mode of the frequency switching interval. The TRF2050’s principle advantage is a result of the fractional-N mode capability. When operated in the fractional-N mode, the reference signal applied to the phase detector can be several times the channel spacing frequency of the wireless system. This enables the PLL loop filter bandwidth to be increased and thus allows the VCO to slew to new frequencies faster. The fractional "frequency" spurs which fall within the wireless system channel of interest are suppressed by fractional compensation circuitry and compensation charge pumps. The TRF2050 also supports a SA7025 emulation mode which emulates the Philips SA7025 fractional-N synthesizer. The TRF2050 is available in a 20-pin plastic Shrink Small Outline Package (SSOP). Visit TI’s RF web-site for more information on this or any other TI RF product. In addition to providing full descriptions of all of TI’s RF products, this web-site provides:
The URL for TI’s RF web-site is:
Vol 27 May, 1998 |
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