product summary CX74076: rx asic for cdma and gps mobile handset applications applications ? ? ? ? ? ? ? ? ? ? cdma and gps phones features three-step gain control cellular lna gps lna external resistor to adjust lna bias current independent cdma and gps mixers buffer lo signal for transmit upconverter 90 db dynamic range vga 200 to 600 mhz vhf oscillator battery cell operation (2.7 v < vcc < 3.3 v) 6 x 6 mm 40-pin rflga? package with down-set paddle description the CX74076 application-specific integrated circuit (asic) is a single intermediate frequency (if), multi-mode receiver intended for use in code division multiple access (cdma) and global positioning system (gps) modes. the CX74076 is a highly integrated super-heterodyne receiver. except for the surface acoustic wave (saw) filters and matching components, the device incorporates all the components required to implement the receiver chain, from the low-noise amplifier (lna) to the in-phase and quadrature (i/q) demodulator stages. two lnas are in the front-end receiver: a three-step gain stage cellular lna (high, mid, and bypass) and a high gain gps lna. after rf lna signal amplification and filtering from the antenna, the received signal is mixed down from rf to the if. there are separate m i xers for cdm a cellular and gps m o des. the cdma mixer has balanced outputs for the if saw filters and can be combined externally to mate to a single-ended saw filter. the gps mixers have a differential output for an external l-c bandpass filter. after if filtering, the if signal is amplified by a variable gain amplifier (vga) and fed to an i/q demodulator, resulting in baseband i/q signals at the output. the CX74076 is also designed with two local oscillator (lo) input ports, one for the cdma mixer and one for the gps mixer. these mixers operate at different rf frequency inputs, but have the same if frequency output. this usually refers to a single if (sif) plan at 183.6 mhz. the cell_lo signal (pin 30) provides an lo port for the cdma-cellular mixer. in the cellular band, the frequency is divided by two by an internal divider, which provides the lo input to the cellular mixer. only one external vco is required for the uhf pll. additionally, the mixer lo signal is coupled and amplified internally, which provides another rf signal to drive the transmtiter upconverter lo port. the vga has a minimum dynamic range of 90 db with a control voltage range of 0.5 to 2.5 v, which is common to all modes. a vhf oscillator operates with external tank circuits to provide lo frequencies for the i/q demodulator in the cellular, pcs, and gps modes. the noise figure, gain, and third order input intercept point (iip3) of each stage in the receiver chip are optimized to meet the system requirements for cdma modes according to tia/eia-98-c. the asic design employs bicmos technology for low cost, high performance, and a high level of integration. a block diagram of the CX74076 is shown in figure 1. skyw orks so lut i ons , inc . pro p r i et ary an d c o nf ide n t i a l 1 103087a [781] 376-3000 i fax [781] 376-3100 i sales@ skyw o rksinc. c om i www.skywor ksinc.c om february 5, 2003
product summary i CX74076 cell_lna_out gps_lna_out cell_mix_in cell_lo gps_mix_in i+ pll i? q+ q? lo_out 2 mix_out+ gps_lo mix_out? gps_mix_out? gps_mix_out+ vga_in+ vga_in? gps_vga_in cell_lna_in gps_lna_in vcotnk? vcotnk+ c1400 90 o lna1 lna2 figure 2. CX74076 rx asic block diagram ordering information model name manufacturing part number product revision receiver asic CX74076 ? 2002, 2003 skyworks solutions, inc. all rights reserved. information in this document is pr ovided in connection with skyworks solutions, inc. ("skyworks") products. these materials are provided by skyworks as a service to its customers and may be used for informational purpo ses only. skyworks assumes no responsibility for errors or omis sions in these materials. skyworks may make changes to its products, specifications and product de scriptions at any time, without notice. skyworks makes n o c o mmitmen t to update the information and shall have no responsibility whatsoever for conflicts, incompatibilities, or other difficulties aris in g from fu tu re c h an g e s to its pr oduct s and pr oduct descr i pt ions. no license, express or implied, by estoppel or otherwise, to any int e llect ual pr oper t y r i ght s is gr ant e d by t h is document . exce pt as may be pr ovided in skyworks terms and conditions of sale for such pr oducts, skyworks assumes no liability whatsoever. th es e ma teria ls a r e prov ided "a s is " with out wa rra nty of a n y k i nd, eith er expres s or implied, rela ting to s a l e a nd/or us e of skyworks? products including warrant ies relating to fitness for a particular purp os e, merch a n ta bility , pe rformance, quality or non-infringement of any patent, copyright or other intellectual property right. skywo rks further does not warrant the accuracy or completenes s of th e informa t ion, text, g r a p h i cs or oth e r i tems conta i ned with in th es e ma teria ls . s k y work s s h a ll not be lia b l e for any special, indirect, incidental, or c onsequential damages, includin g with out limita tion, los t rev e nues or los t profits th at ma y res u lt from th e us e of th es e ma teria ls . s k ywor ks? pr oduct s ar e not int e nded f o r use in medical, lif esav ing or life-sustaining applicatio ns. skyworks customers using o r selling skyworks? pr oduct s f o r use in such applicat ions do so at t h eir own r isk and agree to fully indemnify skyworks for any damages resulting f rom such improper use or sale. the following are trademarks of skyworks solutions, inc.: skywor ks?, the skyworks symbol, spr?, single package radio?, and bre akt hr ough simplicity?. product names or services list ed in this publication are fo r identification purposes only, and may be trademarks of t h ir d par t ies. thir d -par t y br ands and names ar e t h e pr oper t y of their respective owners. rflga? is a trademark of conexant systems, inc. additional information, posted at www.skywor ksinc.com, is incorporated by reference. general information skyworks solutions, inc. 20 sylvan rd. woburn, ma 01801 www.skyworksinc.com
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