descriptionThe TRF3520 radio frequency (RF) modulator/amplifier is a single-chip RF integrated circuit (IC) suitable for900-MHz wireless global system for mobile communications (GSM) applications. It combines a directconversion RF in-phase/quadrature-phase (I/Q) modulator, a single-sideband suppressed carried (SSB) mixer,an RF filter, a power amplifier (PA) driver, a buffered voltage-controlled oscillator (VCO), and a serial interfaceinto one small package. Very few external components are required. During idle operation, the individualfunctional elements may be selectively placed in standby mode for minimum power consumption.1415TXM_V CC TXM_GNDTXM_LO+TXM_LO TXM_GNDTXM_GNDNCPH2PH1MOD_GNDMOD_V CC MOD_GND3635343332313029282726251612345678910 11 12TXO_TNK2TXO_TNK1TXO_GNDNCNCNCPSUBNCDRV_GNDDRV_OUT DRV_OUT+DRV_GND17181920DIG_DIG_CLKDIG_STRDIG_DAT47464544434842TXO_TXO_GNDTXO_SYNNCDB2_GNDMOD_GNDQ+Q DRV_GNDNCI+I 40393841212223243713DIG_GNDDB2_OUTDB2_DRV_ DRV_GNDVBG_INPFB PACKAGEVCCVCCVCCVCCNC specifications per the terms of Texas Instrumentsstandard warranty. Production processing does not necessarily includetesting of all parameters. TRF3520GSM RF MODULATOR/DRIVER AMPLIFIERSLWS060A MAY 19982POST OFFICE BOX 655303 w DALLAS, TEXAS 75265functional block diagramR-PassFilter (BPF) 34I/Q Modulator-SidebandTransmit MixerIF VCOP 2 Low-PassFilter (LPF)To SYNTH (TXO_SYN)To ExternalBand-Pass Filter,Power Amplifier,and DuplexerI +Q +Serial Interface05905DIG_CLKDIG_STRDIG_DATDIG_GNDDIG_VCCTankI Q BufferBufferBufferTXM_LO+TXM_LO DRV_OUT+ 11DRV_OUT 10+ 3320212324464312PowerAmplifierDriver4140393837Divide-by-Two Output (DB2_OUT)TXO_TNK1transmit IF VCOThe transmit intermediate frequency (IF) VCO generates a CW signal in the 200-MHz range. The IF VCOfrequency is controlled by applying voltage to the required external tank varactors. Through on-chip buffers, thetransmit IF VCO output is sent to the SSB transmit mixer and divide-by-two functional blocks, as well as to anexternal synthesizer w TRF3520GSM RF MODULATOR/DRIVER AMPLIFIERSLWS06