The S1M8836/37 is a Fractional-N frequency synthesizer with integrated prescalers, designed for RF operation up to 1.0GHz/2.5GHz and for IF operation up to 520MHz. The fractional-N synthesizer allows fast-locking, low phase noise phase-locked loops to be built easily, thus having rapid channel switching and reducing standby time for extended battery life. The S1M8836/37 based on - fractional-N techniques solves the fractional spur problems in other fractional-N synthesizers based on charge pump compensation. The synthesizer also has an additional feature that the PCS/CDMA channel frequency in steps of 10kHz can be accurately programmed. The S1M8836/37 contains quadruple-modulus prescalers. The S1M8836 RF synthesizer adopts an 8/9/12/13 prescaler(16/17/20/21 for the S1M8837) and the IF synthesizer adopts an 8/9 prescaler. Phase detector gain is user-programmable for maximum flexibility to address IS-95 CDMA and IMT2000. Various program-controlled power down options as well as low supply voltage help the design of wireless cell phones having minimum power consumption. Using the Samsung's proprietary digital phase-locked-loop technique, the S1M8836/37 has a linear phase detector characteristic and can be used for very stable, low noise PLL's. Supply voltage can range from 2.7V to 4.0V. The S1M8836/37 is available in a 24-QFN package.