General Description
The PMB 2347 is a RF/IF double PLL frequency synthesizer implemented in Infineon’ high speed BiCMOS technology B6HFC. The device contains two PLLs with integrated prescalers especially designed for use in battery powered radio equipment and mobile telephones. Primary applications are single- and dual-band digital cellular systems e.g. GSM, PCN (DCS 1800) and PCS systems.

Features
■ Operation range 2.7 to 5.0 V
■ Low operating current consumption
■ Programmable power down modes
■ High input sensitivity and high input
    frequencies: PLL1 (RF): 2.8 GHz
    PLL2 (IF): 500 MHz
■ Programmable dual modulus
    prescaler divide ratio:
    PLL1: 1:64/65 or 1:32/33
    PLL2: 16/17 or 1:8/9
    Dividing ratios:
    A counters: PLL1: 0 to 63
                       PLL2: 0 to 15
    N counters: PLL1: 3 to 16,383
                       PLL2: 3 to 16,383
    R counters 3 to 16,383 for PLL1 and PLL2
■ Fast phase detectors and charge pump outputs without dead zone
■ High phase noise performance
■ Switchable polarity and programmable phase detector currents
■ External reference current setting for PD outputs
■ Fast serial 3-wire bus interface with
    low threshold voltage Schmitt-Trigger inputs for interfacing with low
    voltage baseband circuits
■ Two data registers in PLL2 for fast
    IF band switching
■ A programmable multi-functional
    output port for lock detect (quasidigital lock detect) and test mode