RF137

www.DataSheet4U.com RF137 Transceiver For GSM Applications The RF137 Transceiver is a highly integrated device optimized for use in singleband or multi-band Global System for Mobile Communications (GSM) applications. In the receive path, the device consists of selectable gain Intermediate Frequency (IF) amplifiers and an image reject downconverter with differential IF outputs. In the transmit path, the device consists of an In-Phase and Quadrature (I/Q) modulator and a frequency translational loop designed to perform frequency upconversion with high output spectral purity. This loop has a phase/frequency detector, a charge-pump, a mixer, and buffers for the required isolation between RF output, Local Oscillator (LO), and IF inputs. In addition, the RF137 features an on-chip, dual-loop UHF/VHF frequency synthesizer circuit. It includes two sets of reference dividers, phase/frequency detectors, charge pumps, prescalers, main dividers, and control circuits. The device package and pinout of the RF137 are shown in Figure 1. A block diagram is shown in Figure 2. The signal pin assignments and functional pin descriptions are found in Table 1. The absolute maximum ratings of the device are provided in Table 2, and the operating conditions and electrical specifications are provided in Table 3. Features Image-reject mixer for downconversion to 2nd IF 24 dB selectable attenuation on 1st IF amplifier 12 dB selectable attenuation on 2nd IF amplifier Integrated tr...