• Dual (RF-IF) fractional-N PLL for 1GHz applications
• High-speed lock suitable for (IS136/GSM) applications
• 2.7-5.1V operation
• Low operating current: 7mA at 3.6V
• Dual modulus (32/33) RF and (4/1) IF prescalers
• Normal, Speed-up, and Fractional compensation charge-pumps
• Programmable fractional modulus (0-16)
• 20-pin TSSOP package

Summary:  The TRF2050 is a low-power consumption 1.2-GHz fractional-N/integer-N frequency synthesizer component for wireless applications. Fractional-N division and an integral speed-up charge pump are used to achieve rapid channel switching. Two operating modes available:

1. SA7025 emulation mode in which the part emulates the Philips SA7025 fractional-N synthesizer
2. Extended performance mode (EPM), which provides additional features including fractional accumulator modulos from 1 to 16 (compared to only 5 or 8 for the SA7025) and programmable control of the speed-up mode duration (compared to the SA7025 method of holding the strobe line high).

Along with external loop filters, the TRF2050 provides all functions necessary for voltage-controlled oscillator (VCO) control in a dual phase-locked loop (PLL) frequency synthesizer system. A main channel is provided for radio frequency (RF) channels and an auxiliary channel for intermediate frequency (IF) channels. The current-output charge pumps directly drive passive resistance-capacitance (RC) filter networks to generate VCO control voltages. Rapid main-channel frequency switching is achieved with a charge pump arrangement that increases the current drive and alters the loop-filter frequency response during the speed-up mode portion of the switching interval.