Philips AN95102
This application note describes the UMA1018M and UMA1020M/UMA1020AM from Philips Semiconductors. They permit a low-voltage low-power single-chip solution to designing dual PLL frequency synthesizers.FEATURES
● Dual frequency synthesizers● Operating voltage range 2.7 to 5.5 V for battery powered operation
● Low current consumption, 10 mA typically at 5.5 V (two PLLs 1. INTRODUCTION TO UMA1018M DUAL SYNTHESIZER 1.1 General description The UMA1018M [1] is a low power low voltage single chip solution to a dual frequency synthesizer used in radiocommunications. Designed in a BICMOS process, it operates from 2.7 (3 NiCd cells) to 5.5 V. The UMA1018M contains all the necessary elements with the exception of the VTCXO, VCO and loop filters to build two PLL frequency synthesizers. It is intended that the principal synthesizer operates in the 50 to 1250 MHz range, and the auxiliary synthesizer will work between 20 and 300 MHz. For each synthesizer, fully programmable main and reference dividers are integrated on chip. The reference input FXTAL can operate from 5 to 40 MHz. Fast programming is possible via the three wire serial bus with clock speeds of up to 10 MHz. The principal synthesizer phase detector drives a low current charge pump and a high current charge pump simultaneously.