UMA1019M

The device UMA1019M is designed to operate from 3 NiCd cells, in pocket phones, with low current and nominal 5 V supplies.

The synthesizer UMA1019M operates at RF input frequencies up to 2.4 GHz. The synthesizer has a fully programmable reference divider. All divider ratios are supplied via a 3-wire serial programming bus. Separate power and ground pins are provided to the analog and digital circuits. The ground leads should be externally short-circuited to prevent large currents flowing across the die and thus causing damage. Digital supplies VDD1, VDD2 and VDD3 must also be at the same potential. VCC must be equal to or greater than VDD (i.e. VDD = 3 V and VCC = 5 V for wider tuning range).

The phase detector UMA1019M uses two charge pumps, one provides normal loop feedback, while the other is only active during fast mode to speed-up switching. All charge pump currents (gain) are fixed by an external resistance at pin ISET (pin 14). Only passive loop filters are used; the charge-pumps function within a wide voltage compliance range to improve the overall system performance.