Dual Power PLL Frequency Synthesizer

The ADF4212L is a dual frequency synthesizer that can be used to implement local oscillators (LO) in the up-conversion and down-conversion sections of wireless receivers and transmitters. It can provide the LO for both the RF and IF sections. It consists of a low noise digital phase frequency detector (PFD), a precision charge pump, a programmable reference divider, programmable A and B counters, and a dual modulus prescaler (P/P + 1). The A (6-bit) and B (12-bit) counters, in conjunction with the dual modulus prescaler (P/P + 1), implement an N divider (N = BP + A). In addition, the 15-bit reference counter (R Counter), allows selectable REFIN frequencies at the PFD input. A complete phase-locked loop (PLL) can be implemented if the synthesizer is used with external loop filters and voltage controlled oscillators (VCOs).

Control of all the on-chip registers is via a simple 3-wire interface with 1.8 V compatibility. The devices operate with a power supply ranging from 2.7 V to 3.3 V and can be powered down when not in use.

Applications

* Wireless handsets (GSM, PCS, DCS, DSC1800, CDMA, WCDMA)

* Base stations for wireless Radio (GSM, PCS, DCS,

CDMA, WCDMA)

* Wireless LANS

* Cable TV tuners (CATV)

* Communications test equipment

* IDD total, 7.5 mA

* Bandwidth RF/IF, 2.4 GHz/1.0 GHz

* 2.7 V to 3.3 V power supply

* Separate VP allows extended tuning voltage

* Programmable dual modulus prescaler RF and IF: 8/9, 16/17, 32/33, 64/65

* Programmable charge pump currents

* 3-wire serial interface

* Analog and digital lock detect

* Fastlock mode

* Power-down mode

* 20-lead TSSOP and 20-lead LFCSP packages