描述 Description

The AK1574 is a fractional-N PLL synthesizer with a VCO (Voltage Controlled Oscillator) that has frequency modulation function. It integrates an output divider for VCO signal that operates by 3365MHz frequency at maximum realizing wide range output frequency from 46.875MHz to 1682.5MHz. The AK1574 reduces the power consumption while realizing low normalized phase noise of -221dBc/Hz. It achieves 90mW(3V/Single output) operation when outputting -6dBm. It is capable of replacing VCOs, that use to consist of variable capacitance diode and etc., in various wireless applications especially suitable for hand portable wireless devices. The fast lock-up, that completes in only less than 1ms, suites for intermittent operation of PLL/VCO. It contributes to reducing the system power consumption.



Two set of mode settings that include frequency setting and On/Off settings of RF output pins are available.
?Output Mode A: Frequency setting fRx, RFOUT_A On, RFOUT_B Off (Single output)
?Output Mode B: Frequency setting fTx, RFOUT_A Off, RFOUT_B On (Single output)
By setting as above, the RFOUT_A pin can be used as receiving output and the RFOUT_B pin can be used as transmitting output.
?Output Mode A: Frequency fRx, RFOUT_A On, RFOUT_B On (Differential Output)
By setting as above, two lines of common-frequency can be output. It is able to use for diversity receivers. When both RFOUT_A and B are On, the signal is output as differential signal so that it is capable of being used as single differential output.

Data input format for frequency modulation corresponds to both analog and digital data inputs. Digital I/F data format can be selected from I2S (Inter-IC Sound), Left-justified and SPI.

特性 Features

● Easy to Modulate the Frequency of an Analog Voice Signal InputBy integrating a dedicated A/D converter, (ADC), frequency modulation of analog voice signal inputs are accomplished.This makes it easy to replace a VCO built-in PLL without changing the design considerably from the conventional architecture, (inputting the analog voice signal directly to the VCO without transmitting via a quadrature modulator).● Low Phase Noise and Low Power ConsumptionThe AK1574 is optimized for narrow band radio below 1 GHz.While achieving low normalized phase noise of -221 dBc/Hz, it operates with power consumption of 90 mW, (3V/single output), at -6 dBm output. Lock-up time, which takes several ms to several tens of ms for a VCO with a general variable capacitance diode and winding coil configuration, is completed in less than 1 ms on the AK1574.The intermittent operation the PLL and VCO can reduce the power consumption of the system.Main Specifications·AK1574PLL Synthesizer with VCO support from 46.875 to 1682.5MHz：
·Product Name：AK1574：AK1573/B/C (3 Chip Options)：
·Method：Fractional N；Integer N；
·Operating Frequency：46.875MHz to 1682.5MHz；30MHz to 3000MHz；
·Consumption Current：30mA at 3V, 520.1MHz,-6dBm Output (Single Output)；33mA at 3V, 1600MHz,-5dBm Output；
·Power Supply/Temperature Range：2.7 to 3.45V (IOVDD: 1.7V Operation)/ -40 to +85oC；2.7 to 3.3V/ -40 to +85oC；
·Normalized Phase Noise：-221dBc/Hz (Fractional N in operation)；-223dBc/Hz；
·In-band Phase Noise：-125dBc/Hz at 12.5kHz Offset, 420MHz Output, PFD Frequency =50.4MHz；Not availabe；
·Modulation Function：·Support analog voice signal inputs(integrated ADC)·Various Digital I/F: I2S, Left justified, SPI；Not availabe；
·23-bit ΔΣ Modulator：10Hz or less frequency resolution：Not availabe；
·Variable Output Buffer of Output Current：-12 to +6dBm Output (Single Output)；-12 to +6dBm Output；
·Reference Clock Multiplying/Dividing Circuit：Reduce Integer Boundary Spurious(IBS)；Not availabe；
·Reference Clock Divider Output Function：Common System Clock；Not availabe；
·REFCKIN Frequency：10MHz to 60MHz；10MHz to 300MHz；
·Package：36-pin QFN(5mm×5mm×0.75mm0.4mm pitch)；24-pin QFN(4mm×4mm×0.75mm0.5mm pitch)；

應(yīng)用 Application

Professional Mobile Radio (DMR, NXDN, dPMR, TIA-603, STD-T98/102, etc.) / FM/FSK transmitter