AK1544

The AK1544 consists of a low noise phase frequency comparator, a precision 9 stage current-adjustable charge pump, a reference divider, a programmable divider, and a dual modulus prescaler (P / P + 1). 
The AK1544 achieves high performance and low current consumption in frequency conversion situations, making it ideal for miniaturizing equipment. 
The AK1544 has two general-purpose output ports that can be used to control the RF front end.
The AK1544 achieves a complete PLL by combining a synthesizer with an external loop filter and VCO (voltage controlled oscillator).