[AK1541]
AK1541
20 to 600MHz Delta-Sigma Fractional-N Frequency Synthesizer
1. Overview
The AK1541 is a Delta-Sigma Fractional-N PLL (Phase Locked Loop) frequency synthesizer with a frequency switching
function, covering a wide range of frequencies from 20 to 600MHz. This product consists of an 18-bit Delta-Sigma
modulator, a low-noise phase frequency comparator, a highly accurate charge pump, a reference divider and a
dual-module prescaler (P/P+1).
An excellent PLL can be achieved by combining this synthesizer with the external loop filter and VCO (Voltage Controlled
Oscillator). The access to the registers is controlled via a three-lines serial interface. The operating supply voltage is from
2.7 to 5.5V; and the charge pump and serial interface can be driven by individual supply voltages.
2. Features
Delta-Sigma Fractional-N frequency synthesizer providing shorter lockup time, lower phase noise and low spurious
performance
Operating frequency:
On-chip charge pump for fast lockup
Programmable charge pump current:
In a normal operating scheme, the charge pump current can
be set in 16 steps, in the range from 10.6 to 168.9uA.
In a fast lockup scheme, the charge pump current can be
set in 8 steps, in the range from 0.84 to 2.32mA.
Supply Voltage:
Separate power supply for the charge pump:
On-chip power-saving features
On-chip PLL lock detect feature:
Direct output to the PFD (Phase Frequency Detector) or digital
filtering output can be selected.
Very low consumption current:
Package:
Operating temperature:
3.4mA typ. (excluding a charge pump current)
24pin QFN (0.5mm pitch, 4mm
4mm
0.7mm)
-40C° to 85C°
2.7 to 5.5 V (PVDD and CPVDD pins)
PVDD to 5.5V (CPVDD pin)
20 to 600MHz
MS1043-E-05
1
2013/03
AKM [ ASAHI KASEI MICROSYSTEMS ]
