LMX2470 具有 800 MHz 整数 N PLL 的 2.6 GHz Δ-Σ 分数 N PLL

The LMX2470 is a low power, high performance delta-sigma fractional-N PLL with an auxiliary integer-N PLL. The device is fabricated using National Semiconductor's advanced BiCMOS process.

With delta-sigma architecture, fractional spur compensation is achieved with noise shaping capability of the delta-sigma modulator and the inherent low pass filtering of the PLL loop filter. Fractional spurs at lower frequencies are pushed to higher frequencies outside the loop bandwidth. Unlike analog compensation, the digital feedback techniques used in the LMX2470 are highly resistant to changes in temperature and variations in wafer processing. With delta-sigma architecture, the ability to push close in spur and phase noise energy to higher frequencies is a direct function of the modulator order.

	LMX2470
Output Frequency (Min) (Mhz)	500
Output Frequency (Max) (Mhz)	2600
VCC (V)	2.25 to 2.75

LMX2470 特性

Low in-band phase noise and low fractional spurs
12 bit or 22 bit selectable fractional modulus
Up to 4th order programmable delta-sigma modulator
Enhanced Anti-Cycle Slip Fastlock Circuitry Fastlock Cycle slip reduction Integrated timeout counters
Digital lock detect output
Prescalers allow wide range of N values RF PLL: 16/17/20/21 IF PLL: 8/9 or 16/17
Crystal Reference Frequency up to 110 MHz
On-chip crystal reference frequency doubler.
Phase Comparison Frequency up to 30 MHz
Hardware and software power-down control
Ultra low consumption: ICC = 4.1 mA (typical)

LMX2470 器件用途

Cellular Phones and Base Stations CDMA, WCDMA, GSM/GPRS, TDMA, EDGE, PDC
Applications requiring fine frequency resolution
Satellite and Cable TV Tuners
WLAN Standards

LMX2470 工具与软件

培训内容	型号	软件/工具类型
LMX2470 Evaluation Module	LMX2470EVM	开发电路板/EVM