特点
5th Order, 1MHz Elliptic Filter in SO-8 Package
Pin Selectable 1MHz/500kHz Cutoff Frequency
Signal-to-Noise Ratio (SNR): 75dB
Signal-to-Noise Ratio with ?63dB THD: 69dB
Passband Ripple (f
CUTOFF
= 1MHz): ?0.3dB
Stopband Attenuation Better Than 60dB
No External Components Required
典型应用
典型应用
描述
The LTC?1560-1 is a 5th order, continuous-time, lowpass filter. The elliptic transfer function of the LTC1560-1 was carefully chosen to reach a compromise between selectivity, for antialiasing applications, and transient response . The filter cutoff frequency, f CUTOFF , is pin selectable to either 500kHz (Pin 5 to V + ) or 1MHz (Pin 5 to V ? ). When programmed for 1MHz, the passband ripple is typically ?0.2dB up to 0.55f CUTOFF and ?0.3dB to 0.9f CUTOFF . The transition band gain is ?24dB at 1.4f CUTOFF and ?51dB at 2f CUTOFF . Stopband attenuation is 63dB at 2.43f CUTOFF and above, remaining at least 60dB to 10MHz with proper board layout. When the LTC1560-1 is programmed for f CUTOFF = 500kHz, the filter response closely follows the 1MHz case with the exception of passband flatness near the cutoff frequency; the gain at f CUTOFF is ?1.3dB.
The LTC1560-1, unlike other high frequency filters, is designed for low noise and low distortion. With a 1V RMS input signal, the signal-to-noise ratio is 69dB and the THD is ?63dB. The maximum SNR of 75dB is obtained with a 2.1V RMS input signal. This results in ?46dB THD.
The LTC1560-1 operates with ±5V supplies, has a power saving mode and is available in an SO-8 surface mount package.
Other cutoff frequencies from 450kHz to 1.5MHz can be obtained. Demo board DC135A is available for the LTC1560-1. For more information please contact LTC Marketing.