LM1865

www.DataSheet4U.com LM1865 Advanced FM IF System February 1995 LM1865 Advanced FM IF System General Description Reduced external component cost improved performance and additonal functions are key features to the LM1865 FM IF system The LM1865 is designed for use in electronically tuned radio applications It contains both deviation and signal level stop circuitry in addition to an open-collector stop output The LM1865 generates a reverse AGC voltage (ie decreasing AGC voltage with increasing signal) Y Y Y Meter output proportional to signal level Stop detector with open-collector output Adjustable signal level mute stop threshold controlled either by ultrasonic noise in the recovered audio or by the meter output Adjustable deviation mute stop threshold Separate time constants for signal level and deviation mute stop Dual threshold AGC eliminates need for local distance switch and offers improved immunity from third order intermodulation products due to tuner overload User control of both AGC thresholds Excellent signal to noise ratio AM rejection and system limiting sensitivity Y Y Features Y Y Y On-chip buffer to provide gain and terminate two ceramic filters Low distortion 0 1% typical with a single tuned quadrature coil for 100% modulation Broad off frequency distortion characteristic Low THD at minimum AFT offset Y Y Y Y Block Diagram ee DataSh DataSheet4U.com Order Number LM1865M or LM1865N See NS Package Number M20B or N20A FIGURE 1 TL H 7509 – 1 C1995 N...