GENERAL DESCRIPTION

The TDA1572 integrated AM receiver circuit performs all the active functions and part of the filtering required of an A radio receiver. It is intended for use in mains-fed home receivers and car radios. The circuit can be used for oscillator frequencies up to 50 MHz and can handle RF signals up to 500 mV.

RF radiation and sensitivity to interference are minimized by an almost symmetrical design. The controlled-voltage oscillator provides signals with extremely low distortion and high spectral purity over the whole frequency range, even when tuning with variable capacitance diodes. If required, band switching diodes can easily be applied. Selectivity is obtained using a block filter before the IF amplifier.

Features

• Inputs protected against damage by static discharge

• Gain-controlled RF stage

• Double balanced mixer

• Separately buffered, voltage-controlled and temperature-compensate

• Gain-controlled IF stage with wide AGC range

• Full-wave, balanced envelope detector

• Internal generation of AGC voltage with possibility of second-order filt

• Buffered field strength indicator driver with short-circuit protection

• AF preamplifier with possibilities for simple AF filtering

• Electronic standby switch

• IF output for stereo demodulator and search tuning.