This portable am fm radio use the TEA5711 radio receiver IC which is a high performance Bimos IC for use in AM FM stereo radios with all necessary functions integrated .
Using TEA5711 circuit we can make an simple and compact portable am fm radio using few external components .
Main features of TEA5711 circuit are : wide supply voltage range: 1.8 or 2.1 to 12 V , Low current consumption: 15 mA at AM, 16 mA at FM , High selectivity with distributed IF gain , LED driver for stereo indication , High input sensitivity: 1.6 mV/m (AM), 2.0 mV (FM) for 26 dB S/N , Good strong signal behavior (10 V/m at AM,500 mV at FM) , Low output distortion ( 0.8% at AM, 0.3% at FM ) .
The AM circuit incorporates a double balanced mixer, a one pin low-voltage oscillator (up to 30 MHz) a field-strength indicator output and is designed for distributed selectivity.
The FM circuit incorporates a tuned RF stage, a double balanced mixer, a one-pin oscillator, a field-strength indicator output and is designed for distributed IF ceramic filters.
The PLL stereo decoder incorporates a signal dependent stereo circuit, a soft-mute circuit and a stereo indicator LED driver.
The TEA5711 incorporates internal stabilized power supplies. The maximum supply voltage is 12 V, the minimum voltage can go down temporarily to 1.8 V without any loss in performance.
The TEA5711 portable am fm radio from this schematic works from 522 to 1611 kHz AM and 87.5 to 108 MHz FM.
For AF amplifier is used the TDA7050T circuit .