
Philips Electronics
GENERAL DESCRIPTION
The TEA5594 is a 32-pin integrated radio circuit designed for use in all Electronic Tuned Radio (ETR) sets especially those sets which have to fulfil the immunity requirements of CENELEC.
The AM circuit incorporates:
• A double balanced mixer
• A ‘one-pin’ oscillator with amplitude control operating in the LW/MW frequency range
• An IF amplifier and AM detector
• An AGC circuit which controls the IF amplifier and mixer
The FM circuit incorporates:
• A front-end (fulfilling the “out of band” CENELEC requirements)
• Two IF amplifiers (for distributed selectivity)
• A quadrature demodulator with a ceramic filter
The TEA5594 also contains:
• Oscillator output buffers for AM and FM
• A combined AM/FM IF counter output buffer with counter “enable” function
• A field strength level detector for AM and FM
• A soft mute circuit at FM, adjustable
• An extra IF amplifier to split up IF filtering
FEATUREs
• Low distortion on FM
• AM/FM level/indicator circuit
• A DC AM/FM switch facility
• Supply voltages 2.7 to 15 V
• A local distance switch facility (LOCAL-DX) at FM
• All pins are ESD protected