The µPC2533 is an IC developed as an AM tuner for car stereos and car radios.
It employs an up-conversion type double super-heterodyne configuration (IF1 = 10.71 MHz, IF2 = 450 kHz).
The internal configuration consists of the MIX1 block (MIX1, OSC1, Buff1), MIX2 block (MIX2, OSC2, Buff2), IF amplifier, detection circuit, AGC circuit, signal meter circuit, SD (station detector) circuit, and Lo/DX (short range/long range) circuit.

FEATUREs
• Possible to select stations using only one varactor diode with narrow variable capacitance range
• Tracking adjustment unnecessary
• Coil switching between LW (long wave) and MW (middle wave) unnecessary
• Less sensitivity deviation due to tracking error
• High S/N: 60 dB
• Signal meter output with good linearity
• Signal meter output voltage inclination setting possible by external resistor.
• Can be used with IF (intermediate frequency) counter turning system or high/low tuning system.