Overview
The STK301-220 is a hybrid IC (HIC) for electronically controlled graphic equalizer applications and is equipped with on-chip electronic volume control for 7-band, 2-channel graphic equalization, thereby permitting onetouch up-down control of all band gains. The STK301-220 is a hybrid IC which combines SC system and photoresist techniques with folded board construction while incorporating Sanyo’s unique insulated metal substrate technology (IMST) to the base.

FEATUREs
• All bands are set for L/R simultaneous 2 dB incremental operation (typ).
• All bands are equipped with 13 positions and range between +12 dB maximum boost to –12 dB maximum cut.
• Crossover frequencies include fo; 60 Hz, 150 Hz, 400 Hz, 1 kHz, 2.5 kHz, 6 kHz and 15 kHz.
• The following features can be made available with an electronic graphic equalizer system which incorporates the 3-IC construction consisting of the STK301-220, a controller (universal microcontroller) along with the display LSI (LC75821→LCD, LC7565→FLT, LED):
    — One-touch up-down control of all band gains.
    — Immediate recall of preferred frequency levels tailored to suit musical selections. This is possible using preset functions to retrieving items from one-touch memory.
    — Such functions as setting all bands to 0 dB (flat function), or switching frequency characteristics from 0 dB to center (reverse function) may be simply performed with supported software.
    — Dual control lines permit mutual use with display LSI and help to simplify wiring between microcontroller and LSI.
• Minimal operating shock noise when boost or cut is used.

Applications
• Car stereos
• Portable radio-cassette players
• Home stereos