K170UL4 The 170-series chips are interface circuits, TTL-type, made using bipolar technology with pn junction isolation, designed to work in devices for controlling the circuits for writing and reading information in address and bit lines and for converting signals read from memory blocks of computer memories and devices of discrete automation, for transmission of information via communication lines. The chip K170UL4 is a two-channel bipolar playback amplifier with controlled polarity sensitivity. Contains 118 integral elements.