KR1506HL2 (often written K(R)1506ХЛ2, sometimes labeled “UPT-2”) is a Soviet remote-control command decoder IC, used mainly in color TVs and similar consumer electronics. It was typically designed to work together with KR1506HL1 (that one is the encoder/transmitter side; this one is the decoder/receiver side).

What it does

According to datasheets and reference notes, the KR1506HL2 decodes remote-control commands and produces outputs for typical TV functions such as:

• mains power on/off

• channel/program up/down

• mute

• “continuous” control of volume / brightness / contrast / color (saturation) via built-in DAC output channels

Supply voltage (the “weird” ~18 V / negative supply)

The official data sheet commonly specifies a supply around −16.5…−19.5 V (with the “common (+)” on pin 1 and “supply (−)” on pin 24).

In practice, hobbyists often report that many chips also work from about 12…18 V, and that they run cooler at ~12–15 V.

Crystal / clock frequency

The IC uses a quartz crystal resonator (pin 23). One published spec lists 4.4336 MHz.

DIY circuits sometimes mention other frequencies depending on the exact remote-code implementation and the surrounding circuit.

Pinout highlights (DIP-24, main signals)

From the brief datasheet (KM/KR/KF1506HL2 family):

• 1 — common (+)

• 2–5 — DAC1…DAC4 outputs (analog control channels)

• 6 — auxiliary memory switch output

• 7 — direct data input

• 8–11 — 4-bit parallel output (program/channel number code)

• 12–15 — direct data inputs

• 16 — remote-control signal input (from a photoreceiver/demodulator)

• 17 — data-input register output

• 18 — mode select input

• 19 — “mains power switch” output (power latch)

• 20 — control-signal output

• 21–22 — clock outputs

• 23 — crystal resonator

• 24 — supply (−)