When the junction temperature exceeds 150°C, the Highway 09 reduces output current linearly (thermal foldback). At 160°C, it shuts down completely. Once cooled by 15°C (hysteresis), it restarts automatically.
Some speculated that it was a custom-designed chip for a specific application, while others believed it was a proof-of-concept that never made it to production. The mystery surrounding the Highway 09 IC only deepened. highway 09 ic datasheet
For V_OUT = 9V, choose R1 = 1kΩ (from VOUT to ADJ), R2 = ( (9/1.25) - 1 ) × R1 = 6.2kΩ. Result: V_OUT = 1.25 × (1 + 6.2) = 9.0V. When the junction temperature exceeds 150°C, the Highway
) : Designed for low-power and low-voltage applications, often supporting a wide input range from 4.5V up to 40V in certain automotive variants. Some speculated that it was a custom-designed chip
: Integrated safeguards against over-current, over-temperature, and reverse-battery conditions. Pin Configuration (PDIP16)