43 V regulation in a DO-35 body
The 1N6015C is a 43 V Zener diode from Microchip Technology in the DO-35 axial package, rated for 500 mW continuous power dissipation. The ±2% tolerance on the nominal voltage means the zener voltage stays between 42.14 V and 43.86 V at the test current — tighter than the ±5% common in general-purpose zeners, which matters when the regulation window is part of a reference or clamp design.
Thermal and leakage profile
Reverse leakage is specified at 100 nA maximum when 33 V is applied across the junction — a low figure for a 43 V device, so the diode does not load the circuit when it is supposed to be off. Maximum zener impedance (Zzt) is 150 Ohms. At the knee current, a higher impedance means the voltage shifts more with current — for a 43 V rail that needs to stay within ±2%, the bias current should be set well above the knee to keep the dynamic resistance low.