The LM169 LM369 are precision monolithic temperaturecompensated voltage references They are based on a buried zener reference as pioneered in the LM199 references but do not require any heater as they rely on special temperature-compensation techniques (Patent Pending) The LM169 makes use of thin-film technology enhanced by the discrete laser trimming of resistors to achieve excellent Temperature coefficient (Tempco) of Vout (as low as 1 ppm C) along with tight initial tolerances (as low as 0 05% max) The trim scheme is such that individual resistors are cut open rather than being trimmed (partially cut) to avoid resistor drift caused by electromigration in the trimmed area The LM169 also provides excellent stability vs changes in input voltage and output current (both sourcing and sinking) The devices have a 10 000V output and will operate in either series or shunt mode the output is short-circuit-proof to ground A trim pin is available which permits fine-trimming of Vout and also permits filtering to greatly decrease the output noise by adding a small capacitor (0 05 to 0 5 mF)