Step Digital Control of DC Bus Voltages Adjustments for Power Supply Module 4

One of the highest prolonging machine downtime in the production line in the manufacturing of microelectronic packages is the adjustment and correction of Direct Current (DC) bus voltages of the power supply modules. Power supply module 4 (PS4), which consists of 5 linear power supplies (LPSs): +5V, +15V, -15V, +24V, and -24V, normally uses mechanical potentiometers for its calibration and adjustments that will be used for mixed signals test systems and other applications in the production line. The conventional method of using mechanical potentiometers should be eliminated to have efficient adjustments of the DC bus voltages. This paper presents the development of a step digital control of DC bus voltages adjustments of LPSs. It consists of control interface memory and microcontroller. A digital potentiometer (DigiPot) which is controlled by an ATMEGA328P microcontroller is used to replace the mechanical potentiometer and to digitize the step adjustments. The results show digital step adjustments ranging from 0.02 V to 0.05 V. The prototype developed was able to drive and control DC bus voltages for PS4. It minimizes the adjustment time by 83.3% from the former way of using mechanical potentiometers. Additionally, this project can potentially be used in mixed signal test systems.