The TC7106A/7106 3-1/2 digit analog-to-digital (ADC) converters with liquid crystal display drive can be easily powered from ±5V power supplies. Low cost voltage regulators, such as the TC55 (+5V) and TC59 (–5V), power the TC7106A/7106 in Figure 1. Analog com- mon, internally referenced to 3V below the positive supply potential, is used to supply the converter reference. If only +5V is available, the low cost TC7660 DC-to-DC converter easily generates the –5V supply, as shown in Figure 2. A TC7107A/7107 LED display converter can also be powered by a TC7660.M AN783 ±5V Power Supply Operation with TC7106A/7107A An external voltage reference replaces the internal ref- Author: Microchip Technology Inc. erence in Figure 3. Chip temperature variations caused by changing LED display drive current can cause full- INTRODUCTION scale drift if the internal reference does not have a low temperature coefficient. In……