schmatic

A customer has a product that uses a 3.7V lithium battery to power a control circuit that controls actuators such as motors according to certain logic. The processor needs to detect the battery voltage in order to stop responding to user inputs and send out an alert signal when the battery is discharged below a certain level. Because of cost considerations, the customer chose a very low-cost, simple processor that operates in the 3.0V-5.0V range and has an ADC that does not have a dedicated reference voltage input, but instead uses the power supply as a reference voltage. Previously, for…