This application note describes how to design a high reliability rotary switch or encoder using a Dialog GreenPAK. This switch design is contactless, and therefore ignores contact oxidation and wear. It is ideal for use outdoors where there is long term moisture, dust, temperature extremes, etc.

Dialog GreenPAK SLG46537: The GreenPAK CMIC provides all the circuit functions for this design. It generates a signal (EVAL) for improved signal to noise, receives inputs from each sector pad of the rotary switch, and interprets each sector pad using the Asynchronous State Machine(ASM) to guarantee only one switch selection.

Galvanically isolated interfaces are a common requirement within industrial devices for safety reasons. In this type of application, a digital isolator is used to galvanically isolate an MCU from a communication transceiver or an ADC.

Digital isolators work at two power domains, using an isolated DC power supply in one domain. The low DC voltage for isolated power domain could be achieved with a small and simple push-pull converter. The push-pull converter is a transformer-isolated topology using two transistors switching in complementary mode.

This application note will present a low cost and low power DC/DC push-pull converter based on the Silego GreenPAK SLG46108 device. The following sections will show how to:

• Generate a complementary PWM with dead time using the programmable delay block.
• Generate a start-up sequence using a pipe-delay block.
• Obtain multiple clock frequencies via an internal oscillator.

This design uses a single Dialog GreenPAK SLG46110 to realize a low-side sensing over current detection circuit with a latching output used to enable/disable an external high-side PMOS load switch. By configuring one of the onboard comparators (ACMP1) to perform as a Non-Inverting Amplifier with a gain of 22.5, we can use a very small 0.010 ohm low-side sense resistor to, in this case, detect a 4A maximum current.

There are a variety of applications where signals from different sources (for example, sensors) are sensed with one ADC. Such systems require an analog multiplexer with analog filters for each channel, because each signal source may have its own set of filter requirements (for example, different cutoff frequencies). An alternative space-efficient and cost-efficient solution is to use one tunable analog filter for all channels. The SLG47004 IC solves this task perfectly.

Tamper detection is a function widely used within critical infrastructure systems such as power meters, water meters, security and fire panels, and any other products where a trigger input needs to be detected and the event recorded in non-volatile memory (Flash memory). The SLG46811 GreenPAK mixed-signal IC is ideally suited for this tamper-detection role when paired with the AT45DB161E Flash memory for recording the event.