Design Ideas make power supplies safe

The circuit in Use a TL431 shunt regulator to limit high ac input voltage limits, or clamps, input-ac voltages higher than 260V rms to levels safe for the operation of the power MOSFET in an SMPS. Most isolated, offline SMPSs, including flyback, forward, and resonant, must operate at input voltages of 90 to 260V rms. Some cases even use line-to-line voltages of 400V rms, leading to increased component- voltage ratings and, thus, increased cost of the overall design.

In Autozeroed amplifier with halved noise needs few components you can exploit the fact that in an Analog Devices’ AD8553 the two gain-setting resistors are separate and that the input stage is a voltage-controlled current source to lower the component count in amplifiers with extreme noise-reduction demands.

White and other-color LEDs exhibit significant variation in luminosity as a function of temperature. The circuit in Buck regulator controls white LED with optical feedback uses a red LED to provide optical feedback for a high-current white LED.

Selecting the source, the divisors, and the FLL settings for the Freescale HC08 and newer HCS08 mircrocontrollers’ clock generators allows versatility but also can get complicated. Once you write the bus-clock-initialization routine, you may want to verify that the bus is running at the speed you intend before moving on to the rest of the project. The simple routines Routines directly measure microcontroller-bus clock allow you to check your clock rate directly.