Analog Video Channel

Direct Paralleling, High Power Density LDO
with Robert Dobkin, Vice President, Engineering
and Chief Technical Officer

The LT3080 is a new architecture for linear regulators. It provides better regulation, a simple output adjustment with a single resistor where the output can be adjusted down to zero. Also, this architecture allows easy paralleling of regulators for “no heatsink” operation in an all surfacemount applications. The LT3080 circuit operation and applications for paralleling, spreading the heat, general purpose power supplies and current sources will be shown.

Low Noise, High Voltage DC/DC Converters
with Jim Williams, Staff Scientist

Photomultipliers (PMT), avalanche photodiodes (APD), ultrasonic transducers, capacitance microphones, radiation detectors and similar devices require high voltage, low current bias. Additionally, the high voltage must be pristinely free of noise; well under a millivolt is a common requirement with a few hundred microvolts sometimes necessary. Circuits featuring outputs from 200V to 1000V with output noise below 100µV measured in a 100MHz bandwidth are detailed in this video. Special techniques enable this performance, most notably power stages optimized to minimize high frequency harmonic content. An additional aid to achieving low noise is that load currents rarely exceed 5mA. This freedom permits output filtering methods that are usually impractical. A lab-based circuit noise measurement demonstration concludes the presentation.

How to Make a Thermocouple Meter with the LTC2492
with Mark Thoren, Applications Engineering Manager,
Mixed Signal Products

Thermocouples are perhaps the most common temperature sensor in use. And while they are extremely simple and rugged, the output is very small - tens of microvolts per degree Celsius. Traditionally, thermocouple measurement circuits use a cold junction compensation circuit to drive the thermocouple negative terminal and a low offset amplifier with enough gain to use the entire input span of a 12- or 16-bit ADC. Linear Technology’s LTC2492 greatly simplifies thermocouple instrument design. A simple filter and protection circuit is all that is required to build a rugged, ready-to-use meter. Some software tricks take care of cold junction compensation and the thermocouple’s non-linear output.