Featured Post

High CMRR Instrumentation Amplifier (Schematic and Layout) design for biomedical applications

on
Instrumentation amplifiers are intended to be used whenever acquisition of a useful signal is difficult. IA’s must have extremely high input impedances because source impedances may be high and/or unbalanced. bias and offset currents are low and relatively stable so that the source impedance need not be constant. Balanced differential inputs are provided so that the signal source may be referenced to any reasonable level independent of the IA output load reference. Common mode rejection, a measure of input balance, is very high so that noise pickup and ground drops, characteristic of remote sensor applications, are minimized.Care is taken to provide high, well characterized stability of critical parameters under varying conditions, such as changing temperatures and supply voltages. Finally, all components that are critical to the performance of the IA are internal to the device. The precision of an IA is provided at the expense of flexibility. By committing to the one specific task of
2

Simple Power Switching Circuit Diagram

on
This Simple Power Switching Circuit Diagram provides on/off switching, soft starting, current monitoring, current tripping, and protection against over-current for a 30 Vdc power supply at normal load currents up to 2 A. The switch is turned on by an `on` command pulse; it is turned off by an `off` command pulse. An over-current trip can also be set on the bus side by a 6-digit binary signal, which is converted to an analog voltage and compared with the amplified voltage developed across a load-current-sensing resistor. 

Resistor/capacitor combinations (0.027 µ, 2 kfi) at the inputs of the current-sensing amplifiers act as low-pass filters: this introduces a few hundred /is of delay in the response to over-current, thereby providing some immunity to noise. The 0.022 µ capacitors connected to the drain terminals of the PFETs provide a Miller effect, which reduces the rate of change of the drain voltage and therefore the rate of rise of current at turn-on. The soft-turn-on time depends upon the load impedance and is typically 100 to 200 ms.

 Power Switching Circuit Diagram

Simple Power Switching Circuit Diagram

Comments

Post a Comment