Mirco-Power Circuits

Low Power Voltage Reference

The voltage reference circuit described below, is a special implementation of current source LM334. Characterized by a very small temperature coefficient metatholio output voltage and consumes only 10uA room temperature. This current fluctuates by a few uA, when the ambient temperature varies significantly. The positive rate of temperature change LM334 offset by the negative of the contact base emitter transistors has a direct thermal coupling with the integrated. To achieve the lowest possible temperature coefficient, it is necessary to adjust the output voltage of 1,253 V source to the arrangement easily done through R1. ..

1.5 volt LED flasher schematic

This 1.5 volt led fasher runs more than a year on a single 'd" cell and alternately flashes 2 LEDs at about a 1 second rate. The circuit employs a 74HC14 CMOS hex inverter that will operate at very low voltages (less than 1 volt). One section is used as a squarewave oscillator (pins 1 and 2), while the others are wired to produce a short 10mS pulse on alternate edges of the square wave so the LEDs will alternate back and forth. The output sections each use a capacitor charge pump to increase the voltage for the LEDs. ..

1,5V Earphones Audio Amplifier

This audio amplifier circuit, connected to 32 Ohm impedance mini-earphones, can detect very remote sounds. Useful for theatre, cinema and lecture goers: every word will be clearly heard. You can also listen to your television set at a very low volume, avoiding to bother relatives and neighbors. Even if you have a faultless hearing, you may discover unexpected sounds using this device: a remote bird twittering will seem very close to you...

1.5V Battery FM transmitter

This implementation is adapted to rebroadcast the output of a CD player, television receiver, or radio receiver. I use it so that I can move about the house and listen to my favorite programs without disturbing others. Within and the house, I find that I can get 10 to 20 meters away from the transmitter with the small pocket FM receiver I carry in my shirt pocket. Your mileage may vary. The transmitter as built and pictured below (the transmitter is in the blob of hot melt glue on the end of the battery holder) does not have an on-off switch...

The open cell voltage of a small silver oxide button cell battery remains very close to 1.5 volts over most of the life of the cell. However, there is a relationship between battery health and the internal resistance of the cell. This circuit when used in conjunction with an oscilloscope will measure the internal resistance...

The LTC®1440 series comparators are true micropower devices. They eliminate current peaking during switching, resulting in greatly reduced power consumption versus frequency, or when the inputs are nearly balanced. Figure 2s plot contrasts the LTC1440s power consumption versus frequency with that of another comparator specified as a micropower component. The LTC1440 has about 200 times lower current consumption at higher frequencies, while maintaining a significant advantage below 1kHz...

Three new linear regulators simplify the design of batteryoperated equipment. The LT®1521 is a 300mA, positive low dropout regulator with micropower quiescent current and shutdown. The LT1175 is a 500mA negative complement with adjustable current limit. A third product, the LT1118, has the unique capability of maintaining output regulation while sourcing or sinking load current...

The only SOT-23 op amps featuring Over-The-TopTM operation the ability to operate with either or both inputs above the positive railare the 55mA LT®1782 and the 300mA LT1783. This feature is important in many currentsensing applications, where the inputs are required to operate at or above the supply. The wide supply voltage range, from 2.7V to 18V, gives the LT1782/LT1783 broad appeal as general purpose amplifiers, while the guaranteed offset voltage of 950mV over temperature is the lowest of any SOT-23 op amp. There is even a shutdown feature for ultralow supply current applications...

The LTC®1541 combines a micropower amplifier, comparator and 1.2V reference in an 8-pin package. The part operates from a single 2.5V to 12.6V supply with typical supply current of 5mA. Both op amp and comparator feature a common mode input voltage range that extends from the negative supply to within 1.3V of the positive supply. The op amp output stage swings from rail-to-rail. Figure 1 lists additional features along with a block diagram of the device...

The LTC1155, dual micropower MOSFET driver, generates 12V from a 5V rail to fully enhance logic-level Nchannel switches with no external components required (see Figure 1). Further, the supply current is typically 85mA with the switch fully enhanced and 8mA with the LTC1155 in the standby mode (both inputs off)...

You can expect 100mA output from LT1303 based circuits and 300mA from the LT1372 circuit without modification. All of the circuits feature output disconnect; in shutdown the outputs fall to 0V...

Two combinations of cell count and output voltage are to be strictly avoided: three cells converted to 3.3V and four cells converted to 5V. These combinations are troublesome because no ordinary regulator (boost, buck or linear) can accommodate a situation where the input voltage range overlaps the desired output voltage...

Linear Technology introduces a new micropower DC/DC converter designed to provide high output power from a single cell or higher input voltage. The LT®1308 features an onboard switch capable of handling 2A with a voltage drop of 300mV and operates from an input voltage as low as 1V. The LT1308 features Burst ModeTM operation at light load; efficiency is 75% or better for load currents of 1mA...

Data acquisition applications that require low power dissipation fall into two general areas: products that must use power very efficiently, such as battery-powered portable test equipment, and remotely located data logging equipment. To help meet these requirements, Linear Technology has introduced the LTC®1594 and LTC1598...

The LT®1462/LT1464 duals and the LT1463/LT1465 quads are the first micropower op amps to offer picoampere input bias currents and unity-gain stability when driving capacitive loads. For each amplifier, the LT1462/LT1463 consume only 28mA of supply current; the faster LT1464/ LT1465, just 145mA. Low supply current and operation specified at ±5V supplies make these amplifiers appropriate for portable low power applications...