Solid-state-lighting applications are quickly moving into the mainstream. Although they are more efficient, the LEDs that produce the low-cost light often require a complicated driver circuit. Testing the driver circuit using LEDs, although easy, yields only typical results...
Accurately simulate an LED
Battery simulator has variable ESR response
You may lack experience and hardware when designing battery-operated products. The battery life of a product can depend more on the ESR (equivalent series resistance) than the terminal voltage...
9 ppm distortion, quartz stabilized oscillator
A spectrally pure sine wave oscillator is required for data converter; filter and audio testing. Figure provides a stable frequency output with extremely low distortion. This quartz stabilized 4 kHz oscillator has less than 9 ppm...
Photosensing with ambient background
Trying to shield ambient light from your photo circuit is not a trivial task. You would think that you could just cover your circuit with your hands, but that is not a solution: Pulse oximeters depend on the translucency of flesh...
A single cell laser diode driver using the LT1110
Recently available visible lasers can be operated from 1.5 V supplies, given appropriate drive circuits. Because these lasers are exceptionally sensitive to overdrive, power to the laser must be carefully controlled lest it be damaged...
Method sets voltage in multiple-output converters
When you design a transformer for any power converter, you face several compromises. You must trade off core size against the number of primary turns and flux density...
Low-power, super-regenerative receiver targets 433-MHz ISM band
Designers often choose a super-regenerative receiver – despite its frequency instability and poor selectivity – for battery-powered, short-range, wireless applications in which power consumption is a major issue...
Adjustable 0 V to 5 V power supply
Linear regulator ICs are commonly used in variable power supplies. Common types such as the 317 can be adjusted as low as 1.25 V in single-supply applications. At low output voltages power losses in these regulators can be a problem...
90 µA Precision Voltage-to-Frequency Converter
Figure 1 is a micropower voltage-to-frequency converter. A 0 V to 5 V input produces a 0 kHz to 10 kHz output with a linearity of 0.05%. Gain drift is 80 ppm/°C. Maximum current consumption is only 90 µA...
Inverted regulator increases choice and reduces complexity
Most circuits are referenced to ground, where relatively low-voltage components can monitor and control the low side of a load but not the high side. For example, nearly any low-voltage rail-to-rail-input op amp can detect a voltage increase indicating overcurrent through a resistor that connects between the load and ground...