LINEAR Manuals

This design note describes a new approach to precision LVDT signal conditioning that combines an LTC1967 RMS to DC converter with a separate phase detector circuit. This approach eliminates the losses and errors associated with traditional demodulation methods and also eliminates the complexity and cost associated with phase-locked loops.

LT3466 is a dual step-up converter capable of driving up to 20 white LEDs with a programmable constant current. The device is also capable of driving asymmetric LED strings with independent dimming and shutdown control for multipanel LCD backlight applications. The LT3466 uses a constant-current, step-up architecture to directly regulate LED current, providing consistent light intensity and color across all LEDs regardless of variations in their forward voltage drop. Important features including soft-start, open LED protection, adjustable switching frequency and DC dimming control are integrated into the part, making the LT3466 LED driver an ideal solution for space-constrained portable devices such as cellular phones, PDAs and digital cameras.

This document describes how to replace ORing diodes with MOSFETs to reduce heat and save space. By using the LTC4354 negative voltage diode-OR controller, near-ideal diode behavior can be achieved, and external N-channel MOSFETs are used to replace the diodes. This design reduces power dissipation, saves board space, and increases the input operating range.

This document describes the features and functions of a high-accuracy synchronous step-down controller, including output voltage tracking and programmable margining. The controller is suitable for power supply designs for high-performance servers, ASICs, and memory systems. It has a wide operating range and high accuracy, with input voltages ranging from 4V to 32V and output voltages ranging from 0.6V to 2.5V, with a reference voltage accuracy of ±0.67%. The controller uses a constant on-time, valley current mode control architecture, allowing it to operate at very low duty cycles with fast transient response. Additionally, it has an optional current sensing resistor for high efficiency or most accurate current limit.

This document describes a solution to control inrush current using the LT3467 ThinSOT TM switching regulator. The LT3467 integrates a soft-start function with a built-in 42V, 1.1A switch. By enabling the soft-start feature, the inrush current can be limited to prevent input source collapse and output overshoot.

Low Distortion, Low Noise Differential Amplifier Drives High Speed ADCs in Demanding Communications Transceivers

Linear Technology offers two new buck regulators that operate from a wide input voltage range (3.6V to 36V) and take so little space that they easily solve many difficult power supply problems. The LT®1936 and LT1933 are perfect for applications with disparate power inputs or wide range input power supplies such as automotive batteries, 24V industrial supplies, 5V logic supplies and various wall adapters. Both parts are monolithic current mode PWM regulators which provide excellent line and load regulation and dynamic response. They operate at a 500kHz switching frequency, enabling the use of small, low cost inductors and ceramic capacitors, resulting in low, predictable output ripple.

This product is a high-precision delta-sigma analog-to-digital converter that uses Easy Drive technology to achieve direct sampling of large RC networks. This technology does not require on-chip buffers and has higher performance.

This document describes the industry's first 4-switch buck-boost controller that achieves the highest efficiency using a single inductor. The controller uses a constant frequency current mode architecture and can seamlessly switch between buck, boost, and buck/boost modes within a wide input and output range. It features high efficiency operation, soft-start, and fault protection including overvoltage protection, current foldback, and on-time limitation.

The LTC3703-5 is a synchronous switching regulator controller that can directly step down input voltages up to 60V and withstand transients up to 80V.

This design note introduces a high efficiency two-phase boost converter that minimizes input and output current ripple. The converter uses the LTC1871-7 synchronous buck controller, operating at 300kHz with an output voltage of 24V and an output current of 10A.

The LTC®2923 power supply tracking controller can be used to margin supplies in addition to its usual task of tracking multiple power supplies.

ThinSOT Micropower Buck Regulator Has Low Output Ripple

This document introduces the importance of LT5528 WCDMA ACPR and AltCPR measurements, as well as the test setup for these measurements. The LT5528 is a high linearity direct I/Q modulator that accepts complex modulation signals and generates modulated RF signals at the RF output. However, accurately measuring the spectral regrowth of the LT5528 is challenging due to its dynamic range potentially rivaling that of the measurement equipment, necessitating the consideration of measurement system noise. The document provides specific test setups and measurement parameters.