LINEAR Manuals

Supercapacitors (or ultracapacitors) are increasingly being used for short-term energy storage and applications that require intermittent high energy pulses. This article introduces a power ride-through circuit application, in which a backup energy source cuts in and powers the load if the main power supply fails for a short time. In the past, this type of application was dominated by batteries, but electric double layer capacitors (EDLCs) are quickly gaining ground due to falling price-per-farad, size, and effective series resistance per capacitance (ESR/C). In a power ride-through application, series-stacked capacitors must be charged and cell-voltage balanced. Supercaps are switched into the power path when needed and the power to the load is controlled by a DC/DC converter. The LTC3225 supercapacitor charger has several features that make it a good choice for power ride-through applications. It comes in a small, 10-lead 3mm × 3mm DFN package and features programmable charging current, automatic cell voltage balancing, low drain current on the supercapacitors, and a patent pending, low noise, constant current charger.

This document introduces a new type of power management integrated circuit (PMIC) that combines fast charging, power path control, and efficient DC/DC converters. PMICs can seamlessly manage power flow from various power sources (wall adapters, USB, and batteries) to device systems and charging batteries, while maintaining current limits when necessary.

The LTC2274 is a 105Msps, 16-bit ADC that simplifies the digital connection between the ADC and FPGA by replacing the usual parallel interface with a novel high speed serial interface, thus reducing the typical number of required data input/output (I/O) lines from 16 CMOS or 32 LVDS parallel data lines to a single, self-clocking, differential pair communicating at 2.1Gbps. This frees up valuable FPGA pins and board space. It also allows flexibility to route across analog and digital boundaries—in noise sensi- tive applications, the serial interface provides higher noise immunity.

The LTC3851 is a synchronous step-down switching regulator controller from Linear Technology. Its input range is 4V to 38V, making it suitable for regulating power from a variety of sources, including automotive batteries, 24V industrial supplies, and unregulated wall transformers. The LTC3851 features strong onboard drivers that allow the use of high power external MOSFETs to produce output currents up to 20A with output voltages ranging from 0.8V to 5.5V. The constant frequency peak current mode control architecture provides excellent line and load regulation along with load current sharing capability and dependable cycle-by-cycle current limiting. OPTI-LOOP® compensation simplifies loop stability design and provides well-behaved regulation over a broad range of operating conditions.

The LTC4009 family of high power battery chargers achieve a small circuit size and high performance, while supporting multiple chemistry types and up to 3A 50W fast charging.

The LTC4224 is a dual Hot Swap controller in a 3mm × 2mm DFN package that is perfect for backplane or card resident 1V–6V applications.

This document introduces Linear Technology's ideal diode controller, which can operate over a 0V to 18V input voltage range and has a zero forward voltage drop. The controller can be used as a replacement for Schottky diodes and can save power and space.

This document introduces a low voltage, high current step-down µModule regulator that features a small size, high efficiency and fast transient response.

Introduction to the features and applications of LT3513

This document introduces LTC3608, a high-performance synchronous buck regulator from Linear Technology. The LTC3608 integrates a high-performance synchronous buck controller with super-low RDS(ON) DMOS MOSFETs to produce compact high efficiency converters. It has a maximum input voltage of 32V, can operate at a switching frequency of up to 2MHz, and can deliver an output current of up to 12A. It also uses a highly enhanced package with a height of less than 1mm.

This article describes the complete power solution for digital cameras and other complex compact portable applications designed by Linear Technology. The solution uses a family of devices called PMICs (Power Management Integrated Circuits) that greatly simplify the design of complex rechargeable battery power systems.

This article describes the design of a capacitor charger that can replace batteries for use in power backup circuits. The charger has a small size, adjustable current, automatic cell voltage balancing, low drain current and other features.

This document introduces the LTC6652 precision voltage reference from Linear Technology. The LTC6652 can operate in temperatures from -40℃ to 125℃ and has a 5ppm/℃ temperature drift.

The LTC3862 family of 2-phase, single output non-synchronous boost DC/DC controllers provides a flexible, high performance step-up controller in three convenient package options: GN24, 5mm × 5mm 24-pin exposed pad QFN and 24-pin exposed pad TSSOP. The LTC3862 is optimized for power MOSFETs that require 5V gate drive, whereas the LTC3862-1 is designed for 10V gate drive MOSFETs.

This design document introduces Linear Technology's LTC4440-5 and LT3782A devices for the design of a high power synchronous boost converter. The converter can be designed as a dual-phase design and does not require a heatsink.