Tag Archives: Linear

Battery-charging considerations for low-power applications [PDF]

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By Tahar Allag:

The wearable and personal-electronics industries are booming. Devices in this market vary wildly by application and use. These multifunction devices are designed to help people in their daily activities and make their lives comfortable. They can be found in different shapes, colors, sizes, and safety measures. They may differ significantly from each other, but they all have one thing in common—the need for a battery and a battery charger. These portable devices are typically powered by batteries installed internal to the device, which must be charged efficiently and quickly on a regular basis. The user’s charging experience also needs to meet the requirement of safety, comfort, and convenience.

Battery-charging considerations for low-power applications [PDF] – [Link]

Buck regulator accepts 3.0-V to 42-V input

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Linear Technology Corporation announces the LT8608, a 1.5A, 42V input synchronous step-down switching regulator. A unique synchronous rectification topology delivers 93% efficiency while switching at 2MHz enabling designers to avoid critical noise-sensitive frequency bands, such as AM radio, while using a very compact solution footprint. Burst Mode® operation keeps quiescent current under 2.5μA in no-load standby conditions making it ideal for always-on systems. Its 3.0V to 42V input voltage range makes it ideal for automotive applications which must regulate through cold-crank and stop-start scenarios with minimum input voltages as low as 3.0V and load dump transients in excess of 40V. Its internal 2A switches can deliver up to 1.5A of continuous output current. The LT8608 maintains a minimum dropout voltage of only 200mV (@500mA) under all conditions, enabling it to excel in scenarios such as automotive cold-crank. Spread spectrum frequency modulation and special design techniques offer low EMI operation to minimize noise concerns in automotive and industrial environments. Furthermore, a fast minimum on-time of only 45ns enables 2MHz constant frequency switching from a 16V input to a 1.5V output. The LT8608’s 10-lead thermally enhanced MSOP package and high switching frequency keeps external inductors and capacitors small, providing a compact, thermally efficient footprint.

Buck regulator accepts 3.0-V to 42-V input – [Link]

Linear Bench Power Supply

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Matt Godfrey published his linear lab power supply which has adjustable voltage and current limit. Specs: 0-30V, 0-2A, separate 5V output, display of setpoint and output current and voltage:

This project is a simple linear bench power supply with adjustable voltage and current. It is meant to be a learning experience, putting ideas of circuit design, feedback, stability into practice building a complete practical power supply. I have intentionally avoided using a 3 terminal regulator or purpose built chip and instead implemented the feedback for voltage and current using a couple of opamps. The idea is for this to be a practical final product while giving practice implementing some basic circuits.

Linear Bench Power Supply – [Link]

LTC4123 – Low Power Wireless Charger

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Linear Technology Corporation introduces the LTC4123 to further expand its offerings in wireless battery charging. The LTC4123 combines a 30mW wireless receiver with a constant-current/constant-voltage linear charger for NiMH batteries, such as Varta’s power one ACCU plus series. An external resonant LC tank connected to the LTC4123 enables the IC to receive power wirelessly from an alternating magnetic field generated by a transmit coil.  Integrated power management circuitry converts the coupled AC current into the DC current required to charge the battery. Wireless charging with the LTC4123 allows for a completely sealed product and eliminates the need to constantly replace primary batteries. Zn-Air (Zinc-Air) detection allows applications to work interchangeably with both rechargeable NiMH batteries and primary Zn-Air batteries with the same application circuit. Both battery types can directly power a hearing aid ASIC without the need for additional voltage conversion. By contrast, a 3.7V Li-ion battery requires a step-down regulator in addition to the LTC4123’s functionality to power the ASIC.

LTC4123 – Low Power Wireless Charger – [Link]

 

36V, 800mA Robust Linear Regulator Has Extended SOA

3089

Linear Technology Corporation announces the LT3089, a rugged 800mA wide input voltage range linear regulator with key usability, monitoring and protection features. The device has an extended safe operating area (SOA) compared to existing regulators, making it ideal for high input-to-output voltage and high output current applications where older regulators limit the output. The LT3089 uses a current source reference for single resistor output voltage settings and output adjustability down to 0V. Output current limit can be set externally with a single resistor. This regulator architecture, combined with low millivolt line and load regulation, enables multiple ICs to be paralleled easily for heat spreading and higher output current. The current from the device’s current monitor can be summed with the set current for line-drop compensation, where the output of the LT3089 increases its current to compensate for line drops.

36V, 800mA Robust Linear Regulator Has Extended SOA – [Link]

LTC3106 – 300mA Low Voltage Buck-Boost Converter with PowerPath

3106

Linear Technology announces the LTC3106, a highly integrated, 1.6µA quiescent current 300mV start-up buck-boost DC/DC converter with PowerPath™ management, optimized for multisource, low power systems. The LTC3106 is ideal for powering low power wireless sensors from rechargeable or primary batteries supplemented by energy harvesting. The LTC3106 incorporates maximum power point control (MPPC) making it compatible with common high impedance power sources, including photovoltaic cells, thermoelectric generators (TEGs) and fuel cells.

LTC3106 – 300mA Low Voltage Buck-Boost Converter with PowerPath – [Link]

LTC3643 – 2A Bidirectional Power Backup Supply

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Linear Technology Corporation introduces the LTC3643, a bidirectional, high voltage boost capacitor charger that automatically converts to a buck regulator for system backup. The proprietary, single-inductor topology with integrated PowerPath™ functionality does the work of two separate switching regulators, reducing size, cost and complexity. The LTC3643 operates in two modes – boost charge mode and buck backup mode. The charging mode efficiently charges an electrolytic capacitor array up to 40V with an internal switch current rating of 2A from an input supply between 3V to 17V. In backup mode, when the input supply falls below the programmable power-fail (PFI) threshold, the step-up charger operates in reverse as a synchronous step-down regulator to power and hold up the system rail from the backup capacitor. During backup, the current limit can be programmed from 2A to 4A, making this device ideal for high energy, relatively short duration backup capacitor systems, power failure backup systems, solid-state drives and battery stack charging applications.

LTC3643 – 2A Bidirectional Power Backup Supply – [Link]

LTC3815 – 6A Monolithic Synchronous DC/DC Step-Down Converter

3815

Linear Technology Corporation announces the LTC3815, a high efficiency 6A monolithic synchronous step-down DC/DC converter with an I2C-based PMBus interface for digital power system management (PSM). The LTC3815’s simplified and intuitive PMBus “Lite” command set makes it simple to use. The digital interface provides programming and read back of voltage, current, temperature and faults; all supported by LTpowerPlay™ software. This interface allows the output voltage to be margined over a ±25% range with 0.1% resolution. The default output voltage is set with a single external resistor and will power up to this voltage with or without the serial interface.

LTC3815 – 6A Monolithic Synchronous DC/DC Step-Down Converter – [Link]

LT3091 – –36V, 1.5A Negative Linear Regulator with Programmable Current Limit

3091

Linear Technology Corporation announces the LT3091, the latest addition to our LDO+ family, a 1.5 A low dropout negative linear regulator featuring low noise, rail-to-rail operation, precision programmable current limit and a bidirectional output current monitor. The device is cable-drop compensation capable, easily paralleled for higher current or circuit board heat spreading, and configurable as a 3-terminal floating regulator. The LT3091’s input voltage range is –1.5 V to –36 V. A single resistor programs the adjustable rail-to-rail output voltage from 0 V to –32 V and dropout voltage is only 300 mV (typical at full load).

LT3091 – –36V, 1.5A Negative Linear Regulator with Programmable Current Limit – [Link]

SOS webinar – Simple and efficient solution for wide voltage range applications

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LINEAR TECHNOLOGY
Term: 2015.11.25 10:00 – 11:30 CET

Learn more about available topologies for input voltage higher and lower from output level. Focus on the most efficient way to convert power in four-switch buck-boost topology.

  • available topologies of Vin min < Vout < Vin max and differences between them
  • four-switch buck-boost topology as the most efficient, flexible and the smallest solution
  • buck-boost solutions from Linear Technology, applied to real end-devices
  • Diskusia

SOS webinar – Simple and efficient solution for wide voltage range applications – [Link]