Power supply IC generates low-noise bipolar (+/-) power rails

Summary of Power supply IC generates low-noise bipolar (+/-) power rails


The LTC3265 is a low-noise dual polarity power supply IC featuring a boost charge pump, an inverting charge pump, and two 50mA LDO post-regulators. It supports programmable oscillator frequencies from 50kHz to 500kHz and operates with low quiescent current in Burst Mode. The device utilizes external resistor dividers for voltage adjustment and includes short-circuit and thermal protection. Available in compact DFN and TSSOP packages, it is ideal for industrial instrumentation requiring bipolar bias generators.

Parts used in the LTC3265 Power Supply:

  • Boost Charge Pump
  • Inverting Charge Pump
  • Low Noise Positive LDO Post Regulator
  • Low Noise Negative LDO Post Regulator
  • Programmable Oscillator
  • External Resistor Dividers
  • 18-Lead DFN Package
  • 20-Lead TSSOP Package

Features

  • Boost Charge Pump Generates 2 • VIN_P (VIN_P Range: 4.5V to 16V)
  • Inverting Charge Pump Generates –VIN_N (VIN_N Range: 4.5V to 32V)
  • Low Noise Positive LDO Post Regulator Up to 50mA
  • Low Noise Negative LDO Post Regulator Up to 50mA
  • 135μA Quiescent Current in Burst Mode® Operation with Both LDO Regulators On
  • 50kHz to 500kHz Programmable Oscillator Frequency
  • Stable with Ceramic Capacitors
  • Short-Circuit/Thermal Protection
  • Low Profile 3mm × 5mm 18-Lead DFN and Thermally Enhanced 20-Lead TSSOP Packages

Typical Application

Power supply IC generates low-noise bipolar power rails

Description

The LTC®3265 is a low noise dual polarity output power supply including a boost charge pump, an inverting charge pump and two low noise positive and negative LDO post regulators. The boost charge pump powers the positive LDO post regulator while the inverting charge pump powers the negative LDO regulator. Each LDO can provide up to 50mA of output current. The LDO output voltages can be adjusted using external resistor dividers.

The charge pumps employ low quiescent current Burst Mode operation or low noise constant frequency mode. During Burst Mode operation, the boost charge pump regulates its output (VOUT +) to 0.94 • 2 • VIN_P while the inverting charge pump regulates its output (VOUT ) to –0.94 • VIN_N. In Burst Mode operation the LTC3265 draws only 135μA of quiescent current with both LDOs on. In constant frequency mode, the boost and inverting charge pumps produce outputs equal to 2 • VIN_P and –VIN_N respectively and operate at a fixed 500kHz or to a programmed value between 50kHz to 500kHz using an external resistor. The LTC3265 is available in low profile 3mm × 5mm × 0.75mm 18-lead DFN and thermally enhanced 20-lead TSSOP packages.

Applications

  • Low Noise Bipolar/Inverting Supplies
  • Industrial/Instrumentation Low Noise Bias Generators

Quick Solutions to Questions related to LTC3265 Power Supply:

  • How does the Boost Charge Pump regulate its output?
    In Burst Mode operation, the boost charge pump regulates its output (VOUT +) to 0.94 • 2 • VIN_P.
  • What is the maximum output current each LDO can provide?
    Each LDO can provide up to 50mA of output current.
  • Can the LDO output voltages be adjusted?
    Yes, the LDO output voltages can be adjusted using external resistor dividers.
  • Does the device support constant frequency mode?
    Yes, the charge pumps operate at a fixed 500kHz or a programmed value between 50kHz to 500kHz using an external resistor.
  • What is the quiescent current in Burst Mode with both LDOs on?
    The LTC3265 draws only 135μA of quiescent current in Burst Mode operation with both LDOs on.
  • What are the available package options for the LTC3265?
    The device is available in a low profile 3mm × 5mm 18-lead DFN and a thermally enhanced 20-lead TSSOP package.
  • What protections are included in the LTC3265?
    The device includes Short-Circuit and Thermal Protection.
  • What are typical applications for this power supply IC?
    Typical applications include Low Noise Bipolar/Inverting Supplies and Industrial/Instrumentation Low Noise Bias Generators.

About The Author

Ibrar Ayyub

I am an experienced technical writer holding a Master's degree in computer science from BZU Multan, Pakistan University. With a background spanning various industries, particularly in home automation and engineering, I have honed my skills in crafting clear and concise content. Proficient in leveraging infographics and diagrams, I strive to simplify complex concepts for readers. My strength lies in thorough research and presenting information in a structured and logical format.

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