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58VIN, 2A IOUT, 2.4MHz Step-Down DC/DC Converter Draws Only 85µA of Quiescent Current & Withstands 80V Transients

Sep 28 2009 - MILPITAS, CA
  • Linear Technology Corporation announces the LT3980, a 2A, 58VIN step-down switching regulator with Burst Mode® operation to maintain quiescent current under 85µA. The LT3980 operates within a VIN range of 3.6V to 58V, with overvoltage lockout protection against transients as high as 80V, making the device ideal for load dump and cold-crank conditions commonly found in automotive applications. Its internal 3.4A switch can deliver up to 2A of continuous output current at voltages as low as 0.79V. The LT3980's Burst Mode operation provides ultralow quiescent current, well suited for applications such as automotive or telecom systems, which have always-on circuits and demand optimal battery life. Switching frequency is user programmable from 100kHz to 2.4MHz, enabling the designer to maximize efficiency while avoiding critical noise-sensitive frequency bands. The combination of a 3mm × 4mm DFN-16 package (or thermally enhanced MSOP-16E) and high switching frequency keeps the LT3980's external inductor and capacitors small, providing a compact, thermally efficient footprint.


    The LT3980 utilizes a high efficiency 3.4A, 200mΩ switch, with the necessary boost diode, oscillator, control and logic circuitry integrated into a single chip. Its catch diode current sense (DA pin) protects the circuit during input voltage transients even at high switching frequencies. Low ripple Burst Mode® operation maintains high efficiency at low output currents while keeping output ripple below 15mVPK-PK. Special design techniques used in the LT3980 enable high efficiency over a wide input voltage range, and the device’s current mode topology enables fast transient response and excellent loop stability. Other features include external synchronization (from 250kHz to 2MHz), a power good flag and soft-start capability.


    Pricing for the LT3980EDE and LT3980EMSE starts at $3.55 each, for 1,000-piece quantities. The LT3980IDE and LT3980IMSE are guaranteed to operate from a –40ºC to 125ºC operating junction temperature, priced at $4.18 each, in 1,000-piece quantities. The LT3980HMSE is guaranteed to operate from a –40ºC to 150ºC operating junction temperature and is priced at $4.43 in 1,000 piece quantities. All versions are available from stock. For more information, visit www.linear.com.


    Summary of Features: LT3980


    • Wide Input Range: Operation from 3.6V to 58V
    • Overvoltage Lockout Protects Circuits Through 80V Transients
    • 2A Maximum Output Current
    • Low Ripple (<15mVP-P) Burst Mode® Operation: IQ = 85µA at 12VIN to 3.3VOUT
    • Adjustable Switching Frequency: 100kHz to 2.4MHz
    • Low Shutdown Current: IQ < 1µA
    • Catch Diode Current Sense Protects Circuit Through Short-Circuit & Input Overvoltage
    • Synchronizable Between 250kHz to 2MHz
    • Power Good Flag
    • Saturating Switch Design: 200mΩ On-Resistance
    • Thermal Protection
    • Soft-Start Capability
    • Small 16-Pin Thermally Enhanced MSOP & 3mm × 4mm DFN Packages

    58V with 80V Transient Protection, 2A (IOUT), 2.4MHz Step-Down Switching Regulator with IQ < 85µA in 3mm × 4mm DFN (or MSOP-16E)

    LT3980 PR Image

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