LTC7800 - Low IQ , 60V, High Frequency Synchronous Step-Down Controller

Features

  • Wide VIN Range: 4V to 60V (65V Abs Max)
  • Low Operating IQ : 50μA
  • Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 24V
  • RSENSE or DCR Current Sensing
  • Phase-Lockable Frequency (320kHz to 2.25MHz)
  • Programmable Fixed Frequency (320kHz to 2.25MHz)
  • Selectable Continuous, Pulse-Skipping or Low Ripple
  • Burst Mode® Operation at Light Load
  • Selectable Current Limit
  • Very Low Dropout Operation: 98% Duty Cycle
  • Adjustable Output Voltage Soft-Start or Tracking
  • Power Good Output Voltage Monitor
  • Output Overvoltage Protection
  • Low Shutdown IQ : < 14μA
  • Internal LDO Powers Gate Drive from VIN or EXTVCC
  • No Current Foldback During Start-Up
  • Small 20-Pin 3mm × 4mm QFN Package

Typical Application

LTC7800 Typical Application
LTC7800 Typical Application

Description

The LTC®7800 is a high performance step-down switching regulator DC/DC controller that drives an all N-channel synchronous power MOSFET stage. A constant frequency current mode architecture allows a phase-lockable frequency of up to 2.25MHz.

The 50μA no-load quiescent current extends operating run time in battery-powered systems. OPTI-LOOP® compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC7800 features a precision 0.8V reference and power good output indicator. A wide 4V to 60V input supply range encompasses a wide range of intermediate bus voltages and battery chemistries. The output voltage of the LTC7800 can be programmed between 0.8V to 24V.

The TRACK/SS pin ramps the output voltages during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The PLLIN/MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous conduction mode at light loads.

Packaging

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LTC7800EUDC#PBF 3x4 QFN-20 UDC E 05-08-1742 Yes
LTC7800EUDC#TRPBF 3x4 QFN-20 UDC E 05-08-1742 Yes
LTC7800HUDC#PBF 3x4 QFN-20 UDC H 05-08-1742 Yes
LTC7800HUDC#TRPBF 3x4 QFN-20 UDC H 05-08-1742 Yes
LTC7800IUDC#PBF 3x4 QFN-20 UDC I 05-08-1742 Yes
LTC7800IUDC#TRPBF 3x4 QFN-20 UDC I 05-08-1742 Yes


LTC7800 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC7800EUDC#PBF 3x4 QFN-20 E $4.96 $3.47 Yes
LTC7800EUDC#TRPBF 3x4 QFN-20 E $5.02 $3.53 Yes
LTC7800HUDC#PBF 3x4 QFN-20 H $6.10 $4.27 Yes
LTC7800HUDC#TRPBF 3x4 QFN-20 H $6.16 $4.33 Yes
LTC7800IUDC#PBF 3x4 QFN-20 I $5.69 $3.98 Yes
LTC7800IUDC#TRPBF 3x4 QFN-20 I $5.75 $4.04 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Click here to view our complete list of demo boards

Applications

  • Automotive Always-On Systems
  • Battery Powered Digital Devices
  • Distributed DC Power Systems

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Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

Models for the following parts are available in LTspice:
LTC7800

LTpowerCAD

The LTpowerCAD design tool is a complete power supply design tool program that can significantly ease the tasks of power supply design. It guides users to a solution, selects power stage components, provides detailed power efficiency, shows quick loop bode plot stability and load transient analysis, and can export a final design to LTspice for simulation. Click here to download LTpowerCAD

Design tools for the following parts are available in LTpowerCAD:
LTC7800

Technical Support