LTC1553L - 5-Bit Programmable Synchronous Switching Regulator Controller for Pentium® II Processor

Features

  • 5-Bit Digitally Programmable 1.8V to 3.5V Fixed Output Voltage
  • Provides All Features Required by the Intel Pentium®II Processor VRM 8.2 DC/DC Converter Specification
  • Flags for Power Good, Over-Temperature and Overvoltage Fault
  • 19A Output Current Capability from a 5V Supply
  • Dual N-Channel MOSFET Synchronous Driver
  • Initial Output Accuracy: ±1.5%
  • Excellent Output Accuracy: 177;2% Typ Over Line, Load and Temperature Variations
  • High Efficiency: Over 95% Possible
  • Adjustable Current Limit Without External Sense Resistors
  • Fast Transient Response
  • Available in 2O-Lead SSOP and SW Packages

Typical Application

LTC1553L Typical Application

Description

The LTC1553L is a high power, high efficiency switching regulator controller optimized for a 5V input to 1.8V-3.5V output applications. It features a digitally programmable output voltage, a precision internal reference and an internal feedback system that provides output accuracy of ±1.5% at room temperature and typically ±2% over-temperature, load current and line voltage shifts. The LTC1553L uses a synchronous switching architecture with two external N-channel output devices, providing high efficiency and eliminating the need for a high power, high cost P-channel device. Additionally, it senses the output current across the on-resistance of the upper N-channel FET, providing an adjustable current limit without an external low value sense resistor.

The LTC1553L free-runs at 300kHz and can be synchronized to a faster external clock if desired. It includes all the inputs and outputs required to implement a power supply conforming to the Intel Pentium® II Processor VRM 8.2 DC/DC Converter Specification.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

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

Part Number Package Code Temp Package
Drawing
RoHS
LTC1553LCG#PBF SSOP-20 G C 05-08-1640 (G20) Yes
LTC1553LCG#TRPBF SSOP-20 G C 05-08-1640 (G20) Yes
LTC1553LCSW#PBF SW-20 SW C 05-08-1620 (SW20) Yes
LTC1553LCSW#TRPBF SW-20 SW C 05-08-1620 (SW20) Yes


LTC1553L 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
LTC1553LCG#PBF SSOP-20 C $3.65 $3.25 Yes
LTC1553LCG#TRPBF SSOP-20 C $3.35 Yes
LTC1553LCSW#PBF SW-20 C $3.40 $3.00 Yes
LTC1553LCSW#TRPBF SW-20 C $3.10 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

  • Power Supply for Pentium II, SPARC, ALPHA and PA-RISC Microprocessors
  • High Power 5V to 1.8V-3.5V Regulators

Product Notifications

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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:
LTC1553
LTC1553L

Technical Support