LTC1436A - High Efficiency Low Noise Synchronous Step-Down Switching Regulators

Features

  • Maintains Constant Frequency at Low Output Currents
  • Programmable Fixed Frequency (PLL Lockable)
  • Wide VIN Range: 3.5V to 36V Operation
  • Low Minimum On-Time (</=300ns) for High Frequency, Low Duty Cycle Applications
  • Dual N-Channel MOSFET Synchronous Drive
  • Very Low Dropout Operation: 99% Duty Cycle
  • Low Dropout, 0.5A Linear Regulator for CPU I/O or Low Noise Audio Supplies
  • Built-In Power-On Reset Timer
  • Programmable Soft Start
  • Low-Battery Detector
  • Remote Output Voltage Sense
  • Foldback Current Limiting (Optional)
  • Pin Selectable Output Voltage
  • Logic Controlled Micropower Shutdown: IQ < 25µA
  • Output Voltages from 1.19V to 9V
  • Available in 24-Lead Narrow SSOP and 28-Lead SSOP Packages
Designed for Automotive and Transportation Applications
AEC-Q100 data available for specific packages


Typical Application

LTC1436A Typical Application

Description

The LTC1436A/LTC1437A are synchronous step-down switching regulator controllers that drive external N-channel power MOSFETs in a phase lockable, fixed frequency architecture. The Adaptive PowerTM output stage selectively drives two N-channel MOSFETs at frequencies up to 400kHz while reducing switching losses to maintain high efficiencies at low output currents.

An auxiliary 0.5A linear regulator using an external PNP pass device provides a low noise, low dropout voltage source. A secondary winding feedback control pin (SFB) guarantees regulation regardless of the load on the main output by forcing continuous operation.

An additional comparator is available for use as a lowbattery detector. A power-on reset timer (POR) is included which generates a signal delayed by 65536/fCLK (300ms typically) after the output is within 5% of the regulated output voltage. Internal resistive dividers provide pin selectable output voltages with remote sense capability.

The operating current level is user-programmable via an external current sense resistor. Wide input supply range allows operation from 3.5V to 30V (36V maximum).

Protected by U.S. Patents, including 5481178, 6304066, 5929620, 6580258, 5705919, 5731731

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
LTC1436ACGN-PLL#PBF SSOP-24 GN C 05-08-1641 (GN24) Yes
LTC1436ACGN-PLL#TRPBF SSOP-24 GN C 05-08-1641 (GN24) Yes
LTC1436ACGN#PBF SSOP-24 GN C 05-08-1641 (GN24) Yes
LTC1436ACGN#TRPBF SSOP-24 GN C 05-08-1641 (GN24) Yes
LTC1436AEGN#PBF SSOP-24 GN E 05-08-1641 (GN24) Yes
LTC1436AEGN#TRPBF SSOP-24 GN E 05-08-1641 (GN24) Yes
LTC1436AIGN-PLL#PBF SSOP-24 GN I 05-08-1641 (GN24) Yes
LTC1436AIGN-PLL#TRPBF SSOP-24 GN I 05-08-1641 (GN24) Yes
LTC1436AIGN#PBF SSOP-24 GN I 05-08-1641 (GN24) Yes
LTC1436AIGN#TRPBF SSOP-24 GN I 05-08-1641 (GN24) Yes


LTC1436A Package Drawing
LTC1436A Package Drawing
LTC1436A 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
LTC1436ACGN-PLL#PBF SSOP-24 C $6.15 $5.00 Yes
LTC1436ACGN-PLL#TRPBF SSOP-24 C $5.10 Yes
LTC1436ACGN#PBF SSOP-24 C $6.15 $5.00 Yes
LTC1436ACGN#TRPBF SSOP-24 C $5.10 Yes
LTC1436AEGN#PBF SSOP-24 E $6.55 $5.50 Yes
LTC1436AEGN#TRPBF SSOP-24 E $5.60 Yes
LTC1436AIGN-PLL#PBF SSOP-24 I $7.70 $6.25 Yes
LTC1436AIGN-PLL#TRPBF SSOP-24 I $6.35 Yes
LTC1436AIGN#PBF SSOP-24 I $7.70 $6.25 Yes
LTC1436AIGN#TRPBF SSOP-24 I $6.35 Yes
Buy NowRequest Samples
* 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.

Part Number Description Price Documentation
DC140A-A LTC1436CGN-PLL | DUAL OUTPUT REGULATOR, 5.5V to 28V INPUT, 5V @ 3A and 3.3V @ 0.1A $100.00
DC140A-B LTC1436CGN-PLL | DUAL OUTPUT REGULATOR, 5.5V to 28V INPUT, 5V @ 3A and 12V @ 0.1A Contact Factory
DC163B LTC1436CGN | CONSTANT FREQ. SWITCHING REG. 4.5V-20V INPUT 1.8V@4A, 2.5V@0.5A Contact Factory
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC1436AIGN-PLL#PBF SSOP-24 I $7.70 $6.25 Yes
LTC1436AIGN-PLL#TRPBF SSOP-24 I $6.35 Yes
LTC1436AIGN#PBF SSOP-24 I $7.70 $6.25 Yes
LTC1436AIGN#TRPBF SSOP-24 I $6.35 Yes
Buy NowRequest Samples
* 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.

Applications

  • Notebook and Palmtop Computers, PDAs
  • Cellular Telephones and Wireless Modems
  • Portable Instruments
  • Battery-Operated Devices
  • DC Power Distribution Systems

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:
LTC1436A
LTC1436A-PLL

Technical Support