LTC1778
LTC1778-1

PRODUCTION

Wide Operating Range, No RSENSE Step-Down Controller

Data Sheet (Rev. B) Product Selection Table

Part Models: 6
1ku List Price: Starting From $3.25

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Overview

No Sense Resistor Required
True Current Mode Control
Optimized for High Step-Down Ratios
t_ON(MIN) <=100ns
Extremely Fast Transient Response
Stable with Ceramic C_OUT
Dual N-Channel MOSFET Synchronous Drive
Power Good Output Voltage Monitor (LTC1778)
Adjustable On-Time (LTC1778-1)

Wide V_IN Range: 4V to 36V
±1% 0.8V Voltage Reference
Adjustable Current Limit
Adjustable Switching Frequency
Programmable Soft-Start
Output Overvoltage Protection
Optional Short-Circuit Shutdown Timer
Micropower Shutdown: I_Q <30µA
Available in a 16-Pin Narrow SSOP Package

The LTC1778 is a synchronous stepdown switching regulator controller optimized for CPU power. The controller uses a valley current control architecture to deliver very low duty cycles with excellent transient response without requiring a sense resistor. Operating frequency is selected by an external resistor and is compensated for variations in V_IN.

Discontinuous mode operation provides high efficiency operation at light loads. A forced continuous control pin reduces noise and RF interference, and can assist secondary winding regulation by disabling discontinuous operation when the main output is lightly loaded.

Fault protection is provided by internal foldback current limiting, an output overvoltage comparator and optional short-circuit shutdown timer. Soft-start capability for supply sequencing is accomplished using an external timing capacitor. The regulator current limit level is user programmable. Wide supply range allows operation from 4V to 36V at the input and from 0.8V up to (0.9)V_IN at the output.

Applications

Notebook and Palmtop Computers, PDAs
Distributed Power Systems

Part Models: 6
1ku List Price: Starting From $3.25

Documentation

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.

Part Model	Pin/Package Drawing	Documentation	CAD Symbols, Footprints, and 3D Models
LTC1778EGN#PBF	16-Lead SSOP (Narrow 0.15 Inch)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LTC1778EGN#TRPBF	16-Lead SSOP (Narrow 0.15 Inch)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LTC1778EGN-1#PBF	16-Lead SSOP (Narrow 0.15 Inch)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LTC1778EGN-1#TRPBF	16-Lead SSOP (Narrow 0.15 Inch)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LTC1778IGN#PBF	16-Lead SSOP (Narrow 0.15 Inch)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LTC1778IGN#TRPBF	16-Lead SSOP (Narrow 0.15 Inch)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys

Part Models	Product Lifecycle	PCN

Oct 3, 2024 - 24_0235 (QSOP/SSOP PKG) Migrating Bottom Trace Code Marking to Top Side Laser Marking
		PCN24_0235_Form Material_Report Other Delta Qualification Matrix
LTC1778EGN#PBF	PRODUCTION
LTC1778EGN#TRPBF	PRODUCTION
LTC1778EGN-1#PBF	PRODUCTION
LTC1778EGN-1#TRPBF	PRODUCTION
LTC1778IGN#PBF	PRODUCTION
LTC1778IGN#TRPBF	PRODUCTION
Oct 11, 2022 - 22_0235 Epoxy Change from Henkel 8290 to 8290A for GN Package
		PCN22_0235_Form Material_Report Qualification Results Summary Delta Qualification Matrix
LTC1778EGN#PBF	PRODUCTION
LTC1778EGN#TRPBF	PRODUCTION
LTC1778EGN-1#PBF	PRODUCTION
LTC1778EGN-1#TRPBF	PRODUCTION
LTC1778IGN#PBF	PRODUCTION
LTC1778IGN#TRPBF	PRODUCTION
Apr 6, 2022 - 22_0066 Laser Top Mark for 16QSOP Assembled in ADPG [PNG]
		PCN22_0066_Form Material_Report Delta Qualification Matrix
LTC1778EGN#PBF	PRODUCTION
LTC1778EGN#TRPBF	PRODUCTION
LTC1778EGN-1#PBF	PRODUCTION
LTC1778EGN-1#TRPBF	PRODUCTION
LTC1778IGN#PBF	PRODUCTION
LTC1778IGN#TRPBF	PRODUCTION

This is the most up-to-date revision of the Data Sheet.

Software Resources

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Hardware Ecosystem

Parts	Product Life Cycle	Description
LTC3878	PRODUCTION	Fast, Wide Operating Range No R_SENSE Step-Down DC/DC Controller

Tools & Simulations

LTspice 1

LTC1778 Demo Circuit - No Rsense, Synchronous Step-Down Controller (12V to 2.5V @ 10A)

Models for the following parts are available in LTspice:

LTC1778
LTC1778-1

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

Evaluation Kits

LTC1778EGN | No RSENSE, 5V ≤ VIN ≤ 25V, VOUT = 2.5V @ 10A

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Product Details

Demonstration circuit DC378 is a synchronous step-down buck regulator using the LTC1778 No R_SENSE switching regulator controller. The controller uses a valley current control architecture to deliver very low duty cycles without requiring a sense resistor. The demo board operates with a 5V to 25V supply voltage and provides a 2.5V@10A output.

Resources

DC378A - Demo Manual
8/3/2012

DC378A - Schematic
9/24/2009

DC378A - Design File
9/24/2009

LTC1778EGN Demo Board | IMVPII I/O Power Supply, VIN = 5V-25V, VOUT = 1.2V @ 6A

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Product Details

Demonstration circuit DC385 is a high density synchronous step-down (buck) regulator using the LTC1778 No R_SENSE switching regulator controller. This controller uses a valley current control architecture to deliver very low duty cycles without requiring a sense resistor. The demo board input voltage range is 5V to 25V and it provides 1.2V@6A at the output.