LTC3878 - Fast, Wide Operating Range No RSENSE Step-Down Controller

Features

• Click Here for LTC3878 Evaluation Kit
• Wide V_IN Range: 4V to 38V
• ±1% 0.8V Voltage Reference
• Extremely Fast Transient Response
• t_ON(MIN): 43ns
• Valley Current Mode Control
• Stable for Low ESR Ceramic C_OUT
• No Sense Resistor Required
• Optimized for High Step-Down Ratios
• Pin Compatible with the LTC1778 (No EXTV_CC Pin)
• Power Good Output Voltage Monitor
• Dual N-Channel MOSFET Synchronous Drive
• Adjustable Switching Frequency
• Programmable Current Limit with Foldback
• Programmable Soft-Start
• Output Overvoltage Protection
• Small 16-Pin Narrow SSOP Package

Typical Application

Description

The LTC3878 is a synchronous step-down switching regulator controller optimized for high switching frequency and fast transient response. The constant on-time valley current mode architecture allows for a wide input range, including very low duty factor operation. No external sense resistor or slope compensation is required. The LTC3878 is pin compatible with the LTC1778 in applications that do not use EXTV_CC while offering better efficiency. Consult with the factory to verify compatibility.

Operating frequency is set by an external resistor and compensated for variations in V_IN to offer excellent line stability. Discontinuous mode operation provides high efficiency during light load conditions. A forced continuous control pin allows the user to reduce noise and RF interference. Safety features include output overvoltage protection and programmable current limit with foldback. Soft-start capability for supply sequencing is accomplished through an external timing capacitor. The current limit is user programmable.

The LTC3878 allows operation from 4V to 38V at the input and from 0.8V to 90% V_IN at the output. The LTC3878 is available in a small 16-pin narrow SSOP package.

Packaging

SSOP-16

Order Info

• Part numbers ending in PBF are lead free. Please contact LTC marketing for information on lead based finish parts.
• 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	Pins	Temp	Price (1-99)	Price (1k)*	RoHS Data
LTC3878EGN#PBF	SSOP	16	E	$3.14	$2.20	View
LTC3878EGN#TRPBF	SSOP	16	E		$2.26	View
LTC3878IGN#PBF	SSOP	16	I	$3.44	$2.41	View
LTC3878IGN#TRPBF	SSOP	16	I		$2.47	View
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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.

Evaluation Kits

Part Number	Description	Price
DC1292A	LTC3878EGN Demo Board | Wide Operating Range No Rsense Step-Down Controller	$125.00
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Applications

• Distributed Power Systems
• Embedded Computing
• Communications Infrastructure

Simulate

To simulate selected Linear Technology products, please download LTSpice / SwitcherCAD III. This powerful schematic capture and simulation tool includes macro models for 80% of Linear Technology's switching regulators, over 200 op amp models, as well as resistors, transistors and MOSFET models.

For other simulation tools, visit our Design Simulation and Device Models page.