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LTC3409A - 600mA Low VIN Buck Regulator in 3mm × 3mm DFN

Datasheet

Documentation

Features

1.6V to 5.5V Input Voltage Range
0.62V to 5.5V Output Voltage Range
Internal Soft-Start
Selectable 1.7MHz or 2.6MHz Constant Frequency Operation
Internal Oscillator Can Be Synchronized to an External Clock, 1MHz to 3MHz Range
High Efficiency: Up to 95%
65μA Quiescent Current, Burst Mode® Operation
600mA Output Current (V_IN = 1.8V, V_OUT = 1.2V)
750mA Peak Inductor Current
No Schottky Diode Required
Low Dropout Operation: 100% Duty Cycle
0.612V Reference Voltage
Stable with Ceramic Capacitors
Shutdown Mode Draws <1μA Supply Current
Current Mode Operation for Excellent Line and Load Transient Response
Overtemperature Protection
Available in a Low Profile (0.75mm)
8-Lead (3mm × 3mm) DFN Package

Typical Application

Description

The LTC3409A is a high efficiency, monolithic synchronous buck regulator using a constant frequency, current mode architecture. The LTC3409A improves upon the LTC3409’s light load regulation in Burst Mode operation. The output voltage is adjusted via an external resistor divider.

Fixed switching frequencies of 1.7MHz and 2.6MHz are supported. Alternatively, an internal PLL will synchronize to an external clock in the frequency range of 1MHz to 3MHz. This range of switching frequencies allows the use of small surface mount inductors and capacitors, including ceramics.

Supply current during Burst Mode operation is only 65μA dropping to <1μA in shutdown. The 1.6V to 5.5V input voltage range makes the LTC3409A ideally suited for single cell Li-Ion, Li-Metal and 2-cell alkaline, NiCd or NiMH battery-powered applications. 100% duty cycle capability provides low dropout operation, extending battery life in portable systems. Burst Mode operation can be user-enabled, increasing efficiency at light loads, further extending battery life.

The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Internal soft-start offers controlled output voltage rise time at startup without the need for external components.

	Vref Tolerance
LTC3409	+/-5%
LTC3409A	+/-3%

Packaging

3x3 DFN-8

Order Info

Package Variations and Pricing

Part Number	Package	Pins	Temp	Price (1-99)	Price (1k)^*
LTC3409AEDD#PBF	DFN	8	E	$3.39	$2.37
LTC3409AEDD#TRPBF	DFN	8	E		$2.43
LTC3409AIDD#PBF	DFN	8	I	$4.06	$2.84
LTC3409AIDD#TRPBF	DFN	8	I		$2.90
LTC3409EDD#PBF	DFN	8	E	$3.07	$2.15
LTC3409EDD#TRPBF	DFN	8	E		$2.25
LTC3409IDD#PBF	DFN	8	I	$3.53	$2.47
LTC3409IDD#TRPBF	DFN	8	I		$2.53
LTC3409EDD	DFN	8	E	$6.14	$4.30
LTC3409EDD#TR	DFN	8	E		$4.50

^* 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.