LT1521 - 300mA Low Dropout Regulators with Micropower Quiescent Current and Shutdown

The LT1521/LT1521-3/LT1521-3.3/LT1521-5 are low dropout regulators with micropower quiescent current and shutdown. These devices are capable of supplying 300mA of output current with a dropout voltage of 0.5V.Designed for use in battery-powered systems, the low quiescent current, 12uA operating and 6uA in shutdown, makes them an ideal choice. The quiescent current is well controlled; it does not rise in dropout as it does with many other low dropout PNP regulators.

Other features of the LT1521/LT1521-3/LT1521-3.3/LT1521-5 include the ability to operate with very small output capacitors. They are stable with only 1.5uF on the output while most older devices require between 10uF and 100uF for stability. Small ceramic capacitors can be used,enhancing manufacturability. Also, the input may be connected to voltages lower than the output voltage, including negative voltages, without reverse current flow from output to input. This makes the LT1521 series ideal for backup power situations where the output is held high and the input is low or reversed. Under these conditions only 5uA will flow from the output pin to ground.

Features

Dropout Voltage: 0.5V
Output Current: 300mA
Quiescent Current: 12µA
No Protection Diodes Needed
Adjustable Output from 3.8V to 20V
Fixed Output Voltages: 3V, 3.3V, 5V
Controlled Quiescent Current in Dropout
Shutdown IQ = 6µA
Reverse Battery Protection
No Reverse Current
Thermal Limiting

Typical Application

Applications

Low Current Regulator
Regulator for Battery-Powered Systems
Post Regulator for Switching Supplies

Packaging

Order Information

Part Number	Package	Temp	Price(1-99)	Price (1k)*
LT1521CMS8-3.3#PBF	MS-8	C	$2.65	$2.20
LT1521CMS8-3.3#TRPBF	MS-8	C		$2.26
LT1521CMS8-3#PBF	MS-8	C	$2.65	$2.20
LT1521CMS8-3#TRPBF	MS-8	C		$2.26
LT1521CMS8-5#PBF	MS-8	C	$2.65	$2.20
LT1521CMS8#PBF	MS-8	C	$2.65	$2.20
LT1521CS8-3.3#PBF	SO-8	C	$2.75	$2.20
LT1521CS8-3.3#TRPBF	SO-8	C		$2.26
LT1521CS8-3#PBF	SO-8	C	$2.75	$2.20
LT1521CS8-3#TRPBF	SO-8	C		$2.26
LT1521CS8-5#PBF	SO-8	C	$2.75	$2.20
LT1521CS8-5#TRPBF	SO-8	C		$2.26
LT1521CS8#PBF	SO-8	C	$2.75	$2.20
LT1521CS8#TRPBF	SO-8	C		$2.26
LT1521CST-3.3#PBF	SOT-223	C	$2.36	$1.90
LT1521CST-3.3#TRPBF	SOT-223	C		$1.96
LT1521CST-3#PBF	SOT-223	C	$2.36	$1.90
LT1521CST-3#TRPBF	SOT-223	C		$1.96
LT1521CST-5#PBF	SOT-223	C	$2.36	$1.90
LT1521CST-5#TRPBF	SOT-223	C		$1.96
LT1521IS8-3.3#PBF	SO-8	I	$3.35	$2.65
LT1521IS8-3.3#TRPBF	SO-8	I		$2.71
LT1521IS8-3#PBF	SO-8	I	$3.35	$2.65
LT1521IS8-3#TRPBF	SO-8	I		$2.71
LT1521IS8-5#PBF	SO-8	I	$3.35	$2.65
LT1521IS8-5#TRPBF	SO-8	I		$2.71
LT1521IS8#PBF	SO-8	I	$3.35	$2.65
LT1521IS8#TRPBF	SO-8	I		$2.71
LT1521IST-3.3#PBF	SOT-223	I	$3.15	$2.55
LT1521IST-3.3#TRPBF	SOT-223	I		$2.61
LT1521IST-3#PBF	SOT-223	I	$3.15	$2.55
LT1521IST-3#TRPBF	SOT-223	I		$2.61
LT1521IST-5#PBF	SOT-223	I	$3.15	$2.55
LT1521IST-5#TRPBF	SOT-223	I		$2.61