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dc1728af

DEMONSTRATION CIRCUIT

1728A QUICK START GUIDE 

 DESCRIPTION

LT3015

1.5A, Low Noise, Negative Linear Regulator

 with Precision Current Limit 

Demonstration circuit 1728A is an adjustable 1.5A negative 
linear regulator featuring the LT3015. This device supplies 
up to 1.5A of output current at a typical dropout voltage 
of 300mV. Operating quiescent current is typically 1.1mA 
and drops to < 1μA in shutdown. Quiescent current is also 
well controlled in dropout. In addition to fast transient 
response, the LT3015 exhibits very low output noise, 
making it ideal for noise-sensitive applications.

A key feature of the LT3015 is the capability to supply a 
wide output voltage range. The DC1728A can be set to 
–1.22V, –2.5V, –5.0V, –12.0V, –15.0V, as well as a user 
select option. In addition, the DC1728A is capable of de-
livering up to –1.5A output current, and can be used as a 
high current negative linear regulator, post regulator for 
switching supply, variable voltage supply or low output 
voltage power supply.

L

, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear 

Technology Corporation. All other trademarks are the property of their respective owners.

PERFORMANCE SUMMARY

Internal protection circuitry includes reverse output pro-
tection, precision current limit with foldback and thermal 
limit with hysteresis.

The LT3015 is available as an adjustable device with a 
–1.22V reference voltage. Packages include the 5-lead 
TO-220 and DD-Pak, a thermally enhanced 12-lead MSOP 
and the low profile 8-lead 0.75mm 

×

 3mm 

×

 3mm DFN.

The LT3015 datasheet gives a complete description of the 
device, operation and application information. The data-
sheet should be read in conjunction with this quick start 
guide for working on or modifying the demo circuit 1728A.

Design files for this circuit board are available at 
http://www.linear.com/demo

(T

A

 = 25°C)

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

V

IN

Input Supply Range

V

OUT

 = –1.22V, I

OUT1

 = –1mA

–1.8

–30

V

V

OUT

Output Voltage 

Shunt at 1, 2 for JP2

–1.183

–1.22

–1.257

V

V

OUT

Output Voltage

Shunt at 3, 4 for JP2

–2.425

–2.5

–2.575

V

V

OUT

Output Voltage

Shunt at 5, 6 for JP2

–4.85

–5.0

–5.15

V

V

OUT

Output Voltage

Shunt at 7, 8 for JP2

–11.64

–12.0

–12.36

V

V

OUT

Output Voltage

Shunt at 9, 10 for JP2

–14.55

–15.0

–15.45

V

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