1
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
