LT1965
1
DESCRIPTION
Demonstration circuit 1172A is a low dropout linear
regulator featuring LT
®
1965, w hich comes in 5-lead
TO -220, 5-lead DD-PAK as w ell as the thermally en-
hanced 8-lead M SO P and 8-lead 3mmX3mm DFN
packages. The DC1172A has an input voltage range
from 2.3 to 20V, and is capable of delivering up to
1.1A output current. O perating quiescent current is
500µA, reducing to less than 1µA in shutdow n. The
DC1172A has a very low output noise, w hich makes it
ideal for logic pow er supplies, post regulator for
sw itching supplies and low noise instruments.
The LT1965 datasheet gives a complete description of
the part, operation and application information. The data-
sheet must be read in conjunction w ith this quick start
guide for demo circuit 1172A.
Design files for this circuit board are available. Call
the LTC factory.
, LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT and
Pow erPath are trademarks of Linear Technology Corporation.
Perform ance Sum m ary ( TA = 25
oC )
PAR AM ETER FO R BU CK R EG ULATO R
CO N DITIO N
VALU E
M inimum Input Voltage
2.3V
M aximum Input Voltage
20V
O utput Voltage Vout
V
IN
=2.5V, I
O UT
=1.1A
V
IN
=2.5V, I
O UT
=1.1A
V
IN
=2.5V, I
O UT
=1.1A
V
IN
=3.3V, I
O UT
=1.1A
V
IN
=3.3V, I
O UT
=1.1A
1.2V
+/- 4%
1.5V
+/- 4%
1.8V
+/- 4%
2.5V
+/- 4%
3.3V
+/- 4%
M aximum O utput Current
1.1A
Q U ICK STA RT PROCEDU RE
Demonstration circuit 1172A is easy to set up to evaluate
the performance of the LT1965. Refer to Figure 1 for
proper measurement equipment setup and follow the
procedure below :
1.
Before proceeding to test, insert jumper JP1
into the O FF position, and use VO U T Select
jumper J1 for the desired output voltage 1.2V,
1.5V, 1.8V, 2.5V, 3.3V. If the output voltage is
different from the above values, use the U SER
select option and install a resistor R 5.
2.
Apply input voltage across Vin to G nd. Insert
jumper JP1 into the O N position. Check for the
proper output voltage.
3.
O nce the proper output voltage is established,
adjust the load w ithin the operating range and
observe the output voltage regulation.
DEMO C IR C U IT 1 1 7 2 A
Q U IC K S TAR T G U IDE
L T 1 9 6 5 EDD
1 .1 A L o w Dro p o u t R e g u la to r
Summary of Contents for 1172A
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