Linear Technology 1172A Quick Start Manual

DESCRIPTION
Demonstration circuit 1172A is a low dropout linear
regulator f eaturing 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
f rom 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
Perform ance Sum m ary ( T A = 25 o C )
PAR AM ETER FO R BU CK R EG ULATO R
M inimum I nput Voltage
M aximum I nput Voltage
O utput Voltage V out
M aximum O utput Current
Q U ICK STA RT PROCEDU RE
Demonstration circuit 1172A is easy to set up to evaluate
the perf ormance of the LT1965. Ref er to Figure 1 f or
proper measurement equipment setup and f ollow the
procedure below :
1. Bef ore proceeding to test, insert j umper JP1
into the O FF position, and use VO U T Select
j umper J1 f or the desired output voltage 1.2V,
1.5V, 1.8V, 2.5V, 3.3V. I f the output voltage is
dif f erent f rom the above values, use the U SER
select option and install a resistor R 5.
DEMO C IR C U IT 1 1 7 2 A
Q U IC K S TAR T G U IDE
1 .1 A L o w Dro p o u t R e g u la to r
ideal f or logic pow er supplies, post regulator f or
sw itching supplies and low noise instruments.
The LT1965 datasheet gives a complete description of
the part, operation and application inf ormation. The data-
sheet must be read in conj unction w ith this quick start
guide f or 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.
CO N DI TI O N
V =2.5V, I =1.1A
I N OUT
V =2.5V, I =1.1A
I N OUT
V =2.5V, I =1.1A
I N OUT
V =3.3V, I =1.1A
I N OUT
V =3.3V, I =1.1A
I N OUT
2. Apply input voltage across Vin to G nd. I nsert
j umper JP1 into the O N position. Check f or the
proper output voltage.
3. Once the proper output voltage is established,
adj ust the load w ithin the operating range and
observe the output voltage regulation.
LT1965
L T 1 9 6 5 EDD
VALU E
2.3V
20V
1.2V +/- 4%
1.5V +/- 4%
1.8V +/- 4%
2.5V +/- 4%
3.3V +/- 4%
1.1A
1