1
DEMO MANUAL DC330
LOW DROPOUT REGULATOR
DESCRIPTIO
U
PERFOR
m
A
N
CE SU
ARY
U
W
W
W
TYPICAL PERFOR
M
A
N
CE CHARACTERISTICS A
N
D BOARD PHOTO
U
W
U
supplies and as local regulators in larger systems. Their
ability to tolerate a wide variety of output capacitors makes
them ideal in space- and cost-sensitive systems.
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Input Voltage Range
2.3
20
V
Output Voltage (Note 1)
1.205
1.220
1.235
V
Output Voltage (Note 1)
V
IN
= 2.8V, JP1 or JP3 on Pins 5 and 6
1.764
1.802
1.839
V
Output Voltage (Note 1)
V
IN
= 3V, JP1 or JP3 on Pins 7 and 8
1.954
1.999
2.044
V
Output Voltage (Note 1)
V
IN
= 3.5V, JP1 or JP3 on Pins 9 and 10
2.455
2.506
2.571
V
Output Voltage (Note 1)
V
IN
= 3.8V, JP1 or JP3 on Pins 11 and 12
2.742
2.817
2.894
V
Output Voltage (Note 1)
V
IN
= 4V, JP1 or JP3 on Pins 13 and 14
2.936
3.019
3.103
V
Output Voltage (Note 1)
V
IN
= 4.3V, JP1 or JP3 on Pins 15 and 16
3.207
3.300
3.396
V
Output Voltage (Note 1)
V
IN
= 5V, JP1 or JP3 on Pins 17 and 18
4.848
5.006
5.167
V
Line Regulation
∆
V
IN
= 2.3V to 20V
1
5
mV
Quiescent Current
I
LOAD
= 0mA
20
35
µ
A
Load Regulation
∆
I
LOAD
= 1mA to 100mA
0.2
1
%
SHDN Pin Threshold (LT1761-SD)
On-to-Off
0.45
0.65
V
Off-to-On, I
LOAD
= 100mA
0.8
1.8
V
Output Voltage Noise (LT1761-BYP)
I
LOAD
= 100mA, BW = 10Hz to 100kHz
20
µ
V
RMS
LT1761 100mA Low Noise
Micropower LDO Regulators
DC330 BP
Demonstration circuit DC330 comprises two low noise
micropower voltage regulators using the LT
®
1761 in the
5-lead SOT-23 package. These circuits are primarily used
in cellular phones, voltage controlled oscillators, RF power
, LTC and LT are registered trademarks of Linear Technology Corporation.
T
A
= 25
°
C, V
IN
= 2.3V, V
SHDN
= 5V, I
LOAD
= 1mA, V
OUT
= 1.22V
(JP1 or JP3 set on pins 1 and 2), unless otherwise specified.
Typical Dropout Voltage
DC330 Board Photo
OUTPUT CURRENT (mA)
500
450
400
350
300
250
200
150
100
50
0
DROPOUT VOLTAGE (mV)
1761 G00
0
10 20 30 40
50 60 70
80 90 100
T
J
= 125
°
C
T
J
= 25
°
C
LT1761-BYP (5V Output)
10Hz to 100Hz Output Noise
V
OUT
100
µ
V/DIV
1ms/DIV
I
L
= 100mA
Note 1:
Output voltage variations include
±
1% tolerance of feedback divider network. For tighter voltage range,
use lower tolerance resistors or use fixed voltage output devices.
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