Datasheet

REV. B
–8–
C00132–0–7/01(B)
PRINTED IN U.S.A.
ADP3300
Constant Dropout Post Regulator
The circuit in Figure 6 provides high precision with low drop-
out for any regulated output voltage. It significantly reduces the
ripple from a switching regulator while providing a constant
dropout voltage, which limits the power dissipation of the LDO
to 15 mW. The ADP3000 used in this circuit is a switching
regulator in the step-up configuration.
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
6-Lead Surface Mount Package
(SOT-23)
1 3
4 5
2
6
0.122 (3.10)
0.106 (2.70)
PIN 1
0.071 (1.80)
0.059 (1.50)
0.118 (3.00)
0.098 (2.50)
0.075
(1.90)
BSC
0.037
(0.95) BSC
0.009 (0.23)
0.003 (0.08)
0.022 (0.55)
0.014 (0.35)
10ⴗ
0ⴗ
0.020 (0.50)
0.010 (0.25)
0.006 (0.15)
0.000 (0.00)
0.051 (1.30)
0.035 (0.90)
SEATING
PLANE
0.057 (1.45)
0.035 (0.90)
D1
1N5817
C2
100␮F
10V
L1
6.8␮H
R1
120⍀
ADP3300-5
IN
SD
OUT
GND
C3
2.2␮F
5V @ 50mA
C1
100␮F
10V
ADP3000-ADJ
I
LIM
V
IN
SW1
GND
SW2
FB
V
IN
= 2.5V TO 3.5V
R2
30.1k⍀
1%
Q1
2N3906
Q2
2N3906
R4
274k⍀
R3
124k⍀
1%
Figure 6. Constant Dropout Post Regulator
ADP3300–Revision History
Location Page
Data Sheet changed from REV. A to REV. B.
Edits to FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Edits to GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Edits to ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Addition to the ORDERING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3