REV. 0

ADP3607

–8–

Regulated Adjustable Output Voltage

For the adjustable version of the ADP3607, the regulated out-

put voltage is programmed by a resistor that is inserted between

herent limit of the output voltage of a single doubling charge

pump stage is two times the input voltage. The scaling factor of

2.00 is reduced somewhat due to losses that increase with out-

put current. To increase the scaling factor to attain a more

positive output voltage, an external pump stage can be added

with just passive components as shown in Figure 20. That single

stage increases the scaling factor to a limit of 3, although the

diode drops will limit the ability to noticeably attain that exact

3.00 scaling factor. Even further increases can be achieved

with more external pump stages. High accuracy on the adjust-

able output is achieved through the use of precision trimmed

internal resistors, which eliminates the need to trim the external

resistor or add a second resistor to form a divider. The adjust-

able output voltage is set using the following formula:

V

R

OUT

=+

95

1

.

OUTPUT CURRENT – mA

3.5

0

10

50

+

4.7 F

+

4.7 F

+

4.7 F

GND

D1

IN5819

SD

R

540

45

35

30

25

20

15

4.0

4.5

5.0

5.5

6.0

6.5

R = 47.5k

R = 24.9k

Figure 19. Regulated Adjustable Output Voltage

ADP3607

SD

GND

+

4.7 F

4.7 F

4.7 F

+

+

C1

4.7 F

D2

SD103

D1

1N5819

+

+

R1

104.5k

4.7 F

12V

D3

IN5819

Figure 20. Regulated 12 V from a 5 V Input

Regulated Dual Supply System

The circuit in Figure 21 provides regulated positive and negative

voltages for systems that require dual supplies from a single

battery or power supply.

ADP3607-5

SD

GND

+

10 F

10 F

10 F

+

+

+5V

ADP3605

SD

GND

+

10 F

10 F

+

R1

16.5k

1%

SD103

–2.6V

Figure 21. Regulated Dual Supply System

OUTLINE DIMENSIONS

Dimensions shown in inches and (mm).

8-Lead SOIC

(SO-8)

0.1968 (5.00)

0.1890 (4.80)

8

5

4

1

0.2440 (6.20)

0.2284 (5.80)

PIN 1

0.1574 (4.00)

0.1497 (3.80)

0.0688 (1.75)

0.0532 (1.35)

SEATING

PLANE

0.0098 (0.25)

0.0040 (0.10)

0.0192 (0.49)

0.0138 (0.35)

0.0500

(1.27)

BSC

0.0098 (0.25)

0.0075 (0.19)

0.0500 (1.27)

0.0160 (0.41)

8°

0°

0.0196 (0.50)

0.0099 (0.25)

x 45°

8-Lead TSSOP

(RU-8)

85

4

1

0.256 (6.50)

0.246 (6.25)

0.177 (4.50)

0.169 (4.30)

PIN 1

0.0256 (0.65)

BSC

0.122 (3.10)

0.114 (2.90)

SEATING

PLANE

0.006 (0.15)

0.002 (0.05)

0.0118 (0.30)

0.0075 (0.19)

0.0433

(1.10)

MAX

0.0079 (0.20)

0.0035 (0.090)

0.028 (0.70)

0.020 (0.50)

8

0