ADP1110

–13–

REV. 0

APPLICATION CIRCUITS

All-Surface-Mount, Single-Cell to 5 V Converter

This is a very simple, compact, low-part-count circuit that takes

a single alkaline 1.5 V cell input and produces a 5 V output.

The output current should be kept to 10 mA or less to conserve

battery life.

SW1

SW2

SENSE

GND

SET

AO

ADP1110-5

NC

NC

L1

D1

1N5817

6

7

8

1

2

4

5

3

50µH

+5V

10mA

15µF

ONE

ALKALINE

CELL

CTX50-4

1.5V

Figure 30. All-Surface-Mount, Single-Cell to 5 V Converter

All-Surface-Mount, 3 V to 5 V Step-Up Converter

Similar to the previous circuit, this circuit takes a 3-volt input

and provides a 5 V output at 40 mA. As in the single-cell version,

the circuit is compact and uses only four external components.

SW1

SW2

SENSE

GND

SET

AO

ADP1110-5

NC

NC

L1

6

7

8

1

2

4

5

3

220

Ω

3V

50µH

+5V

40mA

10µF

TWO

ALKALINE

CELLS

D1

1N5817

CTX50-4

Figure 31. All-Surface-Mount, 3 V to 5 V Step-Up

Converter

All-Surface-Mount, 9 V to 5 V Step-Down Converter

Featuring the same low parts count of the step-up design, this

circuit is the complement to the preceding one. The 220

Ω

resistor programs the current limit to around 600 mA.

SW2

SENSE

GND

SET

AO

ADP1110-5

NC

NC

L1

D1

6

8

1

2

4

5

3

220

Ω

50µH

1N5817

+5V

40mA

10µF

9V

BATTERY

7

CTX50-4

Figure 32. All-Surface-Mount, 9 V to 5 V Step-Down

Converter

1.5 V to

5 V Dual-Output Step-Up Converter

This circuit works from a single 1.5 V cell and provides simulta-

neous outputs of +5 V and –5 V. The accuracy of the negative

output suffers slightly because of the extra diode drop of around

0.4 V.

SW2

SENSE

GND

SET

AO

ADP1110-5

NC

NC

6

7

8

1

2

4

5

3

1.5V

L16

8µH

4.7µF

ONE

ALKALINE

CELL

4.7µF

+5V

3mA

NOTE: ALL DIODES 1N5818

–5V

3mA

4.7µF

CTX68-4

Figure 33. 1.5 V to

±5 V Dual-Output Step-Up

Converter

All-Surface-Mount Flash Memory VPP Generator

Figure 34 shows a circuit that can generate the programming

voltage, VPP to program flash memory. The key components

are the MOSFET and the bipolar transistor. These two devices

form a switch that, when ON, allows the ADP1110 to power-up

and function as a step-up converter. The output is +12 V at 120

mA. When the MOSFET switch is OFF, the output of the

circuit drops to just under +5 V thereby disabling the program-

ming capability.

Care should be taken so there is no short-circuit-current limiting

in the circuit in either operating mode.

SW1

SW2

SENSE

GND

SET

AO

ADP1110-12

NC

NC

6

7

8

1

2

4

5

3

L1

50µH

10µF

LOGIC1 = PROGRAM

LOGIC0 = SHUTDOWN

D1

1N5818

CTX50-4

MMBT4403

1k

Ω

MMBF170

+12V

120mA

+5V

10k

Ω

Figure 34. All Surface-Mount Flash Memory VPP Generator