AD260

–7–

REV. 0

The power transformer is designed to operate between 150 kHz

and 250 kHz and will easily deliver more than 1 W of isolated

power when driven push-pull (5 V) on the system side. Different

transformer tap, rectifier and regulator schemes will provide

combinations of

±5 V, 15 V, 24 V or even 30 V or higher.

The output voltage when driven with a low voltage-drop drive

(@ 5 V push-pull) will be 37 V p-p across the entire secondary.

This will drop to 33 V p-p at 4.5 V drive.

3.3 F

TANT.

+

–

52T

CT

LM2524

12

11

14

13

4.7k

915

16

3.3k

0.1 F

10

1

2

4

5

6

7

470pF

GND

INV

NI

+5Vdc

8

3.3 F

TANT.

+

–

52T

CT

MAX

253

1

8

4

3

SHUTDOWN (

ON/OFF)

+5Vdc

7

2

6

Figure 3. System Side Transformer Driver Examples

Application Examples

The following is an example of a typical transformer system-side

drive circuit and a field-side regulation circuit suitable for use in

most general applications.

+5V

REG

96T

CT.

–5V ISO

+5V ISO

I

ENABLE FLD

(PWR-UP ENABLE)

–5V

REG

Figure 4.

a

a

+5Vdc/+4.5Vdc

150mA

+

LOAD

COM

80mA

b

–

COM

20mA

b

+

20mA

b

+5Vdc/+4.5Vdc

150mA

–

COM

20mA

b

+

20mA

a

+5Vdc/+4.5Vdc

150mA

–

COM

40mA

a

+

40mA

a

a

7.72

7.62

15.79

23.5

7.72

a

+5Vdc/+4.5Vdc

150mA

COM

20mA

b

+

20mA

b

+

5V DRIVE

V(MIN) @

4.5V DRIVE

+8.55

17.63

8.64

+26.3

+8.64

"a" DIODES

IN5818/MBR0530

"b" DIODES

IN5819/MBR0540

Figure 5. Field Side Power Supply Rectifier Examples