IX9915

R01

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7

2. Functional Description

IX9915 is the functional equivalent of a 4-terminal 431

type precision shunt regulator and a high voltage

Darlington transistor in the same package.

The typical application for IX9915 is shown in

Figure 5.

Figure 5 IX9915 Application Diagram

This is a simplified application circuit that shows how

the IX9915 can be used in an LED lamp control circuit.

The high voltage Darlington transistor will bleed the

voltage. The 4-terminal 431 type shunt regulator is

Darlington transistor bleeding the current (ON) or not

voltage, the shunt regulator starts to regulate to drive

to make sure this bleeder circuitry only burns a little

scaled sample of its voltage to pin FB, the error

amplifier's non-inverting input. The error amplifier

compares this scaled voltage against an internal high

accuracy reference voltage and generates an output

internal reference voltage causes the error amplifier to

2.1 Regulation Voltage

When connected as shown in the application circuit

above and properly configured, the IX9915 will

To achieve this, the values of the voltage divider

manner:

regulated voltage level will cause a regulation error. As

shown in the Electrical Characteristics table the error

+

_

+

_

OC

FB

V

CC

C

E

B

V

SS

I

OC

I

Q

R

2

R

1

R

E

I

1

I

H

V

REG

R

3

I

3

R

0

V

REF

+V

LINE

Rectifier

Dimmer Switch

AC Supply

-

R

1

R

2

------

V

REG

V

REF

-------------

1

–

=