4

Supertex inc.

www.supertex.com

Doc.# DSFP-LR12

C080113

LR12

Figure 3: High Voltage Adjustable Constant Current Source

Figure 2: SMPS Start-Up Circuit

Typical Application Circuits

FB

LR12

V

V

+

+

-

-

VOUT

ADJ

VIN

PWM IC

R

I

1.20V

R

+

-

100nF

V

15 - 100V

VOUT

ADJ

VIN

LR12

Figure 1: High Input Voltage, 5.0V Output Linear Regulator

* Required for conditions where V

LR12

V

17 - 100V

*

R

2

18.2k

±1%

C

2

100nF

C

1

V

V

+ I

1+

R

2

R

1

VOUT

ADJ

VIN

R

R

1

6.04k

±1%