3

Supertex inc.

www.supertex.com

Doc.# DSFP-HV857

A062013

HV857

Block Diagram

* The inductor used is a 220µH Murata inductor, max DC resistance of 8.4Ω, part # LQH32CN221K21.

Figure 1: Typical Application/ Test Circuit

Sym

Parameter

Min

Typ

Max Units Conditions

V

Peak to Peak output voltage

170

190

210

V

V

I

DDQ

Quiescent V

-

-

150

nA

R

I

DD

Input current going into the VDD pin

-

-

150

µA

V

I

IN

Input current including inductor current

-

20

25

mA

See Figure 1*

V

CS

Output voltage on VCS

-

84

-

V

See Figure 1

f

EL

EL lamp frequency

205

240

275

Hz

See Figure 1

f

SW

Switching transistor frequency

-

80

-

kHz

See Figure 1

D

Switching transistor duty cycle

-

88

-

%

See Figure 1

C

+

_

V

REF

Disable

High

Voltage

Level

Translator

GND

VDD

Q

Q

Q

VA

CS

LX

VB

Q

RSW-Osc

REL-Osc

V

SENSE

EL

Osc

V

DD

Switch

Osc

220µH*

3.3nF

100V

560kΩ

2.0MΩ

BAS21

* Murata Inductor LQH32CN221K21

HV857

OFF = 0V

Enable Signal

+

-

4.7µF

+

-

0.1µF

2.0kΩ

10nF

1

2

3

4

8

7

6

5

VDD

RSW-Osc

REL-Osc

GND

VA

VB

CS

LX

HV857