Aux

Reg

PWM

Int

Reg

SYNC

GT

CS

RT

VIN

ENI

POL

ENO

FB

H/D

VREF

VDD

VCC

5.0V @ 1mA

11

Ω

1.21M

Ω

8.25k

Ω

226k

Ω

1.0µF

100nF

4.7µF

100nF

VN2450

374k

Ω

124k

Ω

ES1J

C

NC

NO

1.0µF

0

1

POL

INT

SYNC

EN

250mA

DF06

NAIS JS1-5V

GND

S1J

270k

Ω

HV9901DB1 Schematic

Modifications

External Relay

Connect the coil of the external relay to the External Relay

terminals and move the Relay Selector shunt to the Ext

position.

Pull-in Current, Pull-in Time, and Hold Current

For use with other relays, these parameters may be changed

data sheet for details.

Monitoring Relay Current

For the on-board relay, coil current may be monitored by

replacing the Relay Selector shunt with either a wire loop (for

current probe use) or with a low value sense resistor (for

voltage probe use). Remember that galvanic isolation is not

provided! See warnings on the first page.

Switching Frequency

to the following equation:

This equation is valid for frequencies 25kHz and above. Be

advised that frequencies below 20kHz may cause the relay coil

to emit audible noise. And avoid higher frequencies that

approach the coil’s resonant frequency.

As provided, the HV9901DB1 supplies 5V for external circuitry.

Other volltages in the range 2.0V to 5.5V may be obtained by













+

=

4

3

1

V

25

.

1

R

R

V

CC

CC

hi

EN

CC

lo

EN

V

V

V

V

7

.

0

3

.

0

)

(

)

(

>

<

6

Ω

21.8GHz

3.23kHz

R

f

PWM

⋅

+

=