HV9901DB1 Datasheet, PDF (1/2 Pages) Supertex, Inc – Universal Relay Driver

Introduction
The HV9901 is a universal relay driver employing PWM
switching techniques utilizing the relay coil’s inductance to
provide efficient operation over a wide supply voltage range.
Relay drive is constant-current. Pull-in current, pull-in time,
and hold current are all programmable via 2 resistors and a
capacitor. An adjustable regulator provides 1mA for external
circuitry.
The HV9901DB1 demo board contains all the circuitry
necessary to demonstrate the operation of the HV9901.
Included on-board are a full-wave input rectifier, fuse, the
HV9901, and a 10A relay. Provisions for connecting an
external relay are available. The circuit may be modified to
accomodate the drive requirements of other relays.
HV9901DB1
Universal Relay Driver
Specifications
Input Voltage
Relay Drive Current
Pull-in Time
Contact Form
Contact Rating
Auxillary Regulator (V_CC)
Enable
Switching Frequency
10–400VDC, 24–277VAC
72mA pull-in, 24mA hold
20ms
SPDT (1FormC)
10A@125VAC, 6A@277VAC
5.0V@1mA
<1.5V off, >3.5V on
21kHz
WARNING!!!
Board Layout and Connections
Do not connect earth-grounded
instruments when connected to the
AC line. Doing so will short the AC
line, resulting in damage to the demo
board and/or the instrument. Use an
isolation transformer on the AC line,
use high voltage differential probes,
or use a floating instrument to make
measurements when connected to
the AC line.
Input
~–
D1
~+
Voltage
F1
Relay
Contacts
Normally Closed
Common
Normally Open
C1
K1
D3
Q1
C2
IC1
R2
R4
C5
R6
R7
Enable Polarity
Selector
Ground
WARNING!!!
No galvanic isolation. Dangerous voltages
are present when connected to the AC line.
Relay
Selector
External
Relay _Sync
V_CC
Enable
Input Voltage
Supply voltage. May be a DC source in the range of
10–400VDC, or an AC source in the range of 24–277VACrms.
A full-wave bridge rectifier on board rectifies the AC. Also
included is a 250mA 2AG fuse.
Relay Contacts
For connecting an external load. The PCB traces are rated at
10A for a 20°C rise.
Relay Selector
In the Int position, the on-board relay is operated. In the Ext
position, a relay connected to the External Relay terminals is
operated.
External Relay
For connection of an off-board relay.
Sync
Synchronizes multiple HV9901s to the same frequency or to a
master clock. Frequency will be the highest independent
frequency. Connect to the Sync pins of other HV9901s or to a
master clock.
Enable
Logic-level enable for relay operation. See Enable Polarity
Selector for polarity.
V_CC
Supplies 5V at 1mA for external circuitry.
Ground
Circuit common. Since galvanic isolation is not provided,
ground will be at the AC line potential!
Enable Polarity Selector
Sets Enable polarity. In the 0 position, Enable is active low. In
the 1 position, Enable is active high.