Relay manufacturers typical application circuits – Rainbow Electronics MAX4821 User Manual
Page 9
Inductive Kickback Protection
The MAX4820/MAX4821 feature built-in inductive kick-
back protection to reduce the voltage spike on OUT_
generated by a relay’s coil inductance when the output
is suddenly switched off. Internal diodes connected
from each output to COM allow the inductor current to
flow back to the supply. Connect the common cathode
(COM) of the internal protection diodes to V
CC
.
COM also can be connected to a higher voltage than
V
CC
(+6V max) for faster kickback recovery. In this con-
figuration, bypass COM to PGND with a 0.1µF capacitor.
MAX4820/MAX4821
3.3V/+5V, 8-Channel, Cascadable Relay Drivers
with Serial/Parallel Interface
_______________________________________________________________________________________
9
COMPANY
PHONE
WEBSITE
Aromat Corp.
310-524-9862 www.aromat.com
CP Clare Corp.
978-524-6700 www.crouzet.com
Coto Techonology
401-943-2686 www.cotorelay.com
Deustch Relays,
Inc.
516-499-6000 www.deutschrelays.com
Fujitsu
Takamisawa
408-745-4900 www.fujitsufta.com
Hella KG Hueck
734-414-0970 www.hella.com
COMPANY
PHONE
WEBSITE
NEC Electronics,
Inc.
800-366-9782 www.nec-global.com
Omron
Electronics, Inc.
847-843-7900 www.oeiweb.omron.com
Rockwell/Allen-
Bradley
414-382-2000 www.ab.com
Siemens
Electromechanical
Component, Inc.
770-371-3000 www.sec.siemens.com
Teledyne Relays
213-777-0077 www.teledynerelays.com
Relay Manufacturers
Typical Application Circuits
MAX4820
RESET
SET
CLK
CS
DIN
DOUT
OUT1
RELAY
COIL 1
RELAY
COIL 8
OUT8
COM
PGND
V
CC
V
CC
V
CC
0.1
µF
GND
MAX4821
RESET
SET
A0
A1
CS
LVL
OUT1
RELAY
COIL 1
RELAY
COIL 8
OUT8
COM
PGND
V
CC
V
CC
V
CC
0.1
µF
GND
A2