n Low peak clamping voltage even during

n Ability to repeatedly protect against high

n Convenient mounting and grounding to any

n Cable shields are passed through and

Specifications are subject to change without notice.

Users should verify actual device performance in their specific applications.

The Bourns® 1840 Series Signal and Dataline Protectors are designed to protect sensitive electronic circuits and components from damaging

surge voltages and currents. Their extremely fast response and low clamping voltages make them particularly suitable for the protection of sensi-

tive signal and datalines associated with computer, data communication, instrumentation, broadcasting and industrial controls. They may be used

directly with EIA standard interfaces RS-232, RS-422, RS-423, RS-485 and with 4-20 mA and 50 mA instrumentation loops. The Model 1840

Series Signal and Dataline Protectors are fast, rugged and capable of protecting against fast rising voltage transients as well as the severe

current surges associated with lightning discharges, in each case up to rated limits.

Method of Operation

resetting a breaker or replacing a fuse to address a transient surge event.

protectors are placed at each node.

Related Bourns® Protectors

100 Amps 10 x 1000 µsec ........................................................................................................300 operations min.

100 Amps 10 x 1000 µsec ........................................................................................................300 operations min.

500 Amps 10 x 1000 µsec ........................................................................................................50 operations min.

1000 Amps 10 x 1000 µsec ......................................................................................................10 operations min.

3 kA, 6 kV / 8 x 20 µsec Combination Wave ............................................................................100 operations min.

10 kA / 8 x 20 µsec ...................................................................................................................10 operations min.

20 kA / 8 x 20 µsec ...................................................................................................................5 operations min.

Breakdown Voltage.................................................................................................................................See table*

ESD @ 8 kV ...........................................................................................................................................10 operations min.

Shield ARC Protection 6 kV / 3 kA .......................................................................................................... 5 operations min.

Wire Size ................................................................................................................................................20 AWG

* Custom voltages are available upon request. Please visit www.bourns.com/docs/Product-Datasheets/SMBJ.pdf for custom allowable

voltages.

Lead-time may be extended for some custom voltages.

EQPT. COMMON

AND/OR GND.

AND/OR GND.

Grounding: The 8-32 mounting screw and attached clamp, and hence the DIN-1 (TS-32)

or DIN-3 (TS-35) rail, serve as the protector ground. The rail (or 8-32 mounting screw if the

clamp is not used) should be connected to the facility ground via an AWG #6 or larger copper

wire. This wire should be as short and straight as possible. Single point grounding will provide

better protection and will permit the protector to be located a distance from the equipment.

(1.91) 18.80

DIMENSIONS: MM

(INCHES)

its aliates (collectively, “Bourns”).

without notice. Users should check for and obtain the latest relevant information and verify that such information is current

statements regarding the suitability of products for certain types of applications are based on Bourns’ knowledge of typical

standard (e.g., ISO/TS 16949) or a particular qualication (e.g., UL listed or recognized), Bourns is not responsible for any

their devices or applications.

applications, nor in any other applications where failure or malfunction may result in personal injury, death, or severe property

or environmental damage. Unless expressly and specically approved in writing by two authorized Bourns representatives

the user’s sole risk. Life-critical applications include devices identied by the U.S. Food and Drug Administration as Class III

standard product is considered for potential use in automotive applications, it should only be used in such sub-category of

or “automotive grade” does not by itself mean that Bourns has approved such product for use in an automotive application.

or any other generally equivalent governmental organization standard applicable to products designed or manufactured for

use in aircraft or space applications.

products’ data sheets in the section entitled “Applications.” Unless expressly and specically approved in writing by two

design, development, production, use or stockpiling of nuclear, chemical or biological weapons or missiles, nor shall they use

apply to all uses and applications that violate national or international prohibitions, including embargos or international

prior authorization from Bourns and/or the U.S. Government, be resold, transferred, or re-exported to any party not eligible

to receive U.S. commodities, software, and technical data.

To the maximum extent permitted by applicable law, Bourns disclaims (i) any and all liability for special, punitive, consequential,

of tness for particular purpose, non-infringement and merchantability.