Name: MDSM-4 Series - 15.3mm Surface Mount Reed Switch
Brand: Littelfuse Inc.

MDSM-4 Series - 15.3mm Surface Mount Reed Switch

Series: MDSM-4

Questions? Contact Littelfuse Support

Disclaimer Notice

Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, automotive, military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse. "Littelfuse" includes Littelfuse, Inc., and all of its affiliate entities.

A sub-miniature, surface mount, normally open switch with a 15.24mm long x 2.28mm diameter (0.600" x 0.090") glass envelope. Capable of switching 200Vdc at 10W. Available sensitivity range of 12-38 AT. High insulation resistance of 10¹⁰ ohms minimum and contact resistance of less than 100 milliohms. Available in axial-leaded version (MDCG-4). Ideally suited for reed relays, security, metering, limit sensing, telecom and office equipment applications. Available in bulk packaging or tape and reel.

Features:

Surface mount, normally open switch capable of switching 200Vdc or 0.5A at up to 10 Watts
Available sensitivity range of 12-38 AT

Benefits:

Hermetically sealed switch contacts are not affected by and have no effect on their external environment
Zero operating power required for contact closure
Excellent for switching micro-controller logic level loads

Applications:

Position sensing
Level sensing
Security
Industrial controls
Telecom
Office equipment
Home appliances

Access specifications, certifications, check availability and order parts below

Catalog #	Switching Power (W)	Switching Voltage (V DC)	Switching Current (A DC)	Breakdown Voltage (V DC)	Max Contact Resistance (Ω)	Magnetic Sensitivity (AT)	Body Length (mm)	Overall Length (mm)	Switch Type	Operating Temperature	Stock	Samples

MDSM-4B-12-18	10	200	0.5	250	0.1	12 to 18	15.24	19.3	A:SPST-NO	-40° to 125°C	Check	Order
MDSM-4B-12-23	10	200	0.5	250	0.1	12 to 23	15.24	19.3	A:SPST-NO	-40° to 125°C	Check	Order
MDSM-4B-17-23	10	200	0.5	250	0.1	17 to 23	15.24	19.3	A:SPST-NO	-40° to 125°C	Check	Order
MDSM-4B-22-28	10	200	0.5	250	0.1	22 to 28	15.24	19.3	A:SPST-NO	-40° to 125°C	Check	Order
MDSM-4B-27-33	10	200	0.5	250	0.1	27 to 33	15.24	19.3	A:SPST-NO	-40° to 125°C	Check	Order
MDSM-4B-32-38	10	200	0.5	250	0.1	32 to 38	15.24	19.3	A:SPST-NO	-40° to 125°C	Check	Order
MDSM-4R-12-18	10	200	0.5	250	0.1	12 to 18	15.24	19.3	A:SPST-NO	-40° to 125°C	Check	Order
MDSM-4R-12-23	10	200	0.5	250	0.1	12 to 23	15.24	19.3	A:SPST-NO	-40° to 125°C	Check	Order
MDSM-4R-17-23	10	200	0.5	250	0.1	17 to 23	15.24	19.3	A:SPST-NO	-40° to 125°C	Check	Order
MDSM-4R-17-28	10	200	0.5	250	0.1	17 to 28	15.24	19.3	A:SPST-NO	-40° to 125°C	Check	Order
MDSM-4R-22-28	10	200	0.5	250	0.1	22 to 28	15.24	19.3	A:SPST-NO	-40° to 125°C	Check	Order
MDSM-4R-22-33	10	200	0.5	250	0.1	22 to 33	15.24	19.3	A:SPST-NO	-40° to 125°C	Check	Order
MDSM-4R-27-33	10	200	0.5	250	0.1	27 to 33	15.24	19.3	A:SPST-NO	-40° to 125°C	Check	Order
MDSM-4R-32-38	10	200	0.5	250	0.1	32 to 38	15.24	19.3	A:SPST-NO	-40° to 125°C	Check	Order
MDSM-4B-17-28 Obsolete: 2017 -08-22	10	200	0.5	250	0.1	17 to 28	15.24	19.3	A:SPST-NO	-40° to 125°C
MDSM-4B-22-33 Obsolete: 2017 -08-22	10	200	0.5	250	0.1	22 to 33	15.24	19.3	A:SPST-NO	-40° to 125°C
MDSM-4B-27-38 Obsolete: 2017 -08-22	10	200	0.5	250	0.1	27 to 38	15.24	19.3	A:SPST-NO	-40° to 125°C
MDSM-4R-27-38 Obsolete: 2017 -08-22	10	200	0.5	250	0.1	27 to 38	15.24	19.3	A:SPST-NO	-40° to 125°C

Catalog #	Certificates

MDSM-4B-12-18
MDSM-4B-12-23
MDSM-4B-17-23
MDSM-4B-17-28
MDSM-4B-22-28
MDSM-4B-22-33
MDSM-4B-27-33
MDSM-4B-27-38
MDSM-4B-32-38
MDSM-4R-12-18
MDSM-4R-12-23
MDSM-4R-17-23
MDSM-4R-17-28
MDSM-4R-22-28
MDSM-4R-22-33
MDSM-4R-27-33
MDSM-4R-27-38
MDSM-4R-32-38

	Reed Switch Selection Guide A quick reference guide to selecting reed switches for electronic applications
	Position and Level Sensing in Washing Machines A most integral appliance in any home is a washing machine. Washing machines have helped made the chore of cleaning clothes quite effortless.
	Littelfuse Reed Switches MDSM-4 datasheet
	Soldering Temperatures Application Note This application note applies to all of Littelfuse?s products that are normally soldered to printed circuit boards (PCBs) including all reed switches.
	Extreme Temperature Reed Switch Operation Application Note Littelfuse reed switches are normally specified to operate in a temperature range of -40 ?C to +125 ?C. T
	Reed Switch and Reed Sensor Activation Application Note Although a reed switch can be activated by placing it inside an electrical coil many reed switches and reed sensors are used for proximity sensing and are activated by a magnet.
	Inductive Load Arc Suppression Application Note When a reed switch or reed sensor is used to control an inductive device (relay coil solenoid transformer small motor etc.)
	Catalog Glossary Reed Switch Terms Application Note Reed Switch Terms Glossary
	Ampere turn versus mT and Gauss Application Note What is the relationship between AT (Ampere*turn) and Tesla or Gauss? What magnet strength will activate a 15 AT reed switch at 5 mm?
	Vibration Testing and Precautions Application Note Littelfuse tests sinusoidal vibration according to Mil. Std. 202G Method 204D Test Condition G (10 ? 2000 Hz frequency sweep at 30 G or 0.06 inch double amplitude whichever is less).
	Capacitive Loads Application Note When there is significant capacitance in a reed sensor reed relay or reed switch circuit the peak current and energy switched by the reed contacts should be considered.
	Reed Switch Extended Shock Capabilities Application Note The maximum shock specifications in the Littelfuse catalog are very conservative for most switches smaller than the DRxxxx type. T
	Rice Cooker Lid Lock Application Note The position sensing lid lock ensures that the lid is securely locked in place.
	Storage of Littelfuse Sensor Parts Application Note The data sheets for Littelfuse parts show temperature ranges for storage. However long term exposure to extreme temperatures in the specified storage temperature range may degrade solderability of terminals.
	Handling of Reed Sensors Relays And Switches Application Note When used within their capabilities Littelfuse reed sensors reed relays and reed switches provide many years of robust performance
	Measuring Reed Switch Sensitivity and Contact Resistance Application Note The purpose of this application note is to document the preferred method of reading the sensitivity and contact resistance of Littelfuse reed switches.
	Flow Sensing in Tankless Water Heaters Application Note Reed switches and sensors are highly effective solutions for flow sensing applications that can be used for detecting the presence of fluid flow in a system or even measure the rate of fluid flow.
	Modifying Reed Switches Application Note When cutting and forming reed switch leads it is important to use the correct support and cutting tools to avoid causing damage to the glass-to-metal hermetic seals.

Part #	Part Description	RoHS	Pb-free	RoHS (2015/ 863/EU) Certificate	REACH (SVHC’s) Declaration	Halogen Free	REACH (SVHC’s)	IPC-Material Declaration
MDSM-4B-12-18	MDSM-4B 5276 12-18	No 12/15/2017	No 12/15/2017	CoC_RoHS10_MDSM-4B-12-18	REACH209_Declaration_MDSM-4B-12-18	Yes 12/15/2017	Does not Contain	IPC_MDSM-4 Part Number - MDSM-4B-12-18 IPC-Material Declaration Select All X IPC_MDSM-4
MDSM-4B-12-23	MDSM-4B 5276 12-23	No 11/27/2013	No 11/27/2013			Yes 11/27/2013		IPC_MDSM-4 Part Number - MDSM-4B-12-23 IPC-Material Declaration Select All X IPC_MDSM-4
MDSM-4B-17-23	MDSM-4B 5276 17-23	No 12/03/2013	No 12/03/2013			Yes 12/03/2013		IPC_MDSM-4 Part Number - MDSM-4B-17-23 IPC-Material Declaration Select All X IPC_MDSM-4
MDSM-4B-22-28	MDSM-4B 5276 22-28	No 11/27/2013	No 11/27/2013			Yes 11/27/2013		IPC_MDSM-4 Part Number - MDSM-4B-22-28 IPC-Material Declaration Select All X IPC_MDSM-4
MDSM-4B-27-33	MDSM-4B 5276 27-33	No 12/03/2013	No 12/03/2013			Yes 12/03/2013		IPC_MDSM-4 Part Number - MDSM-4B-27-33 IPC-Material Declaration Select All X IPC_MDSM-4
MDSM-4B-32-38	MDSM-4B 5276 32-38	No 11/27/2013	No 11/27/2013			Yes 11/27/2013		IPC_MDSM-4 Part Number - MDSM-4B-32-38 IPC-Material Declaration Select All X IPC_MDSM-4
MDSM-4R-12-18	MDSM-4R 5277 12-18	No 02/01/2016	No 02/01/2016	CoC_RoHS10_MDSM-4R-12-18	REACH_SVHC Declaration_MDSM-4R-12-18		Does not Contain	IPC_MDSM-4 Part Number - MDSM-4R-12-18 IPC-Material Declaration Select All X IPC_MDSM-4
MDSM-4R-12-23	MDSM-4R 5277 12-23	No 11/27/2013	No 11/27/2013			Yes 11/27/2013		IPC_MDSM-4 Part Number - MDSM-4R-12-23 IPC-Material Declaration Select All X IPC_MDSM-4
MDSM-4R-17-23	MDSM-4R 5277 17-23	No 02/01/2016	No 02/01/2016	CoC_RoHS10_MDSM-4R-17-23	REACH211_Declaration_MDSM-4R-17-23	Yes 02/01/2016	Does not Contain	IPC_MDSM-4 Part Number - MDSM-4R-17-23 IPC-Material Declaration Select All X IPC_MDSM-4
MDSM-4R-17-28	MDSM-4R 5277 17-28	No 02/01/2016	No 02/01/2016			Yes 02/01/2016		IPC_MDSM-4 Part Number - MDSM-4R-17-28 IPC-Material Declaration Select All X IPC_MDSM-4
MDSM-4R-22-28	MDSM-4R 5277 22-28	No 02/01/2016	No 02/01/2016		REACH219_Declaration_MDSM-4R-22-28	Yes 02/01/2016	Does not Contain	IPC_MDSM-4 Part Number - MDSM-4R-22-28 IPC-Material Declaration Select All X IPC_MDSM-4
MDSM-4R-22-33	MDSM-4R 22-33	No 02/01/2016	No 02/01/2016			Yes 02/01/2016		IPC_MDSM-4 Part Number - MDSM-4R-22-33 IPC-Material Declaration Select All X IPC_MDSM-4
MDSM-4R-27-33	MDSM-4R 5277 27-33	No 11/27/2013	No 11/27/2013			Yes 11/27/2013		IPC_MDSM-4 Part Number - MDSM-4R-27-33 IPC-Material Declaration Select All X IPC_MDSM-4
MDSM-4R-32-38	MDSM-4R 32-38	No 02/01/2016	No 02/01/2016			Yes 02/01/2016		IPC_MDSM-4 Part Number - MDSM-4R-32-38 IPC-Material Declaration Select All X IPC_MDSM-4

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Semiconductors

MDSM-4 Series - 15.3mm Surface Mount Reed Switch

Application Spotlight

Part Number - MDSM-4B-12-18

IPC-Material Declaration

Part Number - MDSM-4B-12-23

IPC-Material Declaration

Part Number - MDSM-4B-17-23

IPC-Material Declaration

Part Number - MDSM-4B-22-28

IPC-Material Declaration

Part Number - MDSM-4B-27-33

IPC-Material Declaration

Part Number - MDSM-4B-32-38

IPC-Material Declaration

Part Number - MDSM-4R-12-18

IPC-Material Declaration

Part Number - MDSM-4R-12-23

IPC-Material Declaration

Part Number - MDSM-4R-17-23

IPC-Material Declaration

Part Number - MDSM-4R-17-28

IPC-Material Declaration

Part Number - MDSM-4R-22-28

IPC-Material Declaration

Part Number - MDSM-4R-22-33

IPC-Material Declaration

Part Number - MDSM-4R-27-33

IPC-Material Declaration

Part Number - MDSM-4R-32-38

IPC-Material Declaration

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