littelfuse.com© 2015 Littelfuse
Specifications are subject to change without notice.
MDSM-4 15.3mm Surface Mount Reed Switch
Description
The MDSM-4 surface mount reed switch is a sub-miniature, 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.
This reed switch is a surface mount version of MDCG-4. It has high insulation
resistance of 1010 ohms minimum and a contact resistance of less than
100 milliohms.
Agency Approvals
Agency Agency File Number Ampere-Turns Range
E47258
E471070 12-38 AT
DEMKO 14 ATEX 1393U 12-38 AT
Switch Type
Contact Form A (SPST-NO)
Materials Body: Glass
Leads: Tin-plated Ni-Fe wire
Surface Mount Reed Switches
Features
• Surface mount, normally
open switch
• Low, stable contact resistance
• Capable of switching 200Vdc or
0.5A at up to 10W
• Available sensitivity 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
• Industrial Controls
• Security
• Limit Switching
• Office Equipment
Dimensions
Dimensions in mm (inch)
Low Power > MDSM-4
RoHS
Note: SPST-NO = Single-pole, single-throw, normally open
Note: Land pattern is Littelfuse recommendation only. User is responsible for proper PCB design.
Electrical Ratings
Contact Rating 1W/VA - max. 10
Voltage 3
Switching 2
Breakdown 4
Vdc - max.
Vac - max.
Vdc - min.
200
140
250
Current 3
Switching 2
Carry
Adc - max.
Aac - max.
Adc - max.
0.50
0.35
1.20
Resistance Contact, Initial
Insulation
Ω - max.
Ω - min.
0.100
1010
Capacitance Contact pF - typ. 0.2
Temperature Operating
Storage 5
°C
°C
-40 to +125
-65 to +125
17.52±0.25
(.690±.010)
(.600)MAX
15.24
19.30±0.25
(.760±.010) 2x0.00 MIN
2x2.34 (.092)
2x1.30 (.051)
(.000)
16.00
(.630)
2.84 MAX
(.112)
RECOMMENDED LAND PATTERN
(.039±.004)
1.00±0.10
(.090)MAX
Ø2.28
Notes:
1. Contact rating - Product of the switching voltage and current should never exceed the wattage rating. Contact Littelfuse for additional load/life information.
2. When switching inductive and/or capacitive loads, the effects of transient voltages and/or currents should be considered. Refer to Application Notes AN108A and AN107 for details.
3. Electrical Load Life Expectancy - Contact Littelfuse with voltage, current values along with type of load.
4. Breakdown Voltage - per MIL-STD-202, Method 301.
5. Storage Temperature - Long time exposure at elevated temperature may degrade solderability of the leads.
littelfuse.com© 2015 Littelfuse
Specifications are subject to change without notice.
littelfuse.com© 2015 Littelfuse
Specifications are subject to change without notice.
MDSM-4 R - 17-23
Series
AT Range
12-18 AT
12-23 AT
17-23 AT
17-28 AT
22-28 AT
22-33 AT
27-33 AT
27-38 AT
32-38 AT
Example:
17-23 AT product in Bulk
packaging is MDSM-4B-17-23
Packaging
R = Tape and Reel
B = Bulk
Note: These AT values are the before-modification values of the bare reed switch.
Drop-Out vs. Pull-In Chart
Packaging
Packaging Option Packaging Specification Quantity Quantity and Packaging Code Taping Width
Tape and Reel EIA-RS-481-1 3000 R 32mm
Bulk N/A 200 B N/A
Part Numbering System
Notes:
1. Operate (including bounce)/Release Time - per EIA/NARM RS-421-A, diode suppressed coil (Coil II).
2. Shock and Vibration - per EIA/NARM RS-421-A and MIL-STD-202.
3. Pull-In Range - Contact Littelfuse for narrower AT ranges available. These AT values are the before modification AT of the MDCG-4.
4. Rating Sensitivity - The value at which contact ratings and operating characteristics are determined. Derating may be required below this value.
Surface Mount Reed Switches
Low Power > MDSM-4
MDSM-4 15.3mm Surface Mount Reed Switch
Note: Chart represents the range of Drop-Out, min to max, for a given Pull-In value of
the MDCG-4 prior to modification into the MDSM-4.
Product Characteristics
Operating Characteristics
Operate Time 10.6ms - max.
Release Time 10.2ms - max.
Shock 211ms 1∕2 sine wave 100G - max.
Vibration 250-2000 Hertz 30G - max.
Resonant Frequency 3.9kHz - typ.
Magnetic Characteristics
Pull-In Range 3Ampere Turns 12-38
Rating Sensitivity 4Ampere Turns 20
Test Coil L4989
Additional Information
Datasheet Samples
Resources
5
0
10
15
20
25
30
Drop-Out (AT, L4989 Coil)
50
Pull-In (AT, L4989 Coil)
10 15 20 25 30 35
40
Max.
Min.
littelfuse.com© 2015 Littelfuse
Specifications are subject to change without notice.
TAPE DIMENSIONS mm (inch)
REEL DIMENSIONS mm (inch)
MDSM-4 15.3mm Surface Mount Reed Switch
Surface Mount Reed Switches
Low Power > MDSM-4
4,00
2,00
(.079)
(.157)
Ø1,50
-0
(.059
)
(.
067 )
Ø1,70
+.004
+0,10
-0
-.002
+.006
-0,05
+0,15
(.240)
6,10
Ø2,00
1,17
(.046)
(.075)
1,90
7.5°
2,82
(.111)
3.0°
(.240)
6,10
(.084)
2,13
(.315)
8,00
(.069)
1,75
(.559)
14,20
(.079)
28,40
(1.118)
(.059 )
Ø1,50
+.004
+0,10
-0
-0
2. ALL POCKET DIMENSI
ONS ARE ±(.004") 0,10mm
3. ALL DIMENSIONS ARE TO INSIDE OF POCKET
1. ALL TAPE & SPROCKET HOLE DIMENSIONS
ARE PER EIA-481 UNLESS NOTED
(.016)
0,41
32,00
(1.260)
7.5°
(.670)
17,02
(.830)
21,08
120° TYP.
1,9±0.4 TYP.
(.075±.016)
Ø21,0±0.4
Ø13,0±0.2
(.512±.008)
(.827±.016)
(1.276 )
MEASURED AT HUB
+.008
+0.2
(32,4 )
-0
-0
38,4 MAX.
(1.512)
(12.992
)
330,00
(3.937±.020)
100,0±0,50 +0,2
5
-0,76
+.010
-.030
