MLRR-3-17-23 - Littelfuse Inc. - Datasheet.Directory

LITTELFUSE REED SWITCH SELECTION GUIDE

A quick reference guide to selecting reed switches for electronic applications

littelfuse.com

LITTELFUSE REED SWITCH SELECTION GUIDE

A quick reference guide to selecting reed switches for electronic applications

Power Size Terminals Switch Type Package Pictures

Product

Series

Body Length

(mm)/[Inch]

Lead-Lead

Length

(mm)/[Inch]

Switching

Power (W)

Switching

Voltage (V)

Breakdown

Voltage**

(Vdc - min.)

Switching

Current (A)

Contact

Resistance (Ω)

Operating

Temperature (°C)

Magnetic

Sensitivity (AT) Certiﬁcation*

Low

Power

Small

Leads

A: SPST-NO Glass MITI-3V1 7.00 [.276] 46.00 (1.811) 10 170 Vdc, 120 Vac 175 0.25 Adc, 0.18 Aac 0.15 -40 to +125 6-10

A: SPST-NO Glass MDSR-10 10.16 [.400] 40.38 [1.590] 10 200 Vdc, 140 Vac 250 0.5 Adc, 0.35 Aac 0.12 -40 to +125 10-25

A: SPST-NO Glass MDSR-7 12.70 [.500] 40.38 [1.590] 10 200 Vdc, 140 Vac 250 0.5 Adc, 0.35 Aac 0.1 -40 to +125 10-25

SMD

A: SPST-NO Glass MISM-3V1 7.00 [.276] 13.72 [.540] 10 170 Vdc, 120 Vac 175 0.25 Adc, 0.18 Aac 0.15 -40 to +125 6-10

A: SPST-NO Glass MDSM-10 10.16 [.400] 15.62 [.615] 10 200 Vdc, 140 Vac 250 0.5 Adc, 0.35 Aac 0.12 -40 to +125 10-25

Medium

Leads

A: SPST-NO Glass FLEX-14 14.00 [.551] 44.30 [1.744] 10 200 Vdc, 140 Vac 250 0.5 Adc, 0.35 Aac 0.1 -40 to +125 10-30

A: SPST-NO Glass MDCG-4 15.24 [.600] 40.38 [1.590] 10 200 Vdc, 140 Vac 250 0.5 Adc, 0.35 Aac 0.1 -40 to +125 12-38

A: SPST-NO Glass MACD-14 14.00 [.551] 44.30 [1.744] 10 200 Vdc, 140 Vac 200 0.5 Adc, 0.35 Aac 0.1 -40 to +125 10-30

C: SPDT-CO Glass MDRR-DT 14.73 [.580] 51.66 [2.034] 5175 Vdc, 120 Vac 200 0.25 Adc, 0.18 Aac 0.1 -40 to +125 15-30

SMD

A: SPST-NO Glass MDSM-4 15.24 [.600] 19.30 [.760] 10 200 Vdc, 140 Vac 250 0.5 Adc, 0.35 Aac 0.1 -40 to +125 12-38

A: SPST-NO Glass MASM-14 14.00 [.551] 19.30 [.760] 10 200 Vdc, 140 Vac 200 0.5 Adc, 0.35 Aac 0.1 -40 to +125 10-30

C: SPDT-CO Glass MDSM-DT 14.73 [.580] 25.40 [1.00] 5175 Vdc, 120 Vac 200 0.25 Adc, 0.18 Aac 0.1 -40 to +125 15-30

Both

Leads

and SMD

A: SPST-NO Overmolded 59165 16.00 [.630] 20.20 [.795] 10 200 Vdc, 140 Vac 250 0.5 Adc, 0.35 Aac 0.1 -40 to +125 10-25

A: SPST-NO Overmolded 59166 16.00 [.630] 19.51 [.768] 10 200 Vdc, 140 Vac 250 0.5 Adc, 0.35 Aac 0.1 -40 to +125 10-25

A: SPST-NO Overmolded 59170 11.43 [.450] 16.25 [.640] 10 200 Vdc, 140 Vac 250 0.5 Adc, 0.35 Aac 0.15 -40 to +125 10-25

Leads

A: SPST-NO Overmolded 59 045-1 17.78 [.700] 15.24 [.600] 10 200 Vdc, 140 Vac 250 0.5 Adc, 0.35 Aac 0.2 -40 to +105 15-30

A: SPST-NO Overmolded 59050-1 22.86 [.900] 20.32 [.800] 10 200 Vdc, 140 Vac 250 0.5 Adc, 0.35 Aac 0.2 -40 to +105 12-28

High

Power

Medium

Leads

A: SPST-NO Glass HA15-2 15.24 [.600] 40.38 [1.590] 20†200 Vdc, 265 Vac 400 0.4 Adc, 0.3 Aac 0.1 -20 to +125 17-23

450 0.5 Adc, 0.35 Aac 22-33

A: SPST-NO Glass MLRR-4 15.24 [.600] 40.38 [1.590] 20 200 Vdc, 140 Vac 250 1.0 Adc, 0.7Aac 0.1 -40 to +125 17-38

A: SPST-NO Glass MLRR-3 15.24 [.600] 56.64 [2.230] 20 200 Vdc, 140 Vac 250 1.0 Adc, 0.7Aac 0.1 -40 to +125 17-38

A: SPST-NO Glass MARR-5 19.69 [.775] 56.77 [2.235] 10 1000 Vdc, 700 Vac 2000 0.5 Adc, 0.35 Aac 0.1 -75 to +125 17-38

SMD

A: SPST-NO Glass MLSM-4 15.24 [.600] 19.56 [.770] 20 200 Vdc, 140 Vac 250 1.0 Adc, 0.7Aac 0.1 -40 to +125 17-38

A: SPST-NO Glass MLSM-3 15.24 [.600] 19.56 [.770] 20 200 Vdc, 140 Vac 250 1.0 Adc, 0.7Aac 0.1 -40 to +125 17-38

Leads

A: SPST-NO Overmolded 59050-2 22.86 [.900] 20.32 [.800] 20 200 Vdc, 265 Vac 400 0.5 Adc, 0.35 Aac 0.2 -20 to +105 17-28

A: SPST-NO Glass MRPR-20 20.32 [.800] 56.64 [2.230] 50 250 Vdc, 265 Vac 750 1.5 Adc, 1.1 Aac 0.1 -20 to +125 17-43

Large

A: SPST-NO Glass DRR-129 50.80 [2.000] 82.55 [3.250] 100 400 Vdc, 280 Vac 600 3.0 Adc, 2.1 Aac 0.1 -40 to +125 42-83

C: SPDT-CO Glass DRR-DTH 39.67 [1.562] 85.73 [3.375] 30 500 Vdc, 350 Vac 1200 0.5 Adc, 0.35 Aac 0.125 -20 to +125 50-80

C: SPDT-CO Glass DRT-DTH 39.67 [1.562] 85.73 [3.375] 50 500 Vdc, 350 Vac 1000 1.5 Adc, 1.0 Aac 0.5 -20 to +125 50-80

Notes:

*Certiﬁcation: Contact Littelfuse for certiﬁed ratings

** Breakdown Voltage - per MIL-STD-202, Method 301

† 20 W for 100-265 VAC loads,10 W for all other loads

• All reed switches are RoHS compliant

• For details on electrical speciﬁcations, visit littelfuse.com

• A:SPST-NO - Single Pole Single Throw - Normally Open

• C:SPDT-CO - Single Pole Double Throw - Change Over

Applications Assistance and Custom Switch Modiﬁcation

Littelfuse offers complete application engineering assistance in selecting the correct switch,

sensitivity, and conﬁguration. Switch life is affected by electrical load and other operating

conditions. Littelfuse offers load / life information per customer request.

Lead Modiﬁcations

Littelfuse can cut and/or form the reed switch leads to meet your dimensional requirements.

Most lead modiﬁcations can be done by Littelfuse with no additional tooling costs.

LITTELFUSE REED SWITCH SELECTION GUIDE

A quick reference guide to selecting reed switches for electronic applications

littelfuse.com

EC124Nv022217

NOTE:

This tool should ONLY be used as a quick reference guide to suggest a starting point in the selection

process. Once a part has been selected, the designer should retrieve the actual datasheet from

Littelfuse.com.

Littelfuse always recommends conducting application testing to verify the correct part selection.

In order to use this quick reference guide, the designer has to know just a few of key parameters,

such as switching power, voltage, current, size, mounting method, and safety certiﬁcations.

Market Segments / Applications:

Reed switches are used in a number of market applications including, but not limited to:

• White goods and small home appliances, such as ﬂuid level and position sensors

• Gas and water metering such as tamper switch and pulse counting

• Safety and security, such as electronic door locks, window/door sensors, and

smokealarms

• Others, such as ﬁtness equipment, electronic shelf labeling, solar trackers, and

equipment for hazardous environments

Visit us at littelfuse.com for assistance with application solutions.

MITI-3V1 MDSR-10 MDSR-7 FLEX-14 MDCG-4 MACD-14 HA15-2 MLRR-4 MLRR-3

This compact reed switch is

somewhat more expensive

than larger parts. It is typically

used only when minimizing

component size is critical.

This switch is also available in

surface-mount* packaging as

the MISM-3V1R (Tape & Reel)

and MISM-3V1B (Bulk Pack).

This cost-effective, small

reed switch is also available in

surface-mount* packaging as

the MDSM-10R (Tape & Reel),

the MDSM-10B (Bulk Pack),

and the 59170 (overmolded*).

This small reed switch is only

slightly larger than the MITI-7

and MDSR-10 switches, but

with the same small glass

diameter as those switches.

The MDSR-7 switch is also

available in an overmolded*

PCB-mount package, including

surface-mount* packaging, as

the 59165 and 59045.

The FLEX-14’s leads are easily

formed or bent to meet an

application’s requirements.

In addition, its slightly shorter

glass length and slightly

longer lead length provide high

ﬂexibility when designing it

into products.

The MDCG-4 is one of

Littelfuse most popular reed

switches and is available in

a wide range of sensitivities.

It is also available in an

overmolded* PCB-mount

package as the 59050, and in

surface-mount* packaging as

the MDSM-4R (Tape & Reel)

and MDSM-4B (Bulk Pack).

The MACD-14 has low

hysteresis between activate

(closure) and deactivate

(opening). This is also known

as close differential. This

feature can be an advantage

in some sensing applications.

One such example is when

the activating magnet travel

distance is limited. It is also

available in surface-mount*

packaging as the MASM-14R

(Tape & Reel) and MASM-14B

(Bulk Pack).

The HA15-2 is physically very

similar to the MDCG-4, but it

uses a pressurized nitrogen

atmosphere that allows

switching 240 Vac power line

mains voltages. The HA15-2

also provides good switching

life on non-suppressed

inductive loads, as well as less

demanding ones. It is available

in a wide variety of Littelfuse

sensor packages.

The MLRR-4 has the smallest

hysteresis between activate

and deactivate (close

differential). This can be an

advantage in some sensing

applications, but it can also

be a disadvantage in sensing

applications where the magnet

is moving slowly. The MLRR-4

is well suited to switching

small incandescent lamps (< 28

V, < 0.2 A). This switch is also

available in surface-mount*

packaging as the MLSM-4R

(Tape & Reel) and MLSM-4B

(Bulk Pack).

This reed switch has the

longest wire leads of any of

the 15.24 mm / 0.600 inch glass

length switches. The MLRR-3

is a cost-effective, small 20

Watt switch. It provides good

switching life on a wide range

of loads. It is also available in

surface-mount* packaging as

the MLSM-3R (Tape & Reel) and

MLSM-3B (Bulk Pack).

*See other side for product image and speciﬁcations.

MARR-5 MRPR-20 MDRR-DT DRR-129 DRR-DTH and DRT-DTH

The MARR-5 has advantages in high voltage and low temperature applications

because its electrical contacts are in a vacuum instead of a nitrogen atmosphere.

The voltage ratings are 1000 Vdc switching and 2000 Vdc breakdown (see data sheet

for additional information). The switch is rated at a rather high 35 AT (Ampere-turn)

in order to meet the 1000 Vdc switching voltage at low currents (< 10 mA). If a higher

switching current or RC arc suppression is used, it’s possible to realize a higher

switching voltage or lower switch AT value. Contact Littelfuse for recommendations.

As the switch AT increases (sensitivity decreases), the contact gap increases,

resulting in increased voltage capability. Typical breakdown voltage is 100 times the

AT value. In addition, the MARR-5 can be used at temperatures near absolute zero

if carefully packaged. For additional information, see Littelfuse Application Note

AN105 – Extreme Temperature Reed Switch Operation.

The MRPR-20 uses a pressurized nitrogen

atmosphere that allows switching up to 265 Vac and

50 VA. This switch maintains a 750 Vdc breakdown

across the sensitivity range of 17 AT to 43 AT. The

MRPR-20 has good switching life capability for a

variety of electrical loads from Vdc logic level to 240

Vac power line mains voltage.

This is a single-pole, double-throw (SPDT) reed

switch, also known as a Form C reed switch.

The addition of a normally closed contact to the

standard normally open contact meets the needs of

a wide variety of applications. It is not unusual for

the normally closed contact to be the only contact

used in an application. However, this capability

results in compromises that affect the switching

voltage and current, as well as cost.

The DRR-129 can offer the highest electrical

contact ratings of any of Littelfuse reed switches

because of its large wire diameter and large contact

gap. However, these characteristics can also

represent disadvantages in terms of size, cost, and

low magnetic sensitivity. For some applications,

however, the DRR-129’s 100 W, 400 V, 3 A switching

capability can be essential.

Like the MDRR-DT, the DRR-DTH and DRT-DTH

are single-pole, double-throw (SPDT) reed

switches. Their large size provides higher electrical

performance but also increases their cost. The

DRR-DTH uses a contact coating similar to many

of Littelfuse reed switches. The DRT-DTH uses

a tungsten contact coating that is very good on

heavy loads; however, it tends to increase contact

resistance when switching light loads such as <

0.25 A, < 6 V.

LITTELFUSE REED SWITCH SELECTION GUIDE

A quick reference guide to selecting reed switches for electronic applications