PRMA1A05B Reed Relay SPST 500mA 5V Equivalent & Substitute Parts

Part Overview

The PRMA1A05B is a Reed SPST (Single-Pole Single-Throw) relay manufactured by Coto Technology, designed for 500 mA switching operations at 5V coil voltage. This component is classified as Obsolete, making substitute parts necessary for new designs and ongoing production requirements. The relay features a non-latching coil with integrated diode protection and PC pin termination suitable for through-hole mounting applications.

Substiute Parts

PRMA1A05B

Coto TechnologyIn Stock: 1276PRMA1A05B Datasheet

Current PartRFQ

HE721A0510

Littelfuse Inc.In Stock: 1491HE721A0510 Datasheet

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DIP05-1A72-12D

Standex-Meder ElectronicsIn Stock: 2751DIP05-1A72-12D Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the PRMA1A05B are evaluated based on the following critical electrical and mechanical parameters:

Essential Matching Parameters:

• Coil Voltage: 5VDC
• Contact Form: SPST-NO (1 Form A)
• Coil Current: 10 mA
• Coil Type: Non Latching
• Features: Diode
• Termination Style: PC Pin
• Mounting Type: Through Hole

Compatible Parameter Ranges:

• Contact Rating (Current): 500 mA minimum
• Switching Voltage: 200V minimum (AC and/or DC)
• Must Operate Voltage: ≤ 3.75 VDC
• Must Release Voltage: ≤ 0.8 VDC
• Operate Time: ≤ 0.5 ms
• Release Time: ≤ 0.5 ms
• Operating Temperature: Must encompass -40°C to 80°C minimum
• Coil Resistance: 500 Ohms

The HE721A0510 (Littelfuse Inc., HE700 Series) qualifies as a direct substitute, meeting all essential parameters with comparable electrical characteristics and active product status. The DIP05-1A72-12D (Standex-Meder Electronics, DIP Series) functions as a similar substitute with higher current rating (1 A) and broader voltage switching capability, suitable where current margin is advantageous.

Parameter Comparison

Engineering Selection Recommendations

HE721A0510 (Littelfuse Inc., HE700 Series): The HE721A0510 functions as the primary direct substitute for the PRMA1A05B. Both components share identical coil voltage, contact form, coil current, and coil resistance specifications. The HE721A0510 carries Active product status and ROHS3 compliance, providing assured long-term availability. The operate and release times are marginally longer (1 ms versus 0.5 ms), which is acceptable in non-critical timing applications. The reduced must-release voltage (0.5 VDC) and extended operating temperature range (-40°C ~ 85°C) offer performance advantages. This substitute is recommended for new designs and production continuity planning.

DIP05-1A72-12D (Standex-Meder Electronics, DIP Series): The DIP05-1A72-12D qualifies as a compatible substitute with enhanced current capacity (1 A rating versus 500 mA). This component maintains all essential coil and termination parameters while offering higher switching margin for applications with potential current growth. The DIP05-1A72-12D supports both AC and DC switching voltages, matching the original specification more closely than the HE721A0510. However, its operating temperature range (-20°C ~ 70°C) is narrower than the PRMA1A05B, requiring evaluation for low-temperature applications below -20°C. This substitute is suitable for new designs where higher current capability is beneficial or current margin is desired.

Both substitute parts maintain compliance with RoHS, REACH, EAR99, and HTSUS classifications, ensuring regulatory alignment with the original component.

Frequently Asked Questions (FAQ)

Q: Can the HE721A0510 replace the PRMA1A05B in existing designs? A: The HE721A0510 is electrically compatible with the PRMA1A05B for applications where the increased operate and release times (1 ms versus 0.5 ms) do not impact system performance. Pin configuration and through-hole mounting are identical, allowing direct substitution in PCB layouts.

Q: What is the primary difference between HE721A0510 and DIP05-1A72-12D substitutes? A: The HE721A0510 matches the PRMA1A05B's 500 mA current rating with identical timing specifications. The DIP05-1A72-12D provides higher 1 A current capacity and faster release time (0.1 ms), but operates over a narrower temperature range (-20°C ~ 70°C). Selection depends on current requirements and operating temperature needs.

Q: Are there packaging considerations when switching between these relays? A: All three components utilize PC pin termination with through-hole mounting. The PRMA1A05B and HE721A0510 are supplied in equivalent packaging formats. The DIP05-1A72-12D is supplied in tube packaging. Physical dimensions should be confirmed against PCB design specifications, though all maintain standard DIP relay footprints.

Q: Which substitute is recommended for new production designs? A: The HE721A0510 is recommended as the primary choice for new designs, as it offers active product status, extended temperature range, and direct electrical parameter matching. The DIP05-1A72-12D is an alternative for applications requiring higher current capacity.

Q: How do the operating temperature ranges compare? A: The PRMA1A05B operates from -40°C to 80°C. The HE721A0510 extends this range to 85°C, providing superior high-temperature performance. The DIP05-1A72-12D operates from -20°C to 70°C, which is narrower and suitable only for applications not requiring operation below -20°C or above 70°C.

Q: Are all three relays RoHS and REACH compliant? A: The PRMA1A05B is RoHS Compliant and REACH Unaffected. Both HE721A0510 and DIP05-1A72-12D are ROHS3 Compliant and REACH Unaffected, meeting current regulatory requirements.