SMP50-68 Equivalent & Substitute Parts

Part Overview

The SMP50-68 is a 68V off-state transient voltage suppressor (TVS) thyristor manufactured by STMicroelectronics in the TRISIL™ series. This surface-mount component is rated for 150 A peak pulse current (8/20µs) and is housed in a DO-214AC (SMA) package. The device is actively produced and maintains full RoHS3 compliance with unlimited moisture sensitivity rating.

TVS thyristors are essential for protecting sensitive electronic circuits from transient overvoltage events. Equivalent and substitute parts are identified when they maintain functional compatibility across critical electrical parameters while accommodating different packaging or sourcing requirements.

Substiute Parts

SMP50-68

STMicroelectronicsIn Stock: 3857SMP50-68 Datasheet

Current PartRFQ

P0720SALRP

Littelfuse Inc.In Stock: 7687P0720SALRP Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of TVS thyristors is determined by alignment of the following critical parameters:

Primary Substitution Criteria:

• Off-state voltage rating within acceptable tolerance
• Peak pulse current rating (8/20µs) matching or exceeding application requirements
• Hold current (Ih) compatibility
• Single-element configuration
• Surface-mount technology

Secondary Considerations:

• Breakover voltage proximity
• Package form factor (DO-214AC vs. DO-214AA represent different footprints)
• Capacitance characteristics for high-frequency applications

The P0720SALRP from Littelfuse Inc. qualifies as a substitute based on matching peak pulse current (150 A at 8/20µs), identical hold current (150 mA), and comparable off-state voltage (65V vs. 68V). Both devices are single-element, surface-mount TVS thyristors with active product status and RoHS3 compliance.

Parameter Comparison

Engineering Selection Recommendations

SMP50-68 Selection Criteria:

• Applications requiring 68V off-state voltage specification
• Designs utilizing DO-214AC (SMA) footprint
• Systems with 40 pF capacitance tolerance
• STMicroelectronics supply chain preference

P0720SALRP Selection Criteria:

• Applications tolerating 65V off-state voltage (3V lower than SMP50-68)
• Designs utilizing DO-214AA (SMB) footprint
• Systems with 60 pF capacitance tolerance (20 pF higher than SMP50-68)
• Littelfuse Inc. supply chain preference
• Applications where on-state voltage specification (4V) is required

Both devices maintain identical peak pulse current (150 A at 8/20µs) and hold current (150 mA) ratings. Both are RoHS3 compliant with unlimited moisture sensitivity. Product status is active for both manufacturers, ensuring continued availability and support.

Package differences (SMA vs. SMB) require PCB layout verification before substitution. Capacitance variance (40 pF vs. 60 pF) may affect high-frequency circuit behavior and requires circuit simulation validation in sensitive applications.

Frequently Asked Questions (FAQ)

Q: Can the P0720SALRP directly replace the SMP50-68 in my circuit?

A: Direct replacement depends on two factors: (1) PCB footprint compatibility—SMA (DO-214AC) and SMB (DO-214AA) packages have different dimensions and land patterns; (2) voltage tolerance—the P0720SALRP operates at 65V off-state versus 68V, a 3V difference that may affect circuit protection thresholds. Verify both conditions before substitution.

Q: What is the significance of the 20 pF capacitance difference?

A: The SMP50-68 has 40 pF capacitance while the P0720SALRP has 60 pF. In high-frequency circuits or sensitive signal paths, this difference may introduce additional parasitic effects. Low-frequency protection applications typically tolerate this variance without performance degradation.

Q: Are both parts RoHS3 compliant?

A: Yes. Both the SMP50-68 and P0720SALRP are RoHS3 compliant with unlimited moisture sensitivity (MSL 1), meeting current environmental and reliability standards.

Q: What does "peak pulse current (8/20µs)" mean?

A: This rating specifies the maximum current the TVS thyristor can safely conduct during an 8-microsecond rise time and 20-microsecond decay transient pulse. Both parts are rated for 150 A under this standard test condition, indicating equivalent surge protection capability.

Q: Why is hold current (Ih) important for substitution?

A: Hold current determines the minimum current required to maintain the thyristor in its conducting state after triggering. Both parts specify 150 mA, ensuring consistent latching behavior and circuit protection response in equivalent applications.

Q: Can I use the P0720SALRP if my circuit requires exactly 68V off-state voltage?

A: The P0720SALRP operates at 65V off-state, which is 3V lower. If your circuit design requires the 68V specification for protection margin or regulatory compliance, the SMP50-68 is the appropriate selection. If your application tolerates 65V operation, substitution is permissible.

Q: What inventory considerations apply to these parts?

A: The SMP50-68 has 3,800 pieces in stock (Cut Tape and Digi-Reel® packaging). The P0720SALRP has 7,658 pieces in stock (Tape & Reel packaging). Packaging format differences may affect procurement lead times and handling requirements.