3KP High-Power TVS Families: Reading Peak Pulse Power Codes

“3KP” is not a promise that a small axial component can dissipate three kilowatts continuously. In the referenced families it identifies a peak-pulse class tied to a defined waveform. Omitting that condition turns a useful family code into a misleading power claim.

For a buyer or engineer investigating 3KP43, separate the family, voltage row, suffix, manufacturer, and package. The useful comparison includes the installation and pulse conditions behind the code, rather than treating the marking as a complete specification.

What does 3KP43 tell you?

In the referenced Good-Ark family, 3KP43 identifies a TVS row with 43 V standoff, while 3KP denotes a 3000 W peak-pulse class under the specified 10/1000 µs waveform. Read the full suffix and manufacturer document for polarity, breakdown, clamping, and current. The code does not specify continuous kilowatt dissipation or universal interchangeability.

Use the complete orderable identity when comparing stock or substitutes. A search for 3kp43 can return plain, A, C, and CA variants from different suppliers. They should not be merged into one invented set of limits.

Separate the voltage code from the pulse-power class

The Good-Ark 3KP5.0–3KP220CA Rev. B datasheet identifies an R-6/P600 axial package and a 3000 W peak entry with a 10/1000 µs waveform. It separately lists steady dissipation under a specified lead-temperature and heatsink condition.

That separation matters. A pulse can briefly impose high instantaneous power while average heat remains manageable under the stated conditions. A continuous fault has a different thermal requirement. Do not use the peak-power class to justify indefinite conduction across an abnormal supply.

The family number also does not identify the receiving circuit’s peak voltage. Standoff, breakdown at a small current, and clamping at a pulse current are separate entries. The voltage in the part name should be read through the source table, not interpreted as an ideal fixed clamp.

Compare the 43 V variants without dropping suffixes

Selected Good-Ark Rev. B entries at the stated source conditions

Parameter	3KP43 / 3KP43C	3KP43A / 3KP43CA
Standoff voltage	43 V	43 V
Breakdown range at 1 mA	47.8–60.5 V	47.8–54.9 V
Maximum clamping entry	76.7 V at 39.2 A	69.4 V at 43.2 A
Maximum leakage at standoff	2 µA	2 µA

The first device in each column is listed as unidirectional; the C or CA counterpart is listed as bidirectional. Keep the manufacturer’s waveform and temperature conditions with these entries. The table is a source-specific comparison, not a general decoding rule for all TVS suppliers.

For example, the Littelfuse 3KP datasheet has its own values and notes. Do not silently combine its breakdown range with Good-Ark’s current or mounting entry. Similar part numbers do not make a mixed-source specification valid.

Build a comparison from the actual pulse

Identify the event source, waveform, available current, temperature, and repetition. Estimate the voltage at the protected node using the appropriate limiting data and connection impedance. A candidate must survive its assigned stress and keep the receiving circuit within supported transient limits.

The peak product of voltage and current is not the total absorbed energy. As a separate hypothetical example, a constant 1000 W for 0.5 ms would be 0.5 J. A real 10/1000 µs pulse is not rectangular, so its energy requires the actual waveform or an appropriate model.

TI’s surge-diode selection report explains source and clamping considerations. If the application waveform differs from the datasheet test, use applicable manufacturer pulse-duration and derating guidance. Do not infer a new rating by multiplying the family code by an arbitrary time.

Also review sustained follow-on energy and restart behavior. A protection part can receive repeated stress if a controller keeps retrying into the same fault. A rare initiating event does not guarantee a single pulse at the TVS.

For a hypothetical receiving circuit limited to 60 V under the relevant transient, a datasheet clamp above that level at the expected current would require further design work. The fact that standoff is only 43 V would not resolve the mismatch. Use the actual current and receiving-circuit conditions; the example is not a verdict on every application of either variant.

Review hot operation separately. Initial temperature changes the available pulse margin, and the board may already be warm from normal load before the event. Preserve the specified derating method and relevant heat path. A cool bench demonstration can be useful evidence while still leaving the worst operating corner unverified.

Why a 1.5KE comparison needs more than a two-to-one ratio

The Vishay 1.5KE source specifies a 1500 W peak class with its waveform and notes. That gives a useful family-level comparison with a 3KP class only when the relevant test conditions are retained.

It does not establish that every 3KP candidate provides twice the usable protection of every 1.5KE candidate. Compare standoff, actual clamp at current, polarity, temperature derating, pulse duration, repetition, package, lead geometry, and thermal conditions separately.

A larger axial body may require different board spacing, support, and lead forming. Lead length and the current-return loop can affect both heat removal and transient voltage. Mechanical adaptation is part of the design change, not a detail outside the electrical comparison.

Check the installed device and the limits of a bench result

Verify marking, orientation, lead dimensions, and the specified drawing before powering the assembly. Compare leakage and low-current breakdown only with suitable controlled equipment and the exact test conditions. A correct static reading does not establish peak-pulse endurance.

For operational evidence, record the waveform at the receiving circuit, relevant current, operating mode, temperature, and pulse sequence. Include the placement and return path. A diode that survives on its own can still allow excessive voltage at a remote load.

Keep post-event criteria clear: circuit function, leakage, breakdown behavior, and visible or mechanical damage may all matter under the product’s requirements. Do not claim an entire protection system is qualified from one unrecorded bench pulse.

Keep the purchasing record tied to the circuit function

Use the TVS protection overview to identify the shunt role and TVS versus Zener when a breakdown reference is being confused with a surge suppressor. The discrete power-device overview provides broader context without changing the source-specific limits.

The TO-247 fast recovery rectifier guide concerns another device and package class. A current or power headline from that rectifier cannot qualify a 3KP replacement.

Check incoming labels and body markings against that approved record. If a distributor lists an abbreviated family name, obtain the complete identity before treating its stock as equivalent. Preserve traceability to the actual source document rather than attaching one manufacturer’s table to an unknown supplier’s similarly named part.

Retain the full manufacturer part number, suffix, package, source revision, voltage window, pulse conditions, derating, and installation requirements with the decision. Resolve missing evidence before approval. The useful conclusion explains why that exact variant fits the actual protection event, rather than merely recognizing the 3KP prefix.

FAQ

Does 3KP mean 3000 W continuous power?

No. In the referenced 3KP documents, it denotes a peak-pulse capability tied to a specified waveform and associated conditions. Continuous dissipation is a separate entry with its own thermal requirements. Read the pulse-duration, temperature, repetition, and mounting notes. A family code cannot justify indefinite conduction across an abnormal supply or replace the energy and interruption analysis for the surrounding protection system.

Are 3KP43 and 3KP43A interchangeable?

Do not assume so. The referenced Good-Ark table gives different breakdown and clamping entries for those variants even though they share 43 V standoff. C and CA counterparts also identify bidirectional versions in that source. Compare the complete manufacturer part number, polarity, voltage window, pulse current, temperature conditions, and package before approving a substitution. Similar markings are insufficient evidence of identical protection behavior.

Can I replace a 1.5KE with a 3KP just by matching voltage?

Only after a complete comparison. Retain the actual manufacturer’s standoff, breakdown, clamp at current, waveform, temperature derating, repetition, polarity, dimensions, and mounting conditions. A higher peak-power class may be useful but does not establish electrical or mechanical equivalence. Check the installed protection path and the voltage at the receiving circuit. Do not treat the family power ratio as a complete substitution rule.