{"id":17528,"date":"2026-09-09T13:40:39","date_gmt":"2026-09-09T05:40:39","guid":{"rendered":"https:\/\/www.wehopower.com\/?post_type=news&#038;p=17528"},"modified":"2026-09-09T14:13:07","modified_gmt":"2026-09-09T06:13:07","slug":"k78xx-500r3-vs-1000r3-vs-2000r3-bom-selection","status":"publish","type":"news","link":"https:\/\/www.wehopower.com\/tl\/news\/k78xx-500r3-vs-1000r3-vs-2000r3-bom-selection\/","title":{"rendered":"K78xx-500R3 vs 1000R3 vs 2000R3: What to Check Before BOM Release"},"content":{"rendered":"\n<style class=\"weho-daily-article-style\" data-weho-style=\"weho-readability-v1\">.weho-daily-article{--ink:#15252f;--muted:#546872;--paper:#fffdf8;--line:#d8dedc;--green:#0f5d50;--green2:#e5f3ef;--amber:#d88719;--amber2:#fff1d7;--red:#a73c32;--red2:#fff1ed;--shadow:0 22px 65px rgba(20,43,48,.12)}.weho-daily-article, .weho-daily-article 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.books>p:empty,div.weho-daily-article[data-weho-package=\"weho-20260909-a01\"] .decision>p:empty{display:none!important}@media(max-width:700px){div.weho-daily-article[data-weho-package=\"weho-20260909-a01\"] .content{padding:22px 16px!important}div.weho-daily-article[data-weho-package=\"weho-20260909-a01\"] h2{font-size:25px!important}div.weho-daily-article[data-weho-package=\"weho-20260909-a01\"] .dek{font-size:20px!important}}div.weho-daily-article[data-weho-package=\"weho-20260909-a01\"] header.hero{position:relative!important;padding:30px!important;background:#f4f7f2!important;color:#192d35!important;border:1px solid #cbd8ca!important;border-top:5px solid #50704c!important;border-radius:12px!important;box-shadow:none!important}div.weho-daily-article[data-weho-package=\"weho-20260909-a01\"] .hero:after{display:none!important}div.weho-daily-article[data-weho-package=\"weho-20260909-a01\"] .hero .gates{display:flex!important;flex-wrap:wrap!important;gap:12px!important;margin-top:24px!important}div.weho-daily-article[data-weho-package=\"weho-20260909-a01\"] .gates>div{flex:1 1 190px!important;padding:16px!important;background:#fff!important;border:1px solid #c5d3c4!important;color:#24352a!important;font-size:17px!important;line-height:1.6!important}div.weho-daily-article[data-weho-package=\"weho-20260909-a01\"] .gates b{color:#4a5b20!important;font-size:15px!important;line-height:1.7!important}div.weho-daily-article[data-weho-package=\"weho-20260909-a01\"] .scope span{font-size:14px!important;color:#5f421d!important;background:#f7ecd6!important}@media(max-width:700px){div.weho-daily-article[data-weho-package=\"weho-20260909-a01\"] header.hero{padding:24px 18px!important}} <\/style>\n<div class=\"weho-daily-article\" data-weho-package=\"weho-20260909-a01\" data-weho-version=\"1.0.0\" data-design=\"graphite-amber-bom-gate\">\n<div class=\"weho-current-layout\">\n<div class=\"page\"><header class=\"hero\"><div class=\"eyebrow\">WEHO commercial selection \u00b7 exact-variant evidence gate<\/div><p class=\"dek\">Screen the published row. Close the load, thermal, fit and integration evidence. Release only the exact documented variant.<\/p><div class=\"gates\" aria-label=\"BOM release gates\"><div><b>01 \u00b7 Voltage<\/b>Exact row and source envelope<\/div><div><b>02 \u00b7 Load<\/b>States, duration and derating<\/div><div><b>03 \u00b7 Fit<\/b>Pin map and dimensions<\/div><div><b>04 \u00b7 Evidence<\/b>Integration and validation<\/div><\/div><div class=\"scope\"><span>Cluster: K78XX-FAMILY-PRE-BOM-EVIDENCE<\/span><span>Primary comparison: K78xx-1000R3<\/span><\/div><\/header><main><article class=\"content\"><div class=\"lead\"><p><strong>Direct answer.<\/strong> Do not choose among K78xx-500R3, K78xx-1000R3 and K78xx-2000R3 from the family suffix or a three-pin appearance alone. First lock the exact output-voltage row and confirm that its published input range covers the real source. Then compare the equipment&#8217;s continuous, startup and other credible load states with controlled current and derating data for the exact ordered variant. Keep the BOM on <strong>HOLD<\/strong> until the supplier resolves the K78xx-1000R3 page&#8217;s 500 mA-versus-1000 mA conflict and supplies the pinout, dimensions, thermal limits and integration data that the three current pages do not provide.<\/p><\/div><figure><img fetchpriority=\"high\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/weho-k78xx-500r3-vs-1000r3-vs-2000r3-bom-selection-hero-69830e160e27.webp?quality=85&#038;strip=all\" alt=\"K78xx-500R3 vs 1000R3 vs 2000R3: What to Check Before BOM Release  title=\" width=\"1440\" height=\"810\" loading=\"eager\" fetchpriority=\"high\" decoding=\"async\" K78xx-500R3 vs 1000R3 2000R3: What to Check Before BOM Release title=\"\"><figcaption>AI-generated conceptual sourcing workbench. The anonymous components are not WEHO K78xx products, the PCB is not a customer design, and the scene is not a dimensional inspection, fit approval or test record.<\/figcaption><\/figure>\n<h2 id=\"the-suffixes-create-a-shortlist-not-a-released-bom\"><span class=\"ez-toc-section\" id=\"The_suffixes_create_a_shortlist_not_a_released_BOM\"><\/span>The suffixes create a shortlist, not a released BOM<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A purchasing engineer can reasonably start with three published WEHO product identities. The <a href=\"https:\/\/www.wehopower.com\/product\/k78xx-500r3-dc-to-dc-power-module\/\">K78xx-500R3 page<\/a>, <a href=\"https:\/\/www.wehopower.com\/product\/k78xx-1000r3-dc-dc-power-module\/\">K78xx-1000R3 page<\/a> and <a href=\"https:\/\/www.wehopower.com\/product\/k78xx-2000r3-dc-dc-power-module\/\">K78xx-2000R3 page<\/a> each describe a non-isolated, stabilized, single-output module in SIP3 packaging. Each table lists output-voltage rows of 3.3, 5, 9, 12 and 15.<\/p>\n<p>That common structure is useful for discovery. It does not establish that the three families share the same pin functions, pitch, body outline, height, electrical behavior or allowable operating current under the buyer&#8217;s conditions. A higher number in a family name also does not approve a higher-current part as a direct substitute on an existing PCB.<\/p>\n<p>Use four gates before asking purchasing to release an exact part number:<\/p>\n<ol>\n<li><strong>Electrical target:<\/strong> exact output-voltage row and the full source-voltage envelope.<\/li>\n<li><strong>Load and temperature:<\/strong> every credible current state, duration, ambient and cooling condition.<\/li>\n<li><strong>Physical interface:<\/strong> controlled pin map, orientation, dimensions and straight- or curved-pin option.<\/li>\n<li><strong>Integration evidence:<\/strong> external components, output quality, protection, EMC and sample validation.<\/li>\n<\/ol>\n<p>If the project is still deciding whether a shared input\/output reference is acceptable, resolve that architecture question first. WEHO&#8217;s <a href=\"https:\/\/www.wehopower.com\/news\/what-is-a-non-isolated-power-module-and-why-use-it\/\">non-isolated power-module overview<\/a> explains the category. This checklist begins after non-isolated conversion has become a legitimate candidate.<\/p>\n<h2 id=\"what-do-the-current-weho-pages-actually-establish\"><span class=\"ez-toc-section\" id=\"What_do_the_current_WEHO_pages_actually_establish\"><\/span>What do the current WEHO pages actually establish?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The safest comparison preserves the wording of each page rather than silently harmonizing it.<\/p>\n<table>\n<thead>\n<tr>\n<th>Published page<\/th>\n<th>Table model pattern<\/th>\n<th style=\"text-align: right;\">Feature-level output-current text<\/th>\n<th style=\"text-align: right;\">Table output-current cell<\/th>\n<th>Published compatibility wording<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>K78xx-500R3<\/td>\n<td>K7803\/05\/09\/12\/15-500R3<\/td>\n<td style=\"text-align: right;\">500 mA<\/td>\n<td style=\"text-align: right;\">500 mA<\/td>\n<td>\u201ccompatible with the K78xx series\u201d<\/td>\n<\/tr>\n<tr>\n<td>K78xx-1000R3<\/td>\n<td>K7803\/05\/09\/12\/15-1000R3<\/td>\n<td style=\"text-align: right;\"><strong>500 mA<\/strong><\/td>\n<td style=\"text-align: right;\"><strong>1000 mA<\/strong><\/td>\n<td>\u201ccompatible with the K78xx series\u201d<\/td>\n<\/tr>\n<tr>\n<td>K78xx-2000R3<\/td>\n<td>K7803\/05\/09\/12\/15-2000R3**(L)**<\/td>\n<td style=\"text-align: right;\">2000 mA<\/td>\n<td style=\"text-align: right;\">2000 mA<\/td>\n<td>\u201ccompatible with the LM78xx series\u201d<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>These are published-page statements, not independent measurements. Two details prevent a clean current-tier conclusion.<\/p>\n<p>First, the K78xx-1000R3 feature list says \u201coutput 500mA,\u201d while its table has one merged 1000 entry under \u201cOutput Current (mA) (Max.\/Min.).\u201d The page does not explain which statement controls. The conflict may be a content error, but that is an inference\u2014not authority to correct it in a BOM.<\/p>\n<p>Second, every part number in the K78xx-2000R3 table carries an <strong>(L)<\/strong> suffix that is absent from the page title. The page does not define that suffix. Ask WEHO to identify the exact orderable code and the meaning of the pin option before copying a model into purchasing data.<\/p>\n<p>The pages also say that straight or curved pins can be packaged, but they do not provide an ordering-code map, pin drawing or dimensions in the supplied page bodies. \u201cSIP3\u201d and \u201cthree pins\u201d are package descriptions, not a mutual-compatibility certificate.<\/p>\n<h2 id=\"gate-1-match-the-exact-voltage-row-to-the-source-envelope\"><span class=\"ez-toc-section\" id=\"Gate_1_match_the_exact_voltage_row_to_the_source_envelope\"><\/span>Gate 1: match the exact voltage row to the source envelope<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>All three tables use 24 as the standard input value. Their ranges are not identical across every family. The table bodies do not print a voltage unit beside the numeric cells, so the page notation is reproduced below without adding an unstated convention.<\/p>\n<table>\n<thead>\n<tr>\n<th style=\"text-align: right;\">Output-voltage row<\/th>\n<th style=\"text-align: right;\">K78xx-500R3 input entry<\/th>\n<th style=\"text-align: right;\">K78xx-1000R3 input entry<\/th>\n<th style=\"text-align: right;\">K78xx-2000R3(L) input entry<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: right;\">3.3<\/td>\n<td style=\"text-align: right;\">24 (4.75\u201336)<\/td>\n<td style=\"text-align: right;\">24 (4.75\u201336)<\/td>\n<td style=\"text-align: right;\">24 (6\u201336)<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: right;\">5<\/td>\n<td style=\"text-align: right;\">24 (6.5\u201336)<\/td>\n<td style=\"text-align: right;\">24 (6.5\u201336)<\/td>\n<td style=\"text-align: right;\">24 (8\u201336)<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: right;\">9<\/td>\n<td style=\"text-align: right;\">24 (12\u201336)<\/td>\n<td style=\"text-align: right;\">24 (12\u201336)<\/td>\n<td style=\"text-align: right;\">24 (13\u201336)<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: right;\">12<\/td>\n<td style=\"text-align: right;\">24 (15\u201336)<\/td>\n<td style=\"text-align: right;\">24 (15\u201336)<\/td>\n<td style=\"text-align: right;\">24 (16\u201336)<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: right;\">15<\/td>\n<td style=\"text-align: right;\">24 (19\u201336)<\/td>\n<td style=\"text-align: right;\">24 (19\u201336)<\/td>\n<td style=\"text-align: right;\">24 (18\u201336)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Select from the range belonging to the <strong>exact output row<\/strong>, not from the most permissive number elsewhere in the family. Record the source at normal operation, low-line operation, high-line operation, startup, shutdown and any credible disturbance that the module is expected to survive or operate through. The published ranges alone do not define transient immunity or absolute-maximum behavior.<\/p>\n<p>If the source envelope crosses a published boundary, do not average it into compliance. Either resolve the source condition, obtain controlled evidence that covers it, or remove that variant from the shortlist.<\/p>\n<h2 id=\"gate-2-turn-the-load-into-a-reviewable-current-envelope\"><span class=\"ez-toc-section\" id=\"Gate_2_turn_the_load_into_a_reviewable_current_envelope\"><\/span>Gate 2: turn the load into a reviewable current envelope<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u201cThe board uses about 400 mA\u201d is not enough information to choose a current tier. Build the requirement from equipment states and keep each number tied to a drawing, component specification or controlled measurement.<\/p>\n<table>\n<thead>\n<tr>\n<th>Equipment state<\/th>\n<th>Current evidence to capture<\/th>\n<th>Duration or duty<\/th>\n<th>Conditions to record<\/th>\n<th>Decision use<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Power applied \/ reset<\/td>\n<td>Input-current or rail-current evidence<\/td>\n<td>Until startup completes<\/td>\n<td>Source level, temperature, load sequence<\/td>\n<td>Confirm startup coverage<\/td>\n<\/tr>\n<tr>\n<td>Normal minimum<\/td>\n<td>Lowest credible steady load<\/td>\n<td>Continuous or stated duty<\/td>\n<td>Enabled circuits and operating mode<\/td>\n<td>Check light-load behavior<\/td>\n<\/tr>\n<tr>\n<td>Normal maximum<\/td>\n<td>Highest simultaneous steady load<\/td>\n<td>Continuous or stated duty<\/td>\n<td>Board revision and active functions<\/td>\n<td>Establish continuous requirement<\/td>\n<\/tr>\n<tr>\n<td>Short operating event<\/td>\n<td>Largest credible non-fault demand<\/td>\n<td>Measured or specified duration<\/td>\n<td>Repetition rate and source condition<\/td>\n<td>Ask whether documented transient capability covers it<\/td>\n<\/tr>\n<tr>\n<td>Shutdown \/ standby<\/td>\n<td>Residual or standby load<\/td>\n<td>Stated state duration<\/td>\n<td>Backfeed paths and enabled circuits<\/td>\n<td>Confirm allowed operating state<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Add a project-owned design allowance only after its purpose is documented. Do not use an arbitrary percentage to hide unknown startup current, temperature derating or a future load that has not been specified.<\/p>\n<p>Then ask the supplier to map this envelope to the exact part number. The current pages do not state whether the single table value is a continuous maximum, how it changes with input voltage or temperature, or how the \u201cMax.\/Min.\u201d column label should be interpreted when only one number is shown. Until those definitions are supplied, the table value is a screening entry\u2014not a release limit.<\/p>\n<h2 id=\"gate-3-prove-form-and-fit-from-an-exact-drawing\"><span class=\"ez-toc-section\" id=\"Gate_3_prove_form_and_fit_from_an_exact_drawing\"><\/span>Gate 3: prove form and fit from an exact drawing<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The compatibility wording differs between the pages: the 500R3 and 1000R3 pages refer to the K78xx series, while the 2000R3 page refers to the LM78xx series. None of the three supplied page bodies publishes the information needed to establish mutual interchangeability.<\/p>\n<p>Request a controlled drawing for the exact candidate and compare:<\/p>\n<ul>\n<li>pin number, function, order and viewing orientation;<\/li>\n<li>pin pitch, diameter or section, and insertion requirements;<\/li>\n<li>body width, depth and height;<\/li>\n<li>straight- versus curved-pin configuration and its order code;<\/li>\n<li>keep-out area, nearby-component clearance and assembly access;<\/li>\n<li>board hole, pad, soldering and inspection requirements, where applicable.<\/li>\n<\/ul>\n<p>For an existing assembly, compare the drawing with both the released PCB data and a controlled observation of the actual board revision. For a new design, put the supplier drawing revision in the component-library record. A generic three-pin symbol or an AI-generated component image must never become footprint evidence.<\/p>\n<h2 id=\"gate-4-close-the-electrical-and-thermal-integration-gaps\"><span class=\"ez-toc-section\" id=\"Gate_4_close_the_electrical_and_thermal_integration_gaps\"><\/span>Gate 4: close the electrical and thermal integration gaps<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Each page claims an operating-temperature range of -40 \u00b0C to +85 \u00b0C, efficiency \u201cup to 96%,\u201d no-load current \u201cas low as 0.2MA,\u201d and no need for an external heat sink. Those phrases lack the conditions needed for a design-release decision.<\/p>\n<p>Do not normalize <code>0.2MA<\/code> to <code>0.2 mA<\/code> without confirmation. Do not interpret \u201cno external heat sink\u201d as full-load approval at +85 \u00b0C. Request the applicable derating information, measurement conditions and mounting assumptions for the exact variant.<\/p>\n<p>The efficiency columns also require clarification. Their header says \u201cMin.\/Typ.,\u201d but every printed pair places the larger number first. The 500R3 feature list says \u201cup to 96%,\u201d while none of its five table pairs contains 96. Preserve the source entries; do not reverse the pairs or build a loss calculation from them until their meaning and test conditions are confirmed.<\/p>\n<p>The maximum capacitive-load rows provide another reason not to treat the families as identical:<\/p>\n<table>\n<thead>\n<tr>\n<th style=\"text-align: right;\">Output-voltage row<\/th>\n<th style=\"text-align: right;\">500R3 published maximum (\u00b5F)<\/th>\n<th style=\"text-align: right;\">1000R3 published maximum (\u00b5F)<\/th>\n<th style=\"text-align: right;\">2000R3(L) published maximum (\u00b5F)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align: right;\">3.3<\/td>\n<td style=\"text-align: right;\">680<\/td>\n<td style=\"text-align: right;\">680<\/td>\n<td style=\"text-align: right;\">680<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: right;\">5<\/td>\n<td style=\"text-align: right;\">680<\/td>\n<td style=\"text-align: right;\">680<\/td>\n<td style=\"text-align: right;\">680<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: right;\">9<\/td>\n<td style=\"text-align: right;\">680<\/td>\n<td style=\"text-align: right;\">680<\/td>\n<td style=\"text-align: right;\">680<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: right;\">12<\/td>\n<td style=\"text-align: right;\">680<\/td>\n<td style=\"text-align: right;\">680<\/td>\n<td style=\"text-align: right;\">470<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align: right;\">15<\/td>\n<td style=\"text-align: right;\">680<\/td>\n<td style=\"text-align: right;\">330<\/td>\n<td style=\"text-align: right;\">330<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>A maximum capacitive-load value does not identify a required minimum capacitor, permitted ESR, placement rule or startup behavior. Ask for the complete external-component network and its conditions. Also obtain the project&#8217;s required output tolerance, line\/load regulation, ripple\/noise measurement method, transient response, switching-frequency information, protection behavior and EMC evidence. None of those fields should be borrowed from another K78xx product name.<\/p>\n<figure><img loading=\"lazy\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/09\/weho-k78xx-500r3-vs-1000r3-vs-2000r3-bom-selection-product-08f7926baaea.png?quality=85&#038;strip=all\" alt=\"K78xx-500R3 vs 1000R3 vs 2000R3: What to Check Before BOM Release  title=\" width=\"1080\" height=\"1460\" loading=\"lazy\" decoding=\"async\" K78xx-500R3 vs 1000R3 2000R3: What to Check Before BOM Release title=\"\"><figcaption>Author-built decision aid based on the cited page fields and their disclosed gaps. It is not a pinout, circuit, dimensional drawing, derating curve, test result or statement that the three families are interchangeable.<\/figcaption><\/figure>\n<h2 id=\"use-one-bom-gate-for-every-candidate\"><span class=\"ez-toc-section\" id=\"Use_one_BOM_gate_for_every_candidate\"><\/span>Use one BOM gate for every candidate<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Keep one row per exact orderable variant. A blank or conflicting item remains open; it is not converted into an implied pass.<\/p>\n<table>\n<thead>\n<tr>\n<th>Release field<\/th>\n<th>Evidence to attach<\/th>\n<th>Pass condition<\/th>\n<th>HOLD trigger<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Exact identity<\/td>\n<td>Quotation and controlled model designation<\/td>\n<td>Page, datasheet, drawing and quote identify the same part<\/td>\n<td>Undefined suffix, pin option or revision<\/td>\n<\/tr>\n<tr>\n<td>Output target<\/td>\n<td>Equipment rail requirement and model table<\/td>\n<td>Exact output row matches the required rail<\/td>\n<td>Nominal label used without tolerance evidence<\/td>\n<\/tr>\n<tr>\n<td>Input envelope<\/td>\n<td>Source limits and operating-state record<\/td>\n<td>Controlled model range covers every required operating condition<\/td>\n<td>One credible condition falls outside or is undefined<\/td>\n<\/tr>\n<tr>\n<td>Load envelope<\/td>\n<td>State-by-state current ledger<\/td>\n<td>Documented current capability covers all required states under stated conditions<\/td>\n<td>Rating definition, transient coverage or allowance is unknown<\/td>\n<\/tr>\n<tr>\n<td>Thermal use<\/td>\n<td>Ambient, enclosure, airflow, orientation and derating evidence<\/td>\n<td>Allowed load covers the installation<\/td>\n<td>\u201cNo heat sink\u201d phrase is the only evidence<\/td>\n<\/tr>\n<tr>\n<td>Form and fit<\/td>\n<td>Pinout and dimensional drawing<\/td>\n<td>Released PCB and mechanical envelope match the exact option<\/td>\n<td>Compatibility inferred from family name or pin count<\/td>\n<\/tr>\n<tr>\n<td>External network<\/td>\n<td>Controlled application requirements<\/td>\n<td>Capacitors and any required network are supported<\/td>\n<td>Only maximum capacitance is known<\/td>\n<\/tr>\n<tr>\n<td>Output quality<\/td>\n<td>Tolerance, regulation, ripple and transient requirements<\/td>\n<td>Model evidence and sample plan cover the load<\/td>\n<td>Generic \u201cstabilized\u201d wording substitutes for limits<\/td>\n<\/tr>\n<tr>\n<td>Protection and EMC<\/td>\n<td>Project requirements and model evidence<\/td>\n<td>Responsibilities and acceptance tests are assigned<\/td>\n<td>Capability is assumed from another family<\/td>\n<\/tr>\n<tr>\n<td>Supply continuity<\/td>\n<td>Current status, change-control terms and approved alternates<\/td>\n<td>Purchasing data reflects current written information<\/td>\n<td>Price, lead time, MOQ or lifecycle status is inferred<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>This gate separates product discovery from qualification. It also prevents a supplier clarification from remaining in an email while the PCB library, BOM and drawing continue to carry an older assumption.<\/p>\n<h2 id=\"how-should-each-family-be-treated-today\"><span class=\"ez-toc-section\" id=\"How_should_each_family_be_treated_today\"><\/span>How should each family be treated today?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>K78xx-500R3 can remain a shortlist candidate<\/strong> when its exact voltage row covers the source and the buyer&#8217;s load may fit within the controlled current and thermal capability supplied for the precise model. Its feature text and table both show 500 mA, but that agreement does not supply derating, pinout or output-quality evidence.<\/p>\n<p><strong>K78xx-1000R3 requires a written current clarification before selection.<\/strong> The page identity and five model rows are usable for directing an inquiry. The conflicting 500 mA feature text and 1000 mA table entry prevent a responsible release limit from being taken from the page alone.<\/p>\n<p><strong>K78xx-2000R3 can remain a shortlist candidate only under the table&#8217;s exact (L) identity pending confirmation.<\/strong> Its input ranges differ from the other two families in every listed voltage row, and its 12 V maximum capacitive-load entry also differs. Confirm the suffix, pin configuration and all operating limits before treating it as the higher-current option.<\/p>\n<p><strong>None of the three should be described as a drop-in upgrade for another.<\/strong> That conclusion requires an exact, revision-controlled form\/fit\/function comparison and the relevant board-level validation.<\/p>\n<h2 id=\"send-an-evidence-ready-selection-request\"><span class=\"ez-toc-section\" id=\"Send_an_evidence-ready_selection_request\"><\/span>Send an evidence-ready selection request<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>For a useful response, send WEHO one compact requirement pack:<\/p>\n<ol>\n<li>required output voltage and tolerance at the load;<\/li>\n<li>minimum, nominal and maximum source voltage, plus relevant startup or disturbance conditions;<\/li>\n<li>continuous, startup and short-duration load states with duration and repetition rate;<\/li>\n<li>ambient range, enclosure, airflow and mounting orientation;<\/li>\n<li>PCB footprint or drawing, height limit and required pin form;<\/li>\n<li>existing input\/output capacitors and any change constraints;<\/li>\n<li>ripple, transient, protection, EMC and compliance requirements;<\/li>\n<li>target quantity, project timing and required document revisions.<\/li>\n<\/ol>\n<p>Ask for the exact orderable part number, current datasheet, pinout and dimensional drawing, current\/derating definition, external-component requirements and written resolution of any page conflict. Use the <a href=\"https:\/\/www.wehopower.com\/contact\/\">WEHO contact page<\/a> for that model-level evidence request. Browse the wider <a href=\"https:\/\/www.wehopower.com\/products\/\">WEHO product catalogue<\/a> only if the K78xx shortlist cannot meet the confirmed requirement.<\/p>\n<p>The requested outcome is an <strong>exact-variant evidence check<\/strong>, not an unsupported promise that one of the three families will fit.<\/p>\n<h2 id=\"faq\"><span class=\"ez-toc-section\" id=\"FAQ\"><\/span>FAQ<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3 id=\"are-k78xx-500r3-k78xx-1000r3-and-k78xx-2000r3-pin-compatible-with-one-another\"><span class=\"ez-toc-section\" id=\"Are_K78xx-500R3_K78xx-1000R3_and_K78xx-2000R3_pin-compatible_with_one_another\"><\/span>Are K78xx-500R3, K78xx-1000R3 and K78xx-2000R3 pin-compatible with one another?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>The supplied page bodies do not establish that. They publish SIP3 packaging and straight\/curved-pin language, but no common pin map, dimensions or cross-family compatibility statement. The 500R3\/1000R3 wording refers to K78xx; the 2000R3 wording refers to LM78xx.<\/p>\n<h3 id=\"does-k78xx-1000r3-have-a-1000-ma-output-rating\"><span class=\"ez-toc-section\" id=\"Does_K78xx-1000R3_have_a_1000_mA_output_rating\"><\/span>Does K78xx-1000R3 have a 1000 mA output rating?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Its table shows a single 1000 entry in the output-current column, while its feature text says output 500 mA. Obtain written clarification and a controlled datasheet before using either number as a design limit.<\/p>\n<h3 id=\"do-the-three-families-have-the-same-input-range\"><span class=\"ez-toc-section\" id=\"Do_the_three_families_have_the_same_input_range\"><\/span>Do the three families have the same input range?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>No. The 500R3 and 1000R3 pages print the same range for corresponding output rows, but the 2000R3 page prints a different range in all five rows. Match the exact output variant to the full source envelope.<\/p>\n<h3 id=\"does-no-need-for-external-heat-sinks-mean-full-output-at-85-c\"><span class=\"ez-toc-section\" id=\"Does_%E2%80%9Cno_need_for_external_heat_sinks%E2%80%9D_mean_full_output_at_85_%C2%B0C\"><\/span>Does \u201cno need for external heat sinks\u201d mean full output at +85 \u00b0C?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>The pages do not state that condition. Confirm the exact variant&#8217;s derating, mounting and cooling requirements before setting an allowable load.<\/p>\n<h3 id=\"can-the-maximum-capacitive-load-row-be-used-as-a-recommended-output-capacitor\"><span class=\"ez-toc-section\" id=\"Can_the_maximum_capacitive-load_row_be_used_as_a_recommended_output_capacitor\"><\/span>Can the maximum capacitive-load row be used as a recommended output capacitor?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>No. It is a maximum entry, not a complete component recommendation. Minimum capacitance, ESR, placement and startup conditions are not supplied in these page bodies.<\/p>\n<h2 id=\"decision-summary\"><span class=\"ez-toc-section\" id=\"Decision_summary\"><\/span>Decision summary<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li><strong>SHORTLIST:<\/strong> the exact voltage row and published input range cover the requirement, but controlled model evidence is still being collected.<\/li>\n<li><strong>HOLD:<\/strong> current definition, 1000R3 conflict, (L) identity, pinout, dimensions, derating or integration data remains unresolved.<\/li>\n<li><strong>REMOVE FROM SHORTLIST:<\/strong> a confirmed source, load, thermal, mechanical or output-quality requirement is outside the exact model&#8217;s documented capability.<\/li>\n<li><strong>RELEASE TO BOM:<\/strong> only after the exact part, revision and supporting evidence match the approved design and validation record.<\/li>\n<\/ul>\n<h2 id=\"source-and-evidence-boundaries\"><span class=\"ez-toc-section\" id=\"Source_and_evidence_boundaries\"><\/span>Source and evidence boundaries<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li><a href=\"https:\/\/www.wehopower.com\/product\/k78xx-500r3-dc-to-dc-power-module\/\">WEHO K78xx-500R3 product page<\/a> \u2014 used only for its published identity, feature text and five-row table.<\/li>\n<li><a href=\"https:\/\/www.wehopower.com\/product\/k78xx-1000r3-dc-dc-power-module\/\">WEHO K78xx-1000R3 product page<\/a> \u2014 used with the 500 mA\/1000 mA conflict preserved.<\/li>\n<li><a href=\"https:\/\/www.wehopower.com\/product\/k78xx-2000r3-dc-dc-power-module\/\">WEHO K78xx-2000R3 product page<\/a> \u2014 used with the table&#8217;s (L) suffix and distinct input\/capacitive-load entries preserved.<\/li>\n<li><a href=\"https:\/\/www.wehopower.com\/news\/what-is-a-non-isolated-power-module-and-why-use-it\/\">What Is a Non-Isolated Power Module and Why Use It?<\/a> \u2014 category context only; it is not evidence of exact K78xx model performance or suitability.<\/li>\n<\/ul>\n<\/article><footer class=\"footer\">Product statements are limited to the cited published-page snapshots; no compatibility or customer-fit approval is implied.<\/footer><\/main><\/div>\n<\/div>\n<script type=\"application\/ld+json\" class=\"weho-package-schema\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"BreadcrumbList\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.wehopower.com\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"News\",\"item\":\"https:\/\/www.wehopower.com\/news\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"K78xx-500R3 vs 1000R3 vs 2000R3: What to Check Before BOM Release\",\"item\":\"https:\/\/www.wehopower.com\/news\/k78xx-500r3-vs-1000r3-vs-2000r3-bom-selection\/\"}]},{\"@type\":\"FAQPage\",\"@id\":\"https:\/\/www.wehopower.com\/news\/k78xx-500r3-vs-1000r3-vs-2000r3-bom-selection\/#faq\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"Are K78xx-500R3, K78xx-1000R3 and K78xx-2000R3 pin-compatible with one another?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"The supplied page bodies do not establish that. They publish SIP3 packaging and straight- or curved-pin wording, but no shared pin map, dimensions or mutual compatibility statement.\"}},{\"@type\":\"Question\",\"name\":\"Does K78xx-1000R3 have a 1000 mA output rating?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Its table shows one 1000 entry in the output-current column, while its feature text says output 500 mA. Obtain written clarification and controlled documentation before using either number as a design limit.\"}},{\"@type\":\"Question\",\"name\":\"Do the three families have the same input range?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"No. The 500R3 and 1000R3 pages print the same range for corresponding output rows, while the 2000R3 page prints a different range in all five rows.\"}},{\"@type\":\"Question\",\"name\":\"Does no need for external heat sinks mean full output at +85 degrees Celsius?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"The pages do not state that condition. Confirm the exact variant's derating, mounting and cooling requirements before setting an allowable load.\"}},{\"@type\":\"Question\",\"name\":\"Can the maximum capacitive-load row be used as a recommended output capacitor?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"No. It is a maximum entry, not a complete component recommendation. Minimum capacitance, ESR, placement and startup conditions are not supplied in the cited page bodies.\"}}]}]}<\/script>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Compare K78xx-500R3, 1000R3 and 2000R3 by exact voltage row, load, thermal evidence, fit and integration gaps before BOM release.<\/p>","protected":false},"author":1,"featured_media":17522,"parent":0,"menu_order":4,"comment_status":"closed","ping_status":"closed","template":"","format":"standard","meta":{"_acf_changed":false,"_joinchat":[],"footnotes":""},"news_category":[149,148],"class_list":["post-17528","news","type-news","status-publish","format-standard","has-post-thumbnail","hentry","news_category-blog","news_category-industry-news","entry"],"acf":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.wehopower.com\/tl\/wp-json\/wp\/v2\/news\/17528","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wehopower.com\/tl\/wp-json\/wp\/v2\/news"}],"about":[{"href":"https:\/\/www.wehopower.com\/tl\/wp-json\/wp\/v2\/types\/news"}],"author":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/tl\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/tl\/wp-json\/wp\/v2\/comments?post=17528"}],"version-history":[{"count":2,"href":"https:\/\/www.wehopower.com\/tl\/wp-json\/wp\/v2\/news\/17528\/revisions"}],"predecessor-version":[{"id":17534,"href":"https:\/\/www.wehopower.com\/tl\/wp-json\/wp\/v2\/news\/17528\/revisions\/17534"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/tl\/wp-json\/wp\/v2\/media\/17522"}],"wp:attachment":[{"href":"https:\/\/www.wehopower.com\/tl\/wp-json\/wp\/v2\/media?parent=17528"}],"wp:term":[{"taxonomy":"news_category","embeddable":true,"href":"https:\/\/www.wehopower.com\/tl\/wp-json\/wp\/v2\/news_category?post=17528"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}