The NKK Switches AS11CH is an AS-series subminiature SPST maintained ON–OFF slide switch with a 3.8 mm actuator and right-angle, bracket-supported through-hole termination. NKK product record Its intended application is low-voltage, low-current logic-level switching, such as a microcontroller configuration input or a hardware enable selector, rather than load-power switching.
Identity correction: The current project description calls this an SPDT ON–ON toggle switch. That is incorrect for AS11CH: the manufacturer identifies it as an SPST ON–OFF slide switch, and the datasheet explicitly omits terminal 2 on single-throw models. This guide does not validate or modify the current symbol, footprint, pad count, or 3D model.
1. Quick Specifications
NKK publishes switch ratings and applicable operating ranges, not a semiconductor-style Absolute Maximum Ratings table. Treat the electrical maxima below as simultaneous contact-rating constraints; they are not typical values or an invitation to operate continuously at every maximum.
Table
Parameter
Manufacturer specification
Classification / practical interpretation
Circuit and action
SPST, ON–NONE–OFF; ON connects 3–1, OFF is open.
Two maintained positions; NONE means no center detent, not a third operating position.
Maximum switched apparent power
0.4 VA maximum, resistive logic-level load.
Rated maximum, not 0.4 A.
Contact voltage
Applicable range 20 mV–28 V; 28 V AC/DC maximum.
Must also satisfy current and VA limits.
Contact current
Applicable range 0.1 mA–0.1 A.
Must also satisfy voltage and VA limits; operation below the published minimum is not established here.
Contact resistance
50 mΩ maximum.
Maximum specified resistance, not typical.
Operating temperature
−30°C to +85°C.
Manufacturer operating range.
Mechanical / electrical life
50,000 operations minimum for each.
Do not extrapolate to inductive loads or over-rated switching.
Mechanical bracket features are not an additional signal throw.
PCB pitch / hole size
Not independently verified from the drawing in this review.
The web extraction suggests a 2.54 mm family grid and Ø0.8 mm holes, but these are not released footprint dimensions. Use the original H-terminal drawing and confirm terminal omission, bracket locations, tolerances, and finished-hole requirements.
Recommended example operating point
3.3 V or 5 V GPIO circuit with 10 kΩ pull-up.
Engineering recommendation, not an NKK typical operating condition; calculated contact current is 0.33 mA or 0.50 mA.
Rating calculation: For a resistive DC circuit, constrain current to both 0.1 A and 0.4/V amperes, with V no greater than 28 V; these operands are the published limits. Thus the rating envelope gives 100 mA at 3.3 V, 80 mA at 5 V, and approximately 14.3 mA at 28 V. These are calculated ceilings, not recommended design currents; inrush and fault current must also be considered.
2. Pinout & Connections
The names below are descriptive schematic labels, not manufacturer-assigned power or logic pin names. The two contacts are unpolarized; either end can serve as the grounded terminal in the example circuit.
Table
Pin Number
Pin Name
Description
Best Practice
1
Contact A
Connects to terminal 3 in ON; open in OFF.
In the GPIO example, connect to GND.
3
Contact B
Other end of the SPST contact pair.
Connect to the sense node; use a 10 kΩ pull-up to the receiver's logic supply.
2
Not fitted
Single-throw models do not have terminal 2.
Do not assign a COM pin or second throw at this position.
Mechanical bracket features
Mounting support
H termination includes a bracket.
Preserve the mounting pattern; do not assume the bracket is a signal contact or an intentional shield/GND connection.
Terminal numbers are not actually marked on the switch, so identify them using the manufacturer's drawing orientation rather than assuming a top-view sequence. Confirm continuity between 1 and 3 in ON and an open circuit in OFF before finalizing assembly instructions.
3. Standard Application Circuit
AS11CH microcontroller GPIO wiring
Use the switch as an active-low configuration input:
R1 is required for this example unless another adequately specified pull-up supplies the same bias. ON reads LOW; OFF reads HIGH. An open contact cannot by itself define a logic level.
Calculated closed-contact current is I = VLOGIC/R1: 0.33 mA at 3.3 V and 0.50 mA at 5 V. Both are inside the switch's published 0.1 mA–0.1 A applicable range. Resistor dissipation is approximately 1.09 mW and 2.5 mW respectively; select resistance tolerance against GPIO leakage and logic thresholds.
Do not assume a weak internal pull-up is adequate for the contact application range. For example, an assumed 100 kΩ pull-up at 3.3 V would produce only 33 µA, below the published 0.1 mA minimum.
Debounce in firmware. As an engineering starting point, accept a new state only after it remains unchanged for 20 ms, then validate that interval using real switches across temperature and life. A guaranteed maximum bounce time was not verified; 20 ms is not a manufacturer specification. Avoid making an irreversible action on the first GPIO edge.
No decoupling capacitor is required by the passive switch itself. Decouple the MCU or buffer according to its own datasheet. If hardware filtering is needed, design an RC network with a Schmitt-trigger receiver, evaluate both edge timings, and limit capacitor-discharge current rather than placing an unrestricted large capacitor directly across the contacts.
For a power-enable function, switch the regulator's enable input with a defined inactive bias rather than its load current. Check enable thresholds, leakage, startup requirements, and default state against that regulator's datasheet.
This part is neither an LED nor a USB connector: LED resistor examples, USB CC resistors, and differential-pair wiring are not applicable.
4. PCB Layout & Routing Guidelines
Use the exact H-terminal mechanical drawing. Preserve electrical and bracket mounting features, and account for the absent terminal 2 on AS11. Pitch, finished-hole sizes, annular rings, and mechanical tolerances remain unverified here; do not substitute a generic three-pin SPDT footprint. Check the resulting hole and pad dimensions against JLCPCB's selected process before release.
Provide actuator access and strain support. C specifies a 3.8 mm actuator and H specifies a right-angle bracket. Keep the actuator's full movement clear of the enclosure and neighboring parts, and locate board supports to avoid flex during operation.
Use solder-friendly plane connections. For a grounded contact attached to a large copper plane, use fabrication-compatible thermal relief to support consistent through-hole soldering. Follow the selected assembly process rather than prescribing an arbitrary spoke geometry.
Route as a low-current input, not a power path. Keep the GPIO sense route short, away from switching nodes, and referenced to ground. Size copper for actual current, copper thickness, and temperature rise; widening copper does not increase the switch's 0.4 VA contact rating. Differential-pair routing is not applicable.
Place support circuitry at the receiver and respect cleaning limits. Keep any filter near the GPIO/buffer and its local return. NKK recommends wave soldering Profile A and single-pole manual soldering Profile B; the switches are not process sealed and require local hand cleaning with an alcohol-based solution. Numeric profile temperature/time limits were not verified from the referenced supplement; obtain that processing document before assembly release.
5. Common Pitfalls / Things to Watch Out For
Mistaking the circuit or overrating the contacts. AS11CH is SPST, not SPDT; it cannot select between two sources, and terminal 2 is absent. The rating is 0.4 VA, not 0.4 A, and voltage/current maxima cannot all be used simultaneously. Do not directly switch motors, relay coils, large capacitive loads, or mains using this logic-level rating.
Treating the input as inherently clean and defined. Omitting the pull-up leaves the OFF-state GPIO floating; omitting debounce can create repeated events. Also do not equate epoxy terminal sealing with a washable or waterproof assembly: NKK states these devices are not process sealed and specifies local hand cleaning.
6. Popular Alternatives & Equivalents
No other-manufacturer drop-in replacement was verified. The following are verified functional candidates, not pin-compatible or footprint-compatible replacements. Their SPDT contacts can provide ON–OFF behavior by using the common and one throw and leaving the other throw unconnected; redesign the pin mapping, footprint, and enclosure interface.
SPDT slide, right-angle surface mount. The consulted manufacturer-authored JS datasheet specifies 0.3 A at 6 VDC and silver-plated copper-alloy contacts.
Functionally similar only. SMT rather than AS11CH through-hole. Not suitable as a 28 V replacement. Silver contacts do not establish equivalent low-level reliability; qualify the intended GPIO contact current.
SPDT slide. E-Switch's exact product page specifies ON–ON, through-hole, 200 mA at 30 VDC. Manufacturer product record The series datasheet specifies silver-plated copper-alloy contacts and −20°C to +70°C.
Functionally similar only. Different geometry and pin map; no right-angle bracket equivalence established. Narrower temperature range and different contact material; qualify low-level switching rather than assuming the higher current rating makes it equivalent.
The exact EG1218 rating and mounting above are confirmed by its manufacturer product record; the corresponding drawing-based datasheet extraction was not independently validated. Neither alternative has been dimensionally overlaid against the AS11CH footprint. Library availability is not a stock guarantee.
7. Sourcing & Purchasing Guide
Table
Attribute
Details
Primary Distributors
Exact-part listings were found at Mouser, DigiKey, Arrow, LCSC, and Future Electronics. Prefer a manufacturer-authorized channel and confirm regional authorization before purchase; listing presence alone does not establish authorization or stock.
Packaging Options
The directly read Mouser listing reports bulk; Future lists bag. Tray appears in distributor search context, but the DigiKey page could not be read directly, so its current packaging is unverified. No tape-and-reel option was verified for AS11CH.
Standard MOQ
Mouser's directly read listing reports 1 unit and factory pack quantity 1; the consulted Future listing reports minimum order 50, multiple 50. These are channel-specific terms, not a universal manufacturer MOQ. DigiKey MOQ could not be independently verified.
Sourcing Advice
Order the complete AS11CH code: AS11 identifies the SPST circuit, C the actuator, and H the right-angle bracket termination. Do not assume a distributor suffix such as -RO denotes reel packaging; its meaning was not verified here. Avoid untraceable marketplace stock; request chain-of-custody and compliance documentation. Confirm actuator length, mounting geometry, quantity, and packaging on the purchase order.
Stock, prices, and lead times change; no inventory commitment is made by this guide. A found LCSC listing does not imply JLCPCB assembly eligibility. Obtain a current quotation and check through-hole assembly support separately.
Sources
Research checked 7 October 2026. Inline evidence citations identify verified datasheet claims; direct manufacturer/distributor links identify separately consulted records.
NKK Switches, Series AS — Subminiature Slides:manufacturer datasheet, Aslides.pdf. Sections used: General Specifications; Poles & Circuits; Actuators; PC Terminals; Typical Switch Dimensions; Processing. Explicit revision/date was not verified. Exact PCB drawing dimensions and numeric solder profiles remain unresolved.
NKK Switches, AS11CH exact-part record:manufacturer product page. No publication date displayed in the retrieved record.
NKK Switches, CN-0331:A Indicators & AS Slides production/marking change notice, dated 26 April 2018, effective January 2019. It documents marking and production-location changes without dimensional or specification changes; use it when evaluating marking differences, not as evidence of arbitrary substitute compatibility.
Mouser, AS11CH:exact-part listing. Used for packaging and minimum order, not electrical limits.
Future Electronics, AS11CH:exact-part listing. Used for bag packaging and minimum-order terms. Its displayed 0.4 A attribute conflicts with NKK's 0.4 VA rating and was not adopted.
DigiKey, AS11CH:exact-part listing. Direct page access failed; packaging and MOQ were not treated as verified.