NE555N and 555 Timer ICs, Kits and Signal Modules

NE555N-related timer components: choose the actual selected device

This collection is organized around NE555N and related 555-timer search terms, but its listings cover more than one type of item. You will find discrete bipolar 555 ICs, DIP-8 and SOP-8 package options, LM555 and selected CMOS-family timer parts, prepared relay-delay boards, square-wave generators, soldering exercises and mixed IC assortments. Some listings mention NE555 merely as an alternative or comparison while selling a different generator board or selectable non-timer IC. The selected variant and the product's own specifications determine what is supplied; the collection name does not certify that every item is an NE555N-marked chip.

The 555 timer as a circuit building block

A single 555 timer combines comparators, a latch, a discharge path and an output stage so that an external RC network can determine pulse or oscillation behavior. Typical applications include a one-shot delay in monostable operation, a repeating square or rectangular waveform in astable operation, and threshold-triggered control. A bare chip does not run a calendar clock, store a time of day, include an adjustable display or switch a load by itself. The commonly quoted one-shot approximation of 1.1 × R × C is a circuit-level starting point, not a promise of calibrated delay from an unspecified chip, module or supplier listing. Resistor and capacitor tolerances, capacitor leakage, temperature, supply variation, trigger waveform and component-specific limits all affect the delivered timing.

Understand the part-number and footprint differences

• NE555N, NE555P and other NE555 DIP-8 selections: Listings use these labels for through-hole, single 555 timers. Choose an explicit DIP-8 option if a breadboard, DIP-8 socket or through-hole PCB is required. Compare the actual body marking, pinout, package drawing and manufacturer's electrical limits for your design. A title listing both NE555N and NE555P is not evidence that both are included.
• NE555D, NE555DR and NE555DT in SOP/SOIC-8 listings: Surface-mount variants need an SMD footprint rather than an ordinary DIP-8 socket. Verify the exact suffix, pin pitch and board land pattern. One multipurpose product can offer an NE555P DIP-8 option alongside an NE555D SOP-8 option; choose the one matching your assembly method.
• LM555CN and LM555CM: Related 555 timer listings appear in DIP-8 and SOP-8 forms respectively. Do not interpret an LM555CN selection as an NE555N by marking or manufacturer. Compare voltage, output capability, timing and operating-temperature requirements against the datasheet for the actual part.
• LMC555CN: A CMOS 555-family option appears within a multi-chip product. CMOS and bipolar 555 variants can differ in power draw, available output current and electrical behavior. Do not assume direct equivalence just because the pin count and basic timing concept resemble a classic NE555.
• NA555DR, SA555DR, SE555DR and NE555PSR: A multi-model SOIC-8 product lists these as alternative variants. Prefixes and suffixes may encode distinct device grades and ordering packages; the chosen model must be checked separately. The listing's broad '100 kHz' headline is not a universal timing limit for every design in the collection.

Discrete chips, sockets and purchase quantities

Pack sizes vary widely: individual product listings show choices such as 10, 20, 30, 50, 100 or even 500 pieces, sometimes with and without a storage box. Treat the numeral on the active variant as the intended purchase quantity, subject to the product's pack breakdown. Several socket-set listings describe 20 pieces as 10 chips plus 10 DIP-8 sockets, whereas another selectable option may be 20 sockets only or 20 chips only. A '10 pair' or '20 pair' option likewise needs its own contents checked. SOP-8 chips do not mate with an ordinary DIP-8 socket without a suitable adapter, which is not included unless the listing explicitly states it. Neither chips nor sockets alone provide a finished oscillator or assembled delay circuit.

Assortment boxes labeled 60, 75, 85, 100 or 150 pieces can contain an NE555 alongside distinct components such as LM358 and LM324 op amps, LM393 and LM339 comparators, ULN2003 or ULN2803 driver arrays, PC817 optocouplers and other ICs. These are mixed development kits, not a box containing the stated total count of NE555N chips. A specific 150-piece listing describes 20 NE555 DIP-8 timers as part of its broader mix, but that breakdown must not be transferred to other 150-piece products. Some supplier component lists conflict on package identifiers; verify each assortment's packing list and physical package rather than using the collection description as a kit guarantee.

Multi-model IC listings: the variant is the product

Many titles are keyword-rich catalogs of separately selectable chips. Variants in this collection include NE555P DIP-8 or NE555D SOP-8 as well as LM358, LM393, NE5532, CD4017, 74HC595, L293D, TL072, TL494, UC3842/UC3843/UC3845, VIPer22A, MAX232, W25Q64, INA219, flash-memory parts and other devices. These alternatives perform different functions and can have different pin counts and package styles. An option labeled 'LM358P', 'ULN2003AN' or 'W25Q64BVSIG' does not deliver an NE555N just because 'NE555' appears elsewhere in the title. Similarly, '10 PCS', '20 PCS', '50 PCS' and '2500 PCS/reel' should be read for the chosen model, not as a mixed pack of all named models. Confirm model, package, count and any included accessories at the variant level.

Assembled delay relays and trigger boards

Some items use a 555-type timing circuit on a populated PCB to operate a relay. Listed options include DC 5 V, 12 V and, for one product, 24 V boards, with selected delay ranges such as 0–5 s, 0–60 s or 0–240 s. These are separate supply-voltage and timing-range variants, not a guarantee that one board accepts every voltage or covers all ranges. Other products distinguish 5 V conduction/on-delay from 12 V disconnect/off-delay choices or offer 1-, 5- and 10-piece board packs. Read the specific product and selected option to establish whether timing starts when power is applied or from an external trigger, whether contacts close or open after the delay, and what happens when a trigger persists or supply power fails.

Some relay listings combine incompatible descriptions of delay-on and delay-off behavior, or give several different board dimensions and time settings in the same product text. Do not infer a single operating sequence or use a generic pin diagram for all boards. Verify the exact purchased board's terminals, supply rating, trigger polarity, contact configuration and independently applicable load rating before integration. Relay contact ratings are not the same as the DC power input rating. A supplier claim about switching 220 V or certification does not independently establish suitability for mains equipment; hazardous-voltage switching calls for proper protective design and qualified installation, not universal wiring advice from a collection page.

Signal-generator boards and training projects

The collection also includes a NE555+CD4017 flow-light soldering kit, an adjustable NE555 frequency board, an inverter-related frequency/mixing board, and compact square-wave or PWM modules whose titles compare them with NE555. A flow-light kit is a learning assembly, not a pack of loose NE555N ICs. One three-board square-wave listing has separate low-frequency and high-frequency variants: approximately 0.8–60 Hz (L) or 50 Hz–6 kHz (H) according to its product description, with duty cycle described as not independently adjustable. Other 5 V generator boards advertise 1 Hz–10 kHz adjustable PWM or approximately 0.02 Hz–10 MHz square-wave operation; these are distinct assembled modules and should not be described as an NE555N chip or assumed to share the same output stage. Frequency claims belong to the exact board and conditions stated in its listing, not the whole collection.

Practical selection checklist

1. Decide what must arrive: a bare single timer IC, a socketed-chip pack, a mixed assortment, an assembled relay timer, a frequency-output module or a soldering practice kit.
2. Match exact part and package: NE555N/NE555P DIP-8 versus NE555D/DR SOP-8 versus LM555 or LMC555 choices; check physical footprint, pin 1 orientation and assembly method. Do not use a shared 555 search term as proof of interchangeability.
3. Check electrical limits: obtain the exact device's datasheet for supply range, input thresholds, reset conditions, output sink/source capability, temperature and timing tolerances. For modules, verify board-level operating voltage and output interface separately.
4. Calculate and validate timing: select the external timing network for the chosen topology; test actual pulse width, duty cycle, startup state, repeatability and drift across the operating environment. A relay board's specified adjustable range applies only to that version.
5. Confirm purchase contents: read the selected model and quantity, whether chip sockets, a storage box, adapters, connectors or a finished PCB are included, and whether multiple model names in the title actually denote separate variants.

Frequently asked questions

Are NE555N and NE555DR the same footprint? No. Listings describe NE555N in DIP-8 and NE555DR in an 8-lead surface-mount package; check exact drawings before PCB substitution.

Does an 85-piece NE555 kit include 85 NE555 chips? Not when the listing describes a multi-type IC assortment. Check its actual model-by-model bill of materials.

Can a square-wave generator labeled 'replace NE555' be used as a bare NE555N? No. It is an assembled signal-source module; match its power and signal output to your project rather than assuming component-level interchangeability.

Does a DC 12 V relay board guarantee a 12 V relay contact output? No. The board's DC supply and its isolated switching contacts are different specifications. Check the purchased board's verified contact configuration and load rating independently.