MC1455DR2 - Programmable Timer Oscillator | onsemi
MPN: MC1455DR2 ✓ نشطMC1455DR2 نظرة عامة
A timer IC is a specialized timing-control device used to create a defined delay, periodic oscillation, or a repeatable pulse sequence. The MC1455 belongs to the 555 timer family, combining analog threshold comparison and switching functions with external timing components. Within the broader semiconductor hierarchy, it is an integrated circuit, timer and oscillator, and ultimately a signal-generation and control component used in industrial, consumer, and instrumentation electronics.
The principal functional characteristics are accurate timing, selectable monostable or astable operating behavior, external resistor-capacitor timing control, trigger support, reset support, and adjustable duty cycle. Its timing network remains external, allowing the designer to select resistance and capacitance values according to the required delay or oscillation frequency. The 8-pin SOIC package also supports compact surface-mount PCB construction while exposing the standard timer functions required for trigger, discharge, control, threshold, reset, output, supply, and ground connections.
Technically, the MC1455 combines two internal threshold comparators with a flip-flop and discharge transistor. In time-delay mode, the trigger input initiates a timing interval that is controlled by one external resistor and capacitor. In oscillation mode, the threshold and trigger functions cooperate with the external network to produce a periodic output. Additional trigger and reset terminals provide external control, while the control-voltage terminal supports common waveform-shaping and duty-cycle adjustment techniques described in the manufacturer documentation.
Typical uses include pulse generation, delayed switching, debounce and one-shot logic, simple clock circuits, tone generation, warning indicators, and control-signal generation. The part is especially appropriate where a compact, standard 555-type interface is preferred over a more complex microcontroller timer or dedicated clock IC. Its external timing network also allows the timing range to be scaled without changing the package or pinout.
The principal design consideration is to use the pin-description table and operating limits in the manufacturer datasheet when assigning signal levels, timing-component values, supply conditions, and output drive requirements. Designers should also review the reset and trigger truth behavior, control-voltage biasing, and discharge-node implementation before placing the circuit in a new PCB design.
This page organizes the verified MC1455DR2 product information, commercial inquiry path, drop-in alternatives, pin assignment, comparison points, and practical application guidance. It also distinguishes verified package and interface facts from parameters that require confirmation against the manufacturer datasheet before production release.
بدائل مباشرة لـ MC1455DR2 — نفس الحزمة، متوافق دبوس بدبوس. تُستثنى القطع ذات الحزم المختلفة التي تتطلب تعديل PCB.
الطرازات في هذه السلسلة
طرازات من نفس السلسلة متوافقة تمامًا مع MC1455DR2 (نفس عامل الشكل والبصمة) — يختلف في Package.
NCV1455BDR2G
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
MC1455BDR2G
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
NE555DR
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←MC1455DR2 المواصفات
| Timer Type | 555 Type |
| Circuit Configuration | Single |
| العلبة | 8-pin SOIC |
| Total Pin Count | 8 pins |
| نوع التركيب | Surface mount |
| Primary Function | Accurate time delay or oscillation |
| Timing Control | External resistor-capacitor network |
| Trigger Input | Supported |
| Reset Terminal | Supported |
| Duty Cycle | Adjustable |
تكوين أطراف MC1455DR2
| دبوس 1 | GND — Ground reference |
| دبوس 2 | TRIGGER — Trigger input |
| دبوس 3 | OUTPUT — Timer output |
| دبوس 4 | RESET — Reset input |
| دبوس 5 | CONTROL VOLTAGE — Control-voltage input |
| دبوس 6 | THRESHOLD — Threshold input |
| دبوس 7 | DISCHARGE — Timing capacitor discharge output |
| دبوس 8 | VCC — Positive supply input |
التطبيقات النموذجية
MC1455DR2 مناسب لـ 6 التطبيقs: Monostable One-Shot Timing, Astable Oscillator and Clock Generation, Industrial Delay and Sequencing Control, Pulse and Tone Generation, Debounce and Missing-Pulse Detection, Power-Supply and Circuit Fault Signaling.
Monostable One-Shot Timing
The MC1455DR2 fits monostable one-shot circuits because it is designed for accurate time-delay operation controlled by an external resistor-capacitor network. The trigger input initiates the timing sequence, while the reset terminal provides an external way to inhibit or terminate the interval. Its 8-pin SOIC package permits compact surface-mount implementation while retaining the familiar 555-style functional arrangement. The timing interval is set by the selected resistance and capacitance rather than an internal programmable register, making the device useful for retriggerable or non-retriggerable pulse-width generation. Before finalizing the RC values, consult the manufacturer datasheet for trigger thresholds, output timing behavior, discharge-device limits, and the applicable supply voltage.
موصى به
Astable Oscillator and Clock Generation
The MC1455DR2 can generate a periodic waveform when configured as an astable oscillator, with the timing network formed by external resistors and a capacitor. Its threshold, trigger, discharge, output, and control-voltage functions support the standard 555 oscillator architecture, while the adjustable duty-cycle capability broadens control over the pulse relationship between the two output states. This makes the device applicable to low-frequency clocks, indicator blinkers, tone generators, and periodic control pulses. Because the oscillator accuracy depends on the external components and the device's timing characteristics, calculate component tolerances carefully and verify startup behavior across the intended temperature range using the manufacturer operating limits.
موصى به
Industrial Delay and Sequencing Control
MC1455DR2 is useful in industrial delay and sequencing control where a reset command and triggered timing interval must coordinate a discrete output event. Its trigger and reset terminals provide the basic external controls needed for event-driven delay logic, while the 8-pin SOIC package supports automated board assembly. A practical implementation can use a sensor or comparator to trigger the timer and drive a relay, transistor, or status indicator from the output. Designers must account for electrical noise, switch bounce, and power-supply variation because these can affect trigger recognition and timing repeatability. Validate the trigger thresholds and output behavior with the manufacturer datasheet before using the circuit in safety-related sequencing.
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Pulse and Tone Generation
The MC1455DR2 supports pulse and tone-generation functions by combining its output stage with external timing components. In an astable configuration it can produce a repeating waveform; in a monostable configuration it can create a defined output pulse following a trigger event. This versatility is useful for test fixtures, audible alert circuits, indicator drivers, and simple excitation sources. The control-voltage terminal can be used for waveform shaping, but its permitted bias range and any resulting timing change must remain within the manufacturer's limits. Keep timing-node connections short and use suitable resistor and capacitor tolerances when predictable frequency or pulse width is important.
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Debounce and Missing-Pulse Detection
MC1455DR2 can support switch-debounce or missing-pulse detection when its trigger, threshold, reset, and timing functions are assigned to the desired sensing behavior. The external RC network determines how long the circuit interprets an event, while the output provides a clean digital indication for downstream logic. In debounce applications, the input network and trigger thresholds must reject mechanical contact chatter without ignoring valid events. In missing-pulse detection, the timing interval should be selected with enough margin for normal process variation. Because the verified product information does not specify detailed input thresholds, timing tolerance, or output drive, engineers should validate these parameters from the manufacturer datasheet and prototype the complete sensing path.
موصى به
Power-Supply and Circuit Fault Signaling
MC1455DR2 can be integrated into fault-signaling logic that turns a monitored event into a delayed or repetitive alert. The reset and trigger inputs allow another circuit to start, cancel, or retrigger the timer, and the output can drive a visual or audible indicator through appropriate interface circuitry. The 8-pin SOIC package is convenient for compact monitor boards, but timing-component tolerances and temperature drift may influence the intended fault threshold. Use the timer only where a delayed indication is acceptable and ensure that the external circuitry does not exceed the output, discharge, or supply limits. Confirm the actual operating limits and qualification status in the manufacturer documentation before using the device in critical protection systems.
موصى به
ملخص المنتجات الموصى بها
بيانات مرجعية هندسية لـ MC1455DR2 — المقارنة وإرشادات التصميم ومعلومات الامتثال.
دليل الاختيار
المقارنة مع البدائل
| المعامل | هذا المنتج | NCV1455BDR2G | MC1455BDR2G | NE555DR |
|---|---|---|---|---|
| Package | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC |
| Brand | onsemi | onsemi | onsemi | Texas Instruments |
| Timer Type | 555 Type | 555 Type | 555 Type | 555 Type |
| Primary Function | Accurate time delay or oscillation | Time delay or oscillation | Time delay or oscillation | Time delay or oscillation |
| Timing Elements | External resistor-capacitor network | External resistor-capacitor network | External resistor-capacitor network | External resistor-capacitor network |
أبرز الفروقات
- Maintains the standard 555-type interface in a compact surface-mount package (مقابلNE555DR)
- Provides direct-replacement positioning for NE555 timer designs (مقابلNE555DR)
- Offers same-family onsemi sourcing paths for design review (مقابلNCV1455BDR2G)
ملاحظات التصميم
Keep the timing capacitor connection from the threshold and discharge pins as short as practical. Place the timing resistors close to their associated IC pins, maintain a continuous ground reference, and route the trigger and reset nets away from high-current switching nodes. The external timing network directly determines oscillator frequency or monostable delay, so long loops can increase parasitic capacitance and make behavior less repeatable. Follow the manufacturer package drawing for pin-1 orientation and verify the land pattern against the exact 8-pin SOIC orderable variant.
Decouple the VCC pin locally with a suitable low-ESR capacitor and provide adequate supply headroom for the load connected to the timer output. The trigger and threshold nodes are timing-critical, so avoid sharing high-impedance timing routes with noisy analog signals. Before finalizing the supply rail, verify the input-voltage range, quiescent current, output-current capability, and absolute maximum limits in the manufacturer datasheet because those numerical limits were not established by the product listings.
Do not assume that every 555-family part is an exact substitute. Confirm the pinout, control-voltage behavior, trigger thresholds, reset function, output polarity, discharge limits, and timing accuracy. The MC1455 is described as a direct replacement for NE555 timers, but an existing board should still be reviewed for device-specific differences. Also avoid relying on a search-result comparison page as final engineering evidence; use the manufacturer datasheets for both the installed part and proposed replacement.
Treat the trigger input as a sensitive threshold signal and reject noise or bounce before it reaches the timer. A small input-conditioning network or Schmitt-trigger interface may be appropriate for mechanical contacts or long cables. Keep the reset path similarly controlled because an unintended reset pulse can interrupt the intended timing sequence. Validate these connections with oscilloscope measurements at the actual IC pins because package and wiring parasitics can otherwise create false triggering.
معلومات الامتثال
No explicit compliance declarations or qualification statements were present in the product listings, so each field remains unknown pending confirmation from the manufacturer datasheet or product documentation.