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Texas Instruments LM555CMX/NOPB
- Part No.:
- LM555CMX/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Programmable Timers and Oscillators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM555CMX/NOPB.pdf
- Description:
- IC OSC SGL TIMER 100KHZ 8-SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:13,984
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Product details
Overview
LM555CMX/NOPB from Texas Instruments is a general-purpose bipolar 555 timer IC operating in astable and monostable modes, with timing accuracy of ±1% (monostable) and ±2.25% (astable), output drive capability of 200 mA sink/source, and temperature stability better than 0.005%/°C. It functions as a precision time-delay generator or free-running oscillator in industrial control, LED flashers, and pulse-width modulation circuits.
For engineers reviewing the LM555CMX/NOPB datasheet, LM555CMX/NOPB pinout, LM555CMX/NOPB application, or LM555CMX/NOPB equivalent, key selection criteria include its SOIC-8 package, 4.5–16 V supply range, TTL-compatible output, adjustable duty cycle via dual-resistor timing network, and direct pin-to-pin compatibility with NE555/SE555 legacy designs.
Technical Context
The LM555CMX/NOPB integrates two comparators, an SR flip-flop, discharge transistor, and output stage in a single bipolar process. Its internal voltage divider sets fixed 1/3 VCC and 2/3 VCC thresholds for trigger and threshold inputs, enabling precise RC-based timing independent of supply voltage variation.
It supports both edge-triggered monostable operation (trigger on falling edge <1/3 VCC) and self-triggering astable operation (pins 2 and 6 tied), with timing determined by external RA, RB, and C values. The control voltage pin (Pin 5) allows external modulation of threshold levels for PWM or frequency tuning.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 4.5 V to 16 V - supports standard 5 V and 12 V logic rails without level-shifting |
| Timing Accuracy (Monostable) | ±1% initial error - enables reliable one-shot delays without calibration |
| Output Drive Capability | 200 mA sink/source - directly drives LEDs, relays, or TTL loads without buffer stages |
| Temperature Stability | Better than 0.005% per °C - ensures consistent timing across 0°C to 70°C industrial range |
| Operating Temperature | 0°C to 70°C - rated for commercial/industrial ambient environments |
| Rise/Fall Time | 100 ns - supports clean switching up to ~3 MHz fundamental oscillation |
| Trigger Threshold | 1/3 VCC - defines precise low-level activation point for monostable triggering |
Pinout & Package
LM555CMX/NOPB is supplied in an 8-pin SOIC (D) package measuring 4.90 mm × 3.91 mm, with standard gull-wing lead form and RoHS-compliant matte tin (SN) finish. It is compatible with automated SMT placement and reflow per JEDEC Level-1-260°C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - GND | Ground reference | Common return path for all internal circuitry and external timing components |
| 2 - TRIGGER | Input comparator (low threshold) | Falling edge below 1/3 VCC initiates monostable timing cycle or resets astable state |
| 3 - OUTPUT | Push-pull output stage | Drives high (up to VCC − 0.25 V at 5 mA) or low (as low as 0.1 V at 10 mA); sinks or sources up to 200 mA |
| 4 - RESET | Asynchronous reset input | Active-low signal forces output low and discharges timing capacitor; connect to VCC if unused |
| 5 - CONTROL VOLTAGE | Internal divider tap | Overrides default 2/3 VCC threshold; used for PWM generation or frequency modulation |
| 6 - THRESHOLD | Input comparator (high threshold) | Rising edge above 2/3 VCC terminates monostable pulse or triggers discharge in astable mode |
| 7 - DISCHARGE | Open-collector transistor collector | Internally shorts to GND during timing capacitor discharge phase; requires external pull-up for astable operation |
| 8 - V+ | Positive supply input | Accepts 4.5–16 V DC; bypass with 0.1 µF ceramic + 1 µF electrolytic capacitors near pin |
Key Features
| Feature | Design Value |
|---|---|
| Direct SE555/NE555 replacement | Pin-to-pin and functionally identical - enables drop-in upgrade of legacy 555-based designs without schematic or layout changes |
| Microsecond-to-hour timing range | RC time constants from ~1 µs to >10,000 s achievable - covers pulse generation, delay, and low-frequency oscillator needs |
| Adjustable duty cycle (astable) | Duty cycle set independently via RA/RB ratio - enables precise waveform shaping for motor control or lighting dimming |
| TTL-compatible output | Output swings rail-to-rail within TTL logic thresholds - interfaces directly with 74LS, 74HC, and microcontroller GPIO |
| Normally-on/off output configuration | Reset and trigger polarity allow active-high or active-low output behavior - simplifies interface with sensors and logic systems |
Applications
| LED Flasher Circuit | Precision Time-Delay Relay |
|---|---|
Use Scenario: A momentary pushbutton activates a visible indicator for a fixed duration in user-interface panels or status displays. IC Role / Device Role / Timing Role: Monostable timer generating a clean, repeatable high pulse to drive an LED through a current-limiting resistor. Use Value: Eliminates need for microcontroller firmware; achieves 5 s ±50 ms delay using 100 kΩ + 47 µF RC network per datasheet Equation t = 1.1·R·C. | Use Scenario: Industrial machine safety system requires exact 2.2 s delay between emergency stop press and actuator de-energization. IC Role / Device Role / Timing Role: Monostable time-delay generator triggered by stop-signal edge, with output controlling relay driver transistor. Use Value: Delivers ±1% initial accuracy and <0.005%/°C drift - maintains compliance with IEC 61800-5-2 timing tolerances over ambient temperature swings. |
| Pulse Width Modulator | Linear Ramp Generator |
Use Scenario: Analog-controlled brightness adjustment for incandescent lamp in HVAC control panel. IC Role / Device Role / Timing Role: Astable oscillator with modulated control voltage (Pin 5) varying duty cycle while maintaining constant frequency. Use Value: Achieves 10:1 PWM range using 0–5 V analog input; output directly drives MOSFET gate via 100 Ω series resistor. | Use Scenario: Test equipment requiring linear voltage ramp for ADC linearity verification or filter characterization. IC Role / Device Role / Timing Role: Monostable configured with constant-current charging source instead of resistor, producing precise linear ramp at threshold pin. Use Value: Generates 0–10 V ramp over 100 ms with <0.5% nonlinearity using matched transistors and LM555CMX/NOPB's stable internal reference. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar timer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| NE555P | Same bipolar architecture, identical pinout, but wider initial timing tolerance (±2% monostable) and no RoHS compliance | Limited to legacy repair or non-RoHS environments; lacks TI's enhanced ESD rating (±500 V HBM) | Select when cost sensitivity outweighs RoHS or ESD requirements; verify thermal derating for SOIC vs. PDIP |
| LMC555IMX/NOPB | CMOS version with 2 V to 15 V supply, 100 µA quiescent current, and rail-to-rail output - not pin-compatible | Requires PCB redesign; suited for battery-powered or low-power timing where LM555CMX/NOPB's 3–6 mA supply current is prohibitive | Choose only when ultra-low power or extended supply range is mandatory; not a drop-in substitute |
Compared with NE555P, LM555CMX/NOPB offers tighter timing accuracy and RoHS compliance; compared with LMC555IMX/NOPB, it provides higher output drive and direct legacy compatibility but consumes more power - select based on whether board space, power budget, or drop-in replacement is the primary constraint.
Availability
LM555CMX/NOPB is available at Aetrix Electronics and suitable for industrial control panels, LED lighting drivers, and test instrumentation requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for LM555CMX/NOPB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and consumer markets.
The LM555 product line delivers robust, cost-effective timing functionality for analog-digital hybrid systems, targeting applications where simplicity, reliability, and broad temperature operation outweigh programmability or ultra-low power.
FAQ
What is the maximum supply voltage for LM555CMX/NOPB?
The absolute maximum supply voltage for LM555CMX/NOPB is 18 V, but the recommended operating range is 4.5 V to 16 V per the datasheet. Operation above 16 V risks exceeding internal power dissipation limits and may reduce long-term reliability. At 16 V, typical supply current is 10–15 mA, and thermal performance must be verified using RθJA = 170°C/W for the SOIC-8 package.
Can LM555CMX/NOPB drive a 12 V relay coil directly?
Yes, LM555CMX/NOPB can drive a 12 V relay coil directly when configured in monostable mode with appropriate current limiting. Its output sinks up to 200 mA at VCC = 15 V with ≤0.25 V saturation voltage, sufficient for typical 12 V/40 mA relay coils. Use a flyback diode across the coil and confirm relay coil resistance yields ≤200 mA at operating voltage to avoid exceeding output ratings.
Is LM555CMX/NOPB pin-compatible with NE555?
Yes, LM555CMX/NOPB is fully pin-compatible with NE555 and SE555. The SOIC-8 footprint, pin numbering, electrical characteristics, and functional behavior match exactly. No schematic or PCB layout changes are required when substituting LM555CMX/NOPB into existing NE555 designs, and it retains identical timing equations and application configurations.
What is the minimum monostable pulse width achievable with LM555CMX/NOPB?
The minimum monostable pulse width for LM555CMX/NOPB is 10 µs, limited by lower comparator storage time when Pin 2 is driven fully to ground. This value is specified in the datasheet under "Additional Information" in Section 8.2.2.1. For pulses shorter than 10 µs, consider a dedicated monostable IC or high-speed logic; for longer durations, use standard RC networks with values up to 20 MΩ total resistance.
Does LM555CMX/NOPB require external bypass capacitors?
Yes, LM555CMX/NOPB requires external bypass capacitors: a 0.1 µF ceramic capacitor in parallel with a 1 µF electrolytic capacitor placed as close as possible to Pins 8 (V+) and 1 (GND). This decoupling prevents supply noise from coupling into the internal comparators and ensures stable timing, especially during high-current output transitions. Failure to implement proper bypassing may cause erratic triggering or timing drift.
LM555CMX/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- 555 Type, Timer/Oscillator (Single)
- Count:
- -
- Frequency:
- 100kHz
- Voltage - Supply:
- 4.5V ~ 16V
- Current - Supply:
- 10 mA
- Operating Temperature:
- 0°C ~ 70°C
- Supplier Device Package:
- 8-SOIC
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
LM555CMX/NOPB FAQ
1.How can I place an order for LM555CMX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM555CMX/NOPB on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LM555CMX/NOPB reliable?
The price and inventory of LM555CMX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM555CMX/NOPB is usually 5 days.
3.What payment methods are accepted for LM555CMX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM555CMX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM555CMX/NOPB?
LM555CMX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM555CMX/NOPB order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LM555CMX/NOPB?
For technical support, including LM555CMX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM555CMX/NOPB requirements.
6.How does Aetrix verify that LM555CMX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM555CMX/NOPB products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LM555CMX/NOPB meets industry standards.
7.What is the process for return or replacement of LM555CMX/NOPB?
All LM555CMX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM555CMX/NOPB, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LM555CMX/NOPB part is unused and in its original packaging.
Return procedure for LM555CMX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM555CMX/NOPB Tags
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