NE555P - Single Precision Timer, 100kHz, DIP-8 | Texas Instruments
MPN: NE555P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.62 | $0.62 |
| 10 | $0.54 | $5.40 |
| 100 | $0.46 | $46.00 |
| 500 | $0.4 | $200.00 |
| 1,000 | $0.34 | $340.00 |
NE555P Overview
The 555 timer is a classic analog building block that combines a precision voltage divider, two comparators, an internal flip-flop, and a high-current discharge transistor into one 8-pin device. Its role in modern electronics places it under the clock & timing / signal generation hierarchy, serving as a low-cost alternative to microcontroller timing or dedicated oscillator chips in non-critical timing paths.
Key specifications include a maximum operating frequency of 100 kHz (up to 500 kHz depending on datasheet parameter), a supply voltage range of 4.5V to 16V, and a TTL-compatible output that can sink or source up to 200 mA. The bipolar architecture provides robust output drive capability, making it suitable for directly driving relays, LEDs, buzzers, and other loads without an external driver stage.
The internal design uses three 5kΩ resistors forming the reference divider (giving the 555 its namesake), a discharge transistor for capacitor reset, and a set/reset flip-flop that latches trigger and threshold events. Threshold and trigger levels are set at 2/3 VCC and 1/3 VCC respectively, providing predictable timing independent of supply voltage within specified limits.
Typical applications include precision timing circuits, pulse generation, sequential timing, missing-pulse detection, and LED/relay drivers. The 200 mA output drive eliminates the need for buffer transistors in most direct-load designs, while the bipolar simplicity ensures reliable operation in hobby, educational, and industrial control systems.
When designing with the NE555P, add a 0.01 μF bypass capacitor directly across the VCC and GND pins to suppress supply noise that could couple into the timing comparators. For astable oscillators, ensure the timing capacitor has low leakage (film or quality electrolytic) because leakage current directly degrades frequency accuracy above 10 kHz.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for NE555P — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with NE555P (same form factor and footprint) — differing in Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
NA555P
✅ Drop-In📋 Reference alternative (not in catalog)
NE555PE4
✅ Drop-In✓ In Stock
$0.22 / Unit
View Datasheet →TLC555CP
✅ Drop-In📋 Reference alternative (not in catalog)
SA555P
✅ Drop-In📋 Reference alternative (not in catalog)
LM555CN
✅ Drop-In📋 Reference alternative (not in catalog)
ICM7555IPA
✅ Drop-In📋 Reference alternative (not in catalog)
NE555P Specifications
| Product Type | Precision Timer / Oscillator (Single) |
| Topology | 555 type, bipolar |
| Number of Timers | 1 |
| Operating Modes | Astable, Monostable |
| Maximum Frequency | 100 kHz |
| Supply Voltage Range | 4.5 V to 16 V |
| Supply Current (typ) | 10 mA |
| Output Current | ±200 mA (sink/source) |
| Output Compatibility | TTL-compatible |
| Trigger Level | 1/3 VCC |
| Threshold Level | 2/3 VCC |
| Duty Cycle Range | Adjustable (typ. up to ~50% without diode trick) |
| Operating Temperature Range | 0 °C to +70 °C |
| Package | 8-PDIP (through-hole DIP-8) |
| Mounting Type | Through-Hole |
| RoHS Status | Compliant |
| Lead-Free | Yes |
NE555P Pin Configuration
| Pin 1 | GND — Ground reference |
| Pin 2 | TRIG — Trigger input (active low, threshold 1/3 VCC) |
| Pin 3 | OUT — Output (TTL-compatible, ±200 mA drive) |
| Pin 4 | RESET — Reset input (active low, must be tied to VCC when unused) |
| Pin 5 | CV — Control voltage input (bypass with 0.01 µF to GND when unused) |
| Pin 6 | THR — Threshold input (threshold 2/3 VCC) |
| Pin 7 | DIS — Discharge (open-collector internal transistor) |
| Pin 8 | VCC — Supply voltage (4.5V to 16V) |
Typical Applications
NE555P is suitable for 6 applications: Astable (Free-Running) Oscillator, Monostable (One-Shot) Pulse Generator, Relay and Solenoid Driver, LED Flasher and Pulse Generator, Missing-Pulse and Frequency Detector, Voltage-Controlled Oscillator (VCO).
Astable (Free-Running) Oscillator
The NE555P in astable mode produces a continuous square wave from microseconds to hours, set by the formula f = 1.44 / ((RA + 2*RB) * C). The 200 mA bipolar output drive lets the oscillator sink/source LEDs or piezo transducers directly without a buffer transistor, while the TTL-compatible swing makes it a one-chip clock source for digital logic in hobby and industrial control panels.
Recommended
Monostable (One-Shot) Pulse Generator
Wired as a monostable, the NE555P delivers a single output pulse of width t = 1.1 * R * C when triggered by a falling edge on pin 2. Threshold stability to within a few percent makes it suitable for debouncing mechanical switches, generating fixed-width gate pulses for power MOSFETs, and missing-pulse detection circuits where a clean, predictable timing response is required.
Recommended
Relay and Solenoid Driver
The 200 mA sink/source capability lets the NE555P directly switch small relays, solenoids, and buzzers without a driver transistor, saving board space and BOM cost. TI datasheet typical application shows the output pin driving an inductive load with a flyback diode. Designers choose NE555P specifically because CMOS timers like TLC555CP lack the headroom for 200 mA relay coils.
Recommended
LED Flasher and Pulse Generator
Set by an external RC network, the NE555P drives LEDs directly via its high-current output, creating simple single- or dual-LED flashers used in indicator lights, alarm panels, and educational kits. The adjustable duty cycle (typically near 50%, or wider with a diode-network mod) lets designers balance ON brightness against OFF time without microcontroller firmware work.
Recommended
Missing-Pulse and Frequency Detector
With the trigger and threshold pins tied together to an AC-coupled input, the NE555P generates an output change when an expected input pulse is missing. The internal 1/3 VCC trigger reference and 2/3 VCC threshold reference provide stable detection across a 4.5V–16V supply, making this configuration common in watchdog circuits, motor speed monitors, and tachometer front-ends.
Recommended
Voltage-Controlled Oscillator (VCO)
Applying an external voltage to pin 5 (control voltage) modulates the NE555P's internal threshold levels, modulating output frequency as a function of input voltage. The bipolar architecture provides predictable 50% duty cycle across the modulation range. This configuration is used in function generators, tone encoders, and PWM-modulated control loops where frequency versus voltage linearity matters more than absolute accuracy.
Recommended
Recommended Products Summary
Engineering reference data for NE555P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | NA555P | NE555PE4 | TLC555CP | SA555P | LM555CN | ICM7555IPA |
|---|---|---|---|---|---|---|---|
| Package | 8-PDIP (DIP-8) | 8-PDIP (DIP-8) - same | 8-PDIP (DIP-8) - same | 8-PDIP (DIP-8) - same | 8-PDIP (DIP-8) - same | 8-PDIP (DIP-8) - same | 8-PDIP (DIP-8) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | STMicroelectronics | onsemi | Renesas Electronics |
| Topology | Bipolar | Bipolar | Bipolar | CMOS | Bipolar | Bipolar | CMOS |
| Supply Voltage Range | 4.5V to 16V | 4.5V to 16V | 4.5V to 16V | 2V to 18V (wider) | 4.5V to 16V | 4.5V to 16V | 2V to 18V (wider) |
| Output Current | ±200 mA | ±200 mA | ±200 mA | ~100 mA (-50%) | ±200 mA | ±200 mA | ~100 mA (-50%) |
| Quiescent Current (typ) | ~10 mA | ~10 mA | ~10 mA | ~1 mA (-90%) | ~10 mA | ~10 mA | ~1 mA (-90%) |
| Initial Timing Accuracy | Standard | Tighter than NE555 (precision grade) | Same as NE555P | Comparable CMOS | Comparable bipolar | Comparable bipolar | Comparable CMOS |
| Operating Temperature | 0°C to +70°C | 0°C to +70°C | 0°C to +70°C | 0°C to +70°C | 0°C to +70°C | 0°C to +70°C | 0°C to +70°C |
| Direct Relay Drive | Yes (200 mA) | Yes (200 mA) | Yes (200 mA) | Verify load (limited ~100 mA) | Yes (200 mA) | Yes (200 mA) | Verify load (limited ~100 mA) |
Key Differentiators
- Higher output drive than CMOS alternatives (vs TLC555CP, ICM7555IPA)
- Industry-standard 555 pinout maintained (vs NA555P, SA555P, LM555CN)
- Cost-optimized general-purpose choice (vs NA555P)
Design Notes
Add a 0.01 µF to 0.1 µF ceramic bypass capacitor as close as possible between VCC (pin 8) and GND (pin 1). The bipolar NE555P draws sharp current spikes during output transitions; without local decoupling, these transients couple into the supply and shift the 1/3 VCC and 2/3 VCC comparator references, distorting frequency and duty cycle. For astable designs above 10 kHz, observe pin 5 control voltage with a scope to confirm it remains stable.
Always tie pin 4 (RESET) to VCC if unused. Leaving it floating allows stray leakage to false-trigger a reset and suppress the output. Pin 5 (CONTROL VOLTAGE) should also be bypassed to GND through a 0.01 µF capacitor to prevent noise injection into the 2/3 VCC reference divider; only experienced VCO designers should drive pin 5 with an external signal.
The DIP-8 NE555P typically dissipates below 100 mW in astable circuits at moderate loads, so heatsinking is unnecessary. However, when driving a 200 mA inductive load such as a relay coil continuously, add a flyback diode (e.g., 1N4148) directly across the coil to clamp back-EMF and protect the internal discharge transistor.
Keep timing capacitor leads short and routed away from switching signals or PWM traces. Capacitor leakage current creates a parallel resistance path that, when comparable to the timing resistor value, shifts the astable frequency. For precision timing above 1 kHz, use a film or NP0/C0G ceramic timing capacitor instead of electrolytic.
Compliance Information
TI part marked NE555P is the Pb-free terminal finish designator; non-automotive grade. Not AEC-Q100 qualified — choose SE555P-Q1 or similar for automotive.
