Texas Instruments NE556V

Overview

NE556V from Texas Instruments is a dual precision timer IC containing two independent NE555-compatible timing circuits in a single 14-pin SOIC package, operating from 4.5 V to 16 V with ±200 mA output drive capability and TTL-compatible outputs. It supports both astable and monostable operation for precise time-delay generation from microseconds to hours, commonly used in pulse-width modulation and missing-pulse detection circuits.

For engineers reviewing the NE556V datasheet, NE556V pinout, NE556V application, or NE556V equivalent, this page delivers verified electrical characteristics, thermal metrics, functional mode truth table, real-world timing accuracy (±150 ppm/°C in astable mode), and validated alternative parts for industrial control, sequential timing, and pulse-shaping designs.

Technical Context

The NE556V implements two identical, independent 555-style timers sharing only power and ground rails - each with dedicated TRIG, THRES, CONT, RESET, DISCH, and OUT pins. Its internal comparators reference fixed fractions of VCC (≈1/3 and ≈2/3) unless overridden by the CONT pin, enabling voltage-controlled timing modulation.

Timing intervals are determined by external RC networks: monostable mode uses one resistor and capacitor (t_w ≈ 1.1 × R_AC_T); astable mode uses two resistors and one capacitor (f ≈ 1.44 / [(R_A + 2R_B)C_T]). RESET is active-low and overrides all other inputs, forcing output low and enabling discharge switch conduction.

Key Specifications

Pinout & Package

NE556V is housed in a 14-pin Small Outline Integrated Circuit (SOIC) package with 1.27 mm pitch, JEDEC MS-012 compliant, and RoHS-compliant NIPDAU lead finish. Thermal resistance is 91.4°C/W junction-to-ambient under standard PCB conditions.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual precision timer applications.

Compared with NE556DR, the NE556V offers identical timing performance and pin compatibility but differs in packaging format and traceability; compared with LM556CN, it trades wider voltage/temp range for tighter commercial qualification and lower unit cost in high-volume production.

Availability

NE556V is available at Aetrix Electronics and suitable for industrial controls, sequential timing circuits, and pulse-shaping applications requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for NE556V 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 company headquartered in Dallas, Texas, designing and manufacturing analog, embedded processing, and logic ICs for industrial, automotive, and consumer markets since 1930.

The NE556V belongs to TI's legacy precision timer product line, engineered specifically for robust, low-cost, RC-based timing functions in commercial-grade equipment where reliability, ease of design-in, and wide operating margin are prioritized over ultra-low power or high-speed performance.

FAQ

What is the maximum operating supply voltage for the NE556V?

The NE556V supports a maximum supply voltage of 16 V under recommended operating conditions. Absolute maximum rating is 18 V, but sustained operation above 16 V risks parametric shift and reduced reliability. At 16 V, output high voltage reaches ≥12.75 V and low voltage remains ≤0.25 V with 10 mA load, ensuring clean logic interfacing.

Can the NE556V operate in astable mode with a 50% duty cycle?

Yes, the NE556V can achieve approximately 50% duty cycle in astable mode by setting RA = RB in the standard two-resistor, one-capacitor configuration. Equation t_H ≈ 0.693 × (RA + RB) × CT and t_L ≈ 0.693 × RB × CT yield t_H/t_L = 2 when RA = RB, resulting in ~66% waveform duty cycle; true 50% requires diode-steered discharge or external logic, but NE556V supports close approximation with minimal external components.

Is the NE556V pin-compatible with the original NE555?

No - the NE556V is a dual-timer device with 14 pins and independent I/O for each section, whereas the NE555 is a single-timer in an 8-pin package. However, each half of the NE556V replicates the NE555's functional pinout (TRIG, THRES, CONT, RESET, DISCH, OUT, GND, VCC) in mirrored layout - enabling drop-in replacement of two NE555s with proper PCB routing for dual-channel designs.

What is the minimum monostable pulse width achievable with the NE556V?

The minimum monostable pulse width for the NE556V is 10 µs, limited by internal comparator storage time when TRIG is grounded. This value is specified across the full 0°C to +70°C operating range. To achieve reliable triggering at this limit, ensure TRIG remains low for ≥10 µs and returns high before threshold crossing; shorter pulses may result in missed or inconsistent output transitions.

Does the NE556V require external capacitors on the CONT pin?

Yes - a bypass capacitor (typically 10 nF ceramic) is strongly recommended between CONT and GND to suppress noise-induced timing jitter. The CONT pin presents high impedance (~10 MΩ), making it susceptible to EMI and supply ripple; without decoupling, timing accuracy degrades significantly, especially in astable mode where CONT directly affects both threshold and trigger reference voltages in the NE556V.