STMicroelectronics TS555CN

Overview

TS555CN from STMicroelectronics is a low-power single CMOS timer IC designed for precision timing in battery-powered and space-constrained systems. It delivers 110 µA typical supply current at 5 V, supports 2.7 MHz maximum astable frequency, operates across 2–16 V supply range, and maintains accurate monostable/astable timing - used in portable instrumentation, sensor wake-up circuits, and LED flash controllers.

For engineers reviewing the TS555CN datasheet, TS555CN pinout, TS555CN application, or TS555CN equivalent, key selection criteria include ultra-low ICC (90–170 µA across 3–12 V), high input impedance (10¹² Ω), reduced supply current spikes during transitions, and functional compatibility with legacy NE555 designs while enabling smaller decoupling and timing capacitors.

Technical Context

The TS555CN implements a CMOS-based relaxation oscillator architecture with dual comparators, SR flip-flop, and push-pull output stage. Its high-impedance inputs (10¹² Ω) minimize loading on RC timing networks, and internal discharge transistor enables precise capacitor discharge control in both monostable and astable configurations.

Unlike bipolar 555 timers, it eliminates supply current surges during output switching via optimized internal driver staging, reducing required bypass capacitance. Timing accuracy remains stable over temperature (±75 ppm/°C) and supply voltage (as low as 0.1 %/V shift in astable mode), supporting reliable operation from -40 °C to +125 °C.

Key Specifications

Pinout & Package

TS555CN is housed in an SO8 (plastic micropackage) surface-mount package measuring 4.9 mm × 6.0 mm × 1.75 mm (D × E × A), RoHS-compliant and ECOPACK® certified.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-power timer applications.

Compared with LMC555IMX/NOPB and TLC555CP, TS555CN offers the lowest ICC (90 µA @ 3 V), highest astable frequency (2.7 MHz), and native SO8 packaging - making it optimal for high-density, long-life, and high-accuracy timing in modern SMT production.

Availability

TS555CN is available at Aetrix Electronics and suitable for portable instrumentation, industrial sensor interfaces, and LED lighting control requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for TS555CN 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, MCU, power, and sensing solutions for automotive, industrial, and consumer markets.

The TS555CN belongs to ST's precision analog timer product line, engineered specifically for ultra-low-power, high-accuracy timing in energy-constrained and thermally demanding environments - not as a general-purpose logic device but as a dedicated timing engine.

FAQ

Can TS555CN operate from a single 1.8 V supply?

No. The absolute minimum supply voltage is +2 V per datasheet Table 2. At 1.8 V, internal comparators and output stage fail to meet threshold and drive specifications. Operation below 2 V risks undefined behavior, including failure to trigger or latch, and is outside guaranteed specifications.

Does TS555CN require external pull-up resistors on the discharge pin?

No. Pin 7 (Discharge) is an open-drain NMOS output with internal pull-down capability during discharge phase and high-impedance state otherwise. External pull-ups are unnecessary and would interfere with capacitor discharge timing - only direct connection to timing capacitor is required.

How does TS555CN's timing accuracy compare to NE555 at 12 V?

At 12 V, TS555CN achieves ±4 % monostable accuracy versus NE555's typical ±5–10 %. More critically, TS555CN exhibits only 0.1 %/V supply sensitivity in astable mode versus NE555's ~1 %/V - delivering significantly tighter frequency stability across varying input rails.

Is the control voltage pin (pin 5) internally bypassed?

No. Pin 5 connects directly to the non-inverting input of the threshold comparator. A 10 nF ceramic capacitor to ground is recommended to suppress noise-induced jitter, especially in high-EMI environments. Leaving it unconnected may cause timing instability due to coupling from adjacent traces or supply ripple.