STMicroelectronics TS556ID

Overview

TS556ID from STMicroelectronics is a dual CMOS timer IC designed for precision timing in monostable and astable configurations. It delivers 220 µA typical supply current at 5 V, supports 2.7 MHz maximum astable frequency, operates across 2–16 V supply range, and features 10¹² Ω input impedance - enabling low-power, high-accuracy timing in battery-powered sensor nodes and industrial control sequencers.

For engineers reviewing the TS556ID datasheet, TS556ID pinout, TS556ID application, or TS556ID equivalent, key selection criteria include its ultra-low ICC (180 µA @ 3 V), reduced supply current spikes during output transitions, TTL/CMOS/MOS logic compatibility, and pin-to-pin functional equivalence with legacy NE556 while offering >26× lower power and 27× higher max frequency.

Technical Context

The TS556 integrates two independent CMOS-based 555-style timers sharing a common supply and ground. Each timer uses high-impedance voltage comparators (trigger threshold = 1/3 VCC, reset threshold = 2/3 VCC) and an RS flip-flop to generate precise timing intervals. Timing accuracy remains stable across temperature (±75 ppm/°C) and supply voltage variations (as low as ±0.1 %/V in astable mode).

Its discharge transistor exhibits low saturation voltage (0.2 V typ @ 10 mA), and output stages drive ±100 mA with VOH = 4.4 V and VOL = 0.6 V at 5 V supply. The internal resistor ladder sets control voltage at ~2/3 VCC, and external timing capacitors charge/discharge between 1/3 and 2/3 VCC - ensuring supply-independent timing constants.

Key Specifications

Pinout & Package

TS556ID is housed in a 14-pin SOIC (SO14) plastic micropackage with 1.27 mm pitch, 8.65 mm × 3.9 mm body, and 1.45 mm max height - optimized for automated SMT assembly and space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NE556N and LM556CN, TS556ID provides superior energy efficiency, higher frequency capability, and surface-mount readiness - making it optimal for new designs targeting compactness, battery life, and thermal robustness without sacrificing pin compatibility.

Availability

TS556ID is available at Aetrix Electronics and suitable for industrial sequencing, portable sensor wake-up, LED dimming control, and ultrasonic driver clock applications requiring stable component supply across automotive, industrial automation, and consumer electronics programs.

Supply support for TS556ID 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, specializing in power management, analog, MEMS, and microcontroller technologies for industrial, automotive, and consumer markets.

The TS556 belongs to ST's precision analog timer product line, engineered specifically to replace legacy bipolar 556 timers with CMOS efficiency while preserving design reuse - targeting low-power industrial controls and battery-operated instrumentation.

FAQ

Can TS556ID operate from a 3.3 V supply?

Yes. TS556ID is fully specified down to 2 V supply, with 180 µA typical ICC at 3 V and guaranteed functionality across –40 °C to +125 °C. Output VOH reaches 2.5 V (min) at 3 V supply, ensuring reliable interfacing with 3.3 V logic families without level shifters.

What is the minimum timing capacitor value usable with TS556ID?

Due to its 10¹² Ω input impedance and low leakage (≤100 nA on Discharge pin), TS556ID supports timing capacitors as small as 200 pF in high-frequency astable configurations (e.g., RA = 470 Ω, RB = 200 Ω). For monostable use, 100 pF is viable with R ≤ 10 kΩ to maintain accuracy.

How does TS556ID reduce decoupling capacitor requirements?

TS556ID suppresses supply current spikes during output transitions via internal current-limiting and slew-rate control. This allows stable operation with only 100 nF ceramic decoupling per VCC pin - versus ≥1 µF typically needed for NE556 - reducing PCB area and cost while improving transient response.

Is TS556ID pin-compatible with NE556 in SO14 packages?

Yes. TS556ID uses identical SO14 pinout and electrical signaling (same trigger/threshold thresholds, reset behavior, and output drive strength) as the obsolete NE556(a), enabling drop-in replacement in existing SOIC-14 layouts without schematic or firmware changes.