STMicroelectronics TS556CN

Overview

TS556CN 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 up to 2.7 MHz astable frequency, operates across 2–16 V supply range, and features 10¹² Ω input impedance - enabling low-power sensor interface and battery-operated pulse generation circuits.

For engineers reviewing the TS556CN datasheet, TS556CN pinout, TS556CN application, or TS556CN equivalent, key selection considerations include its ultra-low ICC versus bipolar NE556, reduced supply current spikes during output transitions, high-impedance trigger/threshold inputs, and SO14 package compatibility with legacy 556 layouts.

Technical Context

The TS556 integrates two independent CMOS-based 555-style timer cores sharing a common VCC and GND. Each section implements a voltage divider (three 50 kΩ resistors), dual comparators, SR flip-flop, discharge transistor, and push-pull output stage - all fabricated in ST's low-power CMOS process.

Timing accuracy is maintained across voltage (±0.1 %/V in astable mode) and temperature (75 ppm/°C), enabled by supply-proportional threshold/trigger reference generation and matched internal resistor ratios. Output rise/fall times are 25 ns/20 ns (10 pF load), supporting clean digital edge generation without external buffering.

Key Specifications

Pinout & Package

TS556CN is housed in a 14-pin SOIC (SO14) plastic micropackage per ECOPACK specifications, with 1.27 mm pitch, 8.75 mm body length, and 4.0 mm body width. Pin 1 is marked by a beveled corner or dot; top-view orientation follows standard JEDEC SOIC convention.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NE556DR and LM556CN, TS556CN provides superior energy efficiency, higher frequency capability, and greater timing stability - making it optimal for modern battery-constrained and high-precision timing designs.

Availability

TS556CN is available at Aetrix Electronics and suitable for industrial sensor nodes, portable medical devices, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TS556CN 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 microcontrollers, power management, analog ICs, and automotive-grade components.

The TS556CN belongs to ST's precision analog timer product line, engineered specifically for low-power, high-accuracy timing in space- and energy-constrained embedded systems.

FAQ

Can TS556CN replace NE556 in existing PCB layouts?

Yes - TS556CN uses the same SO14 package and identical pinout as NE556, including matching VCC, GND, trigger, threshold, discharge, reset, control voltage, and output assignments. No PCB modification is required, though decoupling capacitor value may be reduced due to lower supply current spikes.

What is the maximum load the TS556CN output can drive directly?

At VCC = 5 V, each output can source up to 2 mA or sink up to 8 mA while maintaining VOL ≤ 0.6 V and VOH ≥ 4.4 V. This supports direct drive of small-signal MOSFET gates, LED indicators with series resistors ≥620 Ω, and TTL/CMOS inputs without buffering.

Does TS556CN support independent operation of its two timer sections?

Yes - both sections share only VCC and GND; all other pins (trigger, threshold, reset, control voltage, discharge, output) are fully independent. This enables true dual-channel functionality such as synchronized but non-identical oscillators or cascaded monostable delays.

How does the 10¹² Ω input impedance improve timing capacitor selection?

With leakage current <10 pA, the TS556CN minimizes error from capacitor self-discharge, allowing use of low-cost polyester or ceramic timing capacitors instead of expensive low-leakage types. For example, a 1 µF polyester cap with 100 nA leakage would introduce >10 % timing error in a 10 s monostable - TS556CN avoids this entirely.