Texas Instruments TLC552CD

Overview

TLC552CD from Texas Instruments is a dual LinCMOS™ timer IC with rail-to-rail CMOS output, 2 mW typical power consumption at 5 V, and single-supply operation from 1 V to 18 V. It provides two independent 555-compatible timing circuits in one SOIC-14 package, used for precision oscillators, pulse generators, and delay circuits in industrial control and instrumentation.

For engineers reviewing the TLC552CD datasheet, TLC552CD pinout, TLC552CD application, or TLC552CD equivalent, key selection criteria include its 100 mA sink / 10 mA source output drive, 0°C to 70°C operating range, functional interchangeability with NE556, and low supply-current spikes during transitions.

Technical Context

The TLC552CD integrates two independent monostable/astable timers sharing only VDD and GND. Each timer features high-impedance inputs (10¹² Ω typ), trigger and threshold thresholds at ~⅓ and ~⅔ of VDD, and a dedicated reset input that overrides all other controls. The discharge switch connects DSCH to GND when output is low.

Its LinCMOS™ process enables stable operation up to 2 MHz in astable mode with RA = 470 Ω, RB = 200 Ω, and CT = 200 pF. Control voltage (CONT) allows dynamic adjustment of internal thresholds, while CMOS output ensures compatibility with TTL, CMOS, and MOS logic families.

Key Specifications

Pinout & Package

Package: SOIC-14 (D package), 14-pin surface-mount, RoHS-compliant, MSL Level-1, 260°C peak reflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NE556N and TLC552CN, the TLC552CD delivers identical timing functionality in a space-saving SOIC-14 package with lower quiescent power, rail-to-rail output, and modern reflow compatibility - making it optimal for new SMT designs targeting commercial temperature range.

Availability

TLC552CD is available at Aetrix Electronics and suitable for industrial control panels, portable instrumentation, and LED lighting systems requiring stable component supply across extended production cycles.

Supply support for TLC552CD 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 leader specializing in analog, embedded processing, and logic technologies, with over 90 years of innovation in precision analog and timing solutions.

The TLC552CD belongs to TI's LinCMOS™ timer product line, designed specifically for low-power, high-accuracy timing applications in commercial-grade systems where reliability, small footprint, and mixed-voltage interoperability are essential.

FAQ

What is the maximum operating supply voltage for the TLC552CD?

The TLC552CD supports a maximum supply voltage of 18 V, verified per absolute maximum ratings in the official datasheet. Operation beyond this voltage risks permanent damage to the LinCMOS™ input structures and output transistors. At 18 V, the device draws 0.84–1.2 mA typical supply current and maintains rail-to-rail output swing within specification.

Does the TLC552CD support astable multivibrator operation?

Yes, the TLC552CD supports astable operation for both timers independently. With RA = 470 Ω, RB = 200 Ω, and CT = 200 pF, it achieves up to 2.8 MHz oscillation frequency. The datasheet confirms stable astable behavior across the full 1–18 V supply range and 0°C to 70°C temperature span, with timing error under ±3%.

Is the TLC552CD pin-compatible with the NE556?

Yes, the TLC552CD is functionally interchangeable with the NE556 and shares identical pinout and terminal assignments for both timers. This allows direct replacement in existing NE556 designs without PCB modification. However, note that TLC552CD uses LinCMOS™ technology, delivering lower power, higher input impedance, and rail-to-rail output versus the bipolar NE556.

What is the purpose of the CONT pin on the TLC552CD?

The CONT (control voltage) pin on the TLC552CD adjusts the internal voltage divider that sets the trigger and threshold reference levels. When left open or bypassed with a capacitor, thresholds default to ~⅓ and ~⅔ of VDD. Applying an external voltage to CONT scales these thresholds proportionally - enabling programmable timing intervals or voltage-controlled oscillation (VCO) behavior in each timer section.

Can the TLC552CD drive a 12 V relay directly?

No, the TLC552CD cannot drive a 12 V relay coil directly because its output voltage swing is limited to VDD (max 18 V), but its output current capability is insufficient for typical relay coils (often >50 mA continuous). While the TLC552CD sinks 100 mA peak, sustained coil current causes thermal stress. Use the TLC552CD to drive a logic-level MOSFET or transistor switch instead - its 100 mA sink capability is ideal for controlling such external drivers reliably.