LinCMOS 555 timer for low-power industrial timing
The Texas Instruments TLC555QDR is a LinCMOS 555-type timer/oscillator that runs up to 2.1 MHz while drawing 360 µA supply current.
TLC555QDR
Texas Instruments · LinCMOS™ Series
Texas Instruments TLC555QDR, LinCMOS series, Type 555 Timer/Oscillator (Single), 2.1 MHz, 5V ~ 15V supply, 360 µA supply current, -40°C ~ 125°C, 8-SOIC surface mount package.
[IN STOCK] In Stock: 31 pcs
MOQ 1 · Tape & Reel (TR); Cut Tape (CT) · RoHS · EIA-481 · DAP/DDP · T/T
Technical specifications
| Parameter / Attribute | Specification / Value |
|---|---|
| Type | 555 Type, Timer/Oscillator (Single) |
| Series | LinCMOS™ |
| Mounting | Surface Mount |
| Supply voltage | 5V ~ 15V |
| Current - supply | 360 µA |
| Frequency | 2.1MHz |
| Operating temperature | -40°C ~ 125°C |
| Package | Tape & Reel (TR); Cut Tape (CT) |
| Case | 8-SOIC (0.154\", 3.90mm Width) |
100% Footprint Match · Solder-Ready (No PCB Redesign Needed)
Need Stock or a Drop-in Second-Source for TLC555QDR?
Package: DIP-8 / SOIC-8 · Pin-compatible replacements with immediate Shenzhen spot stock
Footprint Match 98%
Supply Chain & Allocation Reality:
Fifty years after introduction the 555 is still designed in, still taught, and still repaired. The bipolar NE555 remains in mass production across several fabs, so availability is not the issue. The two things that matter are the bipolar-versus-CMOS family boundary - the pinout survives the crossing but the output drive does not - and sourcing lots whose timing and temperature specifications are real; the 555 is a favorite of low-grade clones where timing accuracy is the first spec quietly loosened.
Verified Pin-Compatible Replacements (4 verified alternatives)
LM555 Texas Instruments DIP-8 / SOIC-8
100% Drop-in (Zero Code Change)
Availability & Target Pricing:
Direct House Second Source
Shenzhen Spot Stock (24-48h Dispatch)
Electrical & Core Specs:
The TI second source of the bipolar 555: same function table, same timing equations (monostable 1.1RC, astable 1.44 / ((R1 + 2R2) C)), supply 4.5V to 16V.
4.5V to 16V; output sinks and sources up to 200mA class; quiescent current milliamps class with the classic crowbar spike at output transitions.
Compatibility & Drop-In Notes: Cross-fab substitution is routine. For long-interval or precision timing, check the drift specification of the specific vendor over temperature - the RC network is only half the accuracy story.
Package & Solder Footprint: Same DIP-8 / SOIC-8 pinout; no layout change for the bipolar family.
Shenzhen Warehouse Stock & MOQ: Branded stock with documented specifications; the safe second source where timing tolerance matters.
NE555D Texas Instruments SOIC-8
100% Drop-in (Zero Code Change)
Availability & Target Pricing:
Same Die, Surface-Mount Body
Shenzhen Spot Stock (24-48h Dispatch)
Electrical & Core Specs:
The SMD version of the NE555 in SOIC-8 - identical electrical behavior to the DIP-8 part.
4.5V to 16V; 200mA class output drive, both directions.
Compatibility & Drop-In Notes: The standard repair path when the original was an SMD 555: replace with NE555D (or NE555DR in tape). No rework differences beyond the package.
Package & Solder Footprint: SOIC-8 pads; check the original package (some designs use TSSOP-8 variants from other vendors - not footprint compatible with SOIC-8).
Shenzhen Warehouse Stock & MOQ: Commodity volume; original factory tape-and-reel for automated SMT lines.
TLC555 Texas Instruments DIP-8 / SOIC-8
Pin-to-Pin (Minor Clock/Init Tuning)
Availability & Target Pricing:
CMOS Modernization - Lower Power, Rail-to-Rail Output
Shenzhen Spot Stock (24-48h Dispatch)
Electrical & Core Specs:
CMOS 555: supply 2V to 15V, quiescent current in the hundreds of microamps against roughly 10mA for the bipolar part, no output crowbar current spike at transitions.
2V to 15V; output drive is asymmetric on CMOS: roughly 100mA sink but only about 10mA source typical - far below the bipolar 200mA both ways.
Compatibility & Drop-In Notes: Pin-compatible but not load-compatible: any output that relied on sourcing current (high-side LED, high-side drive) must be re-checked - the CMOS part sources a tenth of the bipolar current. The lower power and absence of the crowbar spike make it the better part in battery and precision designs.
Package & Solder Footprint: Same package and pinout; supply decoupling can be lighter, but keep the timing capacitor quality high - CMOS thresholds are cleaner and the RC dominates.
Shenzhen Warehouse Stock & MOQ: Active TI line; stocked alongside the bipolar parts for design upgrades.
ICM7555 Analog Devices (Maxim line) / Renesas DIP-8 / SOIC-8
Pin-to-Pin (Minor Clock/Init Tuning)
Availability & Target Pricing:
Low-Power CMOS Option with Wide Supply Range
Shenzhen Spot Stock (24-48h Dispatch)
Electrical & Core Specs:
The classic CMOS 555 from the Intersil / Maxim lineage: same timer function, microamp-class quiescent current, no crowbar spike.
Typical 2V to 18V supply window (check the specific vendor datasheet); output drive well below the bipolar 200mA class.
Compatibility & Drop-In Notes: Same substitution discipline as the TLC555: verify every output load, and re-verify the timing capacitor value - CMOS input currents are tiny, so leakage in cheap capacitors becomes the dominant error source.
Package & Solder Footprint: Same pinout; SOIC and DIP options mirror the bipolar part.
Shenzhen Warehouse Stock & MOQ: Multi-vendor stock; a dependable CMOS choice where the TLC555 documentation is not accepted.
Buyer & Quality Checklist for Sourcing Alternatives
- Substituting bipolar to CMOS (TLC555 / ICM7555 / LMC555) keeps the pinout but changes drive: the bipolar part sinks and sources about 200mA, CMOS versions far less - and asymmetrically (strong sink, weak source). Re-check every output load.
- The bipolar 555 draws a large crowbar current spike during output transitions; circuits that were tuned around it (seen in some RF and audio designs) change character with a CMOS swap. Decouple the supply pin close to the package in all cases.
- Timing accuracy depends on internal comparator thresholds, not on external RC precision alone. For any timer that leaves the bench, measure the assembled frequency rather than trusting the calculator number - especially across CMOS and bipolar families, whose thresholds differ.
- Watch for relabeled or re-died 555 lots: cheap parts can pass DC tests and fail the timing drift or temperature specifications that the original design assumed.
- The control-voltage pin (CTRL, pin 5) is often left open on purpose; if the original design fitted a decoupling capacitor there, keep it - it is part of the timing stability, not decoration.
Frequently Asked Technical Questions
Q: Are all 555 timers interchangeable?
A: Within the bipolar family (NE555, LM555, MC1455, NE555D) yes - identical function and pinout. CMOS versions (TLC555, ICM7555, LMC555) share the pinout but differ in supply range, quiescent current and output drive; check the load before dropping one in.
Q: Can a CMOS 555 replace a NE555 in a relay driver?
A: Usually not directly: the bipolar NE555 sources and sinks up to about 200mA, while CMOS timers source far less (their sink capability is much stronger than source). Either keep a bipolar part or add a driver transistor for the relay.
Q: What is the difference between NE555 and SE555?
A: Same function; the SE prefix is the full military-temperature grade with tighter specifications. An SE555 works wherever an NE555 does; the reverse trades away temperature margin. Commercial NE555s are typically rated 0 to +70 degC, SE555 parts up to +125 degC.
Technical details
TLC555QDR
[ALLOC] verified