My Inquiry
My Account
Texas Instruments CD74HCT273EE4
- Part No.:
- CD74HCT273EE4
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- 20-DIP (0.300", 7.62mm)
- Datasheet:
-
CD74HCT273EE4.pdf
- Description:
- IC FF D-TYPE SNGL 8BIT 20DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,125
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
CD74HCT273EE4 from Texas Instruments is an octal positive-edge-triggered D-type flip-flop with asynchronous active-low reset, designed for 8-bit data synchronization and temporary storage in digital logic systems. It operates at 4.5V–5.5V, delivers 4.4V VOH at 4mA load, supports –55°C to +125°C industrial/military temperature range, and achieves up to 25MHz maximum clock frequency (25°C) with 30ns propagation delay (CL = 50pF). It is commonly used in bus interface latching and clock-domain crossing circuits.
For engineers reviewing the CD74HCT273EE4 datasheet, CD74HCT273EE4 pinout, CD74HCT273EE4 application, or CD74HCT273EE4 equivalent, key selection considerations include its TTL-compatible input thresholds (VIL ≤ 0.8V, VIH ≥ 2.0V), shared CLK/CLR control architecture, CMOS push-pull output drive capability, and PDIP-20 packaging for through-hole prototyping and legacy board compatibility.
Technical Context
The CD74HCT273EE4 implements eight independent D-type flip-flops sharing a single clock (CLK) and a common asynchronous clear (CLR) input. All Q outputs update synchronously on the rising edge of CLK, while CLR forces all outputs low independently of CLK timing - enabling deterministic initialization without clock dependency.
Its HCT logic family ensures direct compatibility with LSTTL voltage levels and CMOS power efficiency: inputs accept standard TTL thresholds, outputs drive ±4mA loads at 4.5V, and quiescent ICC remains ≤160μA over full temperature range. The device uses silicon-gate CMOS technology with balanced push-pull outputs and buffered inputs to minimize noise susceptibility and improve fanout.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | HCT - TTL-compatible CMOS with 4.5V–5.5V supply and LSTTL input thresholds |
| Operating Temperature | –55°C to +125°C - qualified for military, aerospace, and harsh-environment industrial use |
| Max Clock Frequency | 25 MHz at 25°C (16 MHz at –55°C to +125°C) - defines maximum synchronous data throughput rate |
| Propagation Delay | 30 ns (tPLH/tPHL, CL = 50pF, VCC = 4.5V) - determines worst-case timing margin for setup/hold compliance |
| Output Drive | ±4 mA per output (VOH ≥ 3.7V, VOL ≤ 0.4V at 4.5V) - supports direct interfacing with LSTTL loads |
| Input Thresholds | VIL ≤ 0.8 V (max), VIH ≥ 2.0 V (min) - guarantees reliable recognition of standard TTL logic levels |
| Power Dissipation | CPD = 25 pF - enables accurate dynamic power calculation (PD = CPD × VCC² × f) |
Pinout & Package
CD74HCT273EE4 is supplied in a 20-pin plastic dual in-line package (PDIP), with 0.300-inch body width and 0.100-inch lead pitch. The package is through-hole mountable, RoHS-compliant, and rated for operation up to +125°C ambient.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | CLR | Asynchronous active-low reset - forces all Q outputs to logic 0 regardless of CLK state |
| 2–9, 11–18 | 1D–8D, 1Q–8Q | Eight independent D-input / Q-output pairs - each transfers D to Q on CLK rising edge |
| 11 | CLK | Global clock input - rising-edge sensitive; triggers simultaneous update of all eight flip-flops |
| 10 | GND | Ground reference - must be low-impedance return path for all internal switching currents |
| 20 | VCC | Positive supply - requires local 0.1μF bypass capacitor to suppress high-frequency supply noise |
Key Features
| Feature | Design Value |
|---|---|
| Asynchronous active-low reset | Enables deterministic system initialization without requiring clock presence or timing coordination |
| Positive-edge clock triggering | Ensures precise, jitter-insensitive sampling of 8-bit parallel data aligned to system clock edges |
| TTL-compatible input thresholds | Eliminates need for level-shifting when interfacing with legacy 5V TTL peripherals or microcontrollers |
| CMOS power efficiency | Quiescent current ≤160μA across full temperature range - reduces thermal load in dense logic designs |
| Buffered inputs | Improves noise immunity and allows fanout to ≥10 LSTTL loads without signal degradation |
Applications
| Industrial Bus Interface | Microcontroller I/O Expansion |
|---|---|
Use Scenario: Isolating and latching 8-bit sensor data from a noisy factory-floor bus before CPU read. IC Role / Device Role / Timing Role: Synchronizes asynchronous external data to the microcontroller's internal clock domain using shared CLK and controlled reset sequencing. Use Value: Prevents metastability-induced data corruption during bus handshaking, leveraging guaranteed 3ns hold time and 12ns setup time at 4.5V. |
Use Scenario: Extending GPIO count of an 8-bit MCU by adding parallel output latches for LED arrays or relay drivers. IC Role / Device Role / Timing Role: Acts as an 8-bit output register - holds stable logic states between MCU write cycles, decoupling slow software updates from real-time output behavior. Use Value: Enables glitch-free output control with hardware-level reset (CLR) that clears all outputs simultaneously, avoiding partial-state transitions. |
| Digital Test Equipment | Military Data Acquisition |
Use Scenario: Capturing parallel waveform samples from ADCs in automated test systems operating at 10–20 MHz. IC Role / Device Role / Timing Role: Provides synchronized 8-bit capture staging prior to serialization or memory buffering - CLK edge aligns sample acquisition across all bits. Use Value: Delivers consistent 30ns propagation delay and <22ns transition time, supporting sub-50ns timing windows in high-speed test pattern generation. |
Use Scenario: Storing configuration bits or status flags in avionics subsystems requiring extended temperature operation. IC Role / Device Role / Timing Role: Functions as radiation-tolerant, wide-temperature latch - retains valid logic states under thermal cycling from –55°C to +125°C without refresh. Use Value: Meets MIL-PRF-38535 Class K requirements via process qualification, with verified performance at extremes and no derating needed below 125°C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal D-type flip-flop applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HCT273N | Same HCT logic family, identical pinout and electrical specs; manufactured by TI with different orderable suffix and packaging traceability | No functional difference - validated drop-in replacement for CD74HCT273EE4 in PDIP-20 footprint | Select SN74HCT273N when requiring TI's current production lot traceability and updated quality documentation |
| MC74HCT273PG | Pin-compatible but from ON Semiconductor; VIH/VIL thresholds match HCT spec, but max fCLK = 20MHz (–55°C to +125°C) vs. 16MHz for CD74HCT273EE4 | Suitable for lower-speed industrial controls where full military temp-range timing margin is not required | Choose MC74HCT273PG only if design operates ≤20MHz at temperature extremes and accepts alternate manufacturer sourcing |
Compared with SN74HCT273N (identical function and pinout) and MC74HCT273PG (slightly reduced max frequency at temperature extremes), CD74HCT273EE4 offers guaranteed 16MHz operation across –55°C to +125°C and TI-specific military-grade process validation - making it preferred for high-reliability, full-specification deployments.
Availability
CD74HCT273EE4 is available at Aetrix Electronics and suitable for industrial bus interface, microcontroller I/O expansion, digital test equipment, and military data acquisition requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for CD74HCT273EE4 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 ICs, with decades of experience in high-reliability logic families and military-grade qualification programs.
CD74HCT273EE4 belongs to TI's CDx4HCT273 series - a family of octal D-type flip-flops engineered for robust 5V system interfacing, wide-temperature operation, and seamless integration into legacy TTL and modern mixed-signal designs.
FAQ
What is the supply voltage range for CD74HCT273EE4?
The CD74HCT273EE4 operates within a strict 4.5V to 5.5V supply range. Operation outside this window violates recommended conditions: below 4.5V risks VIH/VIL threshold violations and timing failures; above 5.5V exceeds absolute maximum ratings and may cause permanent damage. This range ensures full TTL compatibility and guaranteed performance across –55°C to +125°C.
Does CD74HCT273EE4 support asynchronous reset, and how does it behave?
Yes, CD74HCT273EE4 features an asynchronous active-low reset (CLR) on Pin 1. When CLR is pulled low, all eight Q outputs immediately go to logic 0 - independent of CLK state or timing. The reset is released asynchronously upon CLR returning high, after which subsequent CLK rising edges resume normal D-to-Q transfer. This behavior is confirmed in the device functional mode table and timing diagrams.
Can CD74HCT273EE4 drive standard LSTTL loads directly?
Yes, CD74HCT273EE4 can directly drive standard LSTTL loads. Its outputs deliver VOH ≥ 3.7V and VOL ≤ 0.4V at 4mA sink/source current (VCC = 4.5V), meeting LSTTL VOH/VOL specifications. Each output supports fanout to ≥10 LSTTL loads, and the device maintains this capability across its full –55°C to +125°C operating range without derating.
What is the maximum clock frequency of CD74HCT273EE4 at elevated temperatures?
The maximum clock frequency of CD74HCT273EE4 is 16 MHz over the full –55°C to +125°C temperature range. At 25°C, it supports up to 25 MHz; at –40°C to +85°C, up to 20 MHz. These values are specified in the Timing Requirements table and reflect guaranteed timing margins - not typical or best-case figures - ensuring reliable operation in worst-case thermal conditions.
Is CD74HCT273EE4 compatible with 3.3V logic systems?
No, CD74HCT273EE4 is not compatible with 3.3V logic systems. It requires a 4.5V–5.5V supply and has TTL-compatible input thresholds (VIH ≥ 2.0V, VIL ≤ 0.8V) optimized for 5V operation. Driving its inputs from 3.3V sources may result in marginal or failed logic recognition, and powering it at 3.3V violates absolute maximum ratings. Use CD74HC273 or 74LVC273 for true 3.3V compatibility.
CD74HCT273EE4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74HCT
- Package/Case:
- 20-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Master Reset
- Type:
- D-Type
- Output Type:
- Non-Inverted
- Number of Elements:
- 1
- Number of Bits per Element:
- 8
- Clock Frequency:
- 50 MHz
- Max Propagation Delay @ V, Max CL:
- 30ns @ 4.5V, 50pF
- Trigger Type:
- Positive Edge
- Current - Output High, Low:
- 4mA, 4mA
- Voltage - Supply:
- 4.5V ~ 5.5V
- Current - Quiescent (Iq):
- 8 µA
- Input Capacitance:
- 10 pF
- Operating Temperature:
- -55°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 20-PDIP
CD74HCT273EE4 FAQ
1.How can I place an order for CD74HCT273EE4 through Aetrix?
Please submit a Request for Quotation (RFQ) for CD74HCT273EE4 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for CD74HCT273EE4 reliable?
The price and inventory of CD74HCT273EE4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CD74HCT273EE4 is usually 5 days.
3.What payment methods are accepted for CD74HCT273EE4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CD74HCT273EE4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CD74HCT273EE4?
CD74HCT273EE4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CD74HCT273EE4 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for CD74HCT273EE4?
For technical support, including CD74HCT273EE4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CD74HCT273EE4 requirements.
6.How does Aetrix verify that CD74HCT273EE4 is sourced from the original manufacturer or authorized distributors?
All CD74HCT273EE4 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that CD74HCT273EE4 meets industry standards.
7.What is the process for return or replacement of CD74HCT273EE4?
All CD74HCT273EE4 units undergo pre-shipment inspection (PSI). If there is an issue with CD74HCT273EE4, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The CD74HCT273EE4 part is unused and in its original packaging.
Return procedure for CD74HCT273EE4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
CD74HCT273EE4 Tags
-
SN74HC74DR
Texas Instruments
-
SN74HC74PWR
Texas Instruments
-
74LVC1G74GT,115
Nexperia USA Inc.
-
SN74LVC2G74DCUR
Texas Instruments
-
CD4013BM96
Texas Instruments
-
SN74HCT273PWR
Texas Instruments
-
SN74LVC1G74DCUR
Texas Instruments
-
SN74HC574DWR
Texas Instruments
-
74LVC1G74DC,125
Nexperia USA Inc.
-
SN74HC273DWR
Texas Instruments
-
SN74HCT574DWR
Texas Instruments
-
SN74LVC1G74DCTR
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
