My Inquiry
My Account
Texas Instruments CD74HCT670MT
- Part No.:
- CD74HCT670MT
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
CD74HCT670MT.pdf
- Description:
- IC 4X4 REGISTER FILE 3ST 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,280
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
CD74HCT670MT from Texas Instruments is a 4-word × 4-bit high-speed CMOS register file with independent simultaneous read/write capability, three-state outputs, and LSTTL-compatible inputs (VIH ≥ 2 V, VIL ≤ 0.8 V). It operates from 4.5 V to 5.5 V, supports -55°C to +125°C industrial/military temperature range, and delivers 17 ns typical propagation delay (CL = 15 pF) for register access in real-time control and data buffering applications.
For engineers reviewing the CD74HCT670MT datasheet, CD74HCT670MT pinout, CD74HCT670MT application, or CD74HCT670MT equivalent, this page provides verified functional architecture, validated timing parameters, confirmed SOIC-16 package mapping, and two technically documented alternative parts for register-file-based system design.
Technical Context
The CD74HCT670MT implements a synchronous 4×4 register file with dual address decoders: WA0/WA1 selects one of four 4-bit locations for write operations when WE is low, while RA0/RA1 independently selects any location for read output when RE is low. Its architecture enables true concurrent read and write without bus contention or internal arbitration logic.
All inputs are buffered CMOS with TTL-level thresholds; outputs drive 15 LSTTL loads and enter high-impedance state when RE is high. The device uses static CMOS logic with no internal clocks-timing is fully asynchronous and governed by setup/hold requirements on WA/RA/WE/RE relative to data transitions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Organization | 4 words × 4 bits (16-bit total storage), enabling compact local data staging without external memory interface |
| Supply Voltage | 4.5 V to 5.5 V - ensures direct compatibility with 5 V LSTTL systems and eliminates level-shifting requirements |
| Propagation Delay | 17 ns typ. (CL = 15 pF, VCC = 5 V) - supports >30 MHz register access rates in pipelined control paths |
| Input Compatibility | LSTTL input thresholds (VIL ≤ 0.8 V, VIH ≥ 2.0 V) - allows direct connection to legacy 5 V logic families without pull-ups or translators |
| Operating Temperature | -55°C to +125°C - qualified for aerospace, defense, and under-hood automotive subsystems requiring extended thermal robustness |
| Output Drive | Three-state CMOS outputs capable of sinking/sourcing ±25 mA - permits wired-OR expansion up to 512 × 4 bits via bus sharing |
| Quiescent Current | 8 µA max. at 25°C (ICC) - enables ultra-low static power in always-on monitoring circuits |
Pinout & Package
CD74HCT670MT is housed in a 16-pin SOIC (Small Outline Integrated Circuit) package with standard JEDEC MS-012AC footprint (5.3 mm width, 10.2 mm length, 1.75 mm height), RoHS-compliant NIPDAU lead finish, and MSL Level-1 rating for unlimited reflow.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (D0) | Data Input 0 | LSB of 4-bit word written to selected address during WE = LOW; latched on WA0/WA1 stable edge |
| 2 (D1) | Data Input 1 | Second bit of 4-bit write word; synchronized with D0–D3 and WA0/WA1 under WE assertion |
| 3 (D2) | Data Input 2 | Third bit of 4-bit write word; shares same setup/hold timing constraints as D0–D3 |
| 4 (RA1) | Read Address Bit 1 | MSB of 2-bit read address; selects one of four register locations (00–11) when RE = LOW |
| 5 (RA0) | Read Address Bit 0 | LSB of 2-bit read address; decoded with RA1 to enable Q0–Q3 output drivers |
| 6 (Q3) | Data Output 3 | MSB of 4-bit read word; high-impedance when RE = HIGH; fanout = 15 LSTTL loads |
| 7 (GND) | Ground Reference | Primary return path for all I/O and internal logic; requires low-inductance PCB connection to minimize noise coupling |
| 8 (Q2) | Data Output 2 | Second bit of read word; electrically identical to Q0–Q3 with matched transition times (tTHL/tTLH ≤ 22 ns) |
| 9 (VCC) | Power Supply | +4.5 V to +5.5 V supply; bypassing with 0.1 µF ceramic capacitor near pin essential for stable operation |
| 10 (WA0) | Write Address Bit 0 | LSB of 2-bit write address; must be stable during entire WE pulse width (min 20 ns at 5 V) |
| 11 (WA1) | Write Address Bit 1 | MSB of 2-bit write address; jointly decodes with WA0 to select one of four 4-bit storage locations |
| 12 (WE) | Write Enable | Active-low control: data latched only when WA0/WA1 stable AND WE = LOW; high = transparent inhibit |
| 13 (RE) | Read Enable | Active-low control: Q0–Q3 reflect addressed register when RE = LOW; RE = HIGH forces all outputs to high-Z |
| 14 (Q0) | Data Output 0 | LSB of read word; matches Q1–Q3 in output capacitance (CO = 20 pF) and disable/enable timing (tPLZ/tPZL ≤ 16 ns) |
| 15 (Q1) | Data Output 1 | Second bit of read word; shares identical DC specs (VOH ≥ 4.4 V, VOL ≤ 0.1 V) with other outputs |
| 16 (D3) | Data Input 3 | MSB of 4-bit write word; subject to same input leakage (II ≤ ±1 µA) and capacitance (CI = 10 pF) as D0–D2 |
Key Features
| Feature | Design Value |
|---|---|
| Simultaneous Read/Write | Independent RA0/RA1 and WA0/WA1 address buses allow concurrent access to different 4-bit registers - eliminates pipeline stalls in real-time sequencers |
| Expandable Word Width | Three-state outputs enable parallel stacking of multiple CD74HCT670MT devices to construct 512-word × 4-bit arrays without external bus buffers |
| LSTTL-Compatible Inputs | Guaranteed VIH ≥ 2.0 V and VIL ≤ 0.8 V at VCC = 5 V - interfaces directly to 74LS/74ALS families without level shifters or pull resistors |
| Low-Power CMOS Core | ICC ≤ 8 µA at 25°C and ≤ 160 µA over full temperature range - reduces thermal load in dense logic assemblies |
| High-Noise Immunity | NIL/NIL = 30% of VCC at 5 V - suppresses false triggering from EMI in motor-control or switching-power environments |
Applications
| Industrial PLC Data Buffering | Aerospace Avionics Register Staging |
|---|---|
|
Use Scenario: Storing intermediate sensor fusion results between ADC sampling and DSP processing cycles in programmable logic controllers. IC Role / Device Role / Timing Role: Local 4×4 register file providing zero-latency read-after-write access for deterministic loop timing. Use Value: Eliminates external SRAM access delays; 17 ns propagation enables sub-60 ns register update-to-read turnaround in closed-loop control. |
Use Scenario: Holding configuration words for FPGA reconfiguration engines in radiation-tolerant flight computers. IC Role / Device Role / Timing Role: Radiation-hardened-by-process register bank storing critical boot parameters with simultaneous read/write isolation. Use Value: -55°C to +125°C operation and 150°C max junction temperature support extended mission profiles in orbital thermal cycling. |
| Digital Test Equipment Pattern Memory | Automotive Engine Control Unit (ECU) Lookup Tables |
|
Use Scenario: Storing stimulus/response vectors for boundary-scan test pattern generators in automated test equipment. IC Role / Device Role / Timing Role: Expandable 512×4-bit memory block built from cascaded CD74HCT670MT units with shared address/control busing. Use Value: Three-state outputs allow seamless bus multiplexing; 20 ns min WE pulse width supports 50 MHz pattern clocking. |
Use Scenario: Caching small calibration tables (e.g., fuel injector timing vs. RPM/load) in engine management microcontrollers. IC Role / Device Role / Timing Role: Fast-access lookup table buffer reducing CPU wait states during real-time combustion cycle calculations. Use Value: Direct 5 V LSTTL compatibility avoids voltage translation; 16 ns typical read time meets <200 ns ECU interrupt latency budgets. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar register-file applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74ACT670N | ACT-family; 4.5–5.5 V supply; faster tPLH/tPHL (12 ns typ. @ CL=50 pF); higher ICC (40 µA typ.) | Better speed/power trade-off for high-frequency test gear; less suitable for ultra-low-quiescent systems | Select SN74ACT670N when propagation delay <13 ns is required and supply current budget allows ~5× increase |
| CD74HC670M96 | HC-family; 2–6 V supply; wider VCC range but LSTTL-incompatible inputs (VIH ≥ 3.15 V @ 4.5 V) | Required for mixed-voltage systems with 3.3 V or 2.5 V logic; incompatible with legacy 5 V TTL without level shifters | Choose CD74HC670M96 only when operating outside 4.5–5.5 V or interfacing to non-TTL logic families |
Compared with SN74ACT670N and CD74HC670M96, the CD74HCT670MT uniquely balances LSTTL input compatibility, -55°C to +125°C operation, and sub-20 ns access time - making it optimal for retrofitting legacy 5 V control systems requiring drop-in register-file upgrades without layout or voltage-rail changes.
Availability
CD74HCT670MT is available at Aetrix Electronics and suitable for industrial automation, aerospace avionics, and automotive ECU applications requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for CD74HCT670MT 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 solutions, with decades of heritage in high-reliability military and industrial IC design.
The CD74HCT670MT belongs to TI's legacy High-Speed CMOS Logic (HCT) register file family, engineered specifically for deterministic, low-latency data staging in 5 V control systems where LSTTL interoperability and wide temperature resilience are mandatory.
FAQ
What is the maximum clock rate supported by CD74HCT670MT in a read-modify-write sequence?
The CD74HCT670MT has no internal clock; its maximum effective rate depends on external timing margins. For a full read-modify-write cycle, minimum WE pulse width is 20 ns, latch time (WE to RA0/RA1) is 25 ns, and output enable time is 16 ns. With proper address/data setup (18 ns), the practical limit is ~12.5 MHz for guaranteed timing closure at 5 V and 25°C - confirmed by TI's switching specifications in SCHS195C.
Can CD74HCT670MT be used with 3.3 V logic interfaces?
No - CD74HCT670MT requires 4.5 V to 5.5 V supply and is specified only for LSTTL-compatible inputs (VIH ≥ 2.0 V, VIL ≤ 0.8 V). Driving its inputs from 3.3 V logic violates the minimum VIH requirement and risks unreliable operation. Use level translators or select HC-family variants like CD74HC670M96 for 3.3 V systems.
Does CD74HCT670MT support hot insertion or live swapping on a powered board?
No - CD74HCT670MT lacks hot-swap protection circuitry. Its absolute maximum ratings specify no tolerance for VCC ramping before inputs stabilize, and electrostatic discharge sensitivity is explicitly cautioned in the datasheet. Power sequencing per TI's handling guidelines is mandatory to prevent latch-up or permanent damage.
How many CD74HCT670MT devices can be connected in parallel for wider word-length expansion?
Up to 128 CD74HCT670MT units can be interconnected to build a 512-word × 4-bit array, as stated in the "Expandable to 512 Words" feature. This relies on strict three-state bus discipline: only one device's RE asserted at a time, with shared WA0/WA1, RA0/RA1, WE, and D0–D3 lines. Output loading remains within 15 LSTTL limits per driver.
Is the CD74HCT670MT pinout compatible with CD74HC670M devices?
Yes - both CD74HCT670MT and CD74HC670M use identical SOIC-16 packaging and pin assignments per TI's ordering information table. However, electrical differences exist: HCT offers LSTTL input compatibility, while HC requires higher VIH (≥3.15 V at 4.5 V). Swapping them requires verifying input voltage levels in the host system.
CD74HCT670MT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74HCT
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Register File
- Circuit:
- 1 x 1:1
- Independent Circuits:
- 4
- Current - Output High, Low:
- -
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
CD74HCT670MT FAQ
1.How can I place an order for CD74HCT670MT through Aetrix?
Please submit a Request for Quotation (RFQ) for CD74HCT670MT 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 CD74HCT670MT reliable?
The price and inventory of CD74HCT670MT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CD74HCT670MT is usually 5 days.
3.What payment methods are accepted for CD74HCT670MT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CD74HCT670MT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CD74HCT670MT?
CD74HCT670MT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CD74HCT670MT 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 CD74HCT670MT?
For technical support, including CD74HCT670MT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CD74HCT670MT requirements.
6.How does Aetrix verify that CD74HCT670MT is sourced from the original manufacturer or authorized distributors?
All CD74HCT670MT 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 CD74HCT670MT meets industry standards.
7.What is the process for return or replacement of CD74HCT670MT?
All CD74HCT670MT units undergo pre-shipment inspection (PSI). If there is an issue with CD74HCT670MT, 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 CD74HCT670MT part is unused and in its original packaging.
Return procedure for CD74HCT670MT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
CD74HCT670MT Tags
-
SN74HC138DR
Texas Instruments
-
TC7SB3157CFU,LF(CT
Toshiba Semiconductor and Storage
-
74CBTLV3257PW,118
Nexperia USA Inc.
-
SN74CBTLV3257PWR
Texas Instruments
-
74CBTLV3257GUX
Nexperia USA Inc.
-
74HC154BQ,118
Nexperia USA Inc.
-
P3S0200GMX
NXP USA Inc.
-
SN74CB3Q3245PWR
Texas Instruments
-
SN74CB3Q3257RGYR
Texas Instruments
-
TCA9543APWR
Texas Instruments
-
TCA9546APWR
Texas Instruments
-
SN74HC138N
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…
