Texas Instruments CD74HCT670MTG4

Overview

CD74HCT670MTG4 from Texas Instruments is a 4-word × 4-bit high-speed CMOS register file with simultaneous independent read and write capability, three-state outputs, buffered inputs, and operation over -55°C to +125°C. It supports real-time data buffering in digital control systems where concurrent access to memory locations is required.

For engineers reviewing the CD74HCT670MTG4 datasheet, CD74HCT670MTG4 pinout, CD74HCT670MTG4 application, or CD74HCT670MTG4 equivalent, key selection criteria include its 4.5V–5.5V supply range, LSTTL-compatible input thresholds (VIL ≤ 0.8V, VIH ≥ 2.0V), 16ns typical read time at 5V/15pF, and SOIC-16 package compatibility with industrial temperature operation.

Technical Context

The CD74HCT670MTG4 implements a synchronous dual-port register file architecture using static CMOS logic. Its separate write address (WA0/WA1) and read address (RA0/RA1) inputs enable true concurrent read/write operations without internal arbitration logic. The device uses edge-triggered latching on WE low for write enable and RE low for output enable, with no internal clock-timing is fully asynchronous and controlled by external signal edges.

It features TTL-compatible input thresholds and CMOS-level output drive, allowing direct interfacing with legacy LSTTL systems while maintaining low quiescent current (≤160 µA over full temperature range). Three-state outputs support bus sharing and expansion up to 512 words via parallel stacking, with output disable times as low as 14 ns (CL = 15 pF) and propagation delays of 17 ns (typical, reading any word at 5V).

Key Specifications

Pinout & Package

CD74HCT670MTG4 is housed in a 16-pin SOIC (Small Outline Integrated Circuit) package with standard 1.27 mm pitch, JEDEC MS-012AC compliant, and RoHS-compliant NIPDAU lead finish. Moisture Sensitivity Level is Level-1 (unlimited floor life at ≤30°C/60% RH).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar register file applications.

Compared with CD74HC670MT, the CD74HCT670MTG4 provides guaranteed LSTTL input compatibility critical for mixed-technology systems, while SN74ALS670N offers lower latency at the cost of significantly higher power and reduced thermal robustness - making CD74HCT670MTG4 the optimal choice for new industrial and automotive designs demanding both interoperability and ruggedness.

Availability

CD74HCT670MTG4 is available at Aetrix Electronics and suitable for industrial PLC I/O buffering, automotive engine control units, digital signal processor co-processing, and test equipment pattern generation requiring stable component supply across extended temperature ranges.

Supply support for CD74HCT670MTG4 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, personal electronics, and communications markets.

The CD74HCT670MTG4 belongs to TI's High-Speed CMOS Logic (HCT) family, designed specifically to bridge legacy TTL systems with modern low-power CMOS architectures while maintaining pin-for-pin compatibility and robust operation across extreme temperatures.

FAQ

What is the maximum operating frequency supported by the CD74HCT670MTG4?

The CD74HCT670MTG4 does not have a clock input and operates asynchronously, so it has no specified maximum operating frequency. Its performance is governed by timing parameters such as setup/hold times (e.g., tSU = 18 ns, tH = 5 ns at 5V) and propagation delays (17 ns typical for read operations). System-level maximum throughput depends on external controller timing margins and bus loading, not an internal oscillator.

Is the CD74HCT670MTG4 pin-compatible with the CD74HC670MT?

Yes, the CD74HCT670MTG4 is pin-compatible with the CD74HC670MT - both use identical 16-pin SOIC packaging and share identical pin functions, pin numbering, and electrical connections. However, they differ in input threshold specifications: CD74HCT670MTG4 supports LSTTL-compatible inputs (VIL ≤ 0.8V, VIH ≥ 2.0V), whereas CD74HC670MT uses CMOS thresholds referenced to VCC.

Can multiple CD74HCT670MTG4 devices be connected in parallel to increase word depth?

Yes, multiple CD74HCT670MTG4 devices can be connected in parallel to expand word depth up to 512 words × 4 bits. This is achieved by tying corresponding Q0–Q3 outputs together and using shared RA0/RA1 and RE signals, while assigning unique WA0/WA1 and WE lines per device. All outputs must be three-state enabled/disabled synchronously to avoid bus contention.

Does the CD74HCT670MTG4 require external pull-up or pull-down resistors on its control inputs?

No, the CD74HCT670MTG4 does not require external pull-up or pull-down resistors on WA0, WA1, RA0, RA1, WE, or RE inputs. Its CMOS inputs have negligible leakage current (±1 µA max), and internal structure ensures defined logic states with clean digital drive. However, in noisy environments or floating-bus scenarios, weak pull-downs (e.g., 100 kΩ to GND on WE/RE) may improve noise immunity during power-up or reset.

What is the meaning of the "G4" suffix in CD74HCT670MTG4?

The "G4" suffix in CD74HCT670MTG4 indicates a green, RoHS-compliant packaging variant with NIPDAU (nickel-palladium-gold) lead finish and adherence to JS709B low-halogen requirements (Cl/Br ≤ 1000 ppm). It is functionally identical to CD74HCT670MT but meets stricter environmental compliance standards required for export to EU and other regulated markets.