Renesas 74HC670FP-E

Overview

74HC670FP-E from Renesas Electronics is a 4×4 register file IC with three-state outputs, used for temporary data storage and parallel read/write operations in digital logic systems. It features 4-bit word width, 4-word depth, 2.0–6.0 V supply voltage, 21 ns typical read-to-output propagation delay (CL = 50 pF), and operates across –40°C to +85°C. It supports simultaneous write to one address and read from another - commonly deployed in microcontroller peripheral buffering and educational logic design.

For engineers reviewing the 74HC670FP-E datasheet, 74HC670FP-E pinout, 74HC670FP-E application, or 74HC670FP-E equivalent, key selection criteria include its dual-address capability, high-impedance output control, LSTTL-compatible drive strength, and DIP/SOP package compatibility for breadboard and PCB prototyping.

Technical Context

The 74HC670FP-E implements four independent D-type latches with on-chip 2-to-4 binary decoders for both write and read addressing. Write enable (GW) and read enable (GR) are active-low, enabling independent control of input capture and output sourcing. Address inputs WA/WB and RA/RB operate asynchronously to select source/destination locations without clock dependency.

Its three-state outputs support bus-sharing architectures: when GR is high, all Q1–Q4 outputs enter high-impedance state regardless of internal latch values. Input levels meet standard HC logic thresholds (VIH ≥ 3.15 V at VCC = 4.5 V; VIL ≤ 1.35 V), ensuring interoperability with TTL and other 74HC-series devices.

Key Specifications

Pinout & Package

SOP-16 package (JEITA PRSP0016DH-B, Renesas code FP-16DAV), 5.5 mm × 10.06 mm body, 1.27 mm pitch, Ni/Pd/Au-plated leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC670N and CD74HC670E, the 74HC670FP-E offers identical core functionality but in a space-saving SOP-16 package with JEITA-standard dimensions - making it optimal for surface-mount production and compact PCB layouts where DIP is impractical.

Availability

74HC670FP-E is available at Aetrix Electronics and suitable for microcontroller peripheral buffering, educational logic training boards, industrial sensor data aggregation, and legacy system bus interface requiring stable component supply and long-term industrial temperature support.

Supply support for 74HC670FP-E 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

Renesas Electronics Corporation is a Japanese semiconductor manufacturer specializing in microcontrollers, analog, power, and timing solutions for industrial, automotive, and infrastructure markets.

The HD74HC670 product line delivers compact, low-power register file functionality for digital logic subsystems where dual-port access and bus isolation are required - targeting cost-sensitive embedded control and academic hardware platforms.

FAQ

What is the maximum clockless operating frequency supported by the 74HC670FP-E?

The 74HC670FP-E has no internal clock and operates asynchronously. Its effective throughput depends on external timing: minimum pulse widths are 10 ns (write enable), 12 ns (data setup), and 17 ns (latch time) at VCC = 6.0 V. For reliable operation, maintain address stability ≥13 ns before GW low and avoid violating tsu/th timing windows. The 74HC670FP-E thus supports burst read/write cycles up to ~20 MHz in well-designed systems.

Does the 74HC670FP-E support true bidirectional data flow on the same pins?

No, the 74HC670FP-E does not support bidirectional I/O on shared pins. D1–D4 are dedicated inputs only; Q1–Q4 are dedicated three-state outputs only. There is no internal direction control or bus transceiver logic. To achieve bidirectional behavior, external multiplexers or separate input/output registers must be used alongside the 74HC670FP-E.

Can the 74HC670FP-E be operated at 3.3 V while interfacing with 5 V logic?

Yes, the 74HC670FP-E operates reliably at 3.3 V supply and accepts 5 V-tolerant inputs per its absolute maximum rating (VIN up to VCC + 0.5 V). At VCC = 3.3 V, VOH ≈ 3.1 V (min), sufficient to drive 74HC-series inputs. However, it cannot directly drive standard 5 V TTL loads - use a 74HCT-series buffer or level translator if driving legacy 5 V logic.

How does the 74HC670FP-E handle simultaneous read and write to the same address?

When WA/WB equals RA/RB and both GW and GR are asserted low, the 74HC670FP-E outputs reflect the *previously latched* data, not the newly written value. New data appears at Q1–Q4 only after the next read cycle. This behavior is specified in the function table: "Q0" denotes prior state. Thus, the 74HC670FP-E avoids read-modify-write hazards but requires two cycles to observe a write result.

Is there a lead-free and RoHS-compliant version of the 74HC670FP-E?

Yes, the 74HC670FP-E is RoHS-compliant and lead-free. Renesas confirms environmental compliance per EU RoHS Directive in its official documentation. The FP-16DAV package uses Ni/Pd/Au plating and meets JEDEC standards for Pb-free surface mount assembly. Always verify current compliance status via Renesas' official product page or material declaration before high-reliability deployment.