Texas Instruments CD74HC175E

Overview

CD74HC175E from Texas Instruments is a high-speed CMOS quad D-type flip-flop with asynchronous master reset, operating from 2V to 6V, featuring complementary Q/Q̅ outputs per stage, positive-edge clock triggering, and guaranteed operation across –55°C to +125°C for aerospace and industrial control logic. It delivers 10 LSTTL load drive capability and low quiescent current (≤160 µA at 125°C).

For engineers reviewing the CD74HC175E datasheet, CD74HC175E pinout, CD74HC175E application, or CD74HC175E equivalent, this device serves as a radiation-tolerant, wide-temperature latch for synchronous data capture, state storage, and register file implementation in legacy TTL-compatible digital systems requiring deterministic edge-triggered behavior and robust noise immunity (NIL/NIH = 30% of VCC at 5V).

Technical Context

The CD74HC175E implements four independent D-type latches sharing a common clock (CP) and active-low asynchronous master reset (MR), where data at each Dn input transfers to Qn on the rising edge of CP while MR forces all Qn to logic 0 and all Q̅n to logic 1 regardless of clock state. Its silicon-gate CMOS process ensures rail-to-rail output swing and balanced propagation delay (tPLH/tPHL ≤ 45 ns at VCC = 6V, CL = 50 pF).

It supports dual-voltage interoperability via HC logic thresholds (VIH = 1.5V min at 2V, 4.2V min at 6V; VIL = 0.5V max at 2V, 1.8V max at 6V), exhibits low input capacitance (CIN = 10 pF), and maintains stable timing margins with tSU = 20 ns and tH = 5 ns (at VCC = 4.5V), enabling reliable interfacing with microcontrollers, counters, and bus-hold circuits.

Key Specifications

Pinout & Package

CD74HC175E is supplied in a 16-lead plastic dual in-line package (PDIP), with 0.3-inch body width and standard through-hole mounting footprint. Pin 1 is located at the top-left corner adjacent to the notch or dot marking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad D-type flip-flop with reset applications.

Compared with SN74HC175N and MC74HC175ANG, the CD74HC175E uniquely guarantees full functionality across –55°C to +125°C with documented 30% noise margin and 45 ns max propagation delay at 6V, making it the sole option for mission-critical extended-temperature deployments.

Availability

CD74HC175E is available at Aetrix Electronics and suitable for industrial PLC register files, legacy bus interface latches, and aerospace telemetry encoders requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CD74HC175E 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic solutions with over 90 years of innovation in high-reliability IC design.

The CD74HC175E belongs to TI's CD74HC high-speed CMOS logic family, engineered specifically for drop-in replacement of obsolete TTL devices in harsh-environment digital systems requiring wide voltage operation and extended temperature performance.

FAQ

What is the maximum clock frequency supported by the CD74HC175E?

The CD74HC175E supports a maximum clock frequency of 23 MHz at VCC = 6V and TA = 125°C, based on its 45 ns maximum propagation delay (tPLH/tPHL) and 20 ns minimum setup time (tSU). At 5V operation and 25°C, the device achieves up to 29 MHz, making it suitable for medium-speed synchronous logic in industrial controllers and test equipment where precise edge alignment is required.

Does the CD74HC175E have built-in ESD protection?

Yes, the CD74HC175E incorporates on-chip ESD protection diodes rated to ±20 mA per I/O pin, with absolute maximum ratings specifying DC input diode current (IIK) of ±20 mA for VI < –0.5V or VI > VCC + 0.5V. However, the datasheet cautions that these devices are sensitive to electrostatic discharge, so proper handling procedures - including grounded workstations and anti-static packaging - must be followed during assembly and testing of the CD74HC175E.

Can the CD74HC175E directly drive LSTTL loads without buffer stages?

Yes, the CD74HC175E is explicitly rated to drive 10 LSTTL loads per output, verified across its full operating temperature range (–55°C to +125°C). This capability stems from its output structure delivering VOH ≥ 3.98V and VOL ≤ 0.26V at VCC = 4.5V with 4 mA sink/source, meeting LSTTL VIH (2.0V min) and VIL (0.8V max) thresholds with margin - a key design advantage over standard CMOS for mixed-logic system integration.

Is the CD74HC175E pin-compatible with the CD74HCT175E?

Yes, the CD74HC175E and CD74HCT175E share identical PDIP-16 pinouts and functional block diagrams, including MR, CP, D0–D3, Q0–Q3, and Q̅0–Q̅3 assignments. However, they differ in input threshold compatibility: CD74HC175E uses CMOS thresholds (VIH = 3.15V min at 4.5V), while CD74HCT175E matches LSTTL inputs (VIH = 2.0V min). Thus, the CD74HC175E is not a direct drop-in replacement for TTL-driven systems without verifying input voltage levels.

What is the purpose of the complementary Q̅ outputs on the CD74HC175E?

The complementary Q̅ outputs on the CD74HC175E provide inverted logic states for each flip-flop stage without requiring external inverters. This feature enables efficient implementation of toggle-mode counters (via Q̅→D feedback), differential bus drivers, XOR-based parity generators, and synchronous reset conditioning in finite-state machines - reducing component count, propagation delay, and board area in compact digital designs using the CD74HC175E.