Texas Instruments CD74HCT175EG4

Overview

CD74HCT175EG4 from Texas Instruments is a high-speed CMOS quad D-type flip-flop with asynchronous master reset, operating at 4.5V–5.5V, featuring positive-edge clock triggering, complementary Q/Q̅ outputs per stage, and guaranteed operation from –55°C to +125°C. It drives up to 10 LSTTL loads and supports synchronous data latching in digital control, state-machine, and register applications.

For engineers reviewing the CD74HCT175EG4 datasheet, CD74HCT175EG4 pinout, CD74HCT175EG4 application, or CD74HCT175EG4 equivalent, key selection considerations include its LSTTL-compatible input thresholds (VIL ≤ 0.8 V, VIH ≥ 2.0 V), 25 MHz max clock frequency at 4.5 V, 33 ns typical propagation delay (CL = 50 pF), and PDIP-16 package with through-hole mounting compatibility.

Technical Context

This device implements four independent edge-triggered D flip-flops sharing one common clock (CP) and one active-low asynchronous master reset (MR). Each stage transfers the D-input value to Q on the rising edge of CP while simultaneously asserting the inverse at Q̅.

Reset is level-sensitive and overrides clock action: MR low forces all Q outputs to logic 0 and all Q̅ outputs to logic 1 regardless of CP state. Input buffering ensures clean signal integrity, and fanout capability is specified for both standard and bus-driver load conditions across the full temperature range.

Key Specifications

Pinout & Package

CD74HCT175EG4 is supplied in a 16-pin plastic dual in-line package (PDIP) with through-hole mounting. Pin 1 is located at the top-left corner when the notch faces upward.

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 CD74HCT175EG4, SN74HCT175N offers identical electrical and mechanical performance with updated quality assurance and longer-term production visibility, while MC74HCT175NG provides a second-source option with verified functional equivalence and matching industrial temperature grading.

Availability

CD74HCT175EG4 is available at Aetrix Electronics and suitable for industrial automation, aerospace subsystems, and legacy equipment repair requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for CD74HCT175EG4 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 delivering analog, embedded processing, and logic solutions for industrial, automotive, and aerospace markets.

CD74HCT175EG4 belongs to TI's legacy High-Speed CMOS Logic (HCT) family, engineered for seamless 5 V TTL system integration with low power consumption and extended temperature resilience.

FAQ

What is the maximum clock frequency supported by CD74HCT175EG4?

The CD74HCT175EG4 supports a maximum clock frequency of 25 MHz at VCC = 4.5 V and CL = 50 pF, decreasing to 20 MHz at –55°C to +125°C extremes. This rating assumes proper PCB layout, decoupling, and signal integrity - actual system-level timing must account for board trace delays and load capacitance beyond the 50 pF test condition.

Does CD74HCT175EG4 require external pull-up resistors on its inputs?

No, CD74HCT175EG4 does not require external pull-up resistors on MR, CP, or D inputs because all inputs are buffered CMOS with high-impedance characteristics and defined switching thresholds. However, floating inputs must be avoided: unused D inputs should be tied to VCC or GND, and MR must be actively driven or pulled high via a resistor if not controlled by logic.

Can CD74HCT175EG4 operate at 3.3 V supply voltage?

No, CD74HCT175EG4 is not rated for 3.3 V operation. Its HCT-family specification mandates a minimum VCC of 4.5 V and maximum of 5.5 V. At 3.3 V, input thresholds (VIH ≥ 2.0 V) may still be met, but output drive strength, timing margins, and DC parameters fall outside guaranteed specifications - use CD74HC175E or SN74LVC175 instead for 3.3 V systems.

What is the purpose of the complementary Q̅ outputs on CD74HCT175EG4?

The complementary Q̅ outputs on CD74HCT175EG4 provide inverted logic states for each flip-flop stage, enabling direct implementation of differential signaling paths, active-low enable/control functions, or simplified combinational logic without external inverters. This reduces gate count and propagation delay in register-based state machines and bus arbitration circuits.

Is CD74HCT175EG4 RoHS compliant?

Yes, CD74HCT175EG4 is RoHS compliant, as confirmed by Texas Instruments' packaging addendum: it features NiPdAu (NIPDAU) lead finish and meets EU Directive 2011/65/EU requirements. The "G4" suffix explicitly denotes RoHS-compliant packaging per TI's standardized suffix nomenclature.