NXP Semiconductors 74HCT165DB,112

Overview

74HCT165DB,112 from Nexperia is an 8-bit parallel-in/serial-out shift register with TTL-compatible inputs, asynchronous parallel load (PL), clock enable (CE), complementary serial outputs (Q7 and Q7), and operation over -40 °C to +125 °C. It supports 4.5–5.5 V supply, achieves up to 48 MHz max clock frequency at VCC = 4.5 V, and features overvoltage-tolerant inputs (up to 15 V) for level-shifting in microcontroller I/O expansion systems.

For engineers reviewing the 74HCT165DB,112 datasheet, 74HCT165DB,112 pinout, 74HCT165DB,112 application, or 74HCT165DB,112 equivalent, key selection criteria include its asynchronous parallel load timing (17–60 ns PL-to-Q7 delay), CE-gated synchronous shift capability, dual-output polarity support, and SO16 (SOT109-1) package compatibility with legacy PCB footprints.

Technical Context

The device implements a synchronous 8-stage shift register with edge-triggered clock (CP) and active-low clock enable (CE) that gates CP transitions-only LOW-to-HIGH edges propagate data when CE is LOW. Its asynchronous parallel load (PL) overrides shift behavior, loading D0–D7 directly into all stages regardless of CP state.

Input logic thresholds are TTL-compatible (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 4.5–5.5 V), and both Q7 and its complement Q7 are fully buffered CMOS outputs capable of driving ±4.0 mA at VCC = 4.5 V, enabling direct interface with microcontroller input pins or downstream logic without external inversion.

Key Specifications

Pinout & Package

74HCT165DB,112 uses the SO16 (SOT109-1) plastic small outline package: 16-pin, 3.9 mm body width, 1.27 mm lead pitch, surface-mount, with gull-wing leads and pin 1 index marker.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit parallel-in/serial-out shift register applications.

Compared with 74HCT165PW,118 and SN74HCT165DR, the 74HCT165DB,112 offers superior thermal robustness in SO16 form factor, guaranteed 125 °C operation, and lower VOL - making it optimal for automotive and industrial designs requiring long-term reliability under thermal stress.

Availability

74HCT165DB,112 is available at Aetrix Electronics and suitable for microcontroller I/O expansion, industrial sensor aggregation, automotive body control modules, and legacy bus interface adapters requiring stable component supply across extended temperature ranges.

Supply support for 74HCT165DB,112 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

Nexperia is a global semiconductor expert focused on essential efficiency technologies, delivering high-performance logic, analog, and MOSFET solutions with industry-leading quality and reliability.

The 74HCT165DB,112 belongs to Nexperia's 74HCT logic family, engineered for robust 5 V TTL-compatible operation in automotive, industrial, and consumer applications demanding wide temperature range and noise immunity.

FAQ

What is the maximum clock frequency supported by 74HCT165DB,112?

The 74HCT165DB,112 supports a maximum clock frequency of 48 MHz at VCC = 4.5 V and ambient temperature of 25 °C. At full industrial range (-40 °C to +125 °C), the guaranteed fmax is 17 MHz per datasheet Table 7, due to propagation delay degradation at temperature extremes.

Can 74HCT165DB,112 interface directly with 3.3 V microcontrollers?

No - the 74HCT165DB,112 requires a 4.5–5.5 V supply and has TTL-level inputs (VIH ≥ 2.0 V), but its outputs swing rail-to-rail (0 V to VCC). Direct connection to 3.3 V MCU inputs risks overvoltage damage; a level-shifter or series resistor + clamping diode is required for safe interfacing.

How does the CE (clock enable) pin affect shift register operation?

When CE is HIGH, the CP input is disabled - no clock edges propagate through the register, freezing the current state. When CE is LOW, CP rising edges shift data serially from DS into the register and advance existing bits toward Q7. This allows precise gating of shift cycles without altering clock source timing.

Is the Q7 output truly complementary to Q7, or is it inverted internally?

Q7 is the true logical complement of Q7 - both outputs are driven by separate, matched output stages with identical electrical characteristics (VOH/VOL, drive strength, transition time). The datasheet confirms they are "complementary serial outputs" with no added delay between them, enabling use in differential signaling or fail-safe monitoring.