Texas Instruments 8405601DA

Overview

8405601DA from Texas Instruments is a dual D-type positive-edge-triggered flip-flop with asynchronous preset and clear inputs per channel, operating across 2 V to 6 V supply voltage and -40°C to +85°C temperature range. It delivers 35 pF power dissipation capacitance, ≤49 ns propagation delay at 6 V, and supports fanout of up to 10 LSTTL loads. It is used in clock division (÷2/÷4) and momentary-to-toggle switch conversion circuits.

For engineers reviewing the 8405601DA datasheet, 8405601DA pinout, 8405601DA application, or 8405601DA equivalent, this page provides verified functional identity, confirmed SOIC-14 package mapping, validated 14-pin terminal roles, real-world timing and drive specifications, and two technically documented alternative parts for logic-level-compatible design reuse.

Technical Context

The 8405601DA implements two independent CMOS D-flip-flops sharing no internal resources, each with separate asynchronous active-low PRE and CLR inputs, data (D), clock (CLK), true (Q), and complement (Q̅) terminals. Its edge-triggered operation relies on precise setup (≥17 ns at 6 V) and zero hold time requirements, enabling reliable state capture on rising CLK edges.

It uses standard CMOS input structure with ≤10 pF input capacitance and balanced push-pull outputs capable of sourcing/sinking ≥4 mA (at 4.5 V) while maintaining VOH ≥3.98 V and VOL ≤0.33 V. The device operates within absolute maximum ratings including 7 V supply and ±20 mA clamp current, with thermal resistance RθJA = 133.6 °C/W in SOIC-14 package.

Key Specifications

Pinout & Package

8405601DA is packaged in 14-pin SOIC (Small Outline Integrated Circuit) with nominal body size 8.70 mm × 3.90 mm and standard JEDEC MS-012AC footprint. Thermal resistance is RθJA = 133.6 °C/W, suitable for natural convection cooling in dense PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual D-flip-flop applications.

Compared with 8405601DA, SN74HC74D offers identical performance and footprint with full TI support, while MC74HC74ADTR2G provides second-source reliability without layout or firmware changes-both preserve timing margins, drive strength, and voltage compatibility.

Availability

8405601DA is available at Aetrix Electronics and suitable for industrial control logic, digital clock management, test equipment sequencing, and legacy interface bridging requiring stable component supply across long production lifecycles.

Supply support for 8405601DA 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 delivering analog and embedded processing solutions, with leadership in logic, power management, and signal chain technologies since 1930.

The 8405601DA belongs to TI's 74HC high-speed CMOS logic family, designed for low-power, pin-compatible upgrades to legacy TTL circuits in industrial, automotive, and communications equipment.

FAQ

What is the maximum clock frequency supported by the 8405601DA?

The 8405601DA supports a maximum clock frequency of 29 MHz at 6 V supply and -40°C to +85°C operating temperature, as specified in the switching characteristics table. At 4.5 V, the guaranteed maximum is 25 MHz, and at 2 V it drops to 5 MHz. These values reflect worst-case timing under recommended operating conditions-not typical or ideal-case measurements.

Does the 8405601DA require external pull-up or pull-down resistors on unused inputs?

Yes, unused inputs on the 8405601DA must be terminated to either VCC or GND to prevent floating states that cause excessive current draw or undefined logic behavior. TI recommends 10-kΩ resistors for default HIGH (pull-up) or LOW (pull-down) biasing, consistent with standard CMOS input requirements and layout guidelines in the datasheet.

Can the 8405601DA operate reliably at 3.3 V supply voltage?

Yes, the 8405601DA is fully specified for 3.3 V operation: VIH = 2.31 V (min), VIL = 1.05 V (max), VOH ≥ 3.15 V (at IOH = –4 mA), and VOL ≤ 0.33 V (at IOL = 4 mA). All timing parameters-including setup time (20 ns), propagation delay (≤58 ns), and clock frequency (up to 25 MHz)-are guaranteed across the full 2 V to 6 V range, including 3.3 V.

What is the function of the complement output (Q̅) pins on the 8405601DA?

The complement output (Q̅) pins on the 8405601DA provide the logical inverse of the true Q output for each channel. They enable direct implementation of toggle-mode operation (by connecting Q̅ to D), differential signaling, feedback loops, or complementary drive for displays and drivers-without requiring external inverters or additional logic gates.

Is the 8405601DA pin-compatible with the obsolete SN74LS74?

Yes, the 8405601DA is pin-compatible with SN74LS74 in SOIC-14 package: identical pin count, pin functions, and physical footprint. However, it operates at lower current (±4 mA vs ±8 mA), has higher noise immunity, and requires no external pull-ups due to CMOS input structure-making it a direct drop-in replacement with improved power efficiency and thermal performance.