NXP Semiconductors 74ABT16821ADL,518

Overview

74ABT16821ADL,518 from Nexperia is a 20-bit, positive-edge-triggered bus-interface D-type flip-flop with dual independent 10-bit registers and 3-state outputs. It operates at 4.5 V to 5.5 V, delivers ±32 mA/±64 mA output drive, and supports 250 MHz maximum clock frequency in commercial temperature range (−40 °C to +85 °C). It is used in high-speed data buffering and bus isolation for microprocessor and memory interface applications.

For engineers reviewing the 74ABT16821ADL,518 datasheet, 74ABT16821ADL,518 pinout, 74ABT16821ADL,518 application, or 74ABT16821ADL,518 equivalent, this device serves as a high-drive, low-noise register for bidirectional bus control in industrial computing and embedded systems where timing-critical data latching and 3-state bus management are required.

Technical Context

The 74ABT16821ADL,518 implements two independent 10-bit edge-triggered D-type flip-flop sections, each with dedicated clock (nCP) and active-LOW output enable (nOE). Each section latches data on the rising edge of its respective clock, with setup/hold times specified down to 1.8 ns and 1.0 ns respectively.

Its BiCMOS architecture enables simultaneous high-speed operation (tPLH/tPHL ≤ 3.7 ns), robust output drive (+64 mA sink / −32 mA source), and low static current (ICC ≤ 1.0 mA in 3-state mode), making it suitable for driving heavily loaded MOS buses and memory address/data lines without signal integrity degradation.

Key Specifications

Pinout & Package

74ABT16821ADL,518 is housed in a plastic shrink small outline package (SSOP56) with 56 leads and 7.5 mm body width (SOT371-1), optimized for high-density PCB layouts while maintaining thermal and mechanical reliability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 20-bit registered bus-interface applications.

Compared with 74ABT16821ADL,518, the 74ABT16821ADGG offers identical functionality in a more compact TSSOP package, while the SN74ABT16821DLR requires PCB layout changes and provides marginally slower timing-making the original SSOP variant optimal for direct replacement and industrial thermal stability.

Availability

74ABT16821ADL,518 is available at Aetrix Electronics and suitable for microprocessor bus interface, memory address latching, industrial I/O expansion, and digital signal routing hub applications requiring stable component supply and long-term industrial lifecycle support.

Supply support for 74ABT16821ADL,518 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 leader in discrete, logic, and PowerMOS semiconductors, formed in 2017 from the former NXP Standard Products business, with deep expertise in automotive, industrial, and computing applications.

The 74ABT16821ADL,518 belongs to Nexperia's ABT logic family, engineered for high-speed, high-drive 5 V bus-interface applications where noise immunity, timing precision, and industrial temperature operation are essential.

FAQ

What is the maximum clock frequency supported by the 74ABT16821ADL,518?

The 74ABT16821ADL,518 supports a maximum clock frequency of 250 MHz under recommended operating conditions (VCC = 5.0 V ± 0.5 V, −40 °C to +85 °C). This value is verified in the dynamic characteristics table and reflects guaranteed performance across the full industrial temperature range-not just typical or room-temperature values. The 74ABT16821ADL,518 achieves this using BiCMOS circuitry that minimizes propagation delay (tPLH/tPHL ≤ 3.7 ns).

Does the 74ABT16821ADL,518 have power-up 3-state functionality?

Yes, the 74ABT16821ADL,518 features power-up 3-state behavior: all outputs default to high-impedance during power ramp-up, preventing bus contention before system initialization completes. This is confirmed in the "Features and benefits" section and validated by the power-up LOW-level output voltage specification (VOL(pu) ≤ 0.55 V at VCC = 5.5 V). The 74ABT16821ADL,518 also includes power-up reset, ensuring predictable register states at startup.

What is the output drive capability of the 74ABT16821ADL,518?

The 74ABT16821ADL,518 delivers −32 mA source current (IOH) and +64 mA sink current (IOL) per output, as specified in Table 5. This asymmetric drive supports legacy TTL loads and enables robust fan-out to multiple CMOS inputs. These values are guaranteed over the full operating temperature range and are measured at VOH ≥ 2.0 V and VOL ≤ 0.55 V. The 74ABT16821ADL,518 maintains this drive strength without derating up to +85 °C.

Is the 74ABT16821ADL,518 pin-compatible with other packages in the same family?

The 74ABT16821ADL,518 (SSOP56, SOT371-1) shares identical pinout and electrical specifications with the 74ABT16821ADGG (TSSOP56, SOT364-1), making them functionally interchangeable with no schematic or layout changes required. However, mechanical differences-such as body width (7.5 mm vs. 6.1 mm) and height-must be accounted for in PCB footprint and thermal design. The 74ABT16821ADL,518 is not pin-compatible with non-ABT variants like the 74ACT or 74F families.

What ESD protection level does the 74ABT16821ADL,518 provide?

The 74ABT16821ADL,518 exceeds HBM (Human Body Model) ESD protection of 2000 V and MM (Machine Model) ESD protection of 200 V, as documented in Section 2 ("Features and benefits") and Table 6. These ratings are verified per JESD22-A114F and JESD22-A115-A standards and apply to all I/O pins. This level of protection ensures safe handling during assembly and reliable operation in industrial environments where static discharge events are common. The 74ABT16821ADL,518 incorporates on-chip clamping structures to dissipate transient energy without latch-up.