Texas Instruments SN74ABT3612-20PCB

Overview

SN74ABT3612-20PCB from Texas Instruments is a clocked bidirectional FIFO memory IC with two independent 64 × 36 dual-port SRAM buffers, supporting asynchronous or coincident CLKA/CLKB up to 67 MHz, 10 ns read access time, and passive parity checking on both 36-bit ports. It enables high-throughput data bridging between mismatched microprocessor buses in telecom backplanes.

For engineers reviewing the SN74ABT3612-20PCB datasheet, SN74ABT3612-20PCB pinout, SN74ABT3612-20PCB application, or SN74ABT3612-20PCB equivalent, key selection criteria include its dual-clock domain synchronization, programmable almost-full/empty flag offsets (4/8/12/16), mailbox-bypass register support, and 120-pin thin quad flat (PCB) package compatibility with high-density interconnect layouts.

Technical Context

The SN74ABT3612-20PCB implements two independent clocked FIFOs (FIFO1 and FIFO2), each with separate read/write pointers, synchronized flag logic, and dedicated mailbox registers (Mail1/Mail2) for non-queued command transfer. Its dual-port architecture allows simultaneous A→B and B→A buffering without arbitration.

Flag synchronization uses two-stage flip-flop chains: EFA/FFA/AFA/AEA are synchronized to CLKA; EFB/FFB/AFB/AEB to CLKB. Parity checking is implemented via four per-port parity trees, shared with mailbox registers during parity-generation reads, and selectable as odd/even via ODD/EVEN input.

Key Specifications

Pinout & Package

SN74ABT3612-20PCB is housed in a 120-pin thin quad flat package (PCB), measuring 24 mm × 24 mm × 1.4 mm, with 0.5 mm lead pitch and exposed thermal pad. Pin numbering follows standard counter-clockwise top-view layout starting from pin 1 (NC) at top-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar clocked FIFO applications.

Compared with IDT72V2115L10PF and NB3N502MNR2G, SN74ABT3612-20PCB uniquely delivers integrated mailbox registers, programmable flag offsets, and shared parity hardware in a 120-pin footprint-making it optimal for space-constrained, high-reliability dual-processor bridges requiring minimal external logic.

Availability

SN74ABT3612-20PCB is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, and medical imaging systems requiring stable component supply, long-lifecycle support, and traceable sourcing for Class B safety-critical designs.

Supply support for SN74ABT3612-20PCB 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 specializing in analog, embedded processing, and logic solutions, with decades of expertise in high-speed interface and memory products.

The SN74ABT3612-20PCB belongs to TI's ABT-series advanced BiCMOS FIFO family, designed specifically for high-reliability, low-latency data bridging in mixed-clock-domain systems such as communications backplanes and real-time control subsystems.

FAQ

What is the maximum supported clock frequency for SN74ABT3612-20PCB?

The SN74ABT3612-20PCB supports clock frequencies up to 67 MHz on both CLKA and CLKB inputs. This specification is validated across the full commercial temperature range (0°C to 70°C) and applies to both read and write operations with proper setup/hold timing compliance. The 10 ns read access time is guaranteed at this maximum frequency.

Does SN74ABT3612-20PCB support asynchronous clock domains between Port A and Port B?

Yes, SN74ABT3612-20PCB explicitly supports asynchronous operation: CLKA and CLKB may run at different frequencies, phases, or even be stopped independently. All status flags (EFA/FFA/AFA/AEA and EFB/FFB/AFB/AEB) are hardened with two-stage synchronization to their respective clock domains to prevent metastability-induced handshake failures.

How are the almost-full and almost-empty flag thresholds programmed on SN74ABT3612-20PCB?

The SN74ABT3612-20PCB uses FS0 and FS1 inputs to select one of four fixed offset values (4, 8, 12, or 16 words) for both AFA/AEA and AFB/AEB flags. These values are latched into the internal offset register on the rising edge of RST, and remain active until the next reset event. No serial configuration interface is required.

Can SN74ABT3612-20PCB perform parity checking and generation simultaneously on both ports?

No-parity checking is always active on both A0–A35 and B0–B35 inputs, but generation is port-selective and mutually exclusive per read operation. PGA enables parity generation only on Port-A reads; PGB enables it only on Port-B reads. When both are high, parity bits are generated for whichever port is actively reading, not both concurrently.

What is the function of the MBA and MBB pins on SN74ABT3612-20PCB?

MBA and MBB are mailbox-select inputs that route data paths between FIFOs and bypass registers. When MBA is high during a Port-A read, A0–A35 outputs data from Mail2 instead of FIFO2; when MBB is high during a Port-B read, B0–B35 outputs data from Mail1 instead of FIFO1. This enables zero-latency command exchange alongside buffered data flow.