Texas Instruments SCAN921224SLC

Overview

SCAN921224SLC from Texas Instruments (formerly National Semiconductor) is a 10-bit Bus LVDS deserializer IC designed to recover parallel clock and data from a single differential serial stream. It operates at 20–66 MHz input clock rates, delivers 660 Mbps payload data rate, supports IEEE 1149.1 JTAG boundary-scan, and features at-speed BIST for interconnect validation - deployed in high-reliability backplane and UTP cable communication systems.

For engineers reviewing the SCAN921224SLC datasheet, SCAN921224SLC pinout, SCAN921224SLC application, or SCAN921224SLC equivalent, this page provides verified functional role, lock-time behavior under random data, embedded-clock recovery architecture, power-down current (≤1.0 mA), and flow-through BGA pinout layout guidance - all critical for deterministic timing design and system-level test integration.

Technical Context

The SCAN921224SLC uses a PLL-based clock recovery architecture that locks to embedded clock bits (start/stop framing) within the 12-bit serialized stream (10 data + 2 control bits), enabling synchronization without external clock distribution. Its REFCLK input drives local PLL initialization, while LOCK output signals valid data alignment status.

It implements dual synchronization modes: fast lock via SYNC patterns (≤3 µs at 66 MHz) and open-loop random-data lock (mean 3.0 µs, min 0.43 µs), with false-lock detection circuitry preventing misalignment on repetitive multi-transition (RMT) patterns in DIN0–DIN8. The device supports hot insertion and maintains receiver input high-impedance when powered off.

Key Specifications

Pinout & Package

SCAN921224SLC is housed in a 49-lead BGA package (SLC49a), 7×7 mm, 0.8 mm pitch, with flow-through pinout optimized for minimal trace stubs in backplane routing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SCAN921224SLC, SN65LV1023A requires external clock routing and offers no built-in test infrastructure, while DS90CR288A trades JTAG/BIST and deterministic lock behavior for higher bandwidth and channel density - making SCAN921224SLC uniquely suited for safety-critical, testable backplane links.

Availability

SCAN921224SLC is available at Aetrix Electronics and suitable for industrial PLC backplanes, avionics data concentrators, automated test equipment interconnects, and high-reliability telecommunications chassis requiring stable component supply and long-term lifecycle support.

Supply support for SCAN921224SLC 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 acquired National Semiconductor in 2011 and maintains full technical and supply chain responsibility for legacy high-reliability interface products.

The SCAN921224SLC belongs to TI's Bus LVDS serializer/deserializer chipset family, engineered specifically for deterministic, testable, low-skew data transmission across backplanes and cables in harsh electromagnetic environments.

FAQ

What is the primary function of the SCAN921224SLC in a system?

The SCAN921224SLC functions as a 10-bit Bus LVDS deserializer that recovers both clock and data from a single differential serial stream. It extracts embedded clock bits from the 12-bit frame (10 data + 2 control), generates a synchronized RCLK output, and presents validated parallel data on ROUT0–ROUT9 - enabling high-integrity, skew-free communication across backplanes or UTP cables without separate clock lines.

Does the SCAN921224SLC require an external clock source to operate?

Yes, the SCAN921224SLC requires a stable REFCLK input to initialize its internal PLL before lock acquisition. REFCLK must be applied prior to or concurrent with power-up and remain active during operation. While it recovers clock information from the serial stream, REFCLK is essential for PLL startup and phase alignment - unlike fully self-clocked receivers.

How does the SCAN921224SLC handle loss of synchronization during operation?

When the SCAN921224SLC loses lock, the LOCK pin asserts high and ROUT0–ROUT9 enter TRI-STATE. Up to three previously valid data cycles may contain bit errors due to lock-detection latency. Resynchronization occurs either by receiving new SYNC patterns from the serializer (triggered via LOCK feedback) or via random-data relock - with mean times of 3.0 µs at 66 MHz under PRBS215 conditions.

Can the SCAN921224SLC be used in hot-plug applications?

Yes, the SCAN921224SLC supports hot insertion: its receiver inputs remain high-impedance when unpowered, and its random-lock capability allows synchronization to live data streams. Proper mechanical sequencing (GND → VCC → I/O) is required. The device has been verified for hot-plug operation in multi-slot backplanes per application note guidelines.

What test capabilities does the SCAN921224SLC provide beyond standard JTAG?

Beyond IEEE 1149.1 boundary-scan, the SCAN921224SLC implements RUNBIST - an at-system-speed interconnect test executing in ~33 ms at 66 MHz. It validates the entire LVDS link (including cable/backplane) with pass/fail reporting based on measured bit-error-rate (<10⁻⁷). This complements EXTEST for go/no-go physical layer checks and enables production-level link integrity verification.