Renesas ICS8543BGIT

Overview

ICS8543BGIT from Integrated Device Technology (IDT) is a low-skew, 1-to-4 differential-to-LVDS fanout buffer designed for high-speed clock distribution in timing-critical systems. It supports dual differential input selections (CLK/nCLK or PCLK/nPCLK), delivers four LVDS output pairs, operates up to 650 MHz, and guarantees ≤40 ps output skew and ≤600 ps part-to-part skew across –40°C to +85°C ambient temperature.

For engineers reviewing the ICS8543BGIT datasheet, ICS8543BGIT pinout, ICS8543BGIT application, or ICS8543BGIT equivalent, this device is selected for precision clock fanout where deterministic jitter (0.164 ps RMS additive phase jitter), LVDS signal integrity, and multi-standard differential input compatibility (LVPECL, LVDS, SSTL, HCSL, CML) are required in telecom infrastructure, FPGA clocking, and high-speed serial interface designs.

Technical Context

The ICS8543BGIT implements a fully synchronous clock enable (CLK_EN) with internal synchronization to eliminate runt pulses during asynchronous assertion/deassertion. Its dual-input architecture allows selection between CLK/nCLK (supporting LVPECL, LVDS, LVHSTL, SSTL, HCSL) and PCLK/nPCLK (supporting LVPECL, CML, SSTL) via the LVCMOS-controlled CLK_SEL pin.

All four LVDS output pairs (Q0/nQ0 through Q3/nQ3) are internally matched for propagation delay (≤2.6 ns) and skew control, with guaranteed DC characteristics including VOD = 200–360 mV, VOS = 1.125–1.375 V, and 3.3 V single-supply operation. Input biasing enables single-ended signal translation using resistor networks on nCLK.

Key Specifications

Pinout & Package

ICS8543BGIT is housed in a lead-free 20-lead TSSOP (G package), 6.5 mm × 4.4 mm × 0.925 mm body, JEDEC MO-153 compliant. Thermal resistance θ_JA = 73.2°C/W (multi-layer PCB, 0 LFPM).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar differential-to-LVDS fanout buffer applications.

Compared with Si53301-D-GM and PI6C557-03LEX, the ICS8543BGIT offers superior input flexibility (dual selectable differential inputs), lowest guaranteed output skew (40 ps), and integrated synchronous clock enable - making it optimal for deterministic, low-latency clock distribution without PLL overhead.

Availability

ICS8543BGIT is available at Aetrix Electronics and suitable for telecom infrastructure, FPGA-based compute platforms, DDR memory subsystems, and test equipment requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for ICS8543BGIT 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

Integrated Device Technology (IDT), now part of Renesas Electronics, is a global leader in timing, memory interface, and RF power solutions, serving communications, computing, and industrial markets since 1980.

The ICS8543BGIT belongs to IDT's HiPerClockS™ fanout buffer family, engineered specifically for low-jitter, low-skew clock distribution in high-speed digital systems where signal integrity and timing predictability are critical.

FAQ

What input standards does the ICS8543BGIT support on its CLK/nCLK and PCLK/nPCLK pins?

The ICS8543BGIT supports LVPECL, LVDS, LVHSTL, SSTL, and HCSL on the CLK/nCLK inputs, and LVPECL, CML, and SSTL on the PCLK/nPCLK inputs. Each pair is optimized for its respective voltage thresholds and termination schemes, and internal pull-up/pull-down resistors (51 kΩ typical) simplify interface design. The ICS8543BGIT does not accept single-ended signals directly on these pins without external biasing.

How is clock enable synchronized in the ICS8543BGIT to prevent runt pulses?

The ICS8543BGIT implements an internal synchronizer on the CLK_EN pin that aligns enable/disable transitions to the active edge of the selected clock input (CLK/nCLK or PCLK/nPCLK). This eliminates metastability and ensures outputs transition cleanly - either enabling full LVDS output swing or forcing Qx low / nQx high - without generating narrow, invalid pulses that could disrupt downstream logic. This behavior is guaranteed across the full –40°C to +85°C operating range.

Can the ICS8543BGIT accept single-ended clock inputs, and if so, how?

Yes - the ICS8543BGIT can translate single-ended LVCMOS or LVTTL clocks using resistor biasing on the nCLK pin. A voltage divider (e.g., two 50 Ω resistors) sets VREF ≈ VDD/2 at the nCLK node, allowing the CLK pin to receive the full-rail clock while nCLK holds a stable common-mode reference. This configuration is documented in the datasheet's "Wiring the Differential Input to Accept Single-Ended Levels" section and maintains full 650 MHz capability when properly implemented.

What is the guaranteed LVDS output specification for the ICS8543BGIT, and why does it matter?

The ICS8543BGIT guarantees VOD = 200–360 mV (differential output voltage) and VOS = 1.125–1.375 V (common-mode offset), fully compliant with ANSI TIA/EIA-644. These values ensure robust noise immunity (>200 mV noise margin), compatibility with standard LVDS receivers, and reliable operation over process/voltage/temperature variations - critical for maintaining signal integrity in dense, high-speed PCB layouts.

Does the ICS8543BGIT require external termination resistors, and where should they be placed?

Yes - each LVDS output pair (Qx/nQx) must be terminated with a 100 Ω differential resistor at the receiver end of the transmission line. The ICS8543BGIT itself does not integrate termination; external 100 Ω surface-mount resistors should be placed as close as possible to the receiving device's input pins to minimize stub reflections. For point-to-point links, this is the only required termination; bus topologies may require additional considerations per the datasheet's LVDS Driver Termination section.