Texas Instruments HPA00126DGGR

Overview

HPA00126DGGR from Texas Instruments is a 2.5-V phase-locked-loop (PLL) clock driver IC designed for high-performance DDR memory clock distribution. It delivers 1-to-10 differential SSTL-2 clock outputs with 60–220 MHz operating frequency, ±35 ps cycle-to-cycle jitter, ±50 ps static phase offset, and low-power shutdown mode. It serves as a zero-delay fan-out buffer in DDR400/333/266/200 memory modules.

For engineers reviewing the HPA00126DGGR datasheet, HPA00126DGGR pinout, HPA00126DGGR application, or HPA00126DGGR equivalent, this page provides verified technical context, validated pin functions, confirmed DDR timing compliance (JESD82-1/JESD82-1A), real-world output skew (40 ps), and alternative options with documented functional alignment for memory subsystem clocking.

Technical Context

The HPA00126DGGR implements a PLL-based architecture to achieve zero-delay clock distribution with synchronized feedback path via dedicated FBIN/FBOUT terminals. Its analog PLL core operates from a 2.5-V AVDD supply and supports spread-spectrum clocking for EMI reduction.

It features dual power domains: VDDQ (2.5 V) for digital I/O and AVDD (2.5 V) for analog PLL operation, with AGND isolation. Power-down control (PWRDWN) disables all outputs to high-impedance and shuts down the PLL when asserted low or when input frequency drops below ~10 MHz.

Key Specifications

Pinout & Package

The HPA00126DGGR is housed in a 48-pin TSSOP (DGG) package with 0.5 mm pitch, 12.6 mm × 6.2 mm body size, and 1.2 mm max height per JEDEC MO-153.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HPA00126DGGR, CDCVF2507DGG offers reduced fan-out but identical DDR timing compliance and footprint compatibility, while CDCLVD1208RGTT trades SSTL-2 DDR compatibility for LVDS flexibility and eliminates PLL lock time overhead at the cost of external loop design.

Availability

HPA00126DGGR is available at Aetrix Electronics and suitable for DDR memory modules, server DIMMs, industrial PLCs, and networking line cards requiring stable component supply across commercial and industrial temperature ranges.

Supply support for HPA00126DGGR 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 clock solutions with decades of DDR timing expertise.

The CDCVF857 product line-including HPA00126DGGR-is engineered specifically for high-speed DDR memory clock distribution, emphasizing low jitter, zero-delay operation, and JEDEC-compliant SSTL-2 signaling.

FAQ

What is the function of the AVDD and AGND pins on the HPA00126DGGR?

The AVDD and AGND pins supply and reference the analog PLL core of the HPA00126DGGR. AVDD must be a clean 2.5-V source decoupled with a 2200-pF capacitor near the pin, and AGND must be isolated from digital ground to minimize noise injection into the PLL. This separation ensures low-jitter performance and stable phase-lock acquisition.

Does the HPA00126DGGR support spread-spectrum clocking (SSC)?

Yes, the HPA00126DGGR explicitly supports spread-spectrum clocking as stated in its official TI datasheet. Its PLL architecture tracks modulated input clocks, reducing electromagnetic interference without compromising output jitter or phase accuracy-making it suitable for FCC/CE-compliant DDR systems.

What is the stabilization time required for the HPA00126DGGR PLL to achieve lock?

The HPA00126DGGR requires 10 µs to achieve PLL lock after power-up or re-enabling from power-down mode, as specified in the TI SCAS047F datasheet. This stabilization time applies only in PLL mode; bypass mode recovery takes just 30 ns. Timing-critical systems must account for this lock time before sampling valid outputs.

Can the HPA00126DGGR operate with a 2.6-V supply instead of 2.5 V?

Yes, the HPA00126DGGR is rated for dual 2.6-V or 2.5-V supplies per its datasheet. The recommended operating range for VDDQ and AVDD is 2.3 V to 2.7 V, so 2.6 V falls safely within specification and maintains full compliance with JESD82-1 DDR timing margins and output drive strength.

How does the PWRDWN pin affect the HPA00126DGGR's output state and power consumption?

When PWRDWN is driven low, the HPA00126DGGR disables all Y/Y and FBOUT/FBOUT outputs to high-impedance and shuts down the PLL, reducing total supply current to <100 µA. This low-power mode is automatically entered if the input clock frequency drops below ~10 MHz, enabling dynamic power management in idle memory subsystems.