Texas Instruments CDCVF2509PWG4

Overview

CDCVF2509PWG4 from Texas Instruments is a 3.3V phase-lock loop (PLL) clock driver IC designed for synchronous DRAM applications, delivering nine low-skew, low-jitter clock outputs across two banks (5+4), with static phase error ±125ps and cycle-to-cycle jitter typical 70ps at 66–166MHz, meeting PC133 SDRAM registered DIMM Rev. 1.1 specification.

For engineers reviewing the CDCVF2509PWG4 datasheet, CDCVF2509PWG4 pinout, CDCVF2509PWG4 application, or CDCVF2509PWG4 equivalent, this page provides verified technical context, real-world timing behavior, bank-selectable output enable control, integrated 25-Ω series damping, and PLL bypass capability via AVCC strapping - all critical for DDR memory subsystem design and spread-spectrum clocking integration.

Technical Context

The CDCVF2509PWG4 implements a fully integrated PLL architecture with on-chip loop filter, eliminating external RC networks and reducing board space. It synchronizes FBOUT to CLK via external feedback (FBIN→FBOUT hardwire), achieving zero-phase-error alignment under stable input conditions.

Its dual-bank output structure supports independent enable control (1G/2G), 50% duty-cycle correction regardless of input duty cycle, and operates exclusively at 3.3V with analog/digital supply separation (AVCC/VCC). Stabilization time of 1ms is required post-power-up or reference change before phase lock and full timing compliance.

Key Specifications

Pinout & Package

Package: 24-pin TSSOP (PW), 0.65mm pitch, 7.8mm × 4.4mm body, 1.2mm max height, RoHS-compliant NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CDCVF2509PWG4, both alternatives share identical PLL architecture, timing specs, and pinout - differing only in packaging format and reel configuration. CDCVF2509PWG4 adds green (lead-free) marking compliance and large-tape logistics, making it the preferred choice for RoHS-aligned volume manufacturing with traceable sourcing.

Availability

CDCVF2509PWG4 is available at Aetrix Electronics and suitable for PC133 SDRAM modules, spread-spectrum memory interfaces, and industrial embedded memory controllers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for CDCVF2509PWG4 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 company specializing in analog, embedded processing, and logic technologies, with leadership in clocking, interface, and power management solutions.

The CDCVF2509PWG4 belongs to TI's high-performance clock distribution product line, engineered specifically for low-skew, low-jitter synchronization in synchronous DRAM subsystems - targeting PC133 and early DDR memory architectures.

FAQ

What is the stabilization time requirement for CDCVF2509PWG4 to achieve phase lock?

The CDCVF2509PWG4 requires a 1ms stabilization time after power-up or any change to the reference clock (CLK) or feedback signal to achieve full phase lock. During this period, propagation delay, skew, and jitter specifications do not apply. This timing is defined in the switching characteristics table and assumes a fixed-frequency, fixed-phase CLK input. The CDCVF2509PWG4 must complete stabilization before use in production memory timing paths.

Does CDCVF2509PWG4 support spread-spectrum clocking (SSC)?

Yes, the CDCVF2509PWG4 is explicitly designed to be Spread Spectrum Clock-compatible, as stated in its official features list. It maintains low jitter performance under SSC modulation and is supported by TI's "Using CDC2509A/2510A PLL with Spread Spectrum Clocking" application note. The CDCVF2509PWG4's PLL architecture tracks modulated inputs without loss of lock, enabling EMI reduction in memory subsystems while preserving timing margins.

How does the AVCC pin function in CDCVF2509PWG4?

The AVCC pin on the CDCVF2509PWG4 serves as the analog power supply for the internal PLL circuitry. When AVCC is strapped to ground, the PLL is bypassed and the input clock (CLK) is routed directly to all outputs without phase alignment - effectively converting the CDCVF2509PWG4 into a low-skew buffer. This mode is useful for debug, legacy compatibility, or scenarios where deterministic propagation delay (1.8–3.9ns) is prioritized over phase correction.

What is the purpose of the 25-Ω series damping resistors in CDCVF2509PWG4?

The CDCVF2509PWG4 integrates 25-Ω series damping resistors on every output (1Y0–1Y4 and 2Y0–2Y3) to match standard 50-Ω PCB trace impedance when driving point-to-point loads. This eliminates the need for external series termination resistors, reduces component count, improves signal integrity by suppressing reflections, and simplifies layout - especially critical in dense DIMM designs where routing area is constrained. These resistors are part of the die, not package parasitics.

Can CDCVF2509PWG4 drive non-SDRAM loads such as FPGAs or microcontrollers?

While the CDCVF2509PWG4 is optimized for SDRAM clock distribution (per PC133 spec), its nine low-jitter, low-skew 3.3V CMOS outputs can drive other 3.3V logic loads including FPGAs and microcontrollers - provided load capacitance remains ≤25pF and termination matches the 25-Ω series resistor. However, duty-cycle correction and PLL lock behavior are tuned for memory timing; for general-purpose clock buffering without phase alignment needs, simpler non-PLL buffers may offer lower cost and faster startup.