Product details


Technology Family ACT VCC (Min) (V) 4.5 VCC (Max) (V) 5.5 Voltage (Nom) (V) 5 Bits (#) 1 F @ nom voltage (Max) (MHz) 90 ICC @ nom voltage (Max) (mA) 0.08 IOL (Max) (mA) 75 IOH (Max) (mA) -75 Operating temperature range (C) -55 to 125 open-in-new Find other Phase-locked-loop (PLL)/oscillator

Package | Pins | Size

SOIC (D) 16 59 mm² 9.9 x 6 open-in-new Find other Phase-locked-loop (PLL)/oscillator


  • Speed of Bipolar FCT, AS, and S, With Significantly Reduced Power Consumption
  • Digital Design Avoids Analog Compensation Errors
  • Easily Cascadable for Higher-Order Loops
  • Useful Frequency Range
    • DC to 110 MHz Typical (K CLK)
    • DC to 70 MHz Typical (I/D CLK)
  • Dynamically Variable Bandwidth
  • Very Narrow Bandwidth Attainable
  • Power-On Reset
  • Output Capability
    • Standard: XORPD OUT, ECPD OUT
    • Bus Driver: I/D OUT
  • SCR Latch-Up-Resistant CMOS Process and Circuit Design
  • Balanced Propagation Delays
  • ESD Protection Exceeds 2000 V Per MIL-STD-883, Method 3015

open-in-new Find other Phase-locked-loop (PLL)/oscillator


The CD74ACT297 provides a simple, cost-effective solution to high-accuracy, digital, phase-locked-loop applications. This device contains all the necessary circuits, with the exception of the divide-by-N counter, to build first-order phase-locked loops as shown in Figure 1.

Both exclusive-OR phase detectors (XORPDs) and edge-controlled (ECPD) phase detectors are provided for maximum flexibility.

Proper partitioning of the loop function, with many of the building blocks external to the package, makes it easy for the designer to incorporate ripple cancellation or to cascade to higher-order phase-locked loops.

The length of the up/down K counter is digitally programmable according to the K-counter function table. With A, B, C, and D all low, the K counter is disabled. With A high and B, C, and D low, the K counter is only three stages long, which widens the bandwidth, or capture range, and shortens the lock time of the loop. When A, B, C, and D are programmed high, the K counter becomes 17 stages long, which narrows the bandwidth, or capture range, and lengthens the lock time. Real-time control of loop bandwidth by manipulating the A-through-D inputs can maximize the overall performance of the digital phase-locked loop.

This device performs the classic first-order phase-locked-loop function without using analog components. The accuracy of the digital phase-locked loop (DPLL) is not affected by VCC and temperature variations, but depends solely on accuracies of the K clock (K CLK), increment/decrement clock (I/D CLK), and loop propagation delays. The I/D clock frequency and the divide-by-N modulos determine the center frequency of the DPLL. The center frequency is defined by the relationship fc = I/D clock/2N (Hz).

open-in-new Find other Phase-locked-loop (PLL)/oscillator

Technical documentation

= Featured
No results found. Please clear your search and try again. View all 13
Type Title Date
* Datasheet Digital Phase-Locked Loop datasheet (Rev. D) Jun. 27, 2002
Selection guides Logic Guide (Rev. AB) Jun. 12, 2017
Application notes Implications of Slow or Floating CMOS Inputs (Rev. D) Jun. 23, 2016
Application notes Understanding and Interpreting Standard-Logic Data Sheets (Rev. C) Dec. 02, 2015
Technical articles Failure to lock: Why wideband PLL frequency synthesizers lose lock Mar. 22, 2013
User guides LOGIC Pocket Data Book (Rev. B) Jan. 16, 2007
Application notes Semiconductor Packing Material Electrostatic Discharge (ESD) Protection Jul. 08, 2004
Application notes Selecting the Right Level Translation Solution (Rev. A) Jun. 22, 2004
More literature Logic Cross-Reference (Rev. A) Oct. 07, 2003
Application notes TI IBIS File Creation, Validation, and Distribution Processes Aug. 29, 2002
Application notes CMOS Power Consumption and CPD Calculation (Rev. B) Jun. 01, 1997
Application notes Designing With Logic (Rev. C) Jun. 01, 1997
Application notes Using High Speed CMOS and Advanced CMOS in Systems With Multiple Vcc Apr. 01, 1996

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Hardware development

document-generic User guide
This EVM is designed to support any logic device that has a D, DW, DB, NS, PW, P, N, or DGV package in a 14 to 24 pin count.
  • Board design allows for versatility in evaluation
  • Supports a wide-range of logic devices

CAD/CAE symbols

Package Pins Download
SOIC (D) 16 View options

Ordering & quality

Support & training

TI E2E™ forums with technical support from TI engineers

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​​​​​​​


Related videos