CDC329ADG4 Equivalent & Substitute Parts

Part Overview

The CDC329ADG4 is a Clock Fanout Buffer (Distribution) IC manufactured by Texas Instruments, designed for 1:6 clock distribution at 80 MHz. This component features TTL input with CMOS output, operates across a 4.75V to 5.25V supply range, and is housed in a 16-SOIC package. The part is currently discontinued at DiGi Electronics, necessitating identification of functionally equivalent alternatives from the active product portfolio to maintain design continuity and ensure supply chain availability.

Substiute Parts

CDC329ADG4

Texas InstrumentsIn Stock: 781CDC329ADG4 Datasheet

Current PartRFQ

CDC328ADBR

Texas InstrumentsIn Stock: 2167CDC328ADBR Datasheet

MFR RecommendedRFQ

CDC329AD

Texas InstrumentsIn Stock: 1522CDC329AD Datasheet

MFR RecommendedRFQ

CDC391D

Texas InstrumentsIn Stock: 842CDC391D Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the CDC329ADG4 are identified based on the following critical parameters that determine functional compatibility:

Primary Substitution Criteria:

• Fanout Buffer (Distribution) type with 1:6 input-to-output ratio
• TTL input compatibility
• Supply voltage range of 4.75V to 5.25V
• Operating temperature range of -40°C to 85°C
• Surface mount technology
• ROHS3 compliance

Substitution Groups:

Group 1: Same Package, Same Frequency (16-SOIC, 80 MHz)

• CDC329AD: Identical electrical specifications to CDC329ADG4, differentiated only by packaging format (Tube vs. Tape & Reel). Active product status ensures ongoing availability.

Group 2: Same Package, Higher Frequency (16-SOIC, 100 MHz)

• CDC391D: Maintains 16-SOIC package compatibility with increased maximum frequency of 100 MHz. Output type changes from CMOS to TTL, which is compatible with TTL input systems. Active product status.

Group 3: Different Package, Higher Frequency (16-SSOP, 100 MHz)

• CDC328ADBR: Provides 100 MHz operation with TTL output in a 16-SSOP package (0.209", 5.30mm Width). Requires PCB layout modification due to package change but offers higher frequency capability.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (No Design Changes Required): CDC329AD is the primary substitute for CDC329ADG4. Both parts maintain identical electrical specifications, 1:6 fanout ratio, 80 MHz maximum frequency, TTL input with CMOS output, and 16-SOIC package footprint. The only difference is packaging format (Tube vs. Tape & Reel). CDC329AD holds active product status, ensuring continued availability and supply chain reliability.

For Enhanced Performance (Package Footprint Preserved): CDC391D provides a direct footprint replacement with increased maximum frequency of 100 MHz. The output type transitions from CMOS to TTL, which maintains compatibility with TTL input systems. This option is suitable for designs where higher clock distribution frequency is beneficial and TTL output levels are acceptable. CDC391D is active and in stock.

For Higher Frequency with Package Modification: CDC328ADBR offers 100 MHz operation with TTL output in a 16-SSOP package. This option requires PCB layout modification due to the different package footprint (0.209" vs. 0.154" width). Selection of this part is appropriate when PCB redesign is feasible and higher frequency operation is required.

All substitute parts maintain ROHS3 compliance, identical supply voltage range (4.75V to 5.25V), and operating temperature specifications (-40°C to 85°C), ensuring regulatory and thermal compatibility with the original design.

Frequently Asked Questions (FAQ)

Q: Can CDC329AD be used as a direct replacement for CDC329ADG4? A: Yes. CDC329AD is electrically identical to CDC329ADG4, with the same 1:6 fanout ratio, 80 MHz maximum frequency, TTL input, CMOS output, and 16-SOIC package. The parts differ only in packaging format (Tube vs. Tape & Reel). CDC329AD is currently active and available.

Q: What is the difference between CDC329ADG4 and CDC391D? A: Both parts use the 16-SOIC package and maintain the 1:6 fanout ratio. CDC391D operates at 100 MHz maximum frequency compared to CDC329ADG4's 80 MHz. The output type changes from CMOS to TTL. TTL output is compatible with TTL input systems and can drive CMOS inputs, making CDC391D a viable upgrade option.

Q: Why would I choose CDC328ADBR over CDC329AD? A: CDC328ADBR provides 100 MHz operation versus 80 MHz for CDC329AD. However, CDC328ADBR uses a 16-SSOP package instead of 16-SOIC, requiring PCB layout modification. Selection depends on whether the design requires higher frequency operation and whether PCB redesign is acceptable.

Q: Are all substitute parts ROHS3 compliant? A: Yes. CDC329AD, CDC391D, and CDC328ADBR are all ROHS3 compliant, matching the compliance status of CDC329ADG4.

Q: Do the substitute parts operate at the same supply voltage? A: Yes. All substitute parts operate across the same 4.75V to 5.25V supply voltage range as CDC329ADG4.

Q: What is the difference between CMOS and TTL output types in these parts? A: CDC329ADG4 and CDC329AD feature CMOS output, while CDC391D and CDC328ADBR feature TTL output. Both output types are compatible with TTL input systems. TTL output levels are typically lower than CMOS levels but remain within acceptable logic thresholds for standard digital circuits.

Q: Can I use CDC328ADBR if my PCB is designed for 16-SOIC? A: No. CDC328ADBR uses a 16-SSOP package with different pin spacing and dimensions (0.209" width vs. 0.154" for SOIC). Direct substitution on an existing PCB is not possible without layout modification.