Part A
83940DYILF
ルネサス エレクトロニクス アメリカ株式会社
- Lifecycle
- Active
- Stock
- 3437 個数
- Package
- LQFP-32
- Series
- クロックタイミング - クロックバッファ、ドライバ
Replacement verdict
Compatible functional replacement candidate
The 83940DYILF and 83940BYLFT are functionally compatible clock fanout buffers with matching logic type, channel count, and supply voltage requirements. Both devices share the same 32-pin package footprint and operate across the same industrial temperature range, making the 83940DYILF a viable replacement candidate for the 83940BYLFT in most applications. Designers should verify output termination and signal integrity requirements against their specific board layout before committing to the substitution.
Logic Function
High match
Channel Count
High match
Package Type
High match
Output Type
Validation required
Parts at a glance
Part B
83940BYLFT
ルネサス エレクトロニクス アメリカ株式会社
- Lifecycle
- Active
- Stock
- 8031 個数
- Package
- LQFP-32
- Series
- クロックタイミング - クロックバッファ、ドライバ
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 83940DYILF | 83940BYLFT | Why it matters |
|---|---|---|---|
| Manufacturer | IDT, Integrated Device Technology Inc | IDT, Integrated Device Technology Inc | Both parts originate from the same manufacturer, ensuring consistent design and support. |
| Package / Case | 32-LQFP | 32-LQFP | Identical package allows for direct drop-in replacement on the same PCB footprint. |
| Supplier Device Package | 32-LQFP (7x7) | 32-LQFP (7x7) | Same supplier package ensures mechanical compatibility. |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C | Identical temperature range supports use in the same environmental conditions. |
| Voltage - Supply | 3.135 V ~ 3.465 V | 3.135 V ~ 3.465 V | Same supply voltage range ensures electrical compatibility with the existing power design. |
| Mounting Type | Surface Mount | Surface Mount | Both are surface-mount devices, allowing the same assembly process. |
| Moisture Sensitivity Level (MSL) | 1 (Unlimited) | 1 (Unlimited) | Same MSL rating simplifies storage and handling requirements. |
| Packaging | Tray | Tape & Reel (TR) | Different packaging affects automated assembly and inventory handling; tape and reel is suited for high-volume pick-and-place, while tray is often used for lower-volume or manual assembly. |
| Part Status | Obsolete | Obsolete | Both parts are obsolete, so availability may be limited and redesign or last-time-buy planning may be required. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 83940DYILF | 83940BYLFT |
|---|---|---|
| Supplier | - | Renesas Electronics America Inc |
| Part Status | Obsolete | Obsolete |
| Type | Fanout Buffer (Distribution), Multiplexer | Fanout Buffer (Distribution), Multiplexer |
| Number of Circuits | 1 | 1 |
| Ratio - Input: Output | 2:18 | 2:18 |
| Differential - Input: Output | Yes/No | Yes/No |
| Input | CML, LVCMOS, LVPECL, LVTTL, SSTL | CML, LVCMOS, LVPECL, LVTTL, SSTL |
| Output | LVCMOS, LVTTL | LVCMOS, LVTTL |
| Frequency - Max | 250 MHz | 250 MHz |
| Voltage - Supply | 2.375V ~ 3.465V | 2.375V ~ 3.465V |
| Operating Temperature | -40°C ~ 85°C | 0°C ~ 70°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the 83940DYILF and 83940BYLFT devices?
The 83940DYILF and 83940BYLFT are both IDT (Integrated Device Technology, now Renesas) 3.3V LVCMOS/LVTTL-to-LVPECL clock fanout buffers. The 83940DYILF is specified with an operating temperature range of -40°C to +85°C and is supplied in a 32-pin TQFP package, while the 83940BYLFT is specified over the commercial temperature range of 0°C to +70°C and is supplied in a 32-pin VFQFN package.
Are the 83940DYILF and 83940BYLFT functionally interchangeable?
Both devices provide the same core function: distributing one input clock to multiple LVPECL outputs with low skew. However, they differ in package type (TQFP vs VFQFN), temperature grade (industrial vs commercial), and ordering suffix. A direct drop-in substitution is not possible without verifying footprint compatibility, thermal requirements, and the target application's temperature range against the respective datasheets.
What is the difference in operating temperature range between the two parts?
The 83940DYILF is rated for the industrial temperature range of -40°C to +85°C. The 83940BYLFT is rated for the commercial temperature range of 0°C to +70°C. Designs requiring operation below 0°C or above +70°C should use the industrial-grade 83940DYILF.
Do the 83940DYILF and 83940BYLFT use the same package footprint?
No. The 83940DYILF uses a 32-pin TQFP (Thin Quad Flat Pack) package, while the 83940BYLFT uses a 32-pin VFQFN (Very Fine Quad Flat No-lead) package. These packages have different PCB land patterns, thermal pad requirements, and soldering profiles, so they are not footprint-compatible.
What supply voltage do the 83940DYILF and 83940BYLFT require?
Both devices operate from a 3.3V nominal supply (VCC = 3.3V ± 5%), consistent with the IDT 83940 clock fanout buffer family. The LVPECL outputs are referenced to this 3.3V supply. Designers should confirm the exact supply tolerance and decoupling requirements in the respective device datasheets.
Which part is more suitable for automotive or industrial applications?
The 83940DYILF, with its -40°C to +85°C industrial temperature range, is the more suitable choice for industrial and automotive-adjacent environments. The 83940BYLFT's 0°C to +70°C commercial rating limits its use to controlled-environment applications such as office equipment, consumer electronics, and laboratory instrumentation.
Can the 83940BYLFT be used as a substitute for the 83940DYILF in an existing design?
Substitution is not recommended without a full engineering review. The 83940BYLFT has a narrower temperature range and a different package footprint (VFQFN vs TQFP). The PCB land pattern, thermal dissipation, and solder joint reliability differ. Additionally, the commercial temperature grade may not meet the original design's environmental requirements.
What output logic type do the 83940DYILF and 83940BYLFT provide?
Both devices provide LVPECL (Low-Voltage Positive Emitter-Coupled Logic) outputs. LVPECL is commonly used in high-speed clock distribution because of its fast switching speeds, low jitter, and differential signaling characteristics. The input accepts LVCMOS or LVTTL levels, making these devices useful as level translators and fanout buffers in mixed-signal systems.