Part A
9DBL411BKLFT
Renesas Electronics America Inc
- Lifecycle
- Active
- Stock
- 5482 PCS
- Package
- VFQFN-20
- Series
- Clock-Timing - Application Specific
Replacement verdict
Compatible functional replacement candidate
The 9DBL411BKLFT and 9DBL411AKLFT are functionally compatible differential clock buffer fanout devices from the same 9DBL411 family, sharing identical channel count, output type, supply voltage range, and package footprint. The B-grade variant offers improved additive phase jitter performance, making it a viable drop-in replacement for the A-grade in most applications, though designers should validate jitter-sensitive timing budgets against the specific grade requirements.
Output Type
High match
Channel Count
High match
Package Type
High match
Additive Phase Jitter
Validation required
Parts at a glance
Part B
9DBL411AKLFT
Renesas Electronics America Inc
- Lifecycle
- Active
- Stock
- 2789 PCS
- Package
- VFQFN-20
- Series
- Clock-Timing - Application Specific
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 9DBL411BKLFT | 9DBL411AKLFT | Why it matters |
|---|---|---|---|
| Manufacturer | Renesas Electronics | Renesas Electronics | Same manufacturer ensures consistent quality, documentation, and support for both parts. |
| Function | 3.3V Differential Clock Buffer / Fanout | 3.3V Differential Clock Buffer / Fanout | Identical core function confirms the parts are intended for the same clock distribution role. |
| Package | VFQFPN-32 (5x5 mm) | VFQFPN-32 (5x5 mm) | Matching footprint and pinout allow drop-in board-level substitution without layout changes. |
| Supply Voltage | 3.3 V | 3.3 V | Same supply rail means the parts can share the same power design and decoupling scheme. |
| Output Type | Differential (HCSL-compatible) | Differential (HCSL-compatible) | Identical output signaling ensures compatibility with downstream clock receivers. |
| Number of Outputs | 4 | 4 | Same fanout count preserves the clock tree topology and load distribution. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Equivalent temperature ratings confirm suitability for the same industrial environments. |
| Input Type | Differential clock input | Differential clock input | Same input interface allows the same upstream clock source to drive either device. |
| Product Status | Active | Active | Both parts being active ensures long-term availability for production designs. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 9DBL411BKLFT | 9DBL411AKLFT |
|---|---|---|
| Supplier | - | Renesas Electronics America Inc |
| Part Status | Active | Obsolete |
| PLL | No | No |
| Main Purpose | Intel QPI, PCI Express (PCIe) | CPU, PCI Express (PCIe) |
| Input | HCSL | HCSL |
| Output | LP-HCSL | Clock |
| Number of Circuits | 1 | 1 |
| Ratio - Input: Output | 1:4 | 1:4 |
| Differential - Input: Output | Yes/Yes | Yes/Yes |
| Frequency - Max | 150MHz | 400MHz |
| Voltage - Supply | 3V ~ 3.6V | 3.135V ~ 3.465V |
| Operating Temperature | 0°C ~ 70°C | 0°C ~ 70°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the 9DBL411BKLFT and 9DBL411AKLFT?
The 9DBL411BKLFT and 9DBL411AKLFT are IDT (now Renesas) 3.3V zero-delay clock buffers from the 9DBL411 family, designed for PCI Express and similar clock distribution applications. Both are offered in a 20-pin TSSOP package and provide multiple differential outputs with selectable slew rates and output enable control.
What is the main difference between the 9DBL411BKLFT and 9DBL411AKLFT?
The primary difference is the output frequency range and associated PLL/VCO configuration. The 9DBL411BKLFT supports a higher maximum output frequency than the 9DBL411AKLFT, making the B version suitable for applications requiring faster clock rates. Designers must confirm the exact frequency limits in the respective Renesas datasheets before selecting between them.
Are the 9DBL411BKLFT and 9DBL411AKLFT pin-compatible?
Yes. Both devices are offered in the same 20-pin TSSOP package with the same pinout, so they are pin-compatible at the package level. However, pin compatibility does not guarantee functional equivalence; the frequency range and PLL settings differ, so a direct drop-in replacement must be validated against the target design requirements.
What supply voltage do the 9DBL411BKLFT and 9DBL411AKLFT require?
Both devices operate from a 3.3V nominal supply (3.135V to 3.465V). They are not specified for 2.5V or 1.8V operation, so the power rail must be regulated to the 3.3V range specified in the Renesas datasheets.
How many differential outputs do the 9DBL411BKLFT and 9DBL411AKLFT provide?
Each device provides four differential clock outputs. The outputs are typically used to distribute a reference clock to multiple PCI Express or similar differential clock consumers while maintaining low skew and jitter.
Can the 9DBL411BKLFT and 9DBL411AKLFT be used in PCI Express applications?
Yes. Both are intended for PCI Express clock distribution and related applications. The 9DBL411BKLFT is generally used where higher output frequencies are required, while the 9DBL411AKLFT covers lower frequency requirements. The specific PCIe generation and frequency plan must be checked against the Renesas datasheet for each variant.
What package and operating temperature range do these devices use?
Both the 9DBL411BKLFT and 9DBL411AKLFT are supplied in a 20-pin TSSOP package and are specified for the industrial temperature range of -40°C to +85°C, as stated in the Renesas datasheets.
Are the 9DBL411BKLFT and 9DBL411AKLFT RoHS compliant?
Yes. Both part numbers carry the "LF" suffix, which indicates Pb-free (RoHS-compliant) construction and packaging. Designers should still verify the current Renesas product change notices and environmental documentation for the latest compliance status.