9FGL0841CKILFT - 8-Output PCIe Gen 1-5 Clock Generator | Renesas
MPN: 9FGL0841CKILFT ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.5 | $5.50 |
| 10 | $4.95 | $49.50 |
| 100 | $4.4 | $440.00 |
| 500 | $3.95 | $1,975.00 |
| 1,000 | $3.55 | $3,550.00 |
| 3,000 | $3.15 | $9,450.00 |
9FGL0841CKILFT Overview
A PCIe clock generator is a specialized application-specific clock/timing IC that produces the low-jitter 100 MHz HCSL reference clocks required by PCIe PHY layers. Within the broader clock/timing taxonomy, it sits below general-purpose PLLs and frequency synthesizers but above simple clock buffers, providing spread-spectrum clocking (SSC), per-output enable, and PCIe-compliant jitter and skew budgets in a single device. The 9FGL0841/0851 family supports both Common Clocked (CC) and Separate Reference Independent (SRIS/SRNS) PCIe architectures, with two selectable SSC percentages and SSC-off operation.
Key features include 100 MHz HCSL differential outputs, an input that accepts an external reference clock or fundamental-mode crystal, programmable spread spectrum (typically 0% / -0.25% / -0.5%), SMBus-compatible configuration, and per-output OE# pins. The device operates from a single 3.3 V supply and provides low additive jitter suitable for PCIe Gen 5 compliance. The 48-VFQFPN exposed-pad package delivers low thermal resistance for reliable operation in densely populated PCIe riser cards.
Typical applications include servers, high-performance computing (HPC) nodes, NVMe storage arrays, networking switches, workstation motherboards, and PCIe expansion cards. The 8-output count suits multi-host and PCIe-switch fabrics where multiple endpoints require independent clock gating for power savings.
When designing with this part, pay close attention to the differential trace length matching of the HCSL outputs, the bypass network on VDD, and the SMBus address selection pins. Note that Renesas product pages now describe this device family as supporting PCIe Gen 1-6, while the legacy IDT-branded datasheet (2019) covers Gen 1-4.
Drop-in alternatives for 9FGL0841CKILFT — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with 9FGL0841CKILFT (same form factor and footprint) — differing in Package, Number of Outputs, Output Type, Operating Temperature, Product Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
9FGL0841BKILFT
✅ Drop-In✓ In Stock
$2.74 / Unit
View Datasheet →9FGL0851CKILFT
✅ Drop-In📋 Reference alternative (not in catalog)
9FGL0841CKILF
✅ Drop-In📋 Reference alternative (not in catalog)
9DML0451AKILFT
✅ Drop-In✓ In Stock
$2.72 / Unit
View Datasheet →9DML0441AKILF
✅ Drop-In✓ In Stock
$2.25 / Unit
View Datasheet →9FGL0841CKILFT Specifications
| Product Type | PCI Express (PCIe) Clock Generator IC |
| Number of Outputs | 8 differential (HCSL) |
| Output Frequency | 100 MHz |
| Input Clock Type | External clock or fundamental-mode crystal |
| Output Type | HCSL, LVCMOS |
| Supply Voltage (VDD) | 3.3 V |
| PCIe Generation Support | Gen 1-5 (per legacy datasheet); Gen 1-6 (per current Renesas product page) |
| PCIe Architecture Support | Common Clocked (CC), SRnS, SRIS |
| Spread Spectrum | Programmable; SSC off, -0.25%, -0.5% (typical) |
| Per-Output Enable | Yes, dedicated OE# per output (supports CLKREQ#) |
| Configuration Interface | SMBus-compatible |
| Package | 48-VFQFPN (6x6 mm) with exposed pad |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (per distributor listing) |
| Lifecycle Status | Obsolete |
9FGL0841CKILFT Pin Configuration
| Pin 1 | VDD — 3.3 V supply |
| Pin 2 | OE0# — Output enable for CLK0 pair |
| Pin 3 | CLK0_N — HCSL differential output 0 negative |
| Pin 4 | CLK0_P — HCSL differential output 0 positive |
| Pin 5 | GND — Ground |
| Pin 6 | OE1# — Output enable for CLK1 pair |
| Pin 7 | CLK1_N — HCSL differential output 1 negative |
| Pin 8 | CLK1_P — HCSL differential output 1 positive |
| Pin 9 | VDD — 3.3 V supply |
| Pin 10 | OE2# — Output enable for CLK2 pair |
| Pin 11 | CLK2_N — HCSL differential output 2 negative |
| Pin 12 | CLK2_P — HCSL differential output 2 positive |
| Pin 13 | GND — Ground |
| Pin 14 | OE3# — Output enable for CLK3 pair |
| Pin 15 | CLK3_N — HCSL differential output 3 negative |
| Pin 16 | CLK3_P — HCSL differential output 3 positive |
| Pin 17 | VDD — 3.3 V supply |
| Pin 18 | OE4# — Output enable for CLK4 pair |
| Pin 19 | CLK4_N — HCSL differential output 4 negative |
| Pin 20 | CLK4_P — HCSL differential output 4 positive |
| Pin 21 | GND — Ground |
| Pin 22 | OE5# — Output enable for CLK5 pair |
| Pin 23 | CLK5_N — HCSL differential output 5 negative |
| Pin 24 | CLK5_P — HCSL differential output 5 positive |
| Pin 25 | VDD — 3.3 V supply |
| Pin 26 | OE6# — Output enable for CLK6 pair |
| Pin 27 | CLK6_N — HCSL differential output 6 negative |
| Pin 28 | CLK6_P — HCSL differential output 6 positive |
| Pin 29 | GND — Ground |
| Pin 30 | OE7# — Output enable for CLK7 pair |
| Pin 31 | CLK7_N — HCSL differential output 7 negative |
| Pin 32 | CLK7_P — HCSL differential output 7 positive |
| Pin 33 | VDD — 3.3 V supply |
| Pin 34 | REF_OUT — LVCMOS reference clock output |
| Pin 35 | GND — Ground |
| Pin 36 | XIN — Crystal input or reference clock input |
| Pin 37 | XOUT — Crystal output |
| Pin 38 | SDA — SMBus serial data |
| Pin 39 | SCL — SMBus serial clock |
| Pin 40 | SA0 — SMBus address select 0 |
| Pin 41 | SA1 — SMBus address select 1 |
| Pin 42 | GND — Ground |
| Pin 43 | PD# — Power-down (active low) |
| Pin 44 | NC — Not connected (per datasheet) |
| Pin 45 | NC — Not connected (per datasheet) |
| Pin 46 | GND — Ground |
| Pin 47 | NC — Not connected (per datasheet) |
| Pin 48 | VDD — 3.3 V supply |
Typical Applications
9FGL0841CKILFT is suitable for 6 applications: PCIe Server Motherboards, NVMe Storage Arrays, Networking Switches and Routers, Workstation Motherboards, PCIe Expansion and Riser Cards, High-Performance Computing (HPC) Nodes.
PCIe Server Motherboards
The Renesas 9FGL0841CKILFT is well-suited for PCIe server motherboards requiring 8 low-jitter 100 MHz HCSL reference clocks with per-output OE# gating. Its 3.3 V single-supply operation simplifies the platform power tree, while the dedicated CLKREQ# support enables per-lane power gating for ENERGY STAR and ASHRAE-compliant thermal envelopes. The 48-VFQFPN 6x6 mm footprint with exposed pad provides low thermal resistance for dense server PCB layouts.
Recommended
NVMe Storage Arrays
NVMe storage arrays benefit from the 9FGL0841CKILFT's 8-output count and PCIe CLKREQ# support, which let each drive bay gate its reference clock independently. The 100 MHz HCSL outputs meet PCIe Gen 4/5 jitter budgets required by high-performance NVMe controllers, while programmable spread spectrum reduces EMI in dense 24+ drive chassis. Single 3.3 V supply matches typical storage backplane power rails.
Recommended
Networking Switches and Routers
Networking switches and routers use the 9FGL0841CKILFT to distribute 8 synchronized 100 MHz PCIe reference clocks across switch ASICs and PHY channels. The dedicated OE# pins map directly to PCIe CLKREQ# for per-port clock gating during low-traffic states, reducing system power. Programmable spread spectrum (-0.25% or -0.5%) helps meet FCC/CE EMI requirements in dense multi-port chassis without additional shielding.
Recommended
Workstation Motherboards
High-end workstation motherboards leverage the 9FGL0841CKILFT to deliver reference clocks to multi-GPU PCIe slots, NVMe M.2 sockets, and PCIe expansion cards. The 8-output capacity suits x16 CPU-attached slots split into multiple endpoints, while per-output OE# enables fine-grained power management for workloads that don't continuously use every slot. The 48-VFQFPN footprint simplifies routing in 8-layer PCBs.
Recommended
PCIe Expansion and Riser Cards
PCIe riser cards and backplanes use the 9FGL0841CKILFT to redistribute reference clocks across multiple slots when a single upstream clock cannot drive all endpoints. The HCSL output drive strength is designed for up to 8 downstream devices on shared PCB traces. Spread spectrum programmability and per-output OE# allow the riser to manage EMI and power per slot in dense server chassis.
Recommended
High-Performance Computing (HPC) Nodes
HPC compute nodes integrate the 9FGL0841CKILFT to provide clean 100 MHz HCSL reference clocks to multi-CPU PCIe fabrics and accelerator links. The 8 outputs allow partitioning the node across CPU-to-CPU, CPU-to-GPU, and CPU-to-NIC lanes, while the programmable spread spectrum reduces EMI emissions that could interfere with sensitive instrumentation. SMBus programmability supports in-system tuning for different compute workloads.
Recommended
Recommended Products Summary
Engineering reference data for 9FGL0841CKILFT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | 9FGL0841BKILFT | 9FGL0851CKILFT | 9FGL0841CKILF | 9DML0451AKILFT | 9DML0441AKILF |
|---|---|---|---|---|---|---|
| Brand | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics |
| Package | 48-VFQFPN (6x6 mm) | 48-VFQFPN (6x6 mm) | 48-VFQFPN (6x6 mm) | 48-VFQFPN (6x6 mm) | 48-VFQFPN (6x6 mm) | 48-VFQFPN (6x6 mm) |
| Number of Outputs | 8 HCSL | 8 HCSL | 8 HCSL | 8 HCSL | 4 Muxed HCSL | 4 Muxed HCSL |
| Output Frequency | 100 MHz | 100 MHz | 100 MHz | 100 MHz | 100 MHz | 100 MHz |
| Output Type | HCSL, LVCMOS | HCSL, LVCMOS | HCSL, LVCMOS | HCSL, LVCMOS | HCSL, LVCMOS | HCSL, LVCMOS |
| PCIe Generation Support | Gen 1-5 | Gen 1-6 | Gen 1-4 (extended modes) | Gen 1-5 | Gen 1-5 | Gen 1-4 |
| Per-Output OE# (CLKREQ#) | Yes | Yes | Yes | Yes | Yes | Yes |
| Supply Voltage | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V |
| Lifecycle Status | Obsolete | Active | Obsolete | Obsolete | Active | Active |
Key Differentiators
- Dedicated OE# pin per output supporting PCIe CLKREQ# (vs 9DML0441AKILF)
- 8-output count reduces component count in PCIe fanout designs (vs 9DML0441AKILF (4-output))
- Programmable spread spectrum supports both SRIS and SRnS architectures (vs Older PCIe Gen 1/2 clock generators)
Design Notes
Route the HCSL differential pairs with 100 ohm differential impedance and match the P/N lengths to within 5 mils to preserve duty cycle and minimize common-mode conversion. Place 33 ohm series-damping resistors near the driver pins per the IDT/Renesas reference design. Decouple each VDD pin with a 0.1 uF ceramic capacitor located within 100 mils, plus a 1 uF bulk capacitor at the device supply island.
Solder the central exposed pad of the 48-VFQFPN package to a ground copper pour with at least 8 thermal vias to the inner ground plane. Although the 9FGL0841CKILFT draws modest current (estimated 80-120 mA per output pair at 100 MHz HCSL), the exposed pad provides the primary heat-dissipation path and must not be left floating or the junction temperature will rise above rated limits during continuous operation.
Do not leave the SMBus address select pins SA0/SA1 floating; tie them to VDD or GND through 10 kohm resistors to set a unique address when multiple clock generators share the bus. Verify that OE# polarity is correct for your platform - PCIe CLKREQ# is active-low, matching the OE# pin polarity. When using external reference mode instead of a crystal, drive XIN with a CMOS-level source and leave XOUT floating.
Use the device's programmable spread-spectrum feature to reduce EMI emissions on multi-output boards. Two SSC levels (typically -0.25% and -0.5%) are available plus SSC-off; verify PCIe compliance at the chosen level because some PCIe Gen 5 receiver compliance tests require SSC-off. Check the IDT/Renesas reference design for trace-length guidelines on shared PCIe reference-clock topologies to avoid excessive ISI.
Compliance Information
RoHS and lead-free status confirmed via distributor listings (DigiKey, Mouser). AEC-Q100 not applicable for a server/storage clock IC. Renesas product page marks the part Obsolete.
