ASMedia ASM1480 Datasheet

ASMedia ASM1480 PCIe 3.0 Signal Switch Datasheet

General Description ASM1480 is a 16 to 8 channel multiplexer / demultiplexer Switch with Hi-Z outputs.

This device is a bi-directional multiplexes differential signal to one of two corresponding outputs. This design is suitable for current high-speed application up to PCI-Express Rev.3.0.

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Overview Feature Part Number

Description

ASM1480

Function

PCIe 3.0 lane switch (mux/demux)

Channels

16 differential pairs (8 bidirectional switches)

Application

PCIe lane sharing or switching (e.g. between CPU and M.2/PCIe slots)

Max Speed

Up to 8.0 GT/s (PCIe Gen3)

Voltage

3.3 V power supply

Package

42-pin TQFN

Features     

Quick switch for high speed, high bandwidth differential protocols 8 channel, 2:1 Mux/DeMux Switch with single enable Package: 42 pins TQFN Lead free, RoHs compliance.

VCC operation: +3.3V

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Functional Description The ASM1480 provides 8-channel lane switching, typically implemented as: 

2:1 bi-directional switch for differential pairs (TX+/TX-, RX+/RX-).



Allows PCIe routing reconfiguration—e.g., switching CPU PCIe lanes between a discrete GPU and an M.2 SSD.



Controlled by SEL (select) input signal, switching between Source A or Source B.

Diagram: Simplified Functional Block SEL = 0

SEL = 1

Host PCIe ←─────────→ Device A ↘

↙

→ Device B

Pinout and Signal Description While the full pinout is in the datasheet, here are essential signals: Pin Name

Description

SEL

Logic control input; selects which path is active

A[0:7]+/-

First PCIe source/destination (lane group A)

B[0:7]+/-

Second PCIe source/destination (lane group B)

Y[0:7]+/-

Common PCIe output/input (shared path)

VCC

Power supply (3.3 V)

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Pin Name

Description

GND

Ground

Each differential signal is routed through high-speed analog switches, preserving signal integrity across PCIe 3.0 bandwidth.

Electrical Characteristics Parameter

Value

Supply Voltage (Vcc)

3.0 V – 3.6 V

Max Data Rate

8.0 GT/s (PCIe Gen3)

On Resistance (Ron)

Typically < 12 Ω

Crosstalk

< -20 dB at 4 GHz

Insertion Loss

-1.2 dB typical at 4 GHz

Power Consumption

Very low, passive routing switch

Applications 

Motherboard PCIe bifurcation (x16 ↔ x8/x8, or x8/x4/x4)



M.2 SSD switching between CPU lanes and chipset



Notebook platform with hybrid GPU/SSD lane sharing



Server board PCIe expansion with switchable resources



Thunderbolt/USB4-PCIe bridging applications

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Practical Implementation Notes 

Controlled via a GPIO or embedded controller logic (firmware sets the SEL state).



Route differential pairs with matched length and impedance (85 Ω differential).



Avoid long trace stubs or vias that degrade signal integrity.



Used passively—no retiming or buffering; signal integrity depends on PCB design.

Alternatives / Equivalents While the ASM1480 is the most common for 8.0 GT/s applications, alternatives include: Part

Vendor

Notes

PI3PCIE3415

Diodes Inc.

Compatible PCIe 3.0 mux/demux

HD3SS3412

PI2PCIE2215 ASMedia ASM1442

Texas Instruments Diodes Inc.

ASMedia

AVAQSEMICONDUCTOR CO., LIMITED

2-lane switch, PCIe/SATA

Dual 2-lane switch Similar but older gen, lower speed