Part Number: KSZ8895RQXIA

Manufacturer: Microchip Technology


Shipped from: Shenzhen/HK Warehouse

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Technical Specifications of KSZ8895RQXIA

Datasheet  KSZ8895RQXIA datasheet
Category Integrated Circuits (ICs)
Family Interface – Controllers
Manufacturer Microchip Technology
Packaging Tray
Part Status Active
Protocol Ethernet
Function Switch
Interface RMII
Standards 10/100 Base-T/TX PHY
Voltage – Supply 1.8V, 2.5V, 3.3V
Current – Supply
Operating Temperature -40°C ~ 85°C
Package / Case 128-BFQFP
Supplier Device Package 128-PQFP (14×20)

KSZ8895RQXIA Introduction

General Description

The KSZ8895MQX is a Layer 2 controlled, five-port switch with various built-in capabilities to reduce overall system costs. It offers non-blocking configuration and high-performance memory bandwidth using a shared-memory-based switch fabric, making it ideal for low-cost, low-power, five-port, 10/100Mbps switch systems with on-chip termination and internal core power controllers.

Power management, priority ratio, rate programming, tag or port-based VLAN, packet filtering, administration interfaces, and MIB counters are just some of its many features. When Port 5 is set up to partition MAC5 with SW5-MII/RMII from PHY5 with P5-MII/RMII, the KSZ8895 family’s numerous CPU data interfaces may efficiently address both established and forthcoming fast Ethernet applications. The KSZ8895 series has three alternative variants to accommodate various needs:

  • One SW5-MII and one P5-MII interface; five 10/100Base-T/TX transceivers; KSZ8895MQX/MLX.
  • One SW5-RMII and one P5-RMII interface; five 10/100Base-T/TX transceivers; KSZ8895RQX
  • With the KSZ8895FQX, Ports 1, 2, 3, and 5 have their own 10/100Base-T/TX transceiver (port 3 can be set to fiber mode). Port 4 has a single 100Base-FX transceiver. There will be a single SW5-MII and a single P5-MII connector.

Using either the SPI or the SMI interface, you can control all of the MAC and PHY unit registers. Registers for the MIIM can be accessed via the MDC/MDIO bus. Any and all control registers for the unmanaged mode can be programmed in EEPROM. The 128-pin PQFP package is available for the KSZ8895MQX/RQX/FQX. Package options for the KSZ8895MLX include a 128-pin LQFP.

KSZ8895RQXIA Features

Advanced Switch Features

  • Up to 128 VLANs in Use, Supported by IEEE 802.1q (Full-Range 4096 of VLAN IDs).
  • Up to 32 MAC addresses can be stored in a static MAC address table.
  • Per-Port VLAN ID Tagging/Untagging Flexibility.
  • Per-Port Insertion/Extraction of IEEE 802.1p/q Tags Determined by Ingress Port (Egress).
  • Adaptive Rate Control at the Ingress and Exit on a Per-Port Basis.
  • Support for a jitter-free, per-packet-based rate cap.
  • Percentage-based Broadcast Storm Protection (Global and Per Port Basis).
  • Assist with the IEEE 802.1d RSTP (Rapid Spanning Tree Protocol).
  • The Mode-Tail Tag (1 Byte Added Before FCS) Helps at jack 5 tells the CPU which ingress port the packet came in from.
  • High-Performance Memory Bandwidth of 1.4 Gbps and a Completely Non-Blocking Switch Fabric Based on Shared Memory.
  • Ability to enable/disable huge frame sizes of up to 2000 bytes each.
  • Network Exploitation Using IGMP Versions 1 and 2 (IPv4) Ability to filter multicast packets.
  • Adequate QoS for IPv4 and IPv6 Connections.
  • Accept packet filtering based on unknown unicast/multicast addresses and VIDs.
  • Filtering of One’s Own Address Information.

Functional Description

The KSZ8895MQX/RQX/FQX/MLX is a Layer 2 controlled switch that integrates five 10/100 physical layer transceivers and five media access control (MAC) units. There are three modes available for the operation of the gadget. In the first set, the device functions as an integrated five-port switch. Two, it can function as a five-port switch where the fifth logical port is independent of the corresponding physical port. This mode utilizes a media-independent interface (MII/RMII) to allow access to the fifth MAC.

This helps with setting up a unified broadband router. The fifth PHY is reclaimed using the dual MII/RMII functionality in the third mode. As a result, the P5-MII/RMII port can be used for the supplementary broadband gateway setup, allowing access to the fifth PHY. It is possible to place the KSZ8895MQX/RQX/FQX/MLX in either a managed or unmanaged architecture. Managed designs put the KSZ8895MQX/RQX/FQX/MLX under the full command of a host processor using the SPI bus or the MDC/MDIO interface.

I/O strapping or EEPROM programming during system reset time allows for a design free of management. The KSZ8895MQX/RQX/FQX/MLX supports Auto MDI/MDIX on all copper ports and 100BASE-TX, IEEE 802.3 10BASE-T on all media ports. Port 4 of the KSZ8895FQX is 100BASE-FX capable, and port 3 can use either copper or fiber. The KSZ8895MQX is a versatile device that can be used as a fully managed five-port switch or connected to a microprocessor via its SW-MII/RMII interfaces. The design is more efficient using unique analog circuitry and DSP technology, allowing for decreased power consumption and robust electrical noise immunity, which improves the physical signal transmission and reception.

Power consumption is reduced further in the KSZ8895MQX/RQX/FQX compared to the KS8995MQ/RQ/FMQ, and the transformer’s center taps are no longer restricted. Request that the RX and TX transformer center taps are not linked together to save power unless the switches are manufactured with a 0.11 m process, and the Microchip LinkMD functionality is added. There is no difference in functionality between the KSZ8895MQX/RQX/FQX and the KSZ8895MQ/RQ/FMQ.

Physical Layer Transceiver

It’s a 100BASE-TX transmitting system. The 100BASE-TX transmitter is responsible for serializing parallel data, encoding and transmitting MLT3, and converting between NRZ and NRZI. To begin, the circuit performs a parallel-to-serial conversion on the MII data coming from the MAC, transforming it into a serial bit stream operating at 125 MHz. The data and control stream are scrambled following a 4B/5B code converter.

Following its serialization, the data is transformed from NRZ to NRZI format and sent via MLT3 current output. For the 1:1 transformer ratio, the output current is determined by an external 1% 12.4 k resistor. It is in accordance with the ANSI TP-PMD standard for rise/fall times (4 ns on average) and amplitude balance/overshoot/timing jitter. The 100BASE-TX transmitter includes the waveform output previously seen in 10BASE-T.


DC restoration, MLT3-to-NRZI conversion, data, clock recovery, descrambling, NRZI-to-NRZ conversion, 4B/5B decoding, and serial-to-parallel conversion are all tasks performed by the 100BASE-TX receiver function. An equalization filter on the receiving end first addresses inter-symbol interference (ISI) across a twisted pair cable. Because cable length affects both amplitude loss and phase distortion, an equalizer must be tuned to achieve peak performance. The variable equalizer in this setup first makes an estimate based on the strength of the incoming signal relative to the known characteristics of the cable, then fine-tunes itself for optimal performance. This continuing process may adapt to different conditions, such as temperature shifts, on its own.

A DC restoration and data conversion block follows the equalization of the signal. When baseline wander occurs, the dynamic range suffers. The DC restoration circuit helps fix this problem. To get from MLT3 to NRZI, the circuit uses differential data conversion. In addition, the threshold for making slices is dynamic. The clock of 125 MHz is retrieved from the NRZI signal’s edges by the clock recovery circuit. The recovered clock can transform the NRZI signal into a more portable NRZ format. After the signal is de-scrambled, it is decoded using a 4B/5B system. Lastly, the MAC receives its input data in MII format, which was transformed from the NRZ serial data.


In summary, the KSZ8895RQXIA is a high-performance Ethernet switch chip with advanced features and low power consumption, making it a great choice for various industrial, automotive, and building automation applications. When designing a system with this chip, following the manufacturer’s guidelines and best practices is important to ensure proper operation and performance.

Order from ICRFQ, a trusted supplier of high-quality electronic components known for excellent products and outstanding customer service, to get your hands on this exceptional device. Don’t wait any longer to enhance your project – order the KSZ8895RQXIA today!

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