Ethernet switch chipsets

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Ethernet switch chipsets
      chipsets
      interfaces
      IC+
            Tenda S108
      Realtek
magnetics
      bob smith termination
            term res value
      PoE
            ref design
lightnings
      ethernet transformers
      6kV common-mode surge defences
      100A differential-mode surge defences
            chip-side protection

Ethernet switch chipsets

chipsets

Tenda     S105          5port  10/100            IC+ IP175G         Alza 170czk
NETIS     ST3105S       5port  10/100            IC+ IP175G         Alza 180czk
Tenda     S108          8port  10/100            IC+                Alza 200czk
NETIS     ST3108S       8port  10/100            IC+                Alza 210czk

Tenda     SG105         5port  gigabit                              Alza 330czk
Tenda     TEG1005D      5port  gigabit                              Alza 450czk   metal box
Tenda     SG108         8port  gigabit                              Alza 460czk

ZyXEL     GS1200-5      5port  gigabit,managed                      Alza 610czk   VLAN
ZyXEL     GS1200-8      8port  gigabit,managed                      Alza 835czk   VLAN
D-Link    DGS-1100-05   5port  gigabit,managed                      Alza 650czk   VLAN




Tenda S108 - 10/100, 8-port, chipset "IC+"
Tenda G1005D 5-Port Gigabit Ethernet Switch - chipset "realtek" (which?)

TP-Link TL-SG1005D - 5-port, 370czk@alza - RTL8366SB - hackable to managed [ref] [ref]
TP-Link TL-SG1005D - version 5 contains RTL8367

interfaces

the controller chip usually has capability to be configured at reset by reading fixed settings in an EEPROM (SPI, I2C)
or at runtime via MDIO interface

https://www.totalphase.com/support/articles/200349206-MDIO-Background
https://www.electronicdesign.com/microcontrollers/use-mdio-bus-interrogate-complex-devices
https://github.com/spotify/linux/blob/master/drivers/net/phy/mdio-bitbang.c

Ethernet PHY Configuration Using MDIO for Industrial Applications
http://www.ti.com/lit/an/spracc8/spracc8.pdf

IC+

IC+ [ref]
 IP175C
IP178C, IP178D

 IC+ IP175A
 IC+ IP175C
 IC+ IP175D
 IC+ IP175E
 IC+ IP178C

Tenda S108

http://www.epanorama.net/newepa/2013/11/27/netwjork-ethernet-switch-teardown/
left-out rj45 connector pins 4,5,7,8
PSU around MC34063+FET
based around IP178D - hackable?

Realtek

[ref]
Unmanaged FE (10/100 Mbps)
RTL8304E - 2x FE ports (2x MII/RMII/TMII)
RTL8305NB - 5x FE ports  
RTL8304MB - 5x FE ports (1x MII)
RTL8306M - 5x FE ports (1x MII/RMII/TMII)
RTL8309N - 8x FE ports
RTL8316E - 16x FE ports 
RTL8332L-VB - 24x FE ports (2G SFP)
RTL8332L-VB + 2x RTL8208L + RTL8214B - 24x FE ports (4G SFP)

Unmanaged GbE (10/100/1000 Mbps)
RTL8214C - 1x GbE port (QSGMII)
RTL8363SC - 2x GbE ports (1x SGMII/Hi-SGMII)
RTL8363NB - 2x GbE ports (1x RGMII/MII/RMII)
RTL8364NB - 2x GbE ports (2x RGMII/MII/RMII)
RTL8365MB-VB - 4x GbE ports (1x RGMII/MII/RMII)
RTL8366SC - 4x GbE ports (1x RGMII/MII/RMII + SGMII/Hi-SGMII)
RTL8367N-VB - 5x GbE ports
RTL8367SB - 5x GbE ports (2x RGMII/MII/RMII)
RTL8367RB-VB - 5x GbE ports (2x RGMII/MII/RMII)
RTL8367S - 5x GbE ports (1x RGMII/MII/RMII + SGMII/Hi-SGMII)
RTL8370N-VB - 8x GbE ports 
RTL8370MB - 8x GbE ports (1x 2G SFP)
RTL8370MB - 8x GbE ports (2x RGMII/MII/RMII)
RTL8382L-VB + 1x RTL8218B-VC - 16x GbE ports (1x 2G SFP)
RTL8382L-VB + 2x RTL8218B-VC - 24x GbE ports (1x 2G SFP)
RTL8382L-VB + 2x RTL8218B-VC + RTL8214FX - 24x GbE ports (1x 4G SFP)
RTL8396L-VC + 1x RTL8218B-VC - 8x GbE ports (2x SFP+)
RTL8396L-VC + 2x RTL8218B-VC - 16x GbE ports (2x SFP+)
RTL8396L-VC + 3x RTL8218B-VC - 24x GbE ports (2x SFP+)

Industrial FE (10/100 Mbps)
RTL8304MBI - 5x FE ports (1x MII)
RTL8305NBI - 5x FE ports (industrial)
RTL8309NI - 8x FE ports (industrial)
RTL8316SI - 16x FE ports (industrial)
RTL8332MI + 1x RTL8214FCI - 8x FE ports (2x 4G) Combo (industrial)
RTL8332MI + 1x RTL8208LI - 16x FE ports (2x SFP) (industrial)
RTL8332MI + 2x RTL8208LI - 24x FE ports (2x SFP) (industrial)
RTL8332MI + 2x RTL8208LI + RTL8214FCI - 24x FE ports (1x 4G) Combo (industrial)

Industrial GbE (10/100/1000 Mbps)
RTL8363MBI - 2x GbE ports (1x RGMII)
RTL8368MI - 5x GbE ports (3x RGMII)
RTL8380MI - 8x GbE ports (2G SFP)
RTL8370MBI - 8x GbE ports (2G SFP)
RTL8382MI + 1x RTL8214FCI - 24x GbE ports (2G / 4G)
RTL8382MI + 1x RTL8218BI - 24x GbE ports (16G + 2G SFP)
RTL8382MI + 2x RTL8218BI - 24x GbE ports (24G + 2G SFP)
RTL8382MI + 2x RTL8218BI + RTL8214FCI - 24x GbE ports (24G + 4G) Combo

Managed GbE (10/100/1000 Mbps)
RTL8380M - 8x GbE ports (1x 2G SFP)
RTL8380M + RTL8214C - 12x GbE ports (1x 2G SFP)
RTL8382M + RTL8218B - 16x GbE ports (1x 2G SFP)
RTL8382M + 2x RTL8218B - 24x GbE ports (1x 2G SFP)
RTL8392M + 3x RTL8218B + 1x RTL8214QF - 24x GbE ports (1x 4G SFP)
RTL83912M + 3x RTL8218B + 1x RTL8214FC - 24x GbE ports (1x 4G) Combo
RTL8392M + 6x RTL8214QF + 1x RTL8214FC - 24x GbE ports (1x 4G SFP) Combo
RTL8393M + 6x RTL8218B + 1x RTL8214QF - 48x GbE ports (1x 4G SFP)
RTL8393M + 6x RTL8218B + 1x RTL8214FC - 48x GbE ports (1x 4G) Combo
RTL8393M + 12x RTL8214QF + 1x RTL8214FC - 48x GbE ports (1x 4G SFP) Combo 

Managed 2.5G/10G Uplink
RTL9301 + 3x RTL8218D - 24GT x 10GbE ports (4x SFP)
RTL9301 + 3x RTL8218D + 2x RTL8295 - 24GT x 10GbE ports (2x SFP + 2x XAUI)
RTL9301 + 3x RTL8218D + 2x AQR107 - 24GT x 10GbE ports (2x SFP + 2x XGT)
RTL9301 + 3x RTL8218D + AQR407 - 24GT x 10GbE ports (4x XGT)
RTL9301 + 6x RTL8214QF - 24GT x 10GbE ports (4x SFP)
2x RTL9301 + 6x RTL8218D + 2x RTL8295R - 48GT x 10GbE ports (4x SFP)
2x RTL9301 + 6x RTL8218D + 2x AQR107 - 48GT x 10GbE ports (2x SFP + 2x XGT)
RTL9310 + 6x RTL8218D - 48GT x 10GbE ports (4x SFP)
RTL9310 + 6x RTL8218D - 48GT x 10GbE ports (6x SFP)
RTL9310 + 6x RTL8218D + 2x AQR107 - 48GT x 10GbE ports (4x SFP + 2x XGT)
RTL9310 + 6x RTL8218D + 2x RTL8295 - 48GT x 10GbE ports (4x SFP + 2x XAUI)

RTL9301 + RTL8218D + 2x AQR112 + 2x AQR107 - 1x 16GT + 8x 2.5GT ports (2x SFP + 2x XGT)
RTL9302 + 1x AQR112 + 2x AQR107 - 4x 2.5GT ports (2x SFP + 2x XGT)
RTL9302 + 2x AQR112 + 2x AQR107 - 8x 2.5GT ports (2x SFP + 2x XGT)
RTL9302 + 4x AQR112 + 2x AQR107 - 16x 2.5GT ports (2x SFP + 2x XGT) 
RTL9312 + 6x AQR112 + 2x AQR107 - 24x 2.5GT ports (2x SFP + 2x XGT) 
RTL9312 + 6x AQR112 + 2x AQR107 - 24x 2.5GT ports (4x SFP + 2x XGT)
RTL9303 + 2x AQR407 - 8x XGT ports
RTL9313 + 3x AQR407 - 12x XGT ports

magnetics

center taps == CT

bob smith termination

75ohm on each ct, other ends connected together (unused pairs 4,5 and 7,8 just connect each two together) and
 direct to ground (COMPROMISES SURGE ISOLATION!!!)
 to gnd through 1500pF/2kV
...or ct direct to gnd through individual 10nf/1kV

sometimes the unused pairs have their own capacitor to gnd
PoE version:
 each CT has own 75ohm with 22nF/100V
 their ends connected to gnd through 1000pF/2kV
...or... [ref]

each wire of unused pair through 50-ohm, their ends connected, through 50-ohm to a common node
  center taps connected, then through 75ohm to common node
  common node through 1000pF/2kV to chassis

term res value

said 50-ohm is better for cat5

PoE

1nF caps across bridge diodes for enhanced ESD immunity

ref design

https://www.digikey.com/reference-designs/en/power-management/poe-power-over-ethernet/2037
uses ideal diode bridge controller and 8 FETs instead of two diode bridges, to reduce losses

can also be only a cap on the ct of tx pair, rx ct floating [ref]

also, each individual wire can have its own series r-c pair, with grounded end 
...or each wire a resistor, connected together at other end, then cap to ground (NOT FOR PoE!) [ref]

lightnings

[ref]
 far field coupling
 cables limited to 100m, needs at least 300m for over a kilovolt to get induced at
 near field coupling
 has to be routed close to the main current conductor for a long length, unlikely mechanism
 ground potential difference
 "step voltage", same principle
 requries different grounds at the cable end
 lightning must hit ground nearby (within 100m)
 apparently most common cause of failures
 AC-mains coupled spikes?

 common mode surges
 insulated from the chip side, voltage barrier
 differential mode surges
 rare on vanilla ports
 couple through transformer to chip side
 often caused by installed protection devices, where one fires before the other
 !!! protection devices can cause more problems than they solve !!!

 test surges: commonly use 2us rise time (zero to crest), 10us decay (crest to half the max amplitude), also called "2/10"
 common mode:
 open circuit max voltage: 6 kV (from field analyses, estimated max surge voltage encountered in the field)
 short circuit max current: 100 amps
 differential mode:
 open circuit max voltage: 1 kV (assumption of installed protection device)

ethernet transformers

 IEEE spec requires 1500V RMS (2.1 kV peak)
 most transformers can survive 4kV to 8kV surges
 8kV-guaranteed transformers available
 Bob Smith termination capacitor is in parallel to the transformer - WEAK SPOT!!!
 some designs omit it entirely, use just resistors!!
 most common failure spot
 termination network may not be needed at all, centers may be left untapped - do the EMC tests
 lower cap value passes through less energy
 6kV better than 2kV, caps can be put two in series (three maybe?)

6kV common-mode surge defences

 at least 4mm air gaps (BEWARE of jacks with LEDs, the distances may be compromised there)
 do not place overvoltage protections across the insulation barrier
 use 6kV rated Smith caps
 if cost allows, use 6kV rated transformers (while 1.5kV rated ones often go to 4..8kV, there's variability between vendors and even individual units - probability but not certainty)

100A differential-mode surge defences

 most transformers can handle 2/10 100A pulse without fusing-open, energy insufficient to melt wire
 primary winding failures very uncommon
 with rising current, core rapidly saturates, then stops transferring further energy - turns to poor-coupling aircore-like structure
 limits the passed-through energy dramatically - peak current 25A, surge time 2-3us
 less than 2% of input energy passed through
 better add protection on secondary side, chip-side

chip-side protection

 surge clamp diodes in parallel with chip's esd network
 add series resistor (BEWARE of impedance changes, limit to less than 5 ohms
 better, use Bourns transient current suppressor instead of resistor [ref]








...max40200 - ideal diode, 4-pin FET with enable input and left-right side comparator, 1A, tthermal shutdown, loss 43mV/500mA, 85mV/1A

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