A retrofit Light Emitting Diode, LED, tube for connection to an electronic ballast, said retrofit LED tube comprising: - an LED array for emitting light; - an alternating current, AC, LED driver arranged for receiving an AC supply voltage and for driving said LED array based on said received AC supply voltage; - a filament (6, 10) for supporting: - a filament current circulating back to said electronic ballast for enabling lamp recognition by said electronic ballast during a lamp recognition phase, and - a lamp current to said AC LED driver for driving said LED array during a steady-state phase, the filament (6, 10) comprising: - a filament circuit (35, 56) arranged to mimic a fluorescent tube towards the electronic ballast; characterized in that the filament (6, 10) comprises a filament enhancement circuit (32, 55) comprising: - at least one bypass switch (36, 37, 53) arranged for enabling a bypass path for bypassing said filament circuit; - a controller (33, 34, 54) arranged to determine that said lamp recognition phase is completed and arranged for controlling said at least one bypass switch (36, 37, 53) after said lamp recognition phase, wherein the controller (33, 34, 54) is configured to activate said at least one bypass switch (36, 37, 53) after determining that said lamp recognition phase is completed. - an LED array for emitting light; - an alternating current, AC, LED driver arranged for receiving an AC supply voltage and for driving said LED array based on said received AC supply voltage; - a filament (6, 10) for supporting: - a filament current circulating back to said electronic ballast for enabling lamp recognition by said electronic ballast during a lamp recognition phase, and - a lamp current to said AC LED driver for driving said LED array during a steady-state phase, the filament (6, 10) comprising: - a filament circuit (35, 56) arranged to mimic a fluorescent tube towards the electronic ballast; characterized in that the filament (6, 10) comprises a filament enhancement circuit (32, 55) comprising: - at least one bypass switch (36, 37, 53) arranged for enabling a bypass path for bypassing said filament circuit; - a controller (33, 34, 54) arranged to determine that said lamp recognition phase is completed and arranged for controlling said at least one bypass switch (36, 37, 53) after said lamp recognition phase, wherein the controller (33, 34, 54) is configured to activate said at least one bypass switch (36, 37, 53) after determining that said lamp recognition phase is completed. - a filament current circulating back to said electronic ballast for enabling lamp recognition by said electronic ballast during a lamp recognition phase, and - a lamp current to said AC LED driver for driving said LED array during a steady-state phase, the filament (6, 10) comprising: - a filament circuit (35, 56) arranged to mimic a fluorescent tube towards the electronic ballast; characterized in that the filament (6, 10) comprises a filament enhancement circuit (32, 55) comprising: - at least one bypass switch (36, 37, 53) arranged for enabling a bypass path for bypassing said filament circuit; - a controller (33, 34, 54) arranged to determine that said lamp recognition phase is completed and arranged for controlling said at least one bypass switch (36, 37, 53) after said lamp recognition phase, wherein the controller (33, 34, 54) is configured to activate said at least one bypass switch (36, 37, 53) after determining that said lamp recognition phase is completed. - a filament circuit (35, 56) arranged to mimic a fluorescent tube towards the electronic ballast; - at least one bypass switch (36, 37, 53) arranged for enabling a bypass path for bypassing said filament circuit; - a controller (33, 34, 54) arranged to determine that said lamp recognition phase is completed and arranged for controlling said at least one bypass switch (36, 37, 53) after said lamp recognition phase, wherein the controller (33, 34, 54) is configured to activate said at least one bypass switch (36, 37, 53) after determining that said lamp recognition phase is completed.