ICS1894-40
10BASE-T/100BASE-TX INTEGRATED PHYCEIVER WITH RMII INTERFACE
PHYCEIVER
Recommended Component Values
Parameter
Minimum
Typical
Maximum
Tolerance
Units
TCSR Resistor Value
–
1.82k to GND
18.2k to VDD
–
1%
Ω
LED Resistor Value
1k
–
Ω
ICS1894-40 TCSR
ICS1894-40
VDD
8
TCSR
9
18.2KΩ 1%
VDD
1.82KΩ 1%
Note:
1. The bias resistor network sets the 10baseT and 100baseTX output amplitude levels.
2. Amplitude is directly related to current sourced out of the TCSR pin.
3. Resistor values shown above are typical. User should check amplitudes and adjust for transformer effects.
4. The 18.2K resistor provides negative feedback to compensate for VDD changes. Reducing the value of
this resistor will lower the 100baseT amplitude. Reducing the value of the resistor to ground on the other
hand will increase the output signal amplitude.
IDT® 10BASE-T/100BASE-TX INTEGRATED PHYCEIVER WITH RMII INTERFACE
30
ICS1894-40
REV G 060110
IDT [ INTEGRATED DEVICE TECHNOLOGY ]
