SNLA293 May 2022 DP83TC811R-Q1 , DP83TC811S-Q1
Schematics and the right components for MDI, reference clock, and power network are very critical for the performance of 100Base-T1 PHY. This section captures the recommended schematics and component values used during OA TC1 testing.
Parameter/Component | Value |
---|---|
VDDIO | 1.8 V, 2.5 V, or 3.3 V |
De-Coupling Capacitors VDDIO | 10 nF, 100 nF, 1uF, 10uF |
(Optional) Ferrite Bead VDDIO | 1 kΩ at 100 MHz (BLM18AG102SH) |
VDDA | 3.3 V |
De-Coupling Capacitors VDDA | 10 nF, 100 nF, 1uF, 10uF |
(Optional) Ferrite Bead VDDA | 1 kΩ at 100 MHz (BLM18AG102SH) |
Parameter/Component | Value |
---|---|
Filter - R1, R2 (1% accurate) | 22 Ω |
Filter - C1, C2 (2% accurate) | 22pF |
Filter - C3, C4 (2% accurate) | 47pF |
Filter - L1, L2 (2% accurate) | 120nH |
DC Blocking Capacitors (1% accurate, 100V) | 0.1 μF |
Common-Mode Choke | TDK: ACT1210L-201 |
TDK: ACT45L-201 | |
Murata: DLW32MH201XK2 | |
Murata: DLW43MH201XK2L | |
Pulse: AE2002 | |
Common Mode Termination Resistors (1% accurate,0.75 W, Size: 2010) | 1 kΩ |
MDI Coupling Capacitor | 4.7 nF |
ESD Shunt (5% accurate, 0.125 W, Size: 0805) | 100 kΩ |
Isolation Resistor 1 (0.25 W, Size: 1206) | 0 Ω |
Isolation Resistor 2 (0.25 W, Size: 1206) | 0 Ω |
Isolation Capacitor | Not populated |
Crystal | |
R_XI | 100 Ω |
R_XO |
200 Ω Adding series resistor is seen to make crystal oscillator more immune to board parasitics, noise and helps in quick startup. TI recommends to use a resistor of value 200 ohms. As this resistor controls the crystal wattage, its value should be chosen in consultation with the crystal vendor. |