NWK933
MINT
Vdd
SUBGND2
TX_ER
DVDD3
MDC
DGND1
MDIO
TX_EN
LNKST
ACTST
COLST
DGND3
RefCLK
Vdd
Vdd
Vdd
OSCVDD
XTAL1
25MHz
C2
DVDD1
RXVDD3
XTAL2
RXGND3
FDST
SPDST
OSCGND
TXCGND4
TXVDD4
TXREF100
C2
Vdd
Vdd
PA4
RESETN
10K(5%)
5K(5%)
TXREF10
TXVDD3
TXGND3
RXVDD2
RXGND2
1.24K
1%
1.24K
1%
30 (1%)
20 (1%)
30 (1%)
24.9 (1%)
24.9 (1%)
10
0.01µF
20 (1%)
0.01µF
1:√2 MAGNETICS
Figure 7 External Components
Crystal Oscillator
EXTERNAL COMPONENTS
For IEEE802.3 compliance the oscillator must run at
25MHz ±100ppm. The NWK933 on-chip circuitry
contributes less than 40ppm variability to the oscillator
frequency, therefore the crystal must be specified to
60ppm. This must include variations due to
temperature and ageing. The crystal must be capable
of dissipating 0.5mW of power.
Connecting an External 25MHz Reference
If an external clock is used then it should be driven
into the REFCLK input, and XTAL1 must be connected
to ground. XTAL2 must be left unconnected. If a
crystal is used, REFCLK must be connected to ground.
RESETN Pull-up Resistor
External capacitors are required on the XTAL1 &
XTAL2 pins. Manufacturer's recommendations should
be followed.
This resistor is required regardless of whether or not
RESETN is used externally.
Tracking to the crystal and the capacitors must be as
short as possible. Other signal paths must not cross
the area.
RX Input Decoupling
The method of using a split input load resistor and
de-coupling the centre tap reduces common mode
noise.
The NWK933 is supported by the following magnetics:
VENDOR
MAGNETICS
Pulse
H1119
16
MITEL [ MITEL NETWORKS CORPORATION ]
