HDMP-1638 Datasheet, PDF (12/19 Pages) Agilent(Hewlett-Packard) – Gigabit Ethernet Transceiver Chip with Dual Serial I/O and Differential PECL Clock Inputs

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O_TTL
V_CC_TTL
R
R
V_CC_TTL
or
V_CC_RX
I_TTL
V_CC_TTL
R
R
R
GND_TTL
ESD
PROTECTION
GND
ESD
PROTECTION
GND_TTL
V_BB 1.4 V
Figure 9: O-TTL and I-TTL Simplified Circuit Schematic.
HS OUT
ESD
PROTECTION
V_CC_TXHS
V_CC_TXECL
V_CC
+DOUT
Zo
R_PAD
150
-DOUT
R_PAD
Zo
GND
150
GND_TXHS
V_CC
V_CC
0.01 µF _+DIN
2 * Z0
HS IN
+
–
A
+
–
R
R
0.01 µF -DIN
GND
GND
ESD
PROTECTION
NOTES:
1. HS_IN INPUTS SHOULD NEVER BE CONNECTED TO GROUND AS PERMANENT DAMAGE TO THE DEVICE MAY RESULT.
2. THE OPTIONAL SERIES PADDING RESISTORS (R_PAD) HELP DAMPEN LOAD REFLECTIONS. TYPICAL R_PAD VALUES FOR
MISMATCHED LOADS RANGE BETWEEN 25-Z0 Ω.
3. FOR PECL REFCLK INPUT PAIR, THE CONSTANT VOLTAGE SUPPLIES (SHOWN AS A) AND RESISTORS R ARE OMITTED.
Figure 10: HS_OUT and HS_IN Simplified Circuit Schematic.