Rainbow Electronics MAX14998 - Manual (Page 9)

Two-Lane and Four-Lane DisplayPort Passive
Switches with Separate AUX/HPD Control
MAX4998/MAX14998
_______________________________________________________________________________________ 9
Typical Operating Circuit
V DD = +3.3V
NO0+
NO0-
COM0+
COM0-
COM1+
COM1-
COM2+
COM2-
NO1+
NO1-
NO2+
NO2-
NO3+
+1.1V
OF THE 7WZ07
GRAPHICS AND MEMORY
CONTROLLER HUB
DP0
DP1
AUX
COM3+ HPD
SEL1
SEL2
CHANNEL SELECT
CHANNEL SELECT
DOCKING STATION
DP01
DP11
AUX1
NC0+
NC0-
NC1+
NC1-
NC2+
NC2-
DisplayPort
CONNECTOR
DP02
DP12
AUX2
HPD1
MAX4998
V CC = +1.1V
7WZ07 DUAL-GATE LOTIC OPERATES FROM +3.3V V CC
+1.1V
10k Ω
NC3+
HPD2
10k Ω
NOTE: THE APPLICATION SHOWN IS A TWO-LANE SWITCH BETWEEN THE DOCKING STATION AND DisplayPort CONNECTOR ON A LAPTOP. SEL2 NEEDS TO BE CHANGED FIRST
WHEN SWITCHING SO THAT THE AUX/HPD SIGNAL CAN ESTABLISH CONTACT AND SET PARAMETERS THROUGH DDC. THE HPD SIGNALS FROM THE DOCKING STATION AND DP
CONNECTOR NEED TO BE INPUT THROUGH A LEVEL TRANSLATOR, SUCH AS A 7WZ07 OR 742G07 NONINVERTING TO THE MAX4998. EACH OUTPUT IS PULLED UP TO MATCH THE
LOGIC LEVEL OF THE GMCH. THE COM SIDE OF THE MAX4998 NEEDS TO BE CONNECTED DIRECTLY TO THE GMCH, RUNNING AT LOW VOLTAGE (APPROXIMATELY 1.1V). THIS
ESTABLISHES THE COMMON-MODE VOLTAGE FOR THE SWITCH AND KEEPS THE SWITCH WITHIN ITS OPTIMAL RANGE. IF A FOUR-LANE DisplayPort SWITCH IS DESIRED, THE
MAX14998 SHOULD BE USED. THE CIRCUIT IS THE SAME EXCEPT THAT DP0 TO DP3 IS USED WITH AUX, AND THE HPD CIRCUITRY IS THE SAME.
1
2
OF THE 7WZ07
1
2