Rainbow Electronics MAX4886 - Manual (Page 6)

MAX4886
Detailed Description
The MAX4886 high-speed analog switch is ideal for
HDMI/DVI switching applications, permitting 2:1 or 1:2
switching. The MAX4886 contains four differential pairs
for HDMI or DVI switching. The MAX4886 connects either
one monitor to one of two digital video signals or one
HDMI/DVI output to one of two connectors or loads.
The MAX4886 differential switches are based on an
nFET architecture with an internal charge pump for gate
overdrive. This advanced architecture results in an
extremely low capacitance and on-resistance needed
for an excellent returns loss.
The MAX4886 features an 8
Ω (typ) on-resistance and
2.5pF on-capacitance switches for routing RGB and
CLK video signals.
The MAX4886 switches are identical, and any of the
switches can be used to route RGB and CLK video
signals.
The device will also be useful in other high-speed
switching applications such as LVDS and LVPECL.
Analog-Signal Levels
Signal inputs over the full voltage range (0V to V DD ) are
passed through the switch with minimal change in on-
resistance (see the Typical Operating Characteristics
section). The switches are bidirectional. Therefore,
COM_, NC_, and NO_ can be either inputs or outputs.
Logic Inputs (SEL)
The MAX4886 has a logic input that controls the switch
on/off function. Use SEL to switch COM_ to NO_ or
COM_ to NC_. Table 1 and the Functional Diagram
illustrate the MAX4886 Truth Table.
Applications Information
Power-Supply Bypassing and Sequencing
Proper power-supply sequencing is recommended for
all CMOS devices. Do not exceed the absolute
maximum ratings, because stresses beyond the listed
ratings can cause permanent damage to the device.
Always sequence V
DD on first, followed by the switch
inputs and the logic inputs. Bypass at least one V DD
input to ground with a 0.1µF capacitor as close to the
device as possible. Use the smallest physical size pos-
sible for optimal performance.
It is also recommended to bypass more than one V DD
input. A good strategy is to bypass one V DD input with
a 0.1µF capacitor and at least a second V DD input with
a 1nF to 10nF capacitor. (Use 0603 or smaller physical
size ceramic capacitor).
PC Board (PCB) Layout
High-speed switches such as the MAX4886 require
proper PCB layout for optimum performance. Ensure
that impedance-controlled PCB traces for high-speed
signals are matched in length, and as short as possi-
ble. Connect the MAX4886 exposed paddle to a solid
ground plane.
Quad, High-Speed HDMI/DVI 2:1 Digital Video
Switch
6 _______________________________________________________________________________________
NC1+
NC1+
NO1+
NO1-
NC2+
NC2-
NO2+
NO2-
NO4+
NO4-
NC4+
NC4-
NO3+
NO3-
NC3+
NC3-
COM1+
COM1-
COM2+
COM2-
COM3+
COM3-
COM4+
COM4-
MAX4886
SEL
V DD
GND
SEL FUNCTION
0 COM_ to NC_
1 COM_ to NO_
Table 1. Switch Truth Table Functional Diagram