Owner's manual

MAX4885E
Ultra-Low Capacitance 1:2 VGA
Switch with ±15kV ESD
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Pin Description
PIN NAME FUNCTION
1 SDA0 SDA I/O
2 SCL0 SCL I/O
3 R0 RGB Analog I/O
4 G0 RGB Analog I/O
5 B0 RGB Analog I/O
6 H0 Horizontal Sync Input
7 V0 Vertical Sync Input
8V
CC
Supply Voltage. V
CC
= +5.0V ±10%. Bypass V
CC
to GND with a 0.1µF or larger ceramic capacitor.
9V
L
Supply Voltage. +2V ≤ V
L
≤ +5.5V. Bypass V
L
to GND with a 0.1µF or larger ceramic capacitor.
10 GND Ground
11 H1 Horizontal Sync Output*
12 V1 Vertical Sync Output*
13 B2 RGB Analog I/O*
14 B1 RGB Analog I/O*
15 G2 RGB Analog I/O*
16 G1 RGB Analog I/O*
17 R2 RGB Analog I/O*
18 R1 RGB Analog I/O*
19 SCL2 SCL I/O*
20 SCL1 SCL I/O*
21 SDA2 SDA I/O*
22 SDA1 SDA I/O*
23 EN Enable Input. Drive EN high for normal operation. Drive EN low to disable the device.
24 SEL Select Input. Logic input for switching RGB and DDC swiches.
— EP Exposed Pad. Connect exposed pad to ground or leave unconnected.
Detailed Description
The MAX4885E integrates high-bandwidth analog
switches and level-translating buffers to implement a
complete 1:2 multiplexer for VGA signals. The device
provides switching for RGB, HSYNC, VSYNC, SDA_
and SCL_ signals.
The HSYNC and VSYNC inputs feature level-shifting
buffers to support TTL output logic levels from low-volt-
age graphics controllers. These buffered switches may
be driven from as little as +2.0V up to +5.5V. RGB sig-
nals are routed with the same high-performance analog
switches, and SDA_, SCL_ signals are voltage clamped
to a diode drop less than V
L
. Voltage clamping pro-
vides protection and compatibility with SDA_ and SCL_
signals and low-voltage ASICs. In keyboard/video/
mouse (KVM) applications, V
L
is normally set to +5V
because low-voltage clamping is not required, as spec-
ified by the VESA standard.
Drive EN logic-low to shut down the MAX4885E. In shut-
down mode, all switches are high impedance, providing
high-signal rejection. The RGB, HSYNC, VSYNC, SDA_,
and SCL_ outputs are ESD protected to ±15kV by the
Human Body Model.
RGB Switches
The MAX4885E provides three SPDT high-bandwidth
switches to route standard VGA R, G, and B signals
(see Table 1). The R, G, and B analog switches are
identical, and any of the three switches can be used to
route red, green, or blue video signals.
* Terminal as ±15kV ESD protection—Human Body Model.