MAX4887 Datasheet, PDF (7/12 Pages) Maxim Integrated Products – Triple Video Switch

Triple Video Switch
Pin Description
PIN
1
2
3
4
5
6
7, 14
8
9
10
11
12
13
15
16
EP
NAME
V+
R0
G0
B0
GND
EN
N.C.
R1
G1
B1
B2
G2
R2
SEL
QP
EP
FUNCTION
Supply Voltage Input. Bypass V+ to GND with a 0.1µF or larger ceramic capacitor.
RGB Input/Output
RGB Input/Output
RGB Input/Output
Ground
Active-Low Enable Input. Drive EN high to disable the MAX4887. All I/Os are high impedance when
the device is disabled. Drive EN low for normal operation.
Not Internally Connected
RGB Input/Output
RGB Input/Output
RGB Input/Output
RGB Input/Output
RGB Input/Output
RGB Input/Output
Select Input. Logic input for switching RGB switches (see Table 1).
Active-Low Charge-Pump Enable. Drive QP high to disable the internal charge pump (for V+ = 5V
only). RGB switch operates with reduced performance when the charge pump is disabled. Drive QP
low for normal operation.
Exposed Pad. Connect exposed pad to ground plane.
Detailed Description
The MAX4887 triple, high-frequency switch is intended
for notebooks and monitors permitting RGB (red,
green, blue) signals to be switched from one driver to
one of two loads (1:2) or one of two sources to be con-
nected to one load (2:1). The MAX4887 provides three
SPDT high-bandwidth switches to route standard VGA
R, G, and B signals (see Table 1).
A boosted gate-drive voltage is generated by an inter-
nal charge pump to enhance the performance of the
RGB switches. The MAX4887 high-performance switch
utilizes n-channel architecture with internal high-drive
pullup from a low-noise charge pump resulting in very
low on-capacitance. The RGB switches function with
reduced performance when the charge pump is dis-
abled (V+ > 5V). The MAX4887’s global input (EN)
places all inputs/outputs in a high-impedance state,
providing rejection of all signals.
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. All RGB inputs/outputs are
ESD protected to ±8kV Human Body Model (HBM).
R0
R1
R2
G0
G1
G2
B0
B1
B2
SEL
EN
SWITCH
LOGIC
CONTROL
CHARGE
PUMP
QP
MAX4887
Figure 1. Functional Diagram
Analog Signal Levels
Analog signal inputs over the full voltage range (0 to
V+) are passed through the switch with minimal change
in on-resistance (QP = low). When QP = high, the
switches can operate within 1V of V+. The switches are
bidirectional; therefore, R_, G_, and B_ can be either
inputs or outputs.
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