MAX4895E Maxim Integrated Products, MAX4895E Datasheet - Page 6

• Manufacturer Part Number: MAX4895E
• Description: VGA Port Protector
• Manufacturer: Maxim Integrated Products

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VGA Port Protector
HSYNC/VSYNC are buffered to provide level shifting
and drive capability to meet the VESA specification.
Input logic levels (V
the Electrical Characteristics table). The level-shifted
outputs (H1 and V1) are pulled low when EN is driven
low (see Table 1). Logic-level output (V
+5.0V TTL compatible.
The MAX4895E incorporates two nMOS switches for I
level shifting. The SDA, SCL terminals are voltage
clamped to a diode drop less than the V
Voltage clamping provides protection and compatibility
with SDA, SCL signals and low-voltage ASICs. Supply
+2.5V to +3.3V on V
VESA I
are identical, and each switch can be used to route
SDA or SCL signals.
Table 1. HV Truth Table
Table 2. DDC Truth Table
6
EN
EN
_______________________________________________________________________________________
1
0
1
0
Horizontal/Vertical Sync Level Shifter
2
C-compatible signals. The SDA, SCL switches
Display Data Channel Switches
HSYNC/VSYNC level shifting enabled
SDA1, SCL1, high impedance
IL
L
, V
to provide voltage clamping for
IH
SDA0 to SDA1
SCL0 to SCL1
) are connected to V
FUNCTION
FUNCTION
H1, V1 = 0
OL
, V
L
voltage.
OH
L
) are
(see
2
C
There are three terminals for R, G, and B. The only
function of these terminals is to provide high-level ESD
protection to the RGB lines, while at the same time,
keeping the capacitance on the RGB lines to a mini-
mum. The R, G, B terminals are identical, and any of
the three terminals can be used to protect red, green,
or blue video signals.
As with all Maxim devices, ESD-protection structures
are incorporated on all terminals to protect against
electrostatic discharges encountered during handling
and assembly. Additionally, the MAX4895E is protected
to ±15kV on the RGB terminals and outputs H1, V1,
SDA1, and SCL1 by the Human Body Model (HBM). For
optimum ESD performance, bypass V
a 1µF ceramic capacitor.
ESD protection can be tested in various ways. The R,
G, B terminals and outputs H1, V1, SDA1, and SCL1 of
the MAX4895E are characterized for protection to the
following limits:
• ±15kV using the Human Body Model
• ±8kV IEC 61000-4-2 Contact Discharge
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report documenting test
setup, methodology, and results.
ESD Test Conditions
ESD Protection
CC
to ground with
RGB