MAX4885 Datasheet, PDF (1/13 Pages) Maxim Integrated Products – Complete VGA 1:2 or 2:1 Multiplexer

19-0554; Rev 0; 5/06
Complete VGA 1:2 or 2:1 Multiplexer
General Description
The MAX4885 integrates high-bandwidth analog
switches and level-translating buffers to implement a
complete 1:2 or 2:1 multiplexer for VGA signals. The
device provides switching for RGB, display data chan-
nel (DDC), and horizontal and vertical synchronization
(HSYNC, VSYNC) signals. A low-noise charge pump
with internal capacitors provides a boosted gate-drive
voltage to improve performance of the RGB switches.
In the 1:2 multiplexer mode, HSYNC/VSYNC inputs fea-
ture level-shifting buffers to support low-voltage CMOS
or standard TTL-compatible graphics controllers. In the
2:1 multiplexer mode, the output buffers for the
HSYNC/VSYNC inputs are disabled, allowing bidirec-
tional signaling. In both modes, DDC signals are volt-
age-clamped to an external voltage to provide level
translation and protection. The MAX4885 features a
5µA shutdown mode and is ESD protected to ±8kV
Human Body Model (HBM) on externally routed pins.
The MAX4885 is specified over the extended (-40°C to
+85°C) temperature range, and is available in the 32-
pin, 5mm x 5mm TQFN package.
Applications
Notebook Computers
Digital Projectors
Computer Monitors
Servers
KVM Switches
Pin Configuration
TOP VIEW
24 23 22 21 20 19 18 17
G1 25
16 G2
R1 26
15 R2
DDCB1 27
14 DDCB2
DDCA1 28
GND 29
MAX4885
13 DDCA2
12 GND
V+ 30
M 31
*EP
SEL 32
11 V+
10 V_CL
9 EN
1 2345678
TQFN
*EXPOSED PADDLE CONNECTED TO GND
Features
♦ +5V Single-Supply Operation
♦ Programmable Voltage Clamp for Open-Drain
DDC Signals
♦ Low 5Ω (typ) On-Resistance (R, G, B Signals)
♦ Low 13pF (typ) On-Capacitance (R, G, B Signals)
♦ Break-Before-Make Switching Protects Against
Circuit Shorts
♦ ±8kV HBM ESD Protection on Externally Routed
Pins
♦ Low 300µA Supply Current (Lower than 1µA with
Charge Pump Disabled)
♦ Space-Saving, Lead-Free, 32-Pin (5mm x 5mm)
TQFN Package
Ordering Information
PART
TEMP RANGE PIN-PACKAGE
MAX4885ETJ+ -40°C to +85°C 32 TQFN-EP*
*EP = Exposed pad.
+Denotes lead-free package.
PKG
CODE
T3255-4
Typical Operating Circuit
+3.3V
0.1µF
3
GRAPHICS
CONTROLLER
2
2
DOCKING
STATION
+5V
V_CL
V+
MAX4885
R0, B0, G0
R1, G1, B1
H0, V0
H1, V1
DDCA0, DDCB0 ^{DDCA1, DDCB1}
SEL
R2, G2, B2
M
H2, V2
EN
DDCA2, DDCB2
GND
0.1µF
3
2
VGA
2
PORT 1
3
2
VGA
2
PORT 2
________________________________________________________________ Maxim Integrated Products 1
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