Rainbow Electronics MAX4885 - Manual

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
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
MAX4885
Complete VGA 1:2 or 2:1 Multiplexer
________________________________________________________________ Maxim Integrated Products 1
19-0554; Rev 0; 5/06
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
MAX4885
TQFN
TOP VIEW
29
30
28
27
12
11
13
R0 B0 H0 V0
DDCA0
14
QP
H1 V+ GND B1 V2 H2
1 2
DDCA1
4 5 6 7
23 24 22 20 19 18
GND
V+
DDCB2
DDCA2
GND
V+
G0
V1
3
21
31 10 M V CL
32 9 SEL EN
DDCB1
26 15 R2 R1
25 16 G2
DDCB0
B2
8
17
G1
*EXPOSED PADDLE CONNECTED TO GND
*EP
Pin Configuration
Ordering Information
GRAPHICS
CONTROLLER
V CL V+
GND
+3.3V
+5V
EN
SEL
R0, B0, G0
H0, V0
DDCA0, DDCB0
0.1 µF
0.1 µF
VGA
PORT 1
VGA
PORT 2
R2, G2, B2
H2, V2
DDCA2, DDCB2
2
3
2
2
3
2
R1, G1, B1
H1, V1
DDCA1, DDCB1
2
3
2
DOCKING
STATION
M
MAX4885
Typical Operating Circuit
PART TEMP RANGE PIN-PACKAGE
PKG
CODE
MAX4885ETJ+ -40°C to +85°C 32 TQFN-EP* T3255-4
*EP = Exposed pad.
+Denotes lead-free package.