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.
♦
+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
Features
MAX4885
Ordering Information
PART
MAX4885ETJ+
TEMP RANGE
PIN-PACKAGE
PKG
CODE
T3255-4
Applications
Notebook Computers
Digital Projectors
Computer Monitors
Servers
KVM Switches
-40°C to +85°C 32 TQFN-EP*
*EP
= Exposed pad.
+Denotes
lead-free package.
Pin Configuration
H1
H2
V1
B1
V+
V2
B2
Typical Operating Circuit
TOP VIEW
24
G1 25
R1 26
DDCB1 27
DDCA1 28
GND 29
V+ 30
M 31
SEL 32
1
QP
23
22
21
20
GND
19
18
17
16
15
14
13
G2
R2
DDCB2
DDCA2
GND
V+
V
CL
EN
+3.3V
+5V
0.1µF
V
CL
3
GRAPHICS
CONTROLLER
2
DOCKING
STATION
2
V+
0.1µF
MAX4885
R0, B0, G0
H0, V0
DDCA0, DDCB0
SEL
M
EN
R1, G1, B1
H1, V1
DDCA1, DDCB1
R2, G2, B2
H2, V2
DDCA2, DDCB2
GND
3
2
2
3
2
2
VGA
PORT 2
VGA
PORT 1
MAX4885
12
11
*EP
10
9
2
R0
3
G0
4
B0
5
H0
6
V0
7
DDCA0
8
DDCB0
TQFN
*EXPOSED PADDLE CONNECTED TO GND
________________________________________________________________
Maxim Integrated Products
1
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.
Complete VGA 1:2 or 2:1 Multiplexer
MAX4885
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
V
+
, V
CL
.....................................................................-0.3V to +6V
R_, G_, B_, DDCA_, DDCB_, SEL, M,
EN, QP
(Note 1) ...........................................-0.3V to V+ + 0.3V
H_, V_ .......................................................................-0.3V to +6V
Continuous Current Through RGB Switches ....................±70mA
Continuous Current Through HV, DDC Switches…..........±50mA
Peak Current Through RGB Switches
(pulsed at 1ms, 10% duty cycle).................................±140mA
Peak Current Through HV, DDC Switches (pulsed at 1ms,
10% duty cycle)..............................................................±100mA
Continuous Power Dissipation (T
A
= +70°C)
32-Pin TQFN (derate 21.3mW/°C above +70°C) ........1702mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1:
Signals exceeding V+ or GND are clamped by internal diodes. Limit forward-diode current to maximum current rating.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V+ = +5.0V ±10%, V
CL
= +3.3V ±10%, T
A
= T
MIN
to T
MAX
,
QP
= GND, unless otherwise noted. Typical values are at V+ = +5.0V,
V
CL
= +3.3V and T
A
= +25°C.)
PARAMETER
Supply Voltage Range
Clamp Voltage Range
V
+
Quiescent Supply Current
V
CL
Quiescent Supply Current
V
+
Shutdown Current
V
CL
Shutdown Current
RGB ANALOG SWITCHES
On-Resistance
On-Resistance Matching
On-Resistance Flatness
Off-Leakage Current
On-Leakage Current
Charge Injection
HV MULTIPLEXER
Input-Voltage Low
Input-Voltage High
High-Output Drive Current
Low-Output Drive Current
On-Resistance
Charge Injection
V
ILHV
V
IHHV
I
OHHV
I
OLHV
R
ONHV
Q
M = GND
M = GND
V
OUT
= V
+
- 0.5V, M = GND
V
OUT
= +0.5V, M = GND
H_ = V_ = +2.5V, I
IN
= -40mA, M = V+
H_, V_ = 0V, M = V+, C
L
= 1000pF
21
2.0
-16
+16
15
0.8
V
V
mA
mA
Ω
pC
R
ON
∆R
ON
R
FLAT(ON)
I
L(OFF)
I
L(ON)
Q
0V < V
IN
< +2.5V,
I
IN
= -40mA
QP
= GND
QP
= V+
5
6
0.5
0.02
-1
-1
10
8
7.5
10
1.5
0.75
+1
+1
Ω
Ω
Ω
µA
µA
pC
SYMBOL
V+
V
CL
I
+
I
CL
I
+SHDN
I
CLSHDN
V+ = +5.5V
V
CL
= V+ = +5.5V
V+ = +5.5V, all digital inputs to V+ or GND
V
CL
= V+ = +5.5V, all digital inputs to V+ or
GND
QP
= GND
QP
= V+
CONDITIONS
MIN
4.5
2.7
0.3
TYP
MAX
5.5
V+
0.5
1
1
5
1
UNITS
V
V
mA
µA
µA
µA
µA
0V < V
IN
< +2.5V, I
IN
= -40mA
0V < V
IN
< +2.5V, I
IN
= -40mA
R_, G_, B_ = 0V or +5.5V,
EN
= GND
R_, G_, B_ = 0V or +5.5V,
EN
= V+
R_, G_, B_ = 0V,
C
L
= 1000pF
QP
= GND
QP
= V+
2
_______________________________________________________________________________________
Complete VGA 1:2 or 2:1 Multiplexer
ELECTRICAL CHARACTERISTICS (continued)
(V+ = +5.0V ±10%, V
CL
= +3.3V ±10%, T
A
= T
MIN
to T
MAX
,
QP
= GND, unless otherwise noted. Typical values are at V+ = +5.0V,
V
CL
= +3.3V and T
A
= +25°C.)
PARAMETER
DDC MULTIPLEXER
On-Resistance
DDC Leakage
Charge Injection
SWITCH LOGIC (SEL, M,
EN, QP)
Input-Low Voltage
Input-High Voltage
Input Leakage Current
ESD PROTECTION
Human Body Model, all pins
ESD Protection
Human Body Model, R_, G_, B_, H_, V_,
DDCA_, DDCB_
±2
±8
kV
kV
V
IL
V
IH
I
LEAK
V+ = +5.5V
V+ = +4.5V
V
IN
= V+
2.0
-1
+1
0.8
V
V
µA
R
ON(DDC)
I
L(DDC)
Q
V
IN
< +0.4V, V
CL
= +3.0V, I
IN
= -20mA
V
CL
- 0.4V < V
OUT
< V
CL
, V
IN
= V+
DDCA_, DDCB_ = 0V, C
L
= 1000pF
-1
10
20
+1
Ω
µA
pC
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX4885
AC ELECTRICAL CHARACTERISTICS
(V+ = +5.0V ±10%, V
CL
= +3.3V ±10%, T
A
= T
MIN
to T
MAX
,
QP
= GND. Typical values are at V+ = +5.0V, V
CL
= +3.3V and T
A
=
+25°C, unless otherwise noted.) (Note 2)
PARAMETER
Bandwidth
Insertion Loss
Crosstalk
Off-Capacitance
On-Capacitance
Charge-Pump Noise
SYMBOL
f
MAX
I
LOS
V
CT
C
OFF
C
ON
V
NQP
R
S
= R
L
= 50Ω
1MHz < f < 50MHz,
R
S
= R
L
= 50Ω
1MHz < f < 50MHz, V
IN
= 0.7V
P-P
,
R
S
= R
L
= 50Ω
f = 1MHz,
QP
= GND or V+
f = 1 MHz
V
IN
= +1.0V, R
S
= R
L
= 50Ω
QP
= GND
QP
= V+
CONDITIONS
QP
= GND
QP
= V+
QP
= GND
QP
= V+
MIN
TYP
350
350
0.85
1
-40
5
13
17
50
200
1.2
1.6
MAX
UNITS
MHz
dB
dB
pF
pF
µV
_______________________________________________________________________________________
3
Complete VGA 1:2 or 2:1 Multiplexer
MAX4885
TIMING CHARACTERISTICS
(V+ = +5.0V ±10%, V
CL
= +3.3V ±10%, T
A
= T
MIN
to T
MAX
,
QP
= GND. Typical values are at V+ = +5.0V, V
CL
= +3.3V and T
A
=
+25°C, unless otherwise noted.) (Note 2)
PARAMETER
Charge-Pump Startup Time
RGB ANALOG SWITCHES
Turn-On Time
Turn-Off Time
Propagation Delay
Output Skew Between Ports
HV MULTIPLEXER
Turn-On Time
Turn-Off Time
Propagation Delay
DDC MULTIPLEXER
Turn-On Time
Turn-Off Time
Propagation Delay
t
ON
t
OFF
t
PD
V
IN
= +1.0V, R
L
= 100Ω, Figure 1
V
IN
= +1.0V, R
L
= 100Ω, Figure 1
C
L
= 10pF, Figure 2
0.1
0.25
5
µs
µs
ns
t
ON
t
OFF
t
PD
M = 0, Figure 1
M = 0, Figure 1
C
L
= 10pF
M = GND
M = V+
0.1
6
0.1
16
5
µs
µs
ns
t
ON
t
OFF
t
PD
t
SKEW
V
IN
= +1.0V, R
L
= 100Ω, Figure 1
V
IN
= +1.0V, R
L
= 100Ω, Figure 1
C
L
= 10pF, Figure 2, R
L
= R
S
= 50Ω
C
L
= 10pF, Skew between any two ports: R,
G, B. Figure 2, R
S
= R
L
= 50Ω
0.1
0.1
30
7
µs
µs
ns
ps
SYMBOL
t
QPON
CONDITIONS
MIN
TYP
150
MAX
UNITS
µs
Note 2:
Timing parameters are guaranteed by design and correlation over the full operating temperature range.
Typical Operating Characteristics
(V+ = +5.0V, V
CL
= +3.3V and T
A
= +25°C, unless otherwise noted.)
R
ON
vs. V
R0
*
(RGB SWITCHES)
MAX4885 toc01
R
ON
vs. V
R0
*
(RGB SWITCHES)
QP = 0 OR 1
QP = 1
30
25
R
ON
(Ω)
20
15
10
T
A
= +85°C
T
A
= +25°C
R
ON
(Ω)
MAX4885 toc02
R
ON
vs. V
R0
*
(HV SWITCHES)
MAX4885 toc03
10
9
8
7
R
ON
(Ω)
6
5
4
3
2
1
0
0
1
2
V
R0
(V)
*R0, G0, B0 ARE INTERCHANGEABLE.
3
4
5
T
A
= -40°C
T
A
= +25°C
T
A
= +85°C
35
12
10
8
6
4
2
T
A
= +85°C
T
A
= +25°C
T
A
= -40°C
5
0
0
1
2
V
R0
(V)
*R0, G0, B0 ARE INTERCHANGEABLE.
T
A
= -40°C
3
4
0
0
1
2
V
R0
(V)
*R0, G0, B0 ARE INTERCHANGEABLE.
3
4
5
4
_______________________________________________________________________________________
Complete VGA 1:2 or 2:1 Multiplexer
MAX4885
Typical Operating Characteristics (continued)
(V+ = +5.0V, V
CL
= +3.3V and T
A
= +25°C, unless otherwise noted.)
R
ON
vs. V
DDAC0
*
(DDC SWITCHES)
MAX4885 toc04
HV BUFFER OUTPUT VOLTAGE
HIGH vs. TEMPERATURE
MAX4885 toc05
HV BUFFER OUTPUT VOLTAGE
LOW vs. TEMPERATURE
1.8
OUTPUT VOLTAGE LOW (V)
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
I = 16mA
MAX4885 toc06
75
5.0
4.8
OUTPUT VOLTAGE HIGH (V)
4.6
4.4
4.2
4.0
3.8
3.6
3.4
3.2
I = 16mA
2.0
60
R
ON
(Ω)
45
V
CL
= +3.3V
T
A
= +85°C
T
A
= +25°C
T
A
= -40°C
V
CL
= +5.0V
T
A
= +85°C
T
A
= +25°C
T
A
= -40°C
30
15
0
0
0.5
1.0
1.5
2.0
2.5
3.0
V
DDAC0
(V)
*DDAC0 AND DDCB0 ARE INTERCHANGEABLE.
3.0
-40
-15
10
35
60
85
TEMPERATURE (°C)
-40
-15
10
35
60
85
TEMPERATURE (°C)
RGB LEAKAGE CURRENT
vs. TEMPERATURE
0.9
0.8
LEAKAGE CURRENT (nA)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
-40
-15
10
35
60
85
TEMPERATURE (°C)
ON LEAKAGE
0.5
OFF LEAKAGE
0
-40
QP = 0
MAX4885 toc07
HV LEAKAGE CURRENT
vs TEMPERATURE
MAX4885 toc08
DDC LEAKAGE CURRENT
vs. TEMPERATURE
0.9
0.8
LEAKAGE CURRENT (nA)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
ON LEAKAGE
OFF LEAKAGE
-40
-15
10
35
60
85
MAX4885 toc09
1.0
3.0
2.5
LEAKAGE CURRENT (nA)
2.0
1.5
ON LEAKAGE
1.0
OFF LEAKAGE
1.0
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
RGB CHARGE INJECTION
vs. COM VOLTAGE
MAX4885 toc10
SUPPLY CURRENT
vs. TEMPERATURE
MAX4885 toc11
t
ON
vs. TEMPERATURE
(RGB SWITCHES)
QP = 0
MAX4885 toc12
15
0.50
0.45
0.40
SUPPLY CURRENT (mA)
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
6.0
5.0
TURN-ON TIME (µs)
QP = 0
4.0
3.0
QP = 1
2.0
1.0
0
12
CHARGE INJECTION (pC)
9
6
QP = 1
QP = 0
0
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
V
COM
(V)
3
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
5
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