19-6229; Rev 0; 3/12
EVALUATION KIT AVAILABLE
MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
General Description
The MAX14984 is a complete VGA port protector with dual
USB power switches. The device features all the circuitry
required to detect the insertion and removal of a monitor
and automatically connect the graphics controller when a
monitor is detected. A switched 5V output provides up to
55mA to the VGA port in addition to normal VGA signals.
The MAX14984 features a single active-low enable
input to control two 5V USB switches. Each switch sup-
plies 500mA of current with less than 250mV drop from
V
CC
, and is protected against short-circuit faults. Two
active-low fault outputs indicate when a fault condition is
detected on either output.
High-bandwidth analog switches exceed VESA rise/fall
time requirements for the RGB channels. The horizontal
and vertical synchronization (H/V) buffers shift logic lev-
els to support +2.5V to +5.0V CMOS or TTL-compatible
graphics controllers while meeting the VESA drive capa-
bility requirement of
Q8mA.
An internal 2.5V regulator
and pullup resistors on the monitor side translate the
DDC voltage levels to be compatible with low-voltage
graphics controllers.
The MAX14984 features high-ESD protection of
Q8kV
Human Body Model (HBM) on all VGA and USB out-
puts. The device is available in a 24-pin (4mm x 4mm)
TQFN package and is specified over the -40NC to +85NC
extended temperature range.
Benefits and Features
S
Design Flexibility
Graphics Controller Port Is Protected when
V
CC
= 0V
External Pullup Resistors Match DDC Channel
to Graphics Controller Supply
Up to Two USB Ports Supported
S
High Level of Integration for Performance
S5V Provides +5V at 55mA to VGA Port
Internal Pullup Resistors on DDC Outputs to S5V
Low 6pF (typ) RGB Capacitance
2.1ns (typ) t
R
/t
F
with 10pF, 2.2kI Load on
Monitor-Side SYNC Signals
Source and Sink 8mA While Meeting Speed
Requirements
High-ESD Protection on VGA and USB Outputs
Q8kV
Human Body Model (HBM)
S
Saves Space on Board
Internal USB Switches
Pass +5V at 500mA with 250mV (max)
IR Drop
Current Limited/Thermal Protection
4mm x 4mm, 24-Pin TQFN Package
Typical Operating Circuit
+3.3V
1µF
3
2
GRAPHICS
CONTROLLER
2
2
3
2
2
VGA
PORT
+5V
Applications
Servers
Workstations
Desktop PCs
R0, G0, B0
HSYNC0,
VSYNC0
SCL0, SDA0
F1, F2
ENU
V
CC
R1, G1, B1
HSYNC1,
VSYNC1
SCL1, SDA1
S5V
Ordering Information
appears at end of data sheet.
1µF
+3.3V
For related parts and recommended products to use with this part,
refer to
www.maxim-ic.com/MAX14984.related.
MD
MAX14984
USB1
1µF
USB
DEVICE
USB2
ENV
GND
1µF
USB
DEVICE
½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
V
CC
, S5V, H0, V0, SDA0, SCL0,
ENU, ENV,
SDA1,
SCL1, USB1, USB2,
MD, F1, F2
(Note 1) ...........-0.3V to +6V
R0, G0, B0, R1, G1, B1, H1, V1 ..................-0.3V to V
CC
+ 0.3V
Continuous Current Out of USB1, USB2 ..........................500mA
Continuous Current Out of S5V ..........................................60mA
Continuous Current Through all I/O Pins ........................
Q50mA
Peak Current Through RGB, DDC Switches
(1ms Pulse, 10% Duty Cycle)....................................
Q100mA
TQFN
Junction-to-Ambient Thermal Resistance (q
JA
) ..........36°C/W
Continuous Power Dissipation (T
A
= +70C)
TQFN (derate 27.8mW/NC above +70C) ................2222.2mW
Operating Temperature Range .......................... -40NC to +85NC
Junction Temperature .....................................................+150NC
Storage Temperature Range............................ -65NC to +150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
PACKAGE THERMAL CHARACTERISTICS (Note 2)
Junction-to-Case Resistance (q
JA
) ...................................3°C/W
Note 1:
When
F1
and
F2
are connected to a voltage higher than V
CC
, some current will be sinked (see the
Detailed Description).
Note 2:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to
www.maxim-ic.com/thermal-tutorial.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional opera-
tion 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
CC
= 5.0V
Q
5%, T
A
= -40NC to +85NC, unless otherwise noted. Typical values are at V
CC
= 5.0V and T
A
= +25NC.) (Note 3)
PARAMETER
POWER SUPPLY
Supply Voltage
V
CC
I
CC
I
SHDN
V
S5V
I
L
I
LIM
V
USB
I
LOAD
I
LIM
t
BLANK
t
R
t
F
t
ON
t
OFF
I
LUSB
(Note 4)
R
L
= 10I, C
L
= 1FF, 10%–90%,
Figure 1
R
L
= 10I, C
L
= 1FF, 90%–10%, Figure 1
R
L
= 10I, C
L
= 1FF, to 10% of V
OUT
, Figure 1
R
L
= 10I, C
L
= 1FF, to 90% of V
OUT
, Figure 1
V
USB
= 5.25V, V
CC
= 0V, V
ENU
= 0V
I
OUT
= 500mA
500
0.5
7.5
11.6
25.2
100
100
10
1200
1.0
50
V
CC
= +5.25V, V
ENV
= V
ENU
= 0V, SCL0 and
SDA0 not connected
V
CC
= +5.25V, V
ENV
= V
ENU
= 0V,
V
SCL0
= V
SDA0
= 0V
V
CC
= +5.25V, V
ENV
= V
ENU
= V
CC
I
OUT
= 55mA
V
S5V
= +5.25V, V
CC
= 0V, V
ENV
= 0V
55
305
4.75
2.3
6.6
29
135
5.25
5
mA
10
100
300
10
500
250
FA
mV
FA
mA
mV
mA
A
ms
Fs
Fs
Fs
Fs
FA
I
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNIT
Supply Current
Shutdown Supply Current
5-VOLT SWITCH (S5V)
Voltage Drop
Reverse Leakage Current
Current Limit
USB SWITCHES (USB1, USB2)
Voltage Drop
Continuous Load Current
Current-Limit Threshold
Current-Limit Blanking
Period
Output Rise Time
Output Fall Time
Turn-On Delay
Turn-Off Delay
Reverse Leakage Current
Pulldown Resistance
½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½
Maxim Integrated Products
2
MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 5.0V
Q
5%, T
A
= -40NC to +85NC, unless otherwise noted. Typical values are at V
CC
= 5.0V and T
A
= +25NC.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNIT
DDC SWITCHES (SDA0, SCL0, SDA1, SCL1)
SDA1/SCL1 Off-Leakage
Current
SDA0/SCL0 Off-Leakage
Current
On-Resistance
Input Logic-Low
Input Logic-High
Input Leakage Current
Input Hysteresis (H0, V0)
Output Logic-Low
Output Logic-High
Rise/Fall Time
Output Leakage Current
Output Logic-Low
Bandwidth
On-Loss
On-Resistance
On-Resistance Matching
On-Resistance Flatness
On-Capacitance
Off-Capacitance
High-ESD Pins ESD
Protection
All Other Pins ESD
Protection
Thermal-Shutdown
Threshold
Thermal-Shutdown
Hysteresis
Note
Note
Note
Note
3:
4:
5:
6:
T
SHDN
T
SHDN_
HYS
I
OFF
I
LDDC
R
ONDDC
V
IL
V
IH
I
L
V
HYST
V
OL
V
OH
t
R
, t
F
I
LKG
V
OL
f
MAX
I
LOSS
R
ON
DR
ON
R
FLAT(ON)
C
ON
C
OFF
V
ENV
= V
CC
, V
SDA1
= V
SCL1
= 0V or 5.25V
V
CC
= 0V, 3.3kI pullup to +3.3V on SDA0
and SCL0
V
IN
= +0.8V, I
IN
=
Q10mA
-1
+1
10
7
FA
FA
I
V
LOGIC INPUTS (H0, V0,
ENV, ENU)
0.8
2.0
V
IN
= 0V or 5.25V
-1
100
I
SINK
= 8mA, V
CC
= +4.75V
I
SOURCE
= 8mA, V
CC
= +4.75V
10% to 90%, R
L
= 2.2kI, C
L
= 10pF
Output not asserted, V
IN
= 5.25V
I
SINK
= 1mA
R
S
= R
L
= 50I
f = 50MHz, R
S
= R
L
= 50I, 0V
P
V
IN
P
+0.7V,
Figure
2
V
IN
= +0.7V, I
IN
=
Q10mA
0V
P
V
IN
P
+0.7V, I
IN
=
Q10mA,
same device
0V
P
V
IN
P
+0.7V, I
IN
=
Q10mA
f = 1MHz, switches enabled
f = 1MHz, switches disabled
1000
0.4
5
0.25
6
2
8
1
1
2.4
2.1
1
0.3
0.5
+1
V
FA
mV
V
V
ns
FA
V
MHz
dB
I
I
I
pF
pF
PUSH-PULL LOGIC OUTPUTS (H1, V1)
OPEN-DRAIN LOGIC OUTPUTS (F1,
F2, MD)
RGB ANALOG SWITCHES (R0, G0, B0, R1, G1, B1)
PROTECTION SPECIFICATIONS
Human Body Model (Note 5)
Human Body Model (Note 6)
Q8
Q2
+155
25
kV
kV
NC
NC
All units are production tested at T
A
= +25NC. Specifications over temperature are guaranteed by design.
t
BLANK
is the period between detecting an overcurrent condition and the fault output asserting.
See the
Pin Description
section for the ESD status of each pin.
Terminal tested vs. GND. Apply 1FF-bypass capacitors on V
CC
, USB1, USB2, and S5V.
½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½
Maxim Integrated Products
3
MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
Test Circuits /Timing Diagrams
3.3V
V
ENU
0V
t
OFF
t
F
t
ON
t
R
5V
90%
90%
V
USB1,
V
USB2
0V
10%
10%
Figure 1. Timing Diagram for USB Switch Parameters
+5V
1µF
NETWORK
ANALYZER
R0, G0, B0
V
IN
50I
50I
V
ON-LOSS = 20log
OUT
V
IN
0V
ENV
V
CC
MAX14984
R1, G1, B1
GND
V
OUT
MEAS
50I
50I
REF
MEASUREMENTS ARE STANDARDIZED AGAINST SHORTS AT IC TERMINALS.
ON-LOSS IS MEASURED BETWEEN R0 AND R1 ON EACH SWITCH.
SIGNAL DIRECTION THROUGH IS REVERSED; WORST VALUES ARE RECORDED.
Figure 2. On-Loss
½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½
Maxim Integrated Products
4
MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
Typical Operating Characteristics
(V
CC
= +5.0V, T
A
= +25NC, unless otherwise noted)
DDC ON-RESISTANCE
vs. ANALOG SIGNAL VOLTAGE
MAX14984 toc01
RGB ON-RESISTANCE
vs. ANALOG SIGNAL VOLTAGE
I
R0
= 10mA
MAX14984 toc02
50
40
30
20
50
40
30
20
I
SDA0
= 10mA
R
ON
(I)
T
A
= +85°C
10
T
A
= +25°C
10
R
ON
(I)
T
A
= +85°C
T
A
= -40°C
T
A
= +25°C
0
0
0.5
1.0
V
SDA0
(V)
1.5
2.0
0
0
1
2
V
R0
(V)
3
T
A
= -40°C
4
5
FREQUENCY RESPONSE
MAX14984 toc03
HSYNC/VSYNC OUTPUT VOLTAGE
vs. TEMPERATURE
I
SOURCE
/I
SINK
= 8mA
4
V
OH
/V
OL
(V)
3
2
1
-1
FREQUENCY RESPONSE (dB)
-2
-3
-4
-5
-6
-7
-8
-9
-10
1
V
OH
V
OL
GO TO G1
10
100
1k
0
-40
-15
10
T
A
(°C)
35
60
85
FREQUENCY (MHz)
½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½
Maxim Integrated Products
5
MAX14984 toc04
0
5
无线连接
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
