MAXIM MAX14984

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 supplies 500mA of current with less than 250mV drop from
VCC, 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 levels to support +2.5V to +5.0V CMOS or TTL-compatible
graphics controllers while meeting the VESA drive capability 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 outputs. The device is available in a 24-pin (4mm x 4mm)
TQFN package and is specified over the -40NC to +85NC
extended temperature range.
Applications
Benefits and Features
S Design Flexibility
Graphics Controller Port Is Protected when
VCC = 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) tR /tF 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
+5V
1µF
Servers
Workstations
Desktop PCs
3
2
GRAPHICS
CONTROLLER
Ordering Information appears at end of data sheet.
2
2
+3.3V
R0, G0, B0
VCC
R1, G1, B1
HSYNC1,
VSYNC1
HSYNC0,
VSYNC0
SCL0, SDA0
SCL1, SDA1
3
2
VGA
PORT
2
S5V
F1, F2
1µF
ENU
MAX14984
For related parts and recommended products to use with this part,
refer to www.maxim-ic.com/MAX14984.related.
USB1
1µF
USB
DEVICE
MD
USB2
ENV
GND
1µF
USB
DEVICE
����������������������������������������������������������������� 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.)
VCC, 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 VCC + 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
Continuous Power Dissipation (TA = +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)
TQFN
Junction-to-Ambient Thermal Resistance (qJA)...........36°C/W
Junction-to-Case Resistance (qJA)....................................3°C/W
Note 1:When F1 and F2 are connected to a voltage higher than VCC, 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 fourlayer 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 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
(VCC = 5.0V Q 5%, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = 5.0V and TA = +25NC.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNIT
5.25
V
POWER SUPPLY
Supply Voltage
VCC
VCC = +5.25V, VENV = VENU = 0V, SCL0 and
SDA0 not connected
2.3
5
VCC = +5.25V, VENV = VENU = 0V,
VSCL0 = VSDA0 = 0V
6.6
10
ISHDN
VCC = +5.25V, VENV = VENU = VCC
29
100
FA
VS5V
IOUT = 55mA
135
300
mV
10
FA
500
mA
Supply Current
ICC
Shutdown Supply Current
4.75
mA
5-VOLT SWITCH (S5V)
Voltage Drop
Reverse Leakage Current
IL
Current Limit
VS5V = +5.25V, VCC = 0V, VENV = 0V
ILIM
55
305
USB SWITCHES (USB1, USB2)
Voltage Drop
VUSB
Continuous Load Current
ILOAD
500
Current-Limit Threshold
ILIM
0.5
1.0
A
Current-Limit Blanking
Period
tBLANK
7.5
50
ms
Output Rise Time
Output Fall Time
Turn-On Delay
IOUT = 500mA
(Note 4)
RL = 10I, CL = 1FF, 10%–90%, Figure 1
11.6
tF
RL = 10I, CL = 1FF, 90%–10%, Figure 1
25.2
Turn-Off Delay
tOFF
RL = 10I, CL = 1FF, to 10% of VOUT, Figure 1
RL = 10I, CL = 1FF, to 90% of VOUT, Figure 1
Reverse Leakage Current
ILUSB
VUSB = 5.25V, VCC = 0V, VENU = 0V
mV
mA
tR
tON
Pulldown Resistance
250
Fs
Fs
100
100
Fs
10
FA
1200
I
Fs
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MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
ELECTRICAL CHARACTERISTICS (continued)
(VCC = 5.0V Q 5%, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = 5.0V and TA = +25NC.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNIT
DDC SWITCHES (SDA0, SCL0, SDA1, SCL1)
SDA1/SCL1 Off-Leakage
Current
IOFF
VENV = VCC, VSDA1 = VSCL1 = 0V or 5.25V
SDA0/SCL0 Off-Leakage
Current
ILDDC
VCC = 0V, 3.3kI pullup to +3.3V on SDA0
and SCL0
On-Resistance
RONDDC
-1
+1
FA
10
FA
7
VIN = +0.8V, IIN = Q10mA
I
LOGIC INPUTS (H0, V0, ENV, ENU)
Input Logic-Low
VIL
Input Logic-High
VIH
Input Leakage Current
Input Hysteresis (H0, V0)
IL
0.8
V
2.0
VIN = 0V or 5.25V
-1
VHYST
+1
100
V
FA
mV
PUSH-PULL LOGIC OUTPUTS (H1, V1)
Output Logic-Low
VOL
Output Logic-High
VOH
ISINK = 8mA, VCC = +4.75V
ISOURCE = 8mA, VCC = +4.75V
Rise/Fall Time
tR, tF
10% to 90%, RL = 2.2kI, CL = 10pF
0.5
2.4
V
V
2.1
ns
OPEN-DRAIN LOGIC OUTPUTS (F1, F2, MD)
Output Leakage Current
ILKG
Output not asserted, VIN = 5.25V
Output Logic-Low
VOL
ISINK = 1mA
1
FA
0.3
V
RGB ANALOG SWITCHES (R0, G0, B0, R1, G1, B1)
Bandwidth
fMAX
RS = RL = 50I
On-Loss
ILOSS
f = 50MHz, RS = RL = 50I, 0V P VIN P +0.7V,
Figure 2
On-Resistance
RON
On-Resistance Matching
DRON
On-Resistance Flatness
RFLAT(ON)
VIN = +0.7V, IIN = Q10mA
0V P VIN P +0.7V, IIN = Q10mA, same device
1000
MHz
0.4
dB
5
0.25
8
I
1
I
1
I
On-Capacitance
CON
0V P VIN P +0.7V, IIN = Q10mA
f = 1MHz, switches enabled
6
pF
Off-Capacitance
COFF
f = 1MHz, switches disabled
2
pF
High-ESD Pins ESD
Protection
Human Body Model (Note 5)
Q8
kV
All Other Pins ESD
Protection
Human Body Model (Note 6)
Q2
kV
TSHDN
+155
NC
TSHDN_
25
NC
PROTECTION SPECIFICATIONS
Thermal-Shutdown
Threshold
Thermal-Shutdown
Hysteresis
Note
Note
Note
Note
HYS
3: All units are production tested at TA = +25NC. Specifications over temperature are guaranteed by design.
4:tBLANK is the period between detecting an overcurrent condition and the fault output asserting.
5: See the Pin Description section for the ESD status of each pin.
6: Terminal tested vs. GND. Apply 1FF-bypass capacitors on VCC, USB1, USB2, and S5V.
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MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
Test Circuits/Timing Diagrams
3.3V
VENU
0V
tOFF
5V
tON
tF
tR
90%
90%
VUSB1,
VUSB2
10%
0V
10%
Figure 1. Timing Diagram for USB Switch Parameters
+5V
1µF
0V
ENV
NETWORK
ANALYZER
VCC
R0, G0, B0
50I
VIN
50I
V
ON-LOSS = 20log OUT
VIN
MAX14984
R1, G1, B1
VOUT
MEAS
GND
50I
REF
50I
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
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MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
Typical Operating Characteristics
(VCC = +5.0V, TA = +25NC, unless otherwise noted)
ISDA0 = 10mA
40
30
20
TA = +85°C
IR0 = 10mA
40
RON (I)
30
20
TA = +25°C
TA = +85°C
TA = +25°C
10
10
TA = -40°C
0
0.5
1.0
1.5
0
2.0
1
2
3
4
VSDA0 (V)
VR0 (V)
FREQUENCY RESPONSE
HSYNC/VSYNC OUTPUT VOLTAGE
vs. TEMPERATURE
5
MAX14984 toc03
0
-1
-2
ISOURCE /ISINK = 8mA
VOH
4
5
-3
-4
VOH /VOL (V)
FREQUENCY RESPONSE (dB)
TA = -40°C
0
0
MAX14984 toc04
RON (I)
50
MAX14984 toc01
50
MAX14984 toc02
RGB ON-RESISTANCE
vs. ANALOG SIGNAL VOLTAGE
DDC ON-RESISTANCE
vs. ANALOG SIGNAL VOLTAGE
-5
-6
3
2
-7
-8
1
-9
VOL
GO TO G1
-10
1
10
100
FREQUENCY (MHz)
1k
0
-40
-15
10
35
60
85
TA (°C)
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MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
Pin Configuration
R1
G1
B1
H1
V1
S5V
TOP VIEW
18
17
16
15
14
13
SDA1 19
12
ENU
SCL1 20
11
ENV
VCC 21
10
USB2
9
USB1
8
F2
7
F1
MAX14984
VCC 22
SDA0 23
*EP/GND
+
1
2
3
4
5
6
R0
G0
B0
H0
V0
MD
SCL0 24
TQFN
(4mm x 4mm)
*CONNECT THE EXPOSED PAD (EP/GND) TO THE GROUND PLANE.
Pin Description
PIN
NAME
1
R0
RGB Analog Input
FUNCTION
Standard
ESD
2
G0
RGB Analog Input
Standard
3
B0
RGB Analog Input
Standard
4
H0
Horizontal Sync Input
Standard
5
V0
Vertical Sync Input
Standard
6
MD
Monitor Detect Output. MD is an active-low, open-drain output.
Standard
7
F1
Fault Output 1. F1 is an active-low, open-drain output that asserts when a fault
condition is detected on USB1.
Standard
8
F2
Fault Output 2. F2 is an active-low, open-drain output that asserts when a fault
condition is detected on USB2.
Standard
9
USB1
5V USB Power Output 1. USB1 is internally pulled down when not enabled.
High
10
USB2
5V USB Power Output 2. USB2 is internally pulled down when not enabled.
High
11
ENV
Video Enable Input. Drive ENV low to connect the VGA signals to the VGA port.
High
12
ENU
USB Enable Input. Drive ENU low to enable the USB power-supply outputs.
High
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MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
Pin Description (continued)
PIN
NAME
13
S5V
FUNCTION
ESD
Switched 5V Output. S5V is connected when ENV is low and is internally pulled
down when not connected.
High
14
V1
Vertical Sync Output
High
15
H1
Horizontal Sync Output
High
16
B1
RGB Analog Output
High
17
G1
RGB Analog Output
High
18
R1
RGB Analog Output
High
19
SDA1
DDC Input/Output. SDA1 has an internal 2.5kI pullup resistor to S5V
High
20
SCL1
DDC Input/Output. SCL1 has an internal 2.5kI pullup resistor to S5V
High
21, 22
VCC
Supply Voltage. VCC = 5.0V Q5%. Bypass VCC to GND with a 1FF or larger
ceramic capacitor as close as possible to VCC.
Standard
23
SDA0
DDC Input/Output
Standard
24
SCL0
DDC Input/Output
Standard
—
EP/GND
Exposed Pad. The exposed pad is the ground connection for the device.
Connect EP/GND to the ground plane.
—
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MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
Functional Diagram
VCC
S5V
INTERNAL VL
2.5V
REGULATOR
MAX14984
200I
R0
R1
G0
G1
B0
B1
2.5kI
S5V
SDA1
SDA0
2.5kI
SCL1
SCL0
H0
H1
V0
V1
F2
VCC
USB1
F1
MONITOR
DETECTION
1kI
MD
USB2
THERMAL
PROTECTION
ENU
ENV
1kI
CONTROL
LOGIC
GND
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MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
Detailed Description
The MAX14984 integrates high-bandwidth analog
switches and level-translating buffers with current-limited
power switches to implement a VGA port protector. The
device provides switching for red-green-blue (RGB)
signals, horizontal and vertical synchronization (H/V)
pulses, display data channel (DDC) signals, and 5V
power supplies. The power switches provide +5V power
with current limiting and reverse voltage protection to the
VGA port and up to two USB ports.
The device uses a simplified power-supply interface
that operates from a single +5V supply. An internal 2.5V
regulator limits the voltage passed by the DDC switches to
provide compatibility with low-voltage graphics controllers.
The device features two enable inputs, a monitor detection output, and two fault outputs. ENV can be connected
to MD to automatically connect the graphics signal when
a monitor is inserted. The fault outputs signal when a fault
condition is detected on either of the USB power outputs
and they are enabled by ENU.
5V Power Switch (S5V)
Two active-low fault outputs, F1 and F2, assert when a
fault is detected on USB1 or USB2, respectively. Two
fault conditions can be detected: short circuit to GND
and overcurrent draw from the USB port. The switches
are protected against reverse current into VCC while ENU
is high, but this condition is not detected by F1 and F2.
Current-limiting and thermal-shutdown circuitry protects
the device in the presence of any fault.
A blanking period is built in to F1 and F2 that delays
assertion until the current limit has been reached for at
least tBLANK. In addition, an internal 1kI pulldown resistor is connected on each USB output when it is disabled.
The F1 and F2 outputs are tolerant to external voltages
of up to 6V. The MAX14984 limits the current into them
to 600FA.
RGB Switches
The MAX14984 provides three single-pole/single-throw
(SPST) high-bandwidth switches to connect the standard
VGA R, G, and B signals from the graphics controller to
the VGA port. The R, G, B analog switches are identical,
and any of the three switches can be used to route red,
green, or blue video signals.
The MAX14984 provides a switched +5V output in addition to the regular VGA signals (S5V). This output can
supply 55mA with less than 300mV drop from VCC. The
S5V output tolerates +5V while turned off or when VCC is
not present.
The RGB switches are connected when ENV is low.
The power switches are protected against overcurrent
and overtemperature faults. The device limits current
supplied to the monitor side to 300mA (typ). Thermal
protection circuitry shuts off the switch when the temperature exceeds +155NC. The device is re-enabled once
the temperature has fallen to below +130NC.
H1 and V1 are enabled when ENV is low and high impedance when ENV is high. The H and V channels are not
interchangeable.
S5V is connected whenever ENV is low and has a 200I
(typ) pulldown resistor to discharge filter capacitors when
the switch is off.
USB Switches and F1/F2 Outputs
The MAX14984 features two switches that provide power
for up to two USB connectors. One enable input, ENU,
controls both switches simultaneously. Each switch can
provide up to 500mA while only dropping 250mV from
VCC.
Horizontal/Vertical Sync Buffer
The H/V signals are buffered to provide level shifting and
drive capability to meet the VESA specification.
Display Data Channel Switches
(SDA_, SCL_)
The MAX14984 provides two voltage-limited SPST
switches to connect DDC signals (SDA_, SCL_). These
switches limit the voltage that can be passed through to
the graphics controller to less than 2.5V. Internal pullup
resistors on the monitor side of the switches translate
the graphics controller signals to 5V compatible logic.
Connect pullup resistors on SCL0 and SDA0 to define the
logic level of the graphics controller.
The SDA_ and SCL_ switches are connected when ENV
is low and are identical; either switch can be used to
route SDA or SCL I2C signals.
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MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
Monitor Detection and
Automatic Switching
The MAX14984 detects monitor insertion/removal events
by measuring the voltage on B1. The monitor detection
circuitry always correctly indicates the presence of a
monitor as long as V0 is not high impedance. The voltage measurement is only sampled between synchronization pulses on V0 from the controller when a monitor is
inserted to ensure that the video signal is not interrupted
while promptly detecting a removal.
The device automatically connects the graphics controller to the monitor when it is plugged in if configured in
automatic mode. To configure automatic mode, connect
MD to ENV and add a pullup resistor.
Applications Information
Compatibility with Low-Voltage
Graphics Controllers
The MAX14984 provides the level shifting necessary to
drive a standard VGA port using any graphics controller.
Internal buffers drive the H and V signals to VGA standard TTL levels. The DDC switches provide level shifting
by limiting signal levels that can be passed through the
DDC switches to less than 2.5V. Add pullup resistors
from the DDC lines to the graphics controller supply to
set the logic level on the SDA0/SCL0 side.
Power-Supply Decoupling
PC Board Layout
High-speed switches such as the MAX14984 require
proper PCB layout for optimum performance. Ensure that
impedance-controlled PCB traces for high-speed signals
are matched in length and as short as possible. Connect
the exposed pad to a solid ground plane.
High ESD Protection
Electrostatic Discharge (ESD) protection structures are
incorporated on all pins to protect against electrostatic
discharges up to Q2kV Human Body Model (HBM)
encountered during handling and assembly. All VGA
and USB outputs are further protected against ESD up to
Q8kV (HBM) without damage (see the Pin Description).
The ESD structures withstand high ESD both in normal
operation and when the device is powered down. After
an ESD event, the MAX14984 continues to function without latchup.
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents test
setup, test methodology, and test results.
Human Body Model
Figure 3 shows the Human Body Model. Figure 4 shows
the current waveform it generates when discharged
into a low impedance. This model consists of a 100pF
capacitor charged to the ESD voltage of interest that is
then discharged into the device through a 1.5kI resistor.
Bypass VCC to ground with a 1FF or larger ceramic
capacitor as close to the device as possible.
HIGHVOLTAGE
DC
SOURCE
RC
1MΩ
RD
1.5kΩ
CHARGE-CURRENTLIMIT RESISTOR
DISCHARGE
RESISTANCE
CS
100pF
STORAGE
CAPACITOR
Figure 3. Human Body ESD Test Model
IPEAK (AMPS)
Ir
100%
90%
DEVICE
UNDER
TEST
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
36.8%
10%
0
0
TIME
tRL
tDL
Figure 4. Human Body Current Waveform
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MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX14984ETG+
-40NC to +85NC
24 TQFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed paddle.
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maxim-ic.com/packages. Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
24 TQFN-EP
T2444+3
21-0139
90-0021
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MAX14984
Enhanced VGA Port Protector with Monitor
Detection and Dual USB Power Switches
Revision History
REVISION
NUMBER
REVISION
DATE
0
3/12
DESCRIPTION
Initial release
PAGES
CHANGED
—
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical
Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2012
Maxim Integrated Products 12
Maxim is a registered trademark of Maxim Integrated Products, Inc.