MAX14895E [MAXIM]
Enhanced VGA Port Protector DDC Outputs have Internal Pullups; 增强型的VGA端口保护DDC输出具有内部上拉电阻
| 型号： | MAX14895E |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Enhanced VGA Port Protector DDC Outputs have Internal Pullups |
| 文件： | 总11页 (文件大小：1200K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-5819; Rev 0; 3/11
E V A L U A T I O N K I T A V A I L A B L E
General Description
Benefits and Features
The MAX14895E integrates level-translating buffers and
features RED, GRN, and BLU (RGB) port protection for
VGA signals.
S Saves Power in Portable Applications
ꢀLow Quiescent Supply Current: 430µA (typ)
S Eliminates Need for Costly External Components
High-ESD Protection on SDA1, SCL1, SYNCH1,
The device has horizontal sync (SYNCH_) and vertical
sync (SYNCV_) translating buffers that convert low-level
CMOS inputs from a graphics controller to meet full 5V,
TTL-compatible outputs. Each output can drive Q10mA
and meets the VESASM specification. In addition, the
device translates the direct digital control (DDC) signals
to a lower level that is safe for the graphics controller.
SYNCV1, RED, GRN, BLU, EN, V
±1ꢀ5V Human Body Model (HBM)
S
±±5V IEC 61000-4-2 Contact Discharge
S Innovative Design Enables a High Level of
Integration for Performance
Output Current-Limit Switch with Power-Off
Protection
Low Capacitance on RGB Ports (2.2pF typ)
10mA Drive on SYNCH1, SYNCV1
The device features both EN and EN inputs, accepting
active-high or active-low enable inputs. The device also
switches and current limits the 5V supply to a VGA con-
nector or monitor.
S Fully Integrated Solutions Saves Space in Portable
Applications
The RED, GRN, and BLU terminals protect graphics con-
troller outputs against electrostatic discharge (ESD) events.
All eight outputs and EN have high-level ESD protection.
DDC Outputs have Internal Pullups
3mm x 3mm, 16-Pin TQFN Pac5age
The MAX14895E is specified over the extended -40NC to
+85NC temperature range and is available in a 16-pin,
3mm x 3mm TQFN package with exposed pad.
Ordering Information appears at end of data sheet.
Applications
For related parts and recommended products to use with this part,
refer to www.maxim-ic.com/MAX14895E.related.
Notebook Computers
Desktops
Servers
Graphics Cards
Typical Operating Circuit
+5V
1µF
V
CC
V
EN
S
1µF
EN
SYNCH0, SYNCV0
2
2
SYNCH1, SYNCV1
SDA1, SCL1
2
2
SDA0, SCL0
RED
VGA
VGA
OUTPUTS
PORT
MAX14895E
GRN
BLU
GND
VESA is a service mark of the Video Electronics Standards Association Corporation.
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1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-±±±-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX14895E
Enhanced VGA Port Protector
ABSOLUTE MAXIMUM RATINGS
(Voltages referenced to GND.)
Continuous Power Dissipation (T = +70NC)
A
V
, V , EN, SDA0, SCL0 ......................................-0.3V to +6V
TQFN (derate 20.8mW/NC above +70NC)..................1667mW
Operating Temperature Range.......................... -40NC to +85NC
Junction Temperature .....................................................+150NC
Storage Temperature Range............................ -65NC to +150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
CC
S
SDA1, SCL1 ................................................ -0.3V to (V + 0.3V)
EN, RED, GRN, BLU, SYNCH0,
S
SYNCH1, SYNCV0, SYNCV1................ -0.3V to (V
+ 0.3V)
CC
Continuous Current through SDA_, SCL_....................... Q30mA
Continuous Short-Circuit Current SYNCH1, SYNCV1..... Q20mA
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.
PACKAGE THERMAL CHARACTERISTICS (Note 1)
TQFN
Junction-to-Ambient Thermal Resistance (B ) ..........48NC/W
JA
Junction-to-Case Thermal Resistance (B ).................7NC/W
JC
Note 1: 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.
ELECTRICAL CHARACTERISTICS
(V
= +4.75V to +5.25V, T = -40NC to +85NC, unless otherwise noted. Typical values are at V
= +5V, T = +25NC.) (Note 2)
CC
A
CC A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
POWER SUPPLY
Power-Supply Range
V
4.75
5.25
800
V
CC
EN = V , EN = GND,
SYNCH0 = SYNCV0 = GND,
SDA0 = SCL0 = unconnected
CC
Quiescent Supply Current
Shutdown Supply Current
I
430
FA
Q
EN = GND, EN = V
,
CC
I
8
FA
SYNCH0 = SYNCV0 = GND,
SDA0 = SCL0 = unconnected
SHDN
Undervoltage Lockout Threshold
Undervoltage Lockout Hysteresis
V
V
rising
4.3
V
V
UVLO
CC
0.1
2.2
V
= +4.75V to +5.25V, SDA1/SCL1 =
CC
1.6
1.6
2.9
2.8
unconnected, measure SDA0/SCL0
V = +4.75V to +5.25V, SDA0/SCL0 =
CC
200kI to GND, measure SDA0/SCL0,
Internal Logic Supply Voltage
V
V
L
SDA1/SCL1 = unconnected
RED, GRN, BLU
RED, GRN, BLU Capacitance
RED, GRN, BLU Leakage Current
C
f = 1MHz, V
= 1V
P-P
pF
OUT
RED, GRN, BLU
-1
+1
FA
SYNCH0, SYNCV0, EN, EN
Input Logic-High
V
2.0
V
V
IH
Input Logic-Low
V
0.8
IL
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*The parametric values (min, typ, max limits) shown in the Electrical Characteristics table supersede values quoted elsewhere in this data sheet.
MAX14895E
Enhanced VGA Port Protector
ELECTRICAL CHARACTERISTICS* (continued)
(V
= +4.75V to +5.25V, T = -40NC to +85NC, unless otherwise noted. Typical values are at V
= +5V, T = +25NC.) (Note 2)
CC
A
CC A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
+1
UNITS
FA
SYNCH0, SYNCV0 Leakage
Current
SYNCH0/SYNCV0 = GND or V
-1
CC
200
800
kI
EN, EN Input Resistance
SYNCH1, SYNCV1
Output Logic-High
Output Logic-Low
EN = V , EN = GND
CC
V
V
V
= +4.75V, source 10mA
= +4.75V, sink 10mA
2.4
V
V
OH
CC
V
0.5
4
OL
CC
R = 2.2kI, C = 10pF, 10% to 90% of V
L
L
CC
Rising Time
t
ns
ns
ns
Fs
R
(Note 3)
R = 2.2kI, C = 10pF, 90% to 10% of V
L
L
CC
Falling Time
t
4
F
(Note 3)
R = 2.2kI, C = 10pF, EN = V , EN =
L
L
CC
Propagation Delay
Enable Time
t
t
16
17
PD
EN
GND (Figure 1)
R = 2.2kI, C = 10pF, V V
SYNCH1, SYNCV1
L
L
= +4.75V (Figure 1)
SDA�, SCL� (DDC)
On-Resistance
R
V
= V
= 0.5V, I = 10mA
LOAD
55
+1
I
ON
SDA0
SCL0
EN = GND, EN = V
SDA0 = SCL0 = V , SDA1 = SCL1 = GND
,
CC
SDA0, SCL0 Off-Leakage Current
-1
FA
CC
SDA1, SCL1 Reverse-Leakage
Current
V
V
= 0V, V = +5.25V,
CC S
-10
+10
4.0
FA
kI
= V
= +5.25V
SDA1
SCL1
V
= +4.75V, SDA0 = SCL0 =
CC
SDA1, SCL1 Pullup Resistor
R
unconnected, EN = V
, EN = GND,
1.25
200
2.5
PULLUP
CC
I
= 100FA
LOAD
V
OUTPUT
S
Forward Voltage Drop
Reverse-Leakage Current
Current Limit
I
= 60mA, V
= 5V
0.25
10
V
FA
mA
I
LOAD
CC
V
= 0V, V = 5.25V
S
CC
I
600
500
LIM
Discharge Resistor
R
I
= 1mA
300
VS
LOAD
THERMAL SHUTDOWN
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
ESD PROTECTION
+150
10
NC
NC
HBM
IEC 61000-4-2 Contact
15
8
kV
kV
SDA1, SCL1, SYNCH1, SYNCV1,
RED, GRN, BLU, EN, V
S
Note 2: All devices are 100% production tested at T = +25NC. Limits over the operating temperature range are guaranteed by
A
design and not production tested.
Note 3: Guaranteed by design.
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*The parametric values (min, typ, max limits) shown in the Electrical Characteristics table supersede values quoted elsewhere in this data sheet.
MAX14895E
Enhanced VGA Port Protector
2.4V
V
V
/V
SYNCH0 SYNCV0
50%
50%
0V
OUTPUT HIGH
50%
/V
50%
SYNCH1 SYNCV1
OUTPUT LOW
t
t
PHL
PLH
t
= MAX(t , t
)
PD
PLH PHL
2.4V
V
50%
50%
EN
0V
2.4V
V
EN
0V
OUTPUT HIGH
V
/V
50%
SYNCH1 SYNCV1
OUTPUT LOW
t
EN
Figure 1. Timing Diagram
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MAX14895E
Enhanced VGA Port Protector
Typical Operating Characteristics
(V
= +5V, T = +25NC, unless otherwise noted.)
CC
A
HV BUFFER OUTPUT-VOLTAGE HIGH
vs. TEMPERATURE
ON-RESISTANCE vs. SDA0 VOLTAGE
6.0
80
I
= 8mA
OUT
SDA0, SCL0 ARE
5.8
5.6
5.4
5.2
5.0
4.8
4.6
4.4
4.2
4.0
70
60
50
40
30
20
10
0
INTERCHANGEABLE
T = +25°C
A
T = +85°C
A
T = -40°C
A
-40
-15
10
35
60
85
0
0.5
1.0
1.5
2.0
2.5
3.0
TEMPERATURE (°C)
V
(V)
SDA0
HV BUFFER OUTPUT-VOLTAGE LOW
vs. TEMPERATURE
1.0
I
= 8mA
OUT
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
-40
-15
10
35
60
85
TEMPERATURE (°C)
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MAX14895E
Enhanced VGA Port Protector
Pin Configuration
TOP VIEW
12
11
10
9
SYNCV0 13
SYNCV1 14
15
8
7
6
5
SDA1
SDA0
EN
MAX14895E
V
CC
*EP
4
EN 16
V
S
+
1
2
3
TQFN
(3mm x 3mm)
*CONNECT EP TO GND.
Pin Description
PIN
1
NAME
RED
FUNCTION
High-ESD Protection Diodes for RGB Signals
High-ESD Protection Diodes for RGB Signals
High-ESD Protection Diodes for RGB Signals
Ground
2
GRN
BLU
3
4
GND
Supply Voltage Output with Current-Limit Switch. V provides a current-limited voltage from V
when the
S
CC
5
V
S
device is enabled. Bypass V to GND with a 1FF or larger ceramic capacitor as close as possible to the device.
S
6
7
EN
Active-Low Enable Input. Drive EN high and EN low to disable the device. EN is weakly pulled up internally.
SDA0
SDA1
SCL0
SCL1
DDC Data Input from Graphics Controller
8
DDC Data Output to VGA Monitor. Internally pulled up to V
.
CC
9
DDC Clock Input from Graphics Controller
10
11
12
13
14
DDC Clock Output to VGA Monitor. Internally pulled up to V
.
CC
SYNCH0 Horizontal Sync Input
SYNCH1 Horizontal Sync Output
SYNCV0 Vertical Sync Input
SYNCV1 Vertical Sync Output
Supply Voltage Input. Apply a voltage between +4.75V and +5.25V to V
to GND with a 1FF or larger ceramic capacitor as close as possible to the device.
to power the device. Bypass V
CC
CC
15
16
—
V
CC
EN
EP
Active-High Enable Input. Drive EN low and EN high to disable the device. EN is weakly pulled down internally.
Exposed Pad. Connect EP to GND. For enhanced thermal dissipation, connect EP to a large ground plane.
Do not use EP as the only ground connection.
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MAX14895E
Enhanced VGA Port Protector
Functional Diagram/Truth Table
V
CC
THERMAL
SHUTDOWN
MAX14895E
CURRENT-LIMIT
SWITCH
V
S
EN
EN
LOGIC
SDA/SCL PULLUP
RESISTOR
SWITCHES
HIGH ESD
R
VS
HIGH ESD
V
PULLUP-TO-GND
S
R
R
PULLUP
PULLUP
SWITCHES
SDA0
SCL0
SDA1
HIGH ESD
2
I C LEVEL SHIFTER
SCL1
HIGH ESD
SYNCH0
SYNCH1
HIGH ESD
SYNCV0
SYNCV1
HIGH ESD
RED
GRN
BLU
HIGH ESD
HIGH ESD
HIGH ESD
GND
EN EN DEVICE LOGIC
0
0
1
1
0
1
0
1
Enable
Disable
Enable
Enable
2
DEVICE LOGIC/ SYNCH_/SYNCV_ I C LEVEL CURRENT-LIMIT
SDA/SCL PULLUP
RESISTOR SWITCHES
V
PULL-TO-GND
SWITCH
S
EVENT
BUFFER
SHIFTER
SWITCH
Enable
No Overcurrent
On
On
On
On
On
Off
Off
Enable
Overcurrent
On
On
Off
Current Limit
Off
Enable
Overcurrent
Output 0V
Off
On
Thermal Shutdown
Disable
Output 0V
Off
Off
Off
Off
Off
Off
Off
On
Off
V
= 0V
CC
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MAX14895E
Enhanced VGA Port Protector
V
Output
S
S
Detailed Description
The device provides a current-limited voltage on V when
The MAX14895E integrates level-translating buffers and
features RED, GRN, and BLU port protection for VGA sig-
nals. Horizontal and vertical synchronization (SYNCH0,
SYNCV0) inputs feature level-shifting buffers to support
low-voltage CMOS or standard TTL-compatible graphics
controllers. Each output can drive Q10mA and meets
the part is enabled. V is used as the pullup voltage for
internal pullup resistors on SDA1 and SCL1, and can be
used as an external supply. The internal pullup resistors
from SDA1 and SCL1 to V are active when the device is
enabled, and are disabled when the device is in thermal
S
S
shutdown (see the Functional Diagram/Truth Table).
2
VESA specifications. The device also features I C level
The V supply includes an internal resistor to discharge
S
the supply when the device is in thermal shutdown or is
shifting using two nMOS devices.
The device generates its own internal bias supply to
clamp SCL0 and SDA0 to a safe level, removing the need
for another external supply. The device also provides a
disabled (see the Functional Diagram/Truth Table). V is
current limited to prevent damage to host devices. When
S
power is off (V
leakage current up to V = +5.25V.
= 0V), V is protected against reverse-
CC
S
current-limited V
output with power-off protection. This
CC
S
output can be used to switch power to a VGA connector
or the VGA interface of a monitor.
Thermal Shutdown
Thermal-shutdown circuitry protects the device from
overheating. The device enters thermal shutdown when
the junction temperature exceeds +150NC (typ) and
returns to normal operation when the temperature drops
by approximately +10NC (typ) below the thermal-shut-
down threshold. When the device is in thermal shutdown,
both SYNCH1 and SYNCV1 are pulled down to ground,
Horizontal/Vertical Sync Level Shifter
SYNCH0 and SYNCV0 are buffered to provide level shift-
ing and drive capability to meet the VESA specification.
The level-shifted outputs (SYNCH1, SYNCV1) are pulled
low when EN is low and EN is high, or when the device
is in thermal shutdown (see the Functional Diagram/
2
Truth Table). Logic-level outputs (V , V ) are 5V TTL-
the I C level shifters are disabled, the SDA1 and SCL1
pullups are off, and the V discharge resistor is on (see
OL OH
compatible. These two buffers are identical and each
can drive either the horizontal or the vertical synch signal.
S
the Functional Diagram/Truth Table).
Applications Information
Power-Supply Decoupling
Display Data Channel Switches
2
The device incorporates two nMOS switches for I C
level shifting. The SDA0 and SCL0 terminals are voltage
clamped to a diode drop less than the internal V volt-
L
Bypass V
and V to ground with 1FF ceramic capaci-
tors as close as possible to the device.
CC
S
age. Voltage clamping provides protection and compat-
ibility with the SDA0 and SCL0 signals and low-voltage
PCB Layout
ASICs. When power is off (V
are protected against reverse-leakage current up to V =
+5.25V. The SDA_ and SCL_ switches are identical, and
each switch can be used to route SDA_ or SCL_ signals.
= 0V), SDA1 and SCL1
CC
High-speed switches such as the MAX14895E require
proper PCB layout for optimum performance. Ensure that
impedance-controlled PCB traces for high-speed signals
are matched in length and are as short as possible.
Connect the exposed pad to a solid ground plane.
S
RGB Ports
The device includes three terminals for RED, GRN, and
BLU signals. These terminals provide high-level ESD pro-
tection to the RGB lines while keeping the capacitance
on the RGB lines to a minimum. The RED, GRN, BLU
terminals are identical, and any of the three terminals
can be used to protect red, green, or blue video signals.
ESD Protection
As with all Maxim devices, ESD protection structures
are incorporated on all terminals to protect against elec-
trostatic discharges encountered during handling and
assembly. Additionally, the device is protected to Q15kV
on the RED, GRN, BLU, EN, V , SYNCH1, SYNCV1,
SCL1, and SDA1 terminals by the HBM. For optimum
S
EN, EN
The device has dual complementary EN and EN enable
inputs and can accept either active-low or active-high
enable signals. Pull EN low and EN high to place the device
in shutdown (see the Functional Diagram/Truth Table).
ESD performance, bypass V
ceramic capacitor.
to ground with a 1FF
CC
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MAX14895E
Enhanced VGA Port Protector
ESD protection can be tested in various ways. The RED,
IEC 61000-4-2
The IEC 6100-4-2 standard covers ESD testing and per-
formance of finished equipment. However, it does not
specifically refer to integrated circuits. The device assists
in designing equipment to meet IEC 61000-4-2 without
the need for additional ESD protection components.
GRN, BLU, EN, V , SYNCH1, SYNCV1, SCL1, and SDA1
S
terminals of the device are characterized for protection to
the following limits:
•ꢀ Q15kV using the HBM
•ꢀ Q8kV using IEC 61000-4-2 Contact Discharge
The major difference between tests done using the HBM
and IEC 61000-4-2 is higher peak current in IEC 61000-
4-2 because series resistance is lower in the IEC 61000-
4-2 model. Hence, the ESD withstand voltage measured
to IEC 61000-4-2 is generally lower than that measured
using the HBM. Figure 4 shows the IEC 61000-4-2 model,
and Figure 5 shows the current waveform for the IEC
61000-4-2 ESD Contact Discharge test.
Human Body Model
Figure 2 shows the HBM. Figure 3 shows the current
waveform it generates when discharged into a low-
impedance state. This model consists of a 100pF capaci-
tor charged to the ESD voltage of interest that is then
discharged into the device through a 1.5kI resistor.
R
R
R
R
D
C
D
C
1MΩ
1.5kΩ
50MΩ TO 100MΩ
330Ω
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
HIGH-
VOLTAGE
DC
HIGH-
VOLTAGE
DC
DEVICE
UNDER
TEST
DEVICE
UNDER
TEST
C
100pF
STORAGE
CAPACITOR
C
150pF
STORAGE
CAPACITOR
S
S
SOURCE
SOURCE
Figure 2. Human Body ESD Test Model
Figure 4. IEC 61000-4-2 ESD Test Model
I
(AMPS)
PEAK
I
(AMPS)
PEAK
100%
90%
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
I
100%
90%
r
36.8%
10%
0
10%
TIME
t
0
t = 0.7ns TO 1ns
t
RL
R
t
DL
30ns
60ns
Figure 3. Human Body Current Waveform
Figure 5. IEC 61000-4-2 ESD Generator Current Waveform
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MAX14895E
Enhanced VGA Port Protector
Ordering Information
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.
PART
TEMP RANGE
PIN-PACKAGE
MAX14895EETE+T
-40NC to +85NC
16 TQFN-EP*
+Denotes lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
*EP = Exposed pad.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
Chip Information
16 TQFN-EP
T1633+4
21-0136
90-0031
PROCESS: BiCMOS
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MAX14895E
Enhanced VGA Port Protector
Revision History
REVISION REVISION
PAGES
DESCRIPTION
CHANGED
NUMBER
DATE
0
3/11
Initial release
—
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
11
©
2011 Maxim Integrated Products
Maxim is a registered trademark of Maxim Integrated Products, Inc.
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