MAX9546/MAX9547
General Description
The MAX9546/MAX9547 differential interface chipset
converts single-ended voltages to differential voltages for
transport and then converts back to single-ended voltages. These devices eliminate costly, bulky, single-ended
coaxial cables with inexpensive, readily available, differential shielded (ScTP) or unshielded (UTP) twisted pairs.
The fault detection of the MAX9546 and loss-of-signal
detection of the MAX9547 allow proactive and speedy
diagnosis, such as identifying failures in the manufacturing stage and troubleshooting equipment at repair facilities. The MAX9546/MAX9547 are low-cost, convenient
solutions for transporting CVBS/FBAS analog video signals (PAL or NTSC) through hostile environments.
The MAX9546 driver converts the single-ended input into
a differential output with a 6dB fixed gain to drive a backterminated, DC-coupled differential video output to unity
gain. This DC connection allows the detection of a shortcircuit condition at the differential outputs. The FAULT
output indicates a short-circuit condition including a short
to a high battery condition (VBAT = +16V) or ground.
The MAX9547 receiver converts the differential signal
from the MAX9546 into a single-ended signal. Like the
MAX9546 output, the MAX9547 input survives a short to
a high battery condition or ground. The MAX9547 receiver
loss-of-signal output (LOS) operates by detecting the
H-Sync and thus can support both monochrome and color
video signals. The MAX9547 gain is set with an external
impedance between ZT+ and ZT-.
The MAX9546/MAX9547 operate from a 7.5V to 10V
single supply. Both devices include ±15kV ESD Human
Body Model (HBM) protection. The MAX9546/MAX9547
are offered in a thermally enhanced 8-pin SO package
and specified over the -40°C to +85°C extended temperature range.
Applications
●● Security/CCTV Video
●● Avionics/In-Flight Entertainment
19-3873; Rev 4; 9/14
Differential Video Interface Chipset
Features
●● Fault Detection (MAX9546)
●● Loss-of-Signal Detection (MAX9547)
●● Tolerate ±2V Ground-Level Shift between Source and
Load
●● ±15kV ESD Protection (Human Body Model)
●● ±8kV–IEC 1000-4-2 Contact Discharge
●● ±15kV–IEC 1000-4-2 Air-Gap Discharge
●● Preset 6dB Gain (MAX9546)
●● Variable Receiver Gain (MAX9547)
●● 7.5V to 10V Single-Supply Operation
Ordering Information
PART
PINPACKAGE
MAX9546ESA+
8 SO-EP*
S8E-14
Driver
MAX9547ESA+
8 SO-EP*
S8E-14
Receiver
PKG CODE DESCRIPTION
Note: These devices are specified for -40°C to +85°C temperature range.
+Denotes a lead-free package.
*EP = Exposed paddle.
Pin Configuration appears at end of data sheet.
Typical Operating Circuit
VCC
VCC
ZT+
MAX9547
MAX9546
ZTOUT+
IN+
OUT-
IN-
IN
IOUT
CLAMP
FAULT
LOS
VOUT
MAX9546/MAX9547
Differential Video Interface Chipset
Absolute Maximum Ratings
(Voltages are referenced GND.)
VCC to GND........................................................ -0.3V to +11V
IN and FAULT (MAX9546)....................... -0.3V to (VCC + 0.3V)
OUT+, OUT- (MAX9546) (Note 1).............................-2V to +16V
FAULT Short-Circuit Duration to
VCC or GND (MAX9546)........................................Continuous
IN+, IN- (MAX9547) (Note 1)....................................-2V to +16V
IOUT, LOS, ZT+, ZT- (MAX9547).............. -0.3V to (VCC + 0.3V)
Differential Input Voltage (|VIN+ - VIN-|) (MAX9547)..............+5V
IOUT, LOS Short-Circuit Duration to
VCC or GND (MAX9547)........................................Continuous
Continuous Power Dissipation (TA = +70°C)
8-Pin SO-EP (derate 24.4mW/°C above +70°C).....1951.2mW
θJC (Note 2)....................................................................7.0°C/W
θJA.................................................................................41.0°C/W
Operating Temperature Range............................ -40°C to +85°C
Junction Temperature...................................................... +150°C
Storage Temperature Range............................. -65°C to +150°C
Lead Temperature (soldering, 10s).................................. +300°C
Note 1: The Absolute Maximum Ratings of OUT+/OUT- for the MAX9546 and IN+/IN- for the MAX9547 are based on a single-fault
condition, i.e. only one output of MAX9546 (or both outputs together) is shorted to the battery, VCC or GND. The devices will
not survive a double-fault condition, i.e. OUT+ and OUT- shorted to different supplies.
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.maximintegrated.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.
DC Electrical Characteristics–MAX9546
(VCC = +8.5V, RL = 220Ω between OUT+ and OUT-, TA = -40°C to +85°C. Typical values are at TA = +25°C, unless otherwise noted.)
(Note 3)
PARAMETER
SYMBOL
CONDITIONS
Supply Voltage Range
VCC
Guaranteed by PSRR
Quiescent Supply Current
ICC
No load
Voltage Gain
AV
VIN = 1.2VP-P (Note 4)
Input-Voltage Swing
VIN
Guaranteed by AV
Input Clamp Voltage
VCLMP
(Note 5)
Input Clamp Current
ICLMP
(Note 5)
Input Resistance
RIN
Output Common-Mode Voltage
VCOM
Output Impedance
ROUT
Output Fault Current
Power-Supply Rejection Ratio
FAULT Output Logic Level
FAULT Output Leakage Current
www.maximintegrated.com
IF(OUT)
PSRR
MIN
TYP
MAX
7.5
8.5
10.0
V
64
112
mA
2
2.2
V/V
1.2
VP-P
1.8
3.46
7
(Notes 5, 6)
V
13
500
3.0
3.25
9
OUT+ and/or OUT- to + (VCC - 2V)
2
OUT+ and/or OUT- to +2V
4
OUT+ and/or OUT- to -2V
7
OUT+ and/or OUT- to +16V, VCC
unconnected
6
OUT+ or OUT- to -2V, VCC unconnected
24
VCC from 7.5V to Differential mode
10V (Note 7)
Common mode
45
62
46
52
VOL, ISINK = 1.6mA (Note 8)
3.4
V
Ω
mA
dB
0.4
0.01
µA
kΩ
0.1
OUT+ and/or OUT- to +16V
UNITS
V
µA
Maxim Integrated │ 2
MAX9546/MAX9547
Differential Video Interface Chipset
AC Electrical Characteristics–MAX9546
(VCC = +8.5V, RL = 220Ω across OUT+ and OUT-, TA = -40°C to +85°C. Typical values are at TA = +25°C, unless otherwise noted.)
(Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Large-Signal Bandwidth
VIN = 1VP-P, -3dB
18
MHz
Large-Signal Flatness
VIN = 1VP-P, ±0.5dB
15
MHz
OUT+ - OUT-
70
V/µs
Slew Rate
Settling Time (0.1%)
SR
tSETTLING VIN = 1VP-P
Power-Supply Rejection Ratio
PSRR
Common-Mode Balance
(Note 9)
CMB
Droop
400
ns
f = 100kHz, 100mVP-P ripple
63
dB
f = 100kHz
55
f = 3.58MHz
39
Guaranteed by input current
1
dB
%
Differential Gain
DG
(Note 10)
1.37
%
Differential Phase
DP
(Note 10)
0.14
degrees
SNR
SNR (dBRMS)
(Note 10)
-62
dB
2T Pulse to Bar Rating
(Note 10)
-0.22
%KF
2T Pulse Response
(Note 10)
0.30
%KF
At 3.58MHz (Note 10)
Group Delay
2.20
ns
Horizontal Tilt
D/dt
(Notes 10, 15)
0
%
Vertical Tilt
(Notes 10, 15)
6.62
%
DC Electrical Characteristics–MAX9547
(VCC = +8.5V, GND = 0V, RL = 75Ω, ZZT = 75Ω, TA = -40°C to +85°C. Typical values are at TA = +25°C.) (Note 3)
PARAMETER
SYMBOL
Supply Voltage Range
VCC
Supply Current
ICC
Differential Input Voltage Range
|IN+ - IN-|
Common-Mode Input Voltage
Range
Input Current
CONDITIONS
Guaranteed by PSRR
VIN(P-P)
Guaranteed by CMRR (Note 11)
VCOM
Guaranteed by CMRR (Note 11)
∆IIN
Input Resistance
RIN
Differential
Voltage Gain
AV
VIN(P-P) = 1.2V, defined as IOUT x (RL / VIN)
Output Voltage
VOB
Output Voltage Swing
VOUT
IOUT
Power-Supply Rejection Ratio
PSRR
Common-Mode Rejection Ratio
CMRR
www.maximintegrated.com
TYP
MAX
UNITS
7.5
8.5
10.0
V
70
110
mA
1.2
VP-P
5.4
V
6
30
µA
1
4.2
1.0
IIN
Input Offset Current
Maximum Output Current
MIN
80
0.90
IN+ = IN- = 3.2V
1
1.15
V/V
1.2
VP-P
1
VIN = 1V, ZZT = 0
µA
kΩ
V
21
mA
VCC from 7.5V to 10V
26
34
dB
1V ≤ VCOM ≤ 5.4V
42
54
2V ≤ VCOM ≤ 4.4V
46
70
dB
Maxim Integrated │ 3
MAX9546/MAX9547
Differential Video Interface Chipset
DC Electrical Characteristics–MAX9547 (continued)
(VCC = +8.5V, GND = 0V, RL = 75Ω, ZZT = 75Ω, TA = -40°C to +85°C. Typical values are at TA = +25°C.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
VOL, ISINK = 1.6mA (Note 12)
LOS Logic Level
MAX
UNITS
0.4
V
0.01
LOS Leakage Current
Input Fault Current
TYP
IF
IN+ and/or IN- to +16V, RT1 + RT2 = 110Ω
50
IN+ and/or IN- to -2V, RT1 + RT2 = 110Ω
10
IN+ and/or IN- to +16V, VCC unconnected,
RT1 + RT2 = 110Ω
72
IN+ and/or IN- to -2V, VCC unconnected,
RT1 + RT2 = 110Ω
10
µA
mA
AC Electrical Characteristics–MAX9547
(VCC = +8.5V, GND = 0V, RL = 75Ω, ZZT = 75Ω, CL = 50pF, TA = -40°C to +85°C, Typical values are at TA = +25°C.) (Note 3)
PARAMETER
SYMBOL
Large-Signal Bandwidth
Large-Signal Flatness
Slew Rate
Settling Time (0.1%)
CONDITIONS
MIN
TYP
MAX
UNITS
VIN = 1VP-P, -3dB
20
MHz
VIN = 1VP-P, ±0.5dB
15
MHz
50
V/µs
SR
400
ns
Power-Supply Rejection Ratio
tSETTLING
PSRR
f = 100kHz, 100mVP-P ripple
30
dB
Common-Mode Rejection Ratio
CMRR
f = 100kHz, 100mVP-P ripple
53
dB
LOS Timeout Period
tLOS
760
µs
Differential Gain
DG
(Notes 13, 14)
2.65
%
DP
(Notes 13, 14)
0.57
degrees
SNR
(Notes 13, 14)
-72
dB
(Notes 13, 14)
-0.06
%KF
(Notes 13, 14)
0.40
%KF
0
ns
Differential Phase
SNR (dBRMS)
2T Pulse to Bar Rating
2T Pulse Response
Group Delay
D/dt
At 3.58MHz (Notes 13, 14)
Horizontal Tilt
(Notes 13, 14, 15)
0.10
%
Vertical Tilt
(Notes 13, 14, 15)
1.16
%
www.maximintegrated.com
Maxim Integrated │ 4
MAX9546/MAX9547
Differential Video Interface Chipset
AC ELECTRICAL CHARACTERISTICS—MAX9546 Driving MAX9547
(VCC = +8.5V, RL = 220Ω across OUT+ and OUT-, RL = 75Ω (MAX9547), ZZT = 75Ω, TA = -40°C to +85°C. Typical values are at TA
= +25°C, unless otherwise noted.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Differential Gain
DG
3.8
%
Differential Phase
DP
0.6
degrees
5MHz lowpass, 100kHz highpass,
VIN = 1VP-P
80
dB
2T Pulse-to-Bar Rating
2T = 250ns, bar time is 18µs, the beginning
3.5% and the ending 3.5% of the bar time is
ignored
0.2
%
2T Pulse Response
2T = 250ns
0.25
%
Signal-to-Noise Ratio
Group Delay
SNR
10
ns
Horizontal Tilt
(Note 15)
0.12
%
Vertical Tilt
(Note 15)
0.26
%
Note
Note
Note
Note
D/dt
At 3.58MHz
3:
4:
5:
6:
All devices are 100% production tested at TA = +25°C. All temperature limits are guaranteed by design.
Defined as differential output to single-ended input.
Input is AC-coupled.
The RC time constant (3Hz) formed by the source resistance (RS) and coupling capacitor (CIN) is usually used for lead
compensation of the active clamp. The source resistance is 400Ω max. The clamp should remain stable in this condition.
Note
7:
Differential
mode is measured as (OUT+ - OUT-). Common mode is measured as OUT+ + OUT
2
Note 8: A fault is when the outputs both sink and source current and the amount of extra current sink or source is greater than 3mA.
Note 9: Common-mode balance is measured as 20log((OUT+ - OUT-) / (OUT+ + OUT-)).
2
Note 10: These results were measured with a MAX4144 receiver, other receivers may affect results.
Note 11: Ground between MAX9546 and MAX9547 can be a ±2V difference.
Note 12: A loss-of-signal is when the input video signal of the MAX9547 does not change (cross 100mV level from sync tip) for 10
video lines.
Note 13: These results were measured with a MAX4447 transmitter and a MAX4012 buffer amplifier with a gain of 4. Using other
devices may affect results.
Note 14: MAX9547 topology shown in Figure 3.
Note 15: Input capacitor for this test is 0.33µF.
www.maximintegrated.com
Maxim Integrated │ 5
MAX9546/MAX9547
Differential Video Interface Chipset
Typical Operating Characteristics
(VCC = +8.5V, RL = 220Ω between OUT+ and OUT-, RL = 75Ω (MAX9547), ZZT = 75Ω, TA = +25°C, unless otherwise noted.)
10
MAX9547 IOUT CURRENT vs. TEMPERATURE
VIN = 1VP-P
7
25
6
MAX9546 toc03
MAX9546 toc01
MAX9546
GAIN vs. TEMPERATURE
8
MAX9546 toc02
GAIN vs. FREQUENCY
20
23
MAX9547
-10
MAX9546
4
IIOUT (mA)
0
GAIN (dB)
GAIN (dB)
5
3
MAX9547
2
21
19
1
-20
0
17
-1
-30
0.001
1
-2
10
-15
-40
-10
35
60
15
85
-15
-40
10
35
60
FREQUENCY (MHz)
TEMPERATURE (°C)
TEMPERATURE (°C)
MAX9547 COMMON-MODE REJECTION
RATIO vs. FREQUENCY
MAX9547 COMMON-MODE REJECTION
RATIO vs. TEMPERATURE
MAX9546 INPUT CLAMP CURRENT
vs. TEMPERATURE
-20
-30
-30
-50
-50
-60
-60
-70
-70
-80
0.0001
-80
0.001
0.01
0.1
1
10
VCOM = 2V
-40
8
7
VCOM = 5.4V
-40
-15
10
35
60
5
-40
85
-15
TEMPERATURE (°C)
60
85
140
120
100
80
60
40
20
MAX9546 toc08
160
200
180
DIFFERENTIAL ROUT (mΩ)
180
35
MAX9546 DIFFERENTIAL OUTPUT
RESISTANCE vs. TEMPERATURE
MAX9546 toc07
200
10
TEMPERATURE (°C)
MAX9547 DIFFERENTIAL INPUT
RESISTANCE vs. TEMPERATURE
DIFFERENTIAL RIN (kΩ)
9
6
FREQUENCY (MHz)
0
10
ICLMP (µA)
-10
-20
-40
VRIPPLE = 100mVP-P
fRIPPLE = 10kHz
85
MAX9546 toc06
0
MAX9546 toc05
VRIPPLE = 100mVP-P
CMRR (dB)
CMRR (dB)
-10
0.1
MAX9546 toc04
0
0.01
160
140
120
100
80
60
40
20
-40
-15
10
35
TEMPERATURE (°C)
www.maximintegrated.com
60
85
0
-40
-15
10
35
60
85
TEMPERATURE (°C)
Maxim Integrated │ 6
MAX9546/MAX9547
Differential Video Interface Chipset
Typical Operating Characteristics (continued)
(VCC = +8.5V, RL = 220Ω between OUT+ and OUT-, RL = 75Ω (MAX9547), ZZT = 75Ω, TA = +25°C, unless otherwise noted.)
-20
MAX9547
-40
-50
-60
MAX9547
-30
PSRR (dB)
PSRR (dB)
-20
-30
VRIPPLE = 100mVP-P
fRIPPLE = 100kHz
-10
-40
-50
MAX9546
MAX9546
-60
-70
-70
-80
0.0001
0.001
0.01
0.1
1
-80
10
-40
FREQUENCY (MHz)
-15
10
35
60
85
TEMPERATURE (°C)
-30
-40
-50
0.001
0.01
0.1
1
FREQUENCY (MHz)
MAX9546 toc13
40
1
2
3
4
5
6
1.0
10
0.6
30
20
10
0
0.2
-0.2
-10
-0.6
1
2
3
4
5
1
10
FREQUENCY (MHz)
6
SIGNAL-TO-NOISE RATIO vs. FREQUENCY
(MAX9546 DRIVING MAX9547)
OUTPUT RESPONSE TO NTC-7
VIDEO TEST SIGNAL (MAX9546 DRIVING MAX9547)
MAX9546 toc14
0
-10
MAX9546
INPUT
500mV/div
-20
-30
-40
SNR (dB)
MAX9547
OUTPUT
500mV/div
10µs/div
0.1
MAX9546 toc15
DIFFERENTIAL PHASE (deg)
-20
50
GROUP DELAY (ns)
DIFFERENTIAL GAIN (%)
MAX9546 toc12
DIFFERENTIAL PHASE (MAX9546 DRIVING MAX9547)
-1.0
-10
GROUP DELAY vs. FREQUENCY
(MAX9546 DRIVING MAX9547)
DIFFERENTIAL GAIN (MAX9546 DRIVING MAX9547)
5
4
3
2
1
0
-1
-2
-3
0
COMMON-MODE BALANCE (dB)
VRIPPLE = 100mVP-P
MAX9546 COMMON-MODE BALANCE
vs. FREQUENCY
MAX9546 toc10
-10
0
MAX9546 toc09
0
POWER-SUPPLY REJECTION RATIO
vs. TEMPERATURE
MAX9546 toc11
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
-50
-60
-70
-80
-90
-100
110
-120
0.1
1
10
FREQUENCY (MHz)
www.maximintegrated.com
Maxim Integrated │ 7
MAX9546/MAX9547
Differential Video Interface Chipset
Pin Description (MAX9546)
PIN
NAME
1, 8
VCC
FUNCTION
2
IN
3
FAULT
4, 5
GND
Ground
6
OUT-
Negative Differential Output
7
OUT+
Positive Differential Output
EP
EP
Power Supply. Connect together and bypass with a 0.1µF in parallel with a 4.7µF capacitor to GND.
Video Input
Fault Indicator. Active-low, open-drain output. FAULT = low when fault is detected at the output.
FAULT = high when no fault is detected at the output.
Exposed Paddle. Connect to GND.
Pin Description (MAX9547)
PIN
NAME
1
IN+
Positive Differential Input
FUNCTION
2
ZT+
Positive Transconductance Terminal
3
ZT-
Negative Transconductance Terminal
4
IN-
Negative Differential Input
5
GND
Ground
6
LOS
Loss-of-Signal Indicator. Active-low, open-drain output. LOS = low when no signal is detected at the
input. LOS = high when signal is present at the input.
7
IOUT
Current Output
8
VCC
Power Supply. Bypass with a 0.1µF capacitor in parallel with a 4.7µF capacitor to GND.
EP
EP
Exposed Paddle. Connect to GND.
Detailed Description
The MAX9546/MAX9547 differential interface chipset
converts single-ended voltages to differential voltages for
transport and then converts back to single-ended voltages. The chipset is optimized for transporting CVBS/FBAS
analog video signals (PAL or NTSC) through hostile environments. The MAX9546 driver includes a fault output
(FAULT) that indicates shorted transmission cables. The
MAX9547 receiver loss-of-signal output (LOS) indicates
an absence of input signal.
The MAX9546/MAX9547 operate from a 7.5V to 10V
single supply. The differential interface is immune to shortcircuit conditions to supply (VCC), or ground. These devices include ±15kV ESD (Human Body Model) protection.
www.maximintegrated.com
MAX9546
Driver
The MAX9546 driver converts a single-ended video input
into a differential output for transport across a twisted pair
of wires. The input is AC-coupled and the video signal
sync tip is clamped at 3.46V to set the voltage of the input.
The output common-mode voltage is optimized to reject
ground differences between the MAX9546 and MAX9547
up to ±2V. The differential gain is internally set to 2V/V to
drive a back-terminated output to unity gain. The maximum input resistance should not exceed 400Ω to ensure
device stability.
Maxim Integrated │ 8
MAX9546/MAX9547
Differential Video Interface Chipset
Common-Mode Balance
A driver is typically specified as having a property called
common-mode balance (CMB), longitudinal balance, or
simply line imbalance. Although balance is associated
with the source, it assumes a perfectly balanced, correctly
terminated, differential load. Common-mode balance
is a measure of the ratio between the differential to the
common-mode output in decibels as shown below.
(OUT +) − (OUT −)
CMB = 20Log
(OUT +) + (OUT −)
2
Common-mode balance is dominated by the gain-bandwidth product at high frequencies and the output resistance at low frequencies; therefore, it is important to
specify CMB over a frequency range. The receiver-side
balance is determined by the common-mode rejection
ratio (CMRR). The CMRR is usually quite large compared
to the CMB; therefore, the CMB is the limiting factor.
Fault Protection and Detection
The MAX9546 fault protection insures the driver outputs
survive a short to any voltage from -2V to +16V and are
ESD-protected to ±15kV HBM. Faults are indicated by an
open-drain fault output (FAULT) being asserted low and
requires a pullup resistor from FAULT to VCC.
MAX9547
Receiver
The MAX9547 receiver is a differential-to-single-ended converter that removes any common-mode input. The unique
architecture allows the signal gain to be set by a ratio of
two impedances: the user-selected transconductance element or network (ZZT), and an output load resistance, RL.
The gain is set by a fixed internal current gain (K) and the
ratio of ZZT and RL. The ZT terminals can be bridged with
a complex impedance to provide lead-lag compensation.
The output is essentially a voltage-controlled current source
as shown in Figure 1. The MAX9547 output is a current
proportional to the differential input voltage, and inversely
proportional to the impedance of the user-selected transconductance network, ZZT. The current output provides
inherent short-circuit protection for the output terminal.
A differential input voltage applied to the input terminals
causes current to flow in the transconductance element
(ZZT), which is equal to VIN /ZZT. This current in the transconductance element is multiplied by the preset current
gain (K) and appears on the output terminal as a current
equal to (K) x (VIN /ZZT). This current flows through the load
impedance to produce an output voltage according to the
following equation:
www.maximintegrated.com
IN+
1
+
IOUT
7
VIN
IN-
VIN
4
K
ZZT
Figure 1. Operational Mode
V
VOUT = K IN R L
Z ZT
where K = current-gain ratio (K = 1 for MAX9547), RL =
output load impedance, ZZT = transconductance element
impedance, VIN = differential input voltage.
Loss-of-Signal
The receiver includes an LOS output to indicate a signal
by detecting the presence of H-Sync. This allows the
MAX9547 to be used with monochrome or color video.
LOS is an open-drain output and requires a pullup resistor
from LOS to VCC.
Setting the Circuit Gain
The MAX9547 produces an output current by multiplying
the differential input voltage, VIN, by the transconductance ratio, K (RL / ZZT), where K = 1. The voltage gain
(AV) is set by the impedance of the transconductance network (ZZT) and the output load impedance (RL) according
to the following formula:
R
AV =K L
Z ZT
The factor ZZT is the impedance of the user-selected, twoterminal transconductance element or network, connected
across the terminals labeled ZT+ and ZT-. The network
ZZT is selected, along with the output impedance RL, to
provide the desired circuit gain and frequency shaping.
To maintain linearity, the transconductance network should
also be selected so that current flowing through it, equal
to VIN / ZZT, does not exceed 18mA under worst-case
conditions of maximum input voltage and minimum transconductance element impedance (ZZT). Output current
should not exceed ±8.8mA except under fault conditions.
Maxim Integrated │ 9
MAX9546/MAX9547
Differential Video Interface Chipset
Applications Information
brands entirely. The overall performance of the MAX9546/
MAX9547 is dependent on the choice of the receiver or
transmitter, respectively.
Differential Interface
The impedances of the differential interface are made
up of the two source resistors on the driver (MAX9546)
shown as RS and the load resistors on the receiver
(MAX9547) shown as RT in the Typical Application
Circuit. These resistors are chosen so their sum matches
the characteristic impedance (Z0) of the differential transmission line. For example, a Category 5 cable has a characteristic impedance of 110Ω, so the sum of the two RS
or RT resistors must be 110Ω to correctly drive the line.
To balance the signals they must be equal, so RS and RT
are 55Ω each.
Figure 2 illustrates one possible topology for the MAX9546
when using other devices with different offset requirements. Figures 3 and 4 illustrate two possible topologies
for the MAX9547 when using other devices with unknown
or different offset requirements. The circuit shown in
Figure 3 has a smaller PCB footprint at the expense
of requiring higher DC offset currents from the source
device. Figure 4 requires no DC offset currents although
it has a larger PCB footprint.
When using the MAX9546 with AC-coupling capacitors,
the FAULT signal will continue to function but only with
respect to a DC short condition. The LOS signal from the
MAX9547 is unaffected by coupling capacitors.
Using Other Transmitters
and Receivers
The MAX9546/MAX9547 are used with other transmitters and receivers; either other MAXIM devices or other
VDD
R1
3.92kΩ
0.1µF
4.7µF
+3.2 VDC OFFSET
D1
3
2
R4
75Ω
C4
0.33µF
FAULT
1
8
VCC
VCC
U1
MAX9546
IN
OUT+
C3
470µF
0V OFFSET
OUT-
GND
4
7
R2
55Ω
6
GND
5
R3
55Ω
TO A DEVICE
OTHER THAN A
MAX9547 USING
CAT5, ETC.
C5
470µF
+3.2 VDC OFFSET
Figure 2. Suggested MAX9546 Configuration for Use with Other Devices
www.maximintegrated.com
Maxim Integrated │ 10
MAX9546/MAX9547
Differential Video Interface Chipset
+8V
0.1µF
75Ω
Zt
OPTIONAL EQ NETWORK
FOR LONG CABLE RUNS
2
3
1
0V OFFSET
C3
22µF
4
R3
10kΩ
4.7µF
3.92kΩ
8
VCC
ZTP
ZTN
IP
U1
MAX9547
IN
GND
5
LOS
IOUT
6
D1
LED
7
75Ω
R4
110Ω
TO A DEVICE
OTHER THAN A
MAX9546 USING
CAT5, ETC.
0V OFFSET
R6
10kΩ
C4
22µF
+3.2 VDC OFFSET
3.2V LOW-NOISE REFERENCE
10µF
0.1µF
Figure 3. Suggested MAX9547 Configuration When Using Other Devices
www.maximintegrated.com
Maxim Integrated │ 11
MAX9546/MAX9547
Differential Video Interface Chipset
+8V
0.1µF
75Ω
Zt
OPTIONAL EQ NETWORK
FOR LONG CABLE RUNS
2
3
1
0V OFFSET
C3
470µF
TO A DEVICE
OTHER THAN A
MAX9546 USING
CAT5, ETC.
0V OFFSET
R3
51Ω
R805
C4
470µF
4
4.7µF
3.92kΩ
8
VCC
ZTP
ZTN
IP
U1
MAX9547
IN
GND
5
LOS
IOUT
6
D1
LED
7
75Ω
R5
51Ω
R805
+3.2 VDC OFFSET
3.2V LOW-NOISE REFERENCE
100µF
0.1µF
Figure 4. Alternate MAX9547 Configuration for Use with Other Devices
www.maximintegrated.com
Maxim Integrated │ 12
MAX9546/MAX9547
Differential Video Interface Chipset
±15kV ESD Protection
As with all Maxim devices, ESD-protection structures are
incorporated on all pins to protect against electrostatic
discharges encountered during handling and assembly. The driver outputs and receiver inputs have extra
protection against static electricity. Maxim’s engineers
developed state-of-the-art structures to protect these pins
against ESD of ±15kV without damage. The ESD structures withstand high ESD in all states: normal operation
and powered down. After an ESD event, the MAX9546/
MAX9547 keep working without latchup. ESD protection
can be tested in various ways; the driver outputs and
receiver inputs of this product family are characterized for
protection to ±15kV using the Human Body Model. Other
ESD test methodologies include IEC 1000-4-2 Contact
RC
1MΩ
CHARGE-CURRENTLIMIT RESISTOR
HIGHVOLTAGE
DC
SOURCE
Cs
100pF
RD
1.5kΩ
Figure 5. Human Body ESD Test Model
www.maximintegrated.com
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 5 shows the Human Body Model, and Figure
6 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,
which is then discharged into the test device through a
1.5kΩ resistor.
IP 100%
90%
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Discharge and IEC 1000-4-2 Air-Gap Discharge (formerly
IEC 801-2).
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
Ir
AMPERES
DEVICE
UNDER
TEST
36.8%
10%
0
0
tRL
TIME
tDL
CURRENT WAVEFORM
Figure 6. Human Body Current Waveform
Maxim Integrated │ 13
MAX9546/MAX9547
Differential Video Interface Chipset
IEC 1000-4-2
The IEC 1000-4-2 standard covers ESD testing and performance of finished equipment; it does not specifically
refer to integrated circuits (Figure 7).
The major difference between tests done using the
Human Body Model and IEC 1000-4-2 is higher peak
current in IEC 1000-4-2, because series resistance is
CHARGE-CURRENTLIMIT RESISTOR
HIGHVOLTAGE
DC
SOURCE
Cs
150pF
I
RD
330W
100%
90%
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Figure 7.IEC 1000-4-2 ESD Test Model
DEVICE
UNDER
TEST
IPEAK
RC
50Ω to 100Ω
lower in the IEC 1000-4-2 model. Hence, the ESD withstand voltage measured to IEC 1000-4-2 is generally
lower than that measured using the Human Body Model.
Figure 8 shows the current waveform for the ±8kV IEC
1000-4-2 ESD Contact-Discharge test. The Air-Gap test
involves approaching the device with a charged probe.
The Contact-Discharge method connects the probe to the
device before the probe is energized.
10%
tr = 0.7ns TO 1ns
t
30ns
60ns
Figure 8. IEC 1000-4-2 ESD Generator Current Waveform
www.maximintegrated.com
Maxim Integrated │ 14
MAX9546/MAX9547
Differential Video Interface Chipset
Typical Application Circuit
7.5V TO 10V
7.5V TO 10V
4.7µF
0.1µF
GND1
4.7µF
0.1µF
VCC
VCC
GND2
VCC
4.7kΩ
4.7kΩ
ZT+
ZZT
75Ω
FAULT
LOS
ZT-
MAX9546
75Ω
CIN
0.33µF
OUT+
IN
OUT-
75Ω
AC
MAX9547
RS
55Ω
GND
GND1
IN+
RS
55Ω
IOUT
INRT2
55Ω
RT1
55Ω
GND
VOUT
RL
75Ω
GND
GND2
CT
1µF TO 47µF
GND1
GND1
GND2
GND2
NOTE: TYPICAL APPLICATION CIRCUIT FOR 110Ω UNSHIELDED (UTP) CABLE
WITH AN OVERALL UNITY GAIN IN A 75Ω VIDEO APPLICATION.
Pin Configurations
TOP VIEW
MAX9547
MAX9546
+
8
VCC
IN+
1
IN 2
7
OUT+
ZT+
3
6
OUT-
ZT-
GND 4
5
GND
VCC 1
FAULT
SO-EP
+
8
VCC
2
7
IOUT
3
6
LOS
IN- 4
5
GND
SO-EP
Chip Information
PROCESS: BiCMOS
www.maximintegrated.com
Maxim Integrated │ 15
MAX9546/MAX9547
Differential Video Interface Chipset
Package Information
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.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.
8 SO-EP
S8E+14
21-0111
90-0151
www.maximintegrated.com
Maxim Integrated │ 16
MAX9546/MAX9547
Differential Video Interface Chipset
Revision History
REVISION
NUMBER
REVISION
DATE
DESCRIPTION
PAGES
CHANGED
4
9/14
Removed automotive references from Applications and Detailed Description
sections
1, 8
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated 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 and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
© 2014 Maxim Integrated Products, Inc. │ 17
工商网监
湘ICP备2023018690号
