MAX9546/MAX9547
Differential Video Interface Chipset
________________________________________________________________ Maxim Integrated Products 1
19-3873; Rev 3; 10/07
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.
General Description
The MAX9546/MAX9547 differential interface chipset
converts single-ended voltages to differential voltages for
transport and then converts back to single-ended volt-
ages. 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-sig-
nal detection of the MAX9547 allow proactive and
speedy diagnosis, such as identifying failures in the man-
ufacturing stage and troubleshooting equipment at repair
facilities. The MAX9546/MAX9547 are low-cost, conve-
nient 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 back-
terminated, DC-coupled differential video output to unity
gain. This DC connection allows the detection of a short-
circuit 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 receiv-
er 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 tem-
perature range.
Applications
Automotive Video
Car Navigation
In-Car Entertainment
Collision Avoidance/Rearview Cameras
Security/CCTV Video
Avionics/In-Flight Entertainment
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 PIN-
PACKAGE
PKG CODE
DESCRIPTION
MAX9546ESA+
8 SO-EP* S8E-14 Driver
MAX9547ESA+
8 SO-EP* S8E-14 Receiver
Note: These devices are specified for -40°C to +85°C temper-
ature range.
+Denotes a lead-free package.
*EP = Exposed paddle.
Pin Configuration appears at end of data sheet.
Typical Operating Circuit
FAULT
OUT-
CLAMP
OUT+
VCC VCC
ZT+
ZT-
IN+
IOUT VOUT
LOS
IN-
IN
MAX9547
MAX9546
MAX9546/MAX9547
Differential Video Interface Chipset
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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.
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 4-layer
board. For detailed information on package thermal considerations see www.maxim-ic.com/thermal-tutorial.
(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
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
Supply Voltage Range VCC Guaranteed by PSRR 7.5 8.5
10.0
V
Quiescent Supply Current ICC No load 64
112
mA
Voltage Gain AVVIN = 1.2VP-P (Note 4) 1.8 2 2.2 V/V
Input-Voltage Swing VIN Guaranteed by AV1.2 VP-P
Input Clamp Voltage VCLMP (Note 5)
3.46
V
Input Clamp Current ICLMP (Note 5) 7 13 µA
Input Resistance RIN (Notes 5, 6)
500
kΩ
Output Common-Mode Voltage VCOM 3.0
3.25
3.4 V
Output Impedance ROUT 0.1 Ω
OUT+ and/or OUT- to +16V 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
Output Fault Current IF(OUT)
OUT+ or OUT- to -2V, VCC unconnected 24
mA
Differential mode 45 62
Power-Supply Rejection Ratio PSRR VCC from 7.5V to
10V (Note 7) Common mode 46 52 dB
FAULT Output Logic Level VOL, ISINK = 1.6mA (Note 8) 0.4 V
FAULT Output Leakage Current
0.01
µA
DC ELECTRICAL CHARACTERISTICS—MAX9546
(VCC = +8.5V, RL = 220Ωbetween OUT+ and OUT-, TA= -40°C to +85°C. Typical values are at TA= +25°C, unless otherwise
noted.) (Note 3)
MAX9546/MAX9547
Differential Video Interface Chipset
_______________________________________________________________________________________ 3
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
Large-Signal Bandwidth VIN = 1VP-P, -3dB 18 MHz
Large-Signal Flatness VIN = 1VP-P, ±0.5dB 15 MHz
Slew Rate SR OUT+ - OUT- 70 V/µs
Settling Time (0.1%)
tSETTLING
VIN = 1VP-P
400
ns
Power-Supply Rejection Ratio PSRR f = 100kHz, 100mVP-P ripple 63 dB
f = 100kHz 55
Common-Mode Balance (Note 9) CMB f = 3.58MHz 39 dB
Droop Guaranteed by input current 1 %
Differential Gain DG (Note 10)
1.37
%
Differential Phase DP (Note 10)
0.14
SNR (dBRMS) SNR (Note 10) -62 dB
2T Pulse to Bar Rating (Note 10)
-0.22
%KF
2T Pulse Response (Note 10)
0.30
%KF
Group Delay D/dt At 3.58MHz (Note 10)
2.20
ns
Horizontal Tilt (Notes 10, 15) 0 %
Vertical Tilt (Notes 10, 15)
6.62
%
AC ELECTRICAL CHARACTERISTICS—MAX9546
(VCC = +8.5V, RL = 220Ωacross 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
Supply Voltage Range VCC Guaranteed by PSRR 7.5 8.5
10.0
V
Supply Current ICC 70
110
mA
Differential Input Voltage Range
|IN+ - IN-|
VIN
(
P-P
)
Guaranteed by CMRR (Note 11) 1.2 VP-P
Common-Mode Input Voltage
Range VCOM Guaranteed by CMRR (Note 11) 1.0 5.4 V
Input Current IIN 630µA
Input Offset Current ∆IIN 1 4.2 µA
Input Resistance RIN Differential 80 kΩ
Voltage Gain AV
VIN
(
P-P
)
= 1.2V, defined as IOUT x (RL / VIN) 0.90
1
1.15
V/V
Output Voltage VOB IN+ = IN- = 3.2V 1 V
Output Voltage Swing VOUT 1.2 VP-P
Maximum Output Current IOUT VIN = 1V, ZZT = 0 21 mA
Power-Supply Rejection Ratio PSRR VCC from 7.5V to 10V 26 34 dB
1V ≤ VCOM ≤ 5.4V 42 54
Common-Mode Rejection Ratio CMRR 2V ≤ VCOM ≤ 4.4V 46 70 dB
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)
MAX9546/MAX9547
Differential Video Interface Chipset
4 _______________________________________________________________________________________
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
LOS Logic Level VOL, ISINK = 1.6mA (Note 12) 0.4 V
LOS Leakage Current
0.01
µA
IN+ and/or IN- to +16V, RT1 + RT2 = 110Ω50
IN+ and/or IN- to -2V, RT1 + RT2 = 110Ω10
IN+ and/or IN- to +16V, VCC unconnected,
RT1 + RT2 = 110Ω72
Input Fault Current IF
IN+ and/or IN- to -2V, VCC unconnected,
RT1 + RT2 = 110Ω10
mA
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 TYP MAX
UNITS
Large-Signal Bandwidth VIN = 1VP-P, -3dB 20 MHz
Large-Signal Flatness VIN = 1VP-P, ±0.5dB 15 MHz
Slew Rate SR 50 V/µs
Settling Time (0.1%)
tSETTLING 400
ns
Power-Supply Rejection Ratio 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
%
Differential Phase DP (Notes 13, 14)
0.57
degrees
SNR (dBRMS) SNR (Notes 13, 14) -72 dB
2T Pulse to Bar Rating (Notes 13, 14)
-0.06
%KF
2T Pulse Response (Notes 13, 14)
0.40
%KF
Group Delay D/dt At 3.58MHz (Notes 13, 14) 0 ns
Horizontal Tilt (Notes 13, 14, 15)
0.10
%
Vertical Tilt (Notes 13, 14, 15)
1.16
%
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)
MAX9546/MAX9547
Differential Video Interface Chipset
_______________________________________________________________________________________ 5
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
Differential Gain DG 3.8 %
Differential Phase DP 0.6
degrees
Signal-to-Noise Ratio SNR 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
%
Group Delay D/dt At 3.58MHz 10 ns
Horizontal Tilt (Note 15)
0.12
%
Vertical Tilt (Note 15)
0.26
%
AC ELECTRICAL CHARACTERISTICS—MAX9546 Driving MAX9547
(VCC = +8.5V, RL= 220Ωacross 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)
Note 3: All devices are 100% production tested at TA= +25°C. All temperature limits are guaranteed by design.
Note 4: Defined as differential output to single-ended input.
Note 5: Input is AC-coupled.
Note 6: 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 400Ωmax. 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.
MAX9546/MAX9547
Differential Video Interface Chipset
6 _______________________________________________________________________________________
GAIN vs. FREQUENCY
MAX9546 toc01
FREQUENCY (MHz)
GAIN (dB)
10.10.01
-20
-10
0
10
20
-30
0.001 10
MAX9546
MAX9547
GAIN vs. TEMPERATURE
MAX9546 toc02
TEMPERATURE (°C)
GAIN (dB)
6035-10-15
-1
0
1
2
3
4
5
6
7
8
-2
-40 85
MAX9546
VIN = 1VP-P
MAX9547
MAX9547 IOUT CURRENT vs. TEMPERATURE
MAX9546 toc03
TEMPERATURE (°C)
IIOUT (mA)
603510-15
17
19
21
23
25
15
-40 85
MAX9547 COMMON-MODE REJECTION
RATIO vs. FREQUENCY
MAX9546 toc04
FREQUENCY (MHz)
CMRR (dB)
10.10.001 0.01
-70
-60
-50
-40
-30
-20
-10
0
-80
0.0001 10
VRIPPLE = 100mVP-P
MAX9547 COMMON-MODE REJECTION
RATIO vs. TEMPERATURE
MAX9546 toc05
TEMPERATURE (°C)
CMRR (dB)
6035-15 10
-70
-60
-50
-40
-30
-20
-10
0
-80
-40 85
VCOM = 2V
VCOM = 5.4V
VRIPPLE = 100mVP-P
fRIPPLE = 10kHz
MAX9546 INPUT CLAMP CURRENT
vs. TEMPERATURE
MAX9546 toc06
TEMPERATURE (°C)
ICLMP (µA)
603510-15
6
7
8
9
10
5
-40 85
MAX9547 DIFFERENTIAL INPUT
RESISTANCE vs. TEMPERATURE
MAX9546 toc07
TEMPERATURE (°C)
DIFFERENTIAL RIN (kΩ)
603510-15
20
40
60
80
100
120
140
160
180
200
0
-40 85
MAX9546 DIFFERENTIAL OUTPUT
RESISTANCE vs. TEMPERATURE
MAX9546 toc08
TEMPERATURE (°C)
DIFFERENTIAL ROUT (mΩ)
603510-15
20
40
60
80
100
120
140
160
180
200
0
-40 85
Typical Operating Characteristics
(VCC = +8.5V, RL= 220Ωbetween OUT+ and OUT-, RL= 75Ω(MAX9547), ZZT = 75Ω, TA= +25°C, unless otherwise noted.)
MAX9546/MAX9547
Differential Video Interface Chipset
_______________________________________________________________________________________ 7
Typical Operating Characteristics (continued)
(VCC = +8.5V, RL= 220Ωbetween OUT+ and OUT-, RL= 75Ω(MAX9547), ZZT = 75Ω, TA= +25°C, unless otherwise noted.)
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX9546 toc09
FREQUENCY (MHz)
PSRR (dB)
10.10.001 0.01
-70
-60
-50
-40
-30
-20
-10
0
-80
0.0001 10
VRIPPLE = 100mVP-P
MAX9547
MAX9546
POWER-SUPPLY REJECTION RATIO
vs. TEMPERATURE
MAX9546 toc10
TEMPERATURE (°C)
PSRR (dB)
6035-15 10
-70
-60
-50
-40
-30
-20
-10
0
-80
-40 85
VRIPPLE = 100mVP-P
fRIPPLE = 100kHz
MAX9547
MAX9546
OUTPUT RESPONSE TO NTC-7
VIDEO TEST SIGNAL (MAX9546 DRIVING MAX9547)
MAX9546 toc14
10µs/div
MAX9546
INPUT
500mV/div
MAX9547
OUTPUT
500mV/div
SIGNAL-TO-NOISE RATIO vs. FREQUENCY
(MAX9546 DRIVING MAX9547)
MAX9546 toc15
FREQUENCY (MHz)
SNR (dB)
1
110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
-120
0.1 10
DIFFERENTIAL GAIN (MAX9546 DRIVING MAX9547)
DIFFERENTIAL PHASE (MAX9546 DRIVING MAX9547)
MAX9546 toc12
213456
213456
4
5
0.6
1.0
0.2
-0.2
-0.6
-1.0
3
2
DIFFERENTIAL GAIN (%)DIFFERENTIAL PHASE (deg)
1
0
-1
-2
-3
GROUP DELAY vs. FREQUENCY
(MAX9546 DRIVING MAX9547)
MAX9546 toc13
FREQUENCY (MHz)
GROUP DELAY (ns)
1
0
10
20
30
40
50
-10
0.1 10
MAX9546/MAX9547
Differential Video Interface Chipset
8 _______________________________________________________________________________________
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 automotive 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 sin-
gle supply. The differential interface is immune to short-
circuit conditions to an automotive battery (VBAT = 16V),
supply (VCC), or ground. These devices include ±15kV
ESD (Human Body Model) protection.
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 400Ωto ensure device stability.
Pin Description (MAX9546)
PIN NAME FUNCTION
1, 8 VCC Power Supply. Connect together and bypass with a 0.1µF in parallel with a 4.7µF capacitor to
GND.
2 IN Video Input
3FAULT 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.
4, 5 GND Ground
6 OUT- Negative Differential Output
7 OUT+ Positive Differential Output
EP EP Exposed Paddle. Connect to GND.
Pin Description (MAX9547)
PIN NAME FUNCTION
1 IN+ Positive Differential Input
2 ZT+ Positive Transconductance Terminal
3 ZT- Negative Transconductance Terminal
4 IN- Negative Differential Input
5 GND Ground
6LOS 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
8V
CC Power Supply. Bypass with a 0.1µF capacitor in parallel with a 4.7µF capacitor to GND.
EP EP Exposed Paddle. Connect to GND.
MAX9546/MAX9547
Differential Video Interface Chipset
_______________________________________________________________________________________ 9
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, cor-
rectly terminated, differential load. Common-mode bal-
ance is a measure of the ratio between the differential to
the common-mode output in decibels as shown below.
Common-mode balance is dominated by the gain-band-
width product at high frequencies and the output resis-
tance 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 transcon-
ductance element or network (ZZT), and an output load
resistance, RL. The gain is set by a fixed internal cur-
rent gain (K) and the ratio of ZZT and RL. The ZT termi-
nals 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 transconduc-
tance element (ZZT), which is equal to VIN / ZZT. This cur-
rent in the transconductance element is multiplied by the
preset current gain (K) and appears on the output termi-
nal 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:
where K = current-gain ratio (K = 1 for MAX9547), RL=
output load impedance, ZZT = transconductance ele-
ment impedance, VIN = differential input voltage.
Loss-of-Signal
The receiver includes an LOS output to indicate a sig-
nal 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 multiply-
ing the differential input voltage, VIN, by the transcon-
ductance ratio, K (RL / ZZT), where K = 1. The voltage
gain (AV) is set by the impedance of the transconduc-
tance network (ZZT) and the output load impedance
(RL) according to the following formula:
The factor ZZT is the impedance of the user-selected,
two-terminal 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.
AK
R
Z
VL
ZT
=⎛
⎝
⎜
⎞
⎠
⎟
VK
V
ZR
OUT IN
ZT L
=⎛
⎝
⎜
⎞
⎠
⎟
CMB Log OUT OUT
OUT OUT
=+
()()
+
()
+
()
⎛
⎝
⎜
⎜
⎜
⎜
⎞
⎠
⎟
⎟
⎟
⎟
−−
−
20
2
Figure 1. Operational Mode
ZZT
K
VIN
VIN
IN+
IN-
IOUT
1
+
7
-
4
MAX9546/MAX9547
Differential Video Interface Chipset
10 ______________________________________________________________________________________
Applications Information
Differential Interface
The impedances of the differential interface are made
up of the two source resistors on the driver (MAX9546)
shown as RSand the load resistors on the receiver
(MAX9547) shown as RTin the Typical Application
Circuit. These resistors are chosen so their sum match-
es 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 RSor RTresistors must be 110Ωto correctly drive
the line. To balance the signals they must be equal, so
RSand RTare 55Ωeach.
Using Other Transmitters
and Receivers
The MAX9546/MAX9547 are used with other transmit-
ters and receivers; either other MAXIM devices or other
brands entirely. The overall performance of the
MAX9546/MAX9547 is dependent on the choice of the
receiver or transmitter, respectively.
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 cir-
cuit 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 cur-
rents 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.
Figure 2. Suggested MAX9546 Configuration for Use with Other Devices
0V OFFSET
+3.2 VDC OFFSET
+3.2 VDC OFFSET
TO A DEVICE
OTHER THAN A
MAX9547 USING
CAT5, ETC.
VCC
GND
1
4
IN
D1
2
7
6
VCC
8
FAULT OUT+
OUT-
3
C4
0.33µF
R1
3.92kΩ
R4
75Ω
R2
55Ω
R3
55Ω
C3
470µF
C5
470µF
GND
5
MAX9546
U1
4.7µF0.1µF
V
DD
MAX9546/MAX9547
Differential Video Interface Chipset
______________________________________________________________________________________ 11
Figure 3. Suggested MAX9547 Configuration When Using Other Devices
0V OFFSET
0V OFFSET
OPTIONAL EQ NETWORK
FOR LONG CABLE RUNS
+3.2 VDC OFFSET
TO A DEVICE
OTHER THAN A
MAX9546 USING
CAT5, ETC.
10µF 0.1µF
3.2V LOW-NOISE REFERENCE
ZTP VCC
GND
2
8
5
IP
1
6
7
ZTN LOS
IOUT
3
IN
4
C3
22µF
75Ω
Zt
R3
10kΩ
R6
10kΩ
C4
22µF
R4
110Ω
MAX9547
U1
4.7µF
3.92kΩ
75Ω
D1
LED
+8V
0.1µF
MAX9546/MAX9547
Differential Video Interface Chipset
12 ______________________________________________________________________________________
Figure 4. Alternate MAX9547 Configuration for Use with Other Devices
0V OFFSET
0V OFFSET
OPTIONAL EQ NETWORK
FOR LONG CABLE RUNS
+3.2 VDC OFFSET
TO A DEVICE
OTHER THAN A
MAX9546 USING
CAT5, ETC.
100µF 0.1µF
3.2V LOW-NOISE REFERENCE
ZTP VCC
GND
2
8
5
IP
1
6
7
ZTN LOS
IOUT
3
IN
4
C3
470µF
75Ω
Zt
R3
51Ω
R805
R5
51Ω
R805
C4
470µF
MAX9547
U1
4.7µF
3.92kΩ
75Ω
D1
LED
+8V
0.1µF
MAX9546/MAX9547
Differential Video Interface Chipset
______________________________________________________________________________________ 13
±15kV ESD Protection
As with all Maxim devices, ESD-protection structures
are incorporated on all pins to protect against electro-
static discharges encountered during handling and
assembly. The driver outputs and receiver inputs have
extra protection against static electricity. Maxim’s engi-
neers 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 out-
puts and receiver inputs of this product family are char-
acterized for protection to ±15kV using the Human
Body Model. Other ESD test methodologies include IEC
1000-4-2 Contact Discharge and IEC 1000-4-2 Air-Gap
Discharge (formerly IEC 801-2).
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 dis-
charged into a low impedance. This model consists of
a 100pF capacitor charged to the ESD voltage of inter-
est, which is then discharged into the test device
through a 1.5kΩresistor.
Figure 5. Human Body ESD Test Model
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
100pF
RC
1MΩ
RD
1.5kΩ
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
Figure 6. Human Body Current Waveform
IP 100%
90%
36.8%
tRL TIME
tDL
CURRENT WAVEFORM
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
Ir
10%
0
0
AMPERES
MAX9546/MAX9547
Differential Video Interface Chipset
14 ______________________________________________________________________________________
IEC 1000-4-2
The IEC 1000-4-2 standard covers ESD testing and
performance of finished equipment; it does not specifi-
cally 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
lower in the IEC 1000-4-2 model. Hence, the ESD with-
stand 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.
Figure 7.IEC 1000-4-2 ESD Test Model
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
150pF
RC
50Ω to 100Ω
RD
330Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
Figure 8. IEC 1000-4-2 ESD Generator Current Waveform
I
100%
90%
10%
tr = 0.7ns TO 1ns
IPEAK
60ns
30ns
t
MAX9546/MAX9547
Differential Video Interface Chipset
______________________________________________________________________________________ 15
Typical Application Circuit
FAULT
4.7kΩ
75Ω
75Ω
AC
OUT-
OUT+
VCC
7.5V TO 10V
NOTE: TYPICAL APPLICATION CIRCUIT FOR 110Ω UNSHIELDED (UTP) CABLE
WITH AN OVERALL UNITY GAIN IN A 75Ω VIDEO APPLICATION.
4.7µF
0.1µF
GND1 GND2
VCC
GND
GND1
GND1
GND1
GND
IN+
IOUT
VOUT
IN-
CT
1µF TO 47µF
RT1
55Ω
RT2
55Ω
IN
CIN
0.33µF
RS
55Ω
RS
55Ω
MAX9546
LOS
VCC
7.5V TO 10V
4.7µF
0.1µF
GND GND2
GND2
GND2
MAX9547
4.7kΩ
RL
75Ω
ZZT
75Ω
ZT+
ZT-
Pin Configurations
LOS
GNDIN-
1
2
8
7
VCC
IOUTZT+
ZT-
IN+
SO-EP
3
4
6
5
MAX9547
+
Chip Information
PROCESS: BICMOS
OUT-
GNDGND
1
2
8
7
VCC
OUT+IN
FAULT
VCC
SO-EP
TOP VIEW
3
4
6
5
MAX9546
+
MAX9546/MAX9547
Differential Video Interface Chipset
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.
16 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)
8L, SOIC EXP. PAD.EPS
C
11
21-0111
PACKAGE OUTLINE
8L SOIC, .150" EXPOSED PAD
Revision History
Pages changed at Rev 2: 1, 4, 11, 12
Pages changed at Rev 3: 1, 2, 3, 4, 9–16