_______________General Description
The MAX4158/MAX4159/MAX4258/MAX4259 are wide-
band, 2-channel, noninverting video amplifiers with input
multiplexing, capable of driving ±2.5V signals into 50 Ωor
75Ωloads. These devices are current-mode feedback
amplifiers; gain is set by external feedback resistors. The
MAX4158/MAX4159 are optimized for unity gain (0dB)
with a -3dB bandwidth of 350MHz. The MAX4258/
MAX4259 are optimized for gains of two (6dB) or more
with a 250MHz -3dB bandwidth. These devices have low
(0.01%/0.01°) differential gain and phase errors, and oper-
ate from ±5V supplies.
These devices are ideal for use in broadcast and graphics
video systems because of their low, 2pF input capaci-
tance, channel-to-channel switching time of only 20ns,
and wide, 130MHz 0.1dB bandwidth. In addition, the com-
bination of ultra-high speed and low power makes them
suitable for use in general-purpose high-speed applica-
tions, such as medical imaging, industrial instrumentation,
and communications systems.
The MAX4159/MAX4259 have address latching and high-
impedance output disabling, allowing them to be incorpo-
rated into large switching arrays. They are available in
14-pin SO and 16-pin QSOP packages. The MAX4158/
MAX4258 have no address latching or output disabling,
but are available in space-saving 8-pin µMAX and SO
packages.
________________________Applications
Video-Signal Multiplexing
Video Crosspoint Switches
Pixel Switching
Coaxial Cable Drivers
Workstations
High-Definition TV (HDTV)
Broadcast Video
Multimedia Products
High-Speed Signal Processing
____________________________Features
♦Excellent Video Specifications:
0.1dB Gain Flatness to 130MHz
0.01%/0.01° Differential Gain/Phase Error
♦High Speed:
350MHz -3dB Bandwidth (MAX4158/4159)
250MHz -3dB Bandwidth (MAX4258/4259)
700V/µs Slew Rate (MAX4158/4159)
1000V/µs Slew Rate (MAX4258/4259)
20ns Settling Time to 0.1%
♦Fast Switching:
20ns Channel-Switching Time
<70mV Switching Transient
♦Low Power: 100mW
♦Directly Drive 75Ωor 50ΩCables
♦High Output Current Drive: >70mA
♦Address Latch and High-Z Output Disable
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
________________________________________________________________
Maxim Integrated Products
1
19-1164; Rev 2; 3/01
______________Ordering Information
_________________Pin Configurations
PART
MAX4158ESA
MAX4158EUA
MAX4159ESD
MAX4159EEE
-40°C to +85°C
-40°C to +85°C
TEMP. RANGE PIN-PACKAGE
8 SO
8 µMAX
-40°C to +85°C
-40°C to +85°C 14 SO
16 QSOP
MAX4258ESA
MAX4258EUA
MAX4259ESD
MAX4259EEE
-40°C to +85°C
-40°C to +85°C 8 SO
8 µMAX
-40°C to +85°C
-40°C to +85°C 14 SO
16 QSOP
MAX4158/MAX4258
A0
0
1
INPUT
MAX4158/MAX4258
IN0
IN1
V+
IN1
FB
V-
1
2
8
7
A0
OUT
GND
IN0
SO/µMAX
TOP VIEW
3
4
6
5
Pin Configurations continued at end of data sheet.
EVALUATION KIT MANUAL
FOLLOWS DATA SHEET
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS
(V+ = +5V, V- = -5V, VIN = 0V, VOUT = 0V, RL= ∞, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.)
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: Continuous power dissipation maximum rating must also be observed.
Positive Supply Voltage (V+ to GND) ...................................+6V
Negative Supply Voltage (V- to GND).....................................-6V
Amplifier Input Voltage (IN0 or IN1) .....(V- - 0.3V) to (V+ + 0.3V)
FB Current ........................................................................±20mA
Digital Input Voltage (A0, EN, or LE)............-0.3V to (V+ + 0.3V)
Output Short Circuit to GND (Note 1).........................Continuous
Output Short-Circuit Current to V+, V- (Note 1)........................5s
Continuous Power Dissipation (TA= +70°C)
8-Pin SO (derate 5.88mW/°C above +70°C).................471mW
8-Pin µMAX (derate 4.10mW/°C above +70°C)............330mW
14-Pin SO (derate 8.33mW/°C above +70°C)...............667mW
16-Pin QSOP (derate 8.33mW/°C above +70°C)..........667mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
Inferred from the CMRR test
Inferred from the PSRR test
VOUT = -2.5V to 2.5V
MAX4159/MAX4259 only, EN = 5V,
VOUT = -3.0V to 3.0V (Note 2)
f = 0Hz
RL= 50Ω
RL= open circuit
VIN = -2.5V to 2.5V
TA= +25°C
TA= +25°C
VIN = -2.5V to 2.5V
VOUT = -2.5V to 2.5V, RL= 100Ω
CONDITIONS
mA70 100IOUT
Output Current ±2.5 ±3.5
VOUT V
±3.0 ±4.0
Output Voltage Swing
dB50 60CMRRDC Common-Mode Rejection Ratio MΩ1.0 3.0ZT
Open-Loop Transimpedance
mV±1 ±6VOS
Input Offset Voltage (Either Channel)
V±2.5 ±3.0VIN
V±4.5 ±5.5V+, V-Operating Supply-Voltage Range
Input Voltage Range
MΩ110ROUT(d)
Disabled Output Resistance
mΩ40ROUT
Output Resistance Ω50RIN(FB)
FB Pin Input Resistance MΩ120
RIN
µV/°C2TCVOS
Input Offset Voltage Temperature
Coefficient (Either Channel)
µA
±2 ±10
IIN
Input Bias Current (Channel On)
µA
±2 ±12
IFB
FB Pin Bias Current
kΩ100 550
Input Resistance
UNITSMIN TYP MAXSYMBOLPARAMETER
Channel on
Channel off
Open loop, V+ = +4.5V to +5.5V,
V- = -4.5V to -5.5V dB60 78PSRRDC Power-Supply Rejection Ratio
Sinking or sourcing to ground mA120ISC
Output Short-Circuit Current MAX4158/MAX4258 10.9 13.0
EN = GND, MAX4159/MAX4259 10.9 13.0
EN = V+, MAX4159/MAX4259 mA
6.3 8.0
I+Positive Supply Current
MAX4158/MAX4258 9.9 12.0
EN = GND, MAX4159/MAX4259 9.9 12.0
EN = V+, MAX4159/MAX4259 mA
5.0 7.0
I-Negative Supply Current
TA= TMIN to TMAX
TA= TMIN to TMAX
±18
±20
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
_______________________________________________________________________________________ 3
DC ELECTRICAL CHARACTERISTICS (continued)
(V+ = +5V, V- = -5V, VIN = 0V, VOUT = 0V, RL= ∞, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.)
AC ELECTRICAL CHARACTERISTICS—MAX4158/MAX4159
(V+ = +5V, V- = -5V, VIN = 0V, VOUT = 0V, RL= 100Ω, TA= +25°C, unless otherwise noted.)
VIL
= 0
VIH = 5.5V, V+ = +5.5V
CONDITIONS
µA130 300IIH
Logic-High Input Current µA-2 -20IIL
Logic-Low Input Current V2.0VIH
Logic-High Threshold V0.8VIL
Logic-Low Threshold
UNITSMIN TYP MAXSYMBOLPARAMETER
AV= 0dB, VOUT = 2Vp-p (Note 4)
AV= 0dB, VIN = 20mVp-p (Note 4)
AV= 0dB, VIN = 20mVp-p (Note 4)
VOUT = 2V step, AV= 0dB (Note 4)
AV= 0dB, VOUT = 2Vp-p (Note 4)
CONDITIONS
ns10tS
Settling Time to 0.1% V/µs700SRSlew Rate MHz155FPBWFull-Power Bandwidth MHz100BW(0.1)Bandwidth for ±0.1dB Gain Flatness MHz350BW-3dB Bandwidth
UNITSMIN TYP MAXSYMBOLPARAMETER
AV= 0dB (Notes 4, 5) %0.01DGDifferential Gain Error
f = 30MHz, VOUT = 2Vp-p,
AV= 0dB (Note 4)
f = 30MHz, AV= 0dB (Note 4)
f = 30MHz, RS= 50Ω, AV= 0dB,
VIN = ±2Vp-p (Note 4)
AV= 0dB (Notes 4, 5)
f = 30MHz, AV= 0dB, EN = 5V,
VIN = ±2Vp-p (Note 4)
pF3COUT
Output Capacitance
dB105AISO
Off-Isolation (MAX4159 only)
dBc50THDTotal Harmonic Distortion
Ω9ZOUT
Output Impedance
dB70XtalkChannel-to-Channel Crosstalk
degrees0.01DPDifferential Phase Error
Channel on or off pF2CIN
Input Capacitance
f = 100kHz
f = 100kHz
f = 100kHz pA/√Hz
22in(FB)FB Current-Noise Density pA/√Hz
2in
Input Current-Noise Density nV/√Hz
2en
Input Voltage-Noise Density
(Notes 6, 7) ns20tSW
Channel Switching Time TA= TMIN to TMAX (Notes 6, 8) ns10tS
Address Setup Time
(Note 6)
TA= TMIN to TMAX (Notes 6, 8) ns20tLPD
Latch Propagation Delay ns10tTH
Address Hold Time
TA= TMIN to TMAX (Notes 6, 8) ns10tLPW
Latch Pulse Width (Notes 6, 9) ns20tPDE
Enable Delay Time
AV= 0dB (Notes 4, 10)
(Notes 6, 9) mV±70VTRAN
Switching Transient ns20tPDD
Disable Delay Time
LOGIC CHARACTERISTICS (Note 3)
AMPLIFIER CHARACTERISTICS
SWITCHING CHARACTERISTICS
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
4 _______________________________________________________________________________________
AC ELECTRICAL CHARACTERISTICS—MAX4258/MAX4259
(V+ = +5V, V- = -5V, VIN = 0V, VOUT = 0V, RL= 100Ω, TA= +25°C, unless otherwise noted.)
f = 30MHz, VOUT = 2Vp-p,
AV= 6dB (Note 4)
f = 30MHz, AV= 6dB (Note 4)
f = 30MHz, RS= 50Ω, AV= 6dB,
VIN = ±1Vp-p (Note 4)
AV= 6dB (Notes 4, 5)
f = 30MHz, AV= 6dB, EN = 5V,
VIN = ±1Vp-p (Note 4)
pF3COUT
Output Capacitance
dB110
AV= 6dB, VOUT = 2Vp-p (Note 4)
AV= 6dB, VIN = 20mVp-p (Note 4)
AISO
Off-Isolation (MAX4259)
AV= 6dB, VIN = 20mVp-p (Note 4)
dBc50THD
VOUT = 2V step, AV= 6dB (Note 4)
Total Harmonic Distortion
AV= 6dB, VOUT = 2Vp-p (Note 4)
CONDITIONS
Ω9ZOUT
Output Impedance
dB70XtalkChannel-to-Channel Crosstalk
degrees0.02DPDifferential Phase Error
Channel on or off pF2CIN
Input Capacitance
f = 100kHz
f = 100kHz
f = 100kHz pA/√Hz
22in(FB)FB Current-Noise Density pA/√Hz
2in
Input Current-Noise Density nV/√Hz
2en
Input Voltage-Noise Density
(Notes 6, 7) ns20tSW
Channel-Switching Time TA= TMIN to TMAX (Notes 6, 8) ns
ns10tS
Settling Time to 0.1% V/µs1000SRSlew Rate
10tS
Address-Setup Time
(Note 6)
TA= TMIN to TMAX (Notes 6, 8)
(Notes 6, 9) ns20tPDE
Enable Delay Time
AV= 6dB (Notes 4, 10)
(Notes 6, 9)
MHz200FPBWFull-Power Bandwidth MHz130BW(0.1)Bandwidth for ±0.1dB Gain Flatness MHz250BW-3dB Bandwidth
mV±90VTRAN
ns20tLPD
Latch Propagation Delay ns10tTH
Address-Hold Time
TA= TMIN to TMAX (Notes 6, 8) ns10tLPW
Latch Pulse Width
UNITSMIN TYP MAXSYMBOLPARAMETER
Switching Transient ns20tPDD
Disable Delay Time
AV= 6dB (Notes 4, 5) %0.01DGDifferential Gain Error
Note 2: Does not include external feedback network resistance.
Note 3: Applies to all digital input pins (EN, LE, and A0).
Note 4: Specified with feedback network chosen for optimal AC performance. See Tables 1 and 2 for recommended component
values.
Note 5: Input test signal: 3.58MHz sine wave of amplitude 40IRE superimposed on a linear ramp (0IRE to 100IRE). IRE is a unit of
video-signal amplitude developed by the International Radio Engineers. 140IRE = 1.0V.
Note 6: See timing diagram (Figure 5).
Note 7: Channel-switching time specified for switching between the two input channels; does not include signal rise/fall times for
switching between channels with different input voltages.
Note 8: Guaranteed by design; not production tested.
Note 9: Output enable/disable delay times do not include amplifier output slewing times.
Note 10: Switching transient measured while switching between two grounded channels.
AMPLIFIER CHARACTERISTICS
SWITCHING CHARACTERISTICS
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
_______________________________________________________________________________________
5
2
-8 1 10 100 1000
MAX4158/MAX4159
SMALL-SIGNAL FREQUENCY RESPONSE
-4
-6
0
-2
MAX4158/59-01
FREQUENCY (MHz)
GAIN (dB)
VIN = 20mVp-p
AV = +1V/V
RF = 430Ω
RL = 100Ω
0.2
-0.8 1 10 100 1000
MAX4158/MAX4159
GAIN FLATNESS vs. FREQUENCY
-0.4
-0.6
0
-0.2
MAX4158/59-02
FREQUENCY (MHz)
GAIN (dB)
VIN = 20mVp-p
AV = +1V/V
RF = 430Ω
RL = 100Ω
2
-8 1 10 100 1000
MAX4158/MAX4159
LARGE-SIGNAL FREQUENCY RESPONSE
-4
-6
0
-2
MAX4158/59-03
FREQUENCY (MHz)
GAIN (dB)
AV = +1V/V
RF = 430Ω
RL = 100Ω
2Vp-p OUTPUT
4Vp-p OUTPUT
8
-2 1 10 100 1000
MAX4258/MAX4259
SMALL-SIGNAL FREQUENCY RESPONSE
2
0
6
4
MAX4158/59-04
FREQUENCY (MHz)
GAIN (dB)
VIN = 20mVp-p
AV = +2V/V
RF = RG = 510Ω
RL = 100Ω
20
-180 1 10 100 1000
MAX4159
OFF ISOLATION vs. FREQUENCY
-80
-100
-120
-140
-160
-20
0
-60
-40
MAX4158/59-07a
FREQUENCY (MHz)
GAIN (dB)
AV = +1V/V
RL = 100Ω
RF = 430Ω
IN0 = ±2V
IN1 = GND
A0 = GND
EN = 5V
6.2
5.2 1 10 100 1000
MAX4258/MAX4259
GAIN FLATNESS vs. FREQUENCY
5.6
5.4
6.0
5.8
MAX4158/59-05
FREQUENCY (MHz)
GAIN (dB)
VIN = 20mVp-p
AV = +2V/V
RF = RG = 510Ω
RL = 100Ω
8
-2 1 10 100 1000
MAX4258/MAX4259
LARGE-SIGNAL FREQUENCY RESPONSE
2
0
6
4
MAX4158/59-06
FREQUENCY (MHz)
GAIN (dB)
AV = +2V/V
RF = RG = 510Ω
RL = 100Ω
2Vp-p OUTPUT
4Vp-p OUTPUT
20
-180 1 10 100 1000
MAX4259
OFF ISOLATION vs. FREQUENCY
-80
-100
-120
-140
-160
-20
0
-60
-40
MAX4158/59-07b
FREQUENCY (MHz)
GAIN (dB)
AV = +2V/V
RL = 100Ω
RF = RG = 510Ω
IN0 = ±1V
IN1 = GND
A0 = GND
EN = 5V
__________________________________________Typical Operating Characteristics
(V+ = +5V, V- = -5V, TA= +25°C, unless otherwise noted.)
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
6 _______________________________________________________________________________________
____________________________Typical Operating Characteristics (continued)
(V+ = +5V, V- = -5V, TA= +25°C, unless otherwise noted.)
0
-100 10
1100 1000
CROSSTALK vs. FREQUENCY
-50
-60
-70
-80
-90
-20
-10
-40
-30
MAX4158/59-10
FREQUENCY (MHz)
GAIN (dB)
VIN = ±2Vp-p (MAX4158/MAX4159)
VIN = ±1Vp-p (MAX4258/MAX4259)
RS = 50Ω
RL = 100Ω
100
0.01 0.1
0.01 110 100
OUTPUT IMPEDANCE vs. FREQUENCY
0.1
1
10
MAX4158/59-11
FREQUENCY (MHz)
OUTPUT IMPEDANCE (Ω)
MAX4158/MAX4159:
RF = 430Ω, AV = 1
MAX4258/MAX4259:
RF = RG = 510Ω, AV = 2
MAX4258/MAX4259
MAX4158/MAX4159
0
-100
-90
1 10 100
MAX4258/MAX4259
TOTAL HARMONIC DISTORTION
vs. FREQUENCY
-70
-80
MAX4158/59-14b
FREQUENCY (MHz)
THD (dBc)
-50
-60
-30
-40
-20
-10 AV = +2V/V
VOUT = 2Vp-p
RL = 100Ω
RF = RG = 510Ω
3RD
THD
2ND
0.000
±0.020
±0.018
1 10 100
MAX4258/MAX4259
CHANNEL-TO-CHANNEL GAIN MATCHING
vs. FREQUENCY
±0.014
±0.016
MAX4158/59-13
FREQUENCY (MHz)
GAIN ERROR (dB)
±0.010
±0.012
±0.006
±0.008
±0.004
±0.002
AV = +2V/V
RL = 100Ω
RF = RG = 510Ω
VIN = 20mVp-p
0
-90 1 10 100
MAX4158/MAX4159
TOTAL HARMONIC DISTORTION
vs. FREQUENCY
-70
-80
MAX4158/59-14a
FREQUENCY (MHz)
THD (dBc)
-50
-60
-30
-40
-20
-10
3RD
THD
AV = +1V/V
VOUT = 2Vp-p
RL = 100Ω
RF = 430Ω
2ND
10ns/div
MAX4158/MAX4159
LARGE-SIGNAL PULSE RESPONSE
+2V
IN
0V
+2V
OUT
0V
MAX4158/59-15
10ns/div
MAX4258/MAX4259
LARGE-SIGNAL PULSE RESPONSE
+1V
IN
0V
+2V
OUT
0V
MAX4158/59-16
0.000
±0.020
±0.018
1 10 100
MAX4158/MAX4159
CHANNEL-TO-CHANNEL GAIN MATCHING
vs. FREQUENCY
±0.014
±0.016
MAX4158/59-12
FREQUENCY (MHz)
GAIN ERROR (dB)
±0.010
±0.012
±0.006
±0.008
±0.004
±0.002
AV = +1V/V
RL = 100Ω
RF = 430Ω
VIN = 20mVp-p
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
_______________________________________________________________________________________
7
10ns/div
MAX4158/MAX4159
SMALL-SIGNAL PULSE RESPONSE
+100mV
0V IN
-100mV
+100mV
0V OUT
-100mV
MAX4158/59-17
10ns/div
MAX4258/MAX4259
SMALL-SIGNAL PULSE RESPONSE
+50mV
0V IN
-50mV
+100mV
0V OUT
-100mV
MAX4158/59-18
10ns/div
MAX4158/MAX4159 LARGE-SIGNAL
PULSE RESPONSE (CL = 20pF)
+2V
IN
0V
+2V
OUT
0V
MAX4158/59-19
10ns/div
MAX4258/MAX4259 LARGE-SIGNAL
PULSE RESPONSE (CL = 20pF)
+1V
IN
0V
+2V
OUT
0V
MAX4158/59-20
20ns/div
MAX4158/MAX4159
ADDRESS SWITCHING TRANSIENT
+6V
+4VA0
+2V
0V
+100mV
0V OUT
-100mV
MAX4158/59-23
IN0 = IN1 = 0V
10ns/div
MAX4158/MAX4159 SMALL-SIGNAL
PULSE RESPONSE (CL = 20pF)
+100mV
0V IN
-100mV
+100mV
0V OUT
-100mV
MAX4158/59-21
10ns/div
MAX4258/MAX4259 SMALL-SIGNAL
PULSE RESPONSE (CL = 20pF)
+50mV
0V IN
-50mV
+100mV
0V OUT
-100mV
MAX4158/59-22
20ns/div
MAX4258/MAX4259
ADDRESS SWITCHING TRANSIENT
+6V
+4V
+2VA0
0V
+100mV
0V OUT
-100mV
MAX4158/59-24
IN0 = IN1 = 0V
20ns/div
MAX4159/MAX4259
EN SWITCHING DELAY
+6V
+4V
+2V
0V
+2V
+1V OUT
0V
MAX4158/59-25
EN
____________________________Typical Operating Characteristics (continued)
(V+ = +5V, V- = -5V, TA= +25°C, unless otherwise noted.)
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
8 _______________________________________________________________________________________
____________________________Typical Operating Characteristics (continued)
(V+ = +5V, V- = -5V, TA= +25°C, unless otherwise noted.)
12
8-60 -40 20 100
SUPPLY CURRENT
vs. TEMPERATURE
9
11
MAX4158/59-28
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
-20 040
10
60 80
I+
EN = 0V
I-
3.50
2.50 -60 -40 20 100
TRANSIMPEDANCE
vs. TEMPERATURE
2.75
3.25
MAX4158/59-29
TEMPERATURE (°C)
TRANSIMPEDANCE (MΩ)
-20 040
3.00
60 80
5.0
3.0 -60 -40 20 100
POSITIVE OUTPUT SWING
vs. TEMPERATURE
3.5
4.5
MAX4158/59-32
TEMPERATURE (°C)
POSITIVE OUTPUT SWING (V)
-20 040
4.0
60 80
NO LOAD
50Ω LOAD
0.50
-0.50 -60 -40 20 100
INPUT BIAS CURRENT
vs. TEMPERATURE
-0.25
0.25
MAX4158/59-30
TEMPERATURE (°C)
INPUT BIAS CURRENT (µA)
-20 040
0
60 80
-3.0
-5.0 -60 -40 20 100
NEGATIVE OUTPUT SWING
vs. TEMPERATURE
-4.5
-3.5
MAX4158/59-33
TEMPERATURE (°C)
NEGATIVE OUTPUT SWING (V)
-20 040
-4.0
60 80
NO LOAD
50Ω LOAD
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
_______________________________________________________________________________________ 9
____________________________Typical Operating Characteristics (continued)
(V+ = +5V, V- = -5V, TA= +25°C, unless otherwise noted.)
______________________________________________________________Pin Description
1.50
0.50 -60 -40 20 100
INPUT OFFSET VOLTAGE
vs. TEMPERATURE
0.75
1.25
MAX4158/59-34
TEMPERATURE (°C)
OFFSET VOLTAGE (V)
-20 040
1.00
60 80
150
100 -60 -40 20 100
OUTPUT SHORT-CIRCUIT CURRENT
vs. TEMPERATURE
110
120
140
130
MAX4158/59-35
TEMPERATURE (°C)
SHORT-CIRCUIT CURRENT (mA)
-20 040 60 80
POSITIVE OUTPUT
NEGATIVE OUTPUT
Positive Power-Supply Voltage116
Amplifier Output127
Channel-Address Logic Input (see
Truth Table
)138
Latch-Enable Logic Input (see
Truth Table
)14—
Amplifier Input, Channel 153
No Connection. Not internally connected. Connect to ground plane for
best RF performance.
——
Negative Power-Supply Voltage74
Amplifier Feedback Input95
Power Supply, Analog and Digital Ground. Connect GND to ground plane
for best RF performance.
2, 4, 6,
8, 10
2
Amplifier Input, Channel 031
Output Enable Logic Input. Connect EN to logic low or leave open for
normal operation. Connect to logic high to disconnect amplifier output
(output is high impedance).
1—
V+12
OUT13
A014
LE16
IN15
N.C.7, 15
V-8
FB10
GND
2, 4, 6,
9, 11
IN03
EN
1
SO QSOP
NAME FUNCTION
MAX4158
MAX4258
PIN
MAX4159
MAX4259
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
10 ______________________________________________________________________________________
_______________Detailed Description
The MAX4158/MAX4159 are optimized for closed-loop
gains (AVCL) of 1V/V (0dB) or greater; the MAX4258/
MAX4259 are optimized for closed-loop gains of 2V/V
(6dB) or greater. These low-power, high-speed, cur-
rent-mode feedback amplifiers operate from ±5V sup-
plies. They drive video loads (including 50Ωand 75Ω
cables) with excellent distortion characteristics.
Differential gain and phase errors are 0.01%/0.01° for
MAX4158/MAX4159 and 0.01%/0.02° for MAX4258/
MAX4259, respectively.
The input multiplexers feature very short switching
times and small switching transients. They also have
high input resistance and constant input capacitance,
so overall input impedance can be set by external input
terminating resistors. Each video input is isolated by an
AC-ground pin, which reduces channel-to-channel
capacitance and minimizes crosstalk.
The MAX4159/MAX4259 have address latching and an
output enable function that places the output in a high-
impedance state. These functions allow multiple
mux/amps to be paralleled together to form larger
switching arrays.
________________________Truth Tables
Input Control Logic
X = Don’t Care
MAX4159/MAX4259
Output Control Logic
All logic levels (EN, LE, and A0) default low (0) if left open circuit.
Output disable is completely independent of input address and
latch.
__________Applications Information
Theory of Operation
Since the MAX4158/MAX4159/MAX4258/MAX4259 are
current-mode feedback amplifiers, their open-loop
transfer function is expressed as a transimpedance,
∆VOUT/∆IFB, or ZT. The frequency behavior of this
open-loop transimpedance is similar to the open-loop
gain of a voltage-mode feedback amplifier. That is, it
has a large DC value and decreases at approximately
6dB per octave at high frequency.
Analyzing the current-mode feedback amplifier in a
gain configuration (Figure 1) yields the following trans-
fer function:
VOUT / VIN = G x ZT(S) / (ZT(S) + G x RIN(FB) + RF)
where G = AVCL = 1 + RF/ RG.
At low gains, G x RIN(FB) << RF. Therefore, unlike tradi-
tional voltage-mode feedback amplifiers, the closed-
loop bandwidth is essentially independent of
closed-loop gain. Note also that at low frequencies,
ZT>> [G x RIN(FB) + RF] so:
VOUT / VIN = G = 1 + RF/ RG
Layout and Power-Supply Bypassing
The MAX4158/MAX4159/MAX4258/MAX4259 have
extremely high bandwidth, and consequently require
careful board layout, including the possible use of con-
stant-impedance microstrip or stripline techniques.
MAX4158
MAX4159
MAX4258
MAX4259
RG
FB
ZT
RIN(FB)
OUT
+1
IN0
IN1
VIN
RF
+1
Figure 1. Current-Mode Feedback Amplifier
On
AMPLIFIER
OUTPUT
Off
0Output on
LOGIC
INPUT
(EENN)FUNCTION
1 Output off; high impedance
LE A0
AMPLIFIER
INPUT
LOGIC
INPUTS FUNCTION
[LAST]1 X Channel addresses latched;
retains last input address.
IN10 1 Channel 1 selected
IN00 0 Channel 0 selected
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
______________________________________________________________________________________ 11
To realize the full AC performance of these high-speed
amplifiers, pay careful attention to power-supply
bypassing and board layout. The PC board should
have at least two layers: a signal and power layer on
one side, and a large, low-impedance ground plane on
the other side. The ground plane should be as free of
voids as possible, with one exception: the feedback pin
(FB) should have as low a capacitance to ground as
possible. This means that there should be no ground
plane under FB or under the components (RFand RG)
connected to it. With multilayer boards, locate the
ground plane on a layer that incorporates no signal or
power traces.
Regardless of whether or not a constant-impedance
board is used, it is best to observe the following guide-
lines when designing the board:
1) Do not use wire-wrap boards (they are much too
inductive) or breadboards (they are much too
capacitive).
2) Do not use IC sockets. IC sockets increase reac-
tances.
3) Keep lines as short and as straight as possible. Do
not make 90° turns; round all corners.
4) Observe high-frequency bypassing techniques to
maintain the amplifier’s accuracy and stability.
5) Bear in mind that, in general, surface-mount compo-
nents have shorter bodies and lower parasitic reac-
tance, giving much better high-frequency
performance than through-hole components.
The bypass capacitors should include a 10nF ceramic
surface-mount capacitor between each supply pin and
the ground plane, located as close to the package as
possible. Optionally, place a 10µF tantalum capacitor at
the power-supply pins’ points of entry to the PC board
to ensure the integrity of incoming supplies. The power-
supply trace should lead directly from the tantalum
capacitor to the V+ and V- pins. To minimize parasitic
inductance, keep PC traces short and use surface-
mount components.
Ground pins have been placed between input channels
to minimize crosstalk between the two input channels.
(The grounds extend inside the package all the way to
the silicon.) These pins should be connected to a com-
mon ground plane on the PC board.
Input termination resistors and output back-termination
resistors, if used, should be surface-mount types, and
should be placed as close to the IC pins as possible.
Choosing Feedback
_________________and Gain Resistors
As with all current-mode feedback amplifiers, the fre-
quency response of the MAX4158/MAX4159/MAX4258/
MAX4259 is critically dependent on the value of the
feedback resistor RF. RF, in conjunction with an internal
compensation capacitor, forms the dominant pole in the
feedback loop. Reducing RF’s value increases the pole
frequency and the -3dB bandwidth, but also increases
peaking due to interaction with other nondominant
poles. Increasing RF’s value reduces peaking and
bandwidth.
Tables 1 and 2 show optimal values for the feedback
resistor (RF) and gain-setting resistor (RG) for all parts.
Note that the MAX4258/MAX4259 offer superior AC per-
formance for all gains except unity gain (0dB). These
values provide optimal AC response using surface-
mount resistors and good layout techniques. The
MAX4159/MAX4259 evaluation kit provides a practical
example of such layout techniques.
Stray capacitance at FB causes feedback resistor
decoupling and produces peaking in the frequency-
response curve. Keep the capacitance at FB as low as
possible by using surface-mount resistors, and avoid-
ing the use of a ground plane beneath or beside these
resistors and the FB pin. Some capacitance is unavoid-
able; if necessary, its effects can be counteracted by
adjusting RF. 1% resistors are recommended to main-
tain consistency over a wide range of production lots.
Table 1. MAX4158/MAX4159 Bandwidth
and Gain vs. Gain-Setting Resistors
200 1101102 6 110
514 80 12
40 6
32.5 130
14.510 20 130
-3dB BW
(MHz) 0.1dB BW
(MHz)
RG
(Ω)RF
(Ω)
GAIN
350 100
∞4301 0
(dB)(V/V)
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
12 ______________________________________________________________________________________
Table 2. MAX4258/MAX4259 Bandwidth
and Gain vs. Gain-Setting Resistors
DC Errors and Noise
The MAX4158/MAX4159/MAX4258/MAX4259 output
offset voltage, VOUT (Figure 2) can be calculated with
the following equation:
VOUT = VOS x [1 + RF/ RG] + IBx RSx [1 + RF/ RG] +
IFB x RF
where:
VOS = input offset voltage (in volts)
1 + RF/ RG= amplifier closed-loop gain (dimensionless)
IB= input bias current (in amps)
IFB = feedback input bias current (in amps)
RG= gain-setting resistor (in ohms)
RF= feedback resistor (in ohms)
RS= source resistor (in ohms)
The following equation represents output noise density:
where:
in= input noise current density (in A/√Hz)
en= input noise voltage density (in V/√Hz)
The MAX4158/MAX4159/MAX4258/MAX4259 have a
very low, 2nV/√Hz noise voltage. The current noise at
the input (in) is 2pA/√Hz, and the current noise at the
feedback input (in(FB)) is 22pA/√Hz.
An example of DC-error calculations, using the
MAX4258 typical data and the typical operating circuit
with RF= RG= 510Ω(RF|| RG= 255Ω) and RS= 50Ω,
gives:
VOUT = [1 x 10-3 x (1 + 1)] + [2 x 10-6 x 50 x (1 + 1)] +
[2 x 10-6 x 510]
VOUT = 3.22mV
Calculating total output noise in a similar manner yields
the following:
With a 200MHz system bandwidth, this calculates to
168µVRMS (approximately 1.01mVp-p, using the six-
sigma calculation).
Video Line Driver
The MAX4158/MAX4159/MAX4258/MAX4259 are opti-
mized to drive coaxial transmission lines when the
cable is terminated at both ends (Figure 3). Cable fre-
quency response may cause variations in the flatness
of the signal.
enOUT = 1 + 1
enOUT = 1.9nV/ Hz
( )
( )
( )
+
+
− − −
x
x x x x x2 10 50 222 10 255 22 10 2
1
12 12 9
e OUT = 1+R /R
n F G
( ) ( )
[ ]
+
( )
+
[ ]
( )
||
x
i x R i x R R e
n S n FB F G n
222
MAX4158
MAX4159
MAX4258
MAX4259
RG
FB
IFB
IBIN_
VOUT
OUT
RS
RF
514 195 92
90 14
-3dB BW
(MHz) 0.1dB BW
(MHz)
45 180
250 130510
20
RG
(Ω)RF
(Ω)
10 20 180
2 6
GAIN
510
(V/V) (dB)
Figure 2. Output Offset Voltage
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
______________________________________________________________________________________ 13
Driving Capacitive Loads
A correctly terminated transmission line is purely resis-
tive and presents no capacitive load to the amplifier.
Consequently, the MAX4158/MAX4159/MAX4258/
MAX4259 are optimized for AC performance and are
not designed to drive highly capacitive loads. Reactive
loads will decrease phase margin and may produce
excessive ringing and oscillation (see
Typical
Operating Characteristics
). The circuit of Figure 4
reduces this problem. The small (usually 5Ωto 20Ω)
isolation resistor RISO, placed before the reactive load,
prevents ringing and oscillation. At higher capacitive
loads, AC performance is limited by the interaction of
load capacitance with the isolation resistor.
MAX4158
MAX4159
MAX4258
MAX4259
RG
FB
IN_
RISO
OUT
RF
CLRL
MAX4158
MAX4159
MAX4258
MAX4259
RG
FB
INO
INI
OUT
RT
75Ω
RT
75Ω
RT
75Ω
75Ω CABLE 75Ω CABLE
RF
RT
75Ω
75Ω CABLE
Figure 4. Using an Isolation Resistor (RISO) for High
Capacitive Loads
Figure 3. Video Line Driver
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
14 ______________________________________________________________________________________
Input Voltage Range
The guaranteed input voltage range is ±2.5V. Exceeding
this value can cause unpredictable results, including out-
put clipping, excessive input current, and switching
delays.
Multiplexer
The input multiplexer (mux) is controlled by TTL/CMOS-
compatible address inputs (see
Truth Tables
.) There is
no internal memory except the address latch (LE) on
the MAX4159/MAX4259. If power is first applied with
the latch enabled, IN0 is selected.
Input capacitance is a constant, low 2pF for either input
channel, regardless of whether or not the channel is
selected.
All logic levels (EN, LE, and A0) default low if left open-
circuit.
A0
tStH
ENABLE/DISABLE TIMES
HIGH IMPEDANCE
ADDRESSING TIMES
LE
EN
OUT
OUT
tSW
tPdD tPdE
tLPD tLPW
Figure 5. Switching Timing Diagram
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
______________________________________________________________________________________ 15
_____________________Pin Configurations/Functional Diagrams/Truth Tables
___________________Chip Information
TRANSISTOR COUNT: 239
14
13
12
11
10
9
8
1
2
3
4
5
6
7
LE
A0
OUT
V+
GND
IN0
GND
EN
MAX4159/MAX4259
GND
FB
GND
V-
GND
IN1
SO
N.C. = NOT INTERNALLY CONNECTEDX = DON’T CARE
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
LE
N.C.
A0
OUT
V+
GND
FB
GND
EN
GND
IN0
GND
IN1
GND
N.C.
V-
MAX4159/MAX4259
QSOP
TOP VIEW
LOGIC LOGIC
EN
0
1
OUTPUT
MAX4159/MAX4259
ON
OFF (HI-Z)
LE
0
0
1
A0
0
1
X
INPUT
MAX4159/MAX4259
IN0
IN1
LAST
MAX4158/MAX4159/MAX4258/MAX4259
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
________________________________________________________Package Information
8LUMAXD.EPS
QSOP.EPS
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
© 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.