19-0436; Rev 1; 3/96
KIT
ATION
EVALU
E
L
B
A
IL
AVA
500MHz, Low-Power Op Amps
____________________________Features
The MAX4100/MAX4101 op amps combine ultra-highspeed performance with low-power operation. The
MAX4100 is compensated for unity-gain stability, while
the MAX4101 is compensated for stability in applications with a closed-loop gain (AVCL) of 2V/V or greater.
The MAX4100/MAX4101 require only 5mA of supply
current while delivering a 500MHz unity-gain bandwidth
(MAX4100) or a 200MHz -3dB bandwidth (MAX4101)
with a 250V/µs slew rate.
♦ 500MHz Unity-Gain Bandwidth (MAX4100)
200MHz -3dB Bandwidth (AVCL = 2V/V, MAX4101)
These high-speed op amps have a wide output voltage
swing of ±3.5V and a high current-drive capability of
80mA.
________________________Applications
Video Cable Driver
♦ 65MHz 0.1dB Gain Flatness (MAX4100)
♦ 250V/µs Slew Rate
♦ 0.06%/0.04° Differential Gain/Phase
♦ High Output Drive: 80mA
♦ Low Power: 5mA Supply Current
♦ Fast Settling Time:
18ns to 0.1%
35ns to 0.01%
______________Ordering Information
PART
TEMP. RANGE
PIN-PACKAGE
Ultrasound
MAX4100ESA
-40°C to +85°C
8 SO
Gamma Cameras
MAX4100EUA
-40°C to +85°C
8 µMAX*
MAX4101ESA
-40°C to +85°C
8 SO
Portable Instruments
* Contact factory for availability of µMAX package.
Active Filters
ADC Buffers
________Typical Application Circuit
__________________Pin Configuration
+5V
TOP VIEW
0.1µF
1000pF
INPUT
75Ω
MAX4100
MAX4101
75Ω
IN- 2
75Ω
0.1µF
1000pF
IN+ 3
MAX4100
MAX4101
8
N.C.
7
VCC
6
OUT
5
N.C.
75Ω
-5V
390Ω
N.C. 1
VEE 4
75Ω
SO/µMAX*
390Ω
75Ω
VIDEO/RF DISTRIBUTION AMPLIFIER
* Contact factory for availability of MAX4100 µMAX package.
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
MAX4100/MAX4101
_______________General Description
MAX4100/MAX4101
500MHz, Low-Power Op Amps
ABSOLUTE MAXIMUM RATINGS
Power-Supply Voltage (VCC, VEE) .........................................±6V
Voltage on Any Pin to Ground or Any Other Pin .........VCC to VEE
Short-Circuit Duration (VOUT to GND) ...........................Indefinite
Continuous Power Dissipation (TA = +70°C)
SO (derate 5.88mW/°C above +70°C) .........................471mW
µMAX (derate 4.10mW/°C above +70°C) ....................330mW
Operating Temperature Ranges
MAX4100E_A/MAX4101E_A ............................-40°C to +85°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°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.
ELECTRICAL CHARACTERISTICS
(VCC = 5V, VEE = -5V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
8
mV
DC SPECIFICATIONS
Input Offset Voltage
Input Offset Voltage Drift
Input Bias Current
Input Offset Current
VOS
VOUT = 0V
1
TCVOS
VOUT = 0V
15
IB
VOUT = 0V, VIN = -VOS
3
9
µV/°C
µA
IOS
VOUT = 0V, VIN = -VOS
0.05
0.5
µA
Common-Mode Input Resistance
RINCM
Either input
5
MΩ
Common-Mode Input Capacitance
CINCM
Either input
1
pF
Input Voltage Noise
en
Integrated Voltage Noise
Input Current Noise
f = 100kHz
f = 1MHz to 100MHz
in
Integrated Current Noise
f = 100kHz
f = 1MHz to 100MHz
Common-Mode Input Voltage
VCM
Common-Mode Rejection
CMR
VCM = ±2.5V
Power-Supply Rejection
PSR
VS = ±4.5V to ±5.5V
100
MAX4101
75
MAX4100
0.8
MAX4101
0.8
MAX4100
10
MAX4101
10
nARMS
V
dB
dB
51
56
RL = ∞
±3.5
±3.8
RL = 100Ω
±3.1
±3.5
Short to ground or either supply voltage
pA/√Hz
2.5
RL = 100Ω
RL = 30Ω, TA = 0°C to +85°C
ISC
µVRMS
90
58
VIN = 0V
nV/√Hz
75
60
ISY
2
MAX4100
53
Quiescent Supply Current
Short-Circuit Output Current
6
55
VOUT = ±2.0V, VCM = 0V
Output Current
MAX4101
RL = ∞
AOL
VOUT
8
-2.5
Open-Loop Voltage Gain
Output Voltage Swing
MAX4100
5
65
dB
6
mA
V
80
mA
90
mA
_______________________________________________________________________________________
500MHz, Low-Power Op Amps
(VCC = 5V, VEE = -5V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
AC SPECIFICATIONS
-3dB Bandwidth
BW
0.1dB Bandwidth
Slew Rate
SR
Settling Time
VOUT ≤ 0.1VRMS
200
65
MAX4100, AVCL = +2
50
-2V ≤ VOUT ≤ 2V
18
to 0.01%
35
13
10% to 90%, -50mV ≤ VOUT ≤ 50mV, RL = 100Ω
1.5
tR, tF
Differential Gain
DG
f = 3.58MHz
Differential Phase
DP
f = 3.58MHz
Input Capacitance
CIN
MHz
MHz
250
to 0.1%
10% to 90%, -2V ≤ VOUT ≤ 2V, RL = 100Ω
Rise/Fall Times
MAX4100, AVCL = +1
0.06
MAX4101, AVCL = +2
0.07
MAX4100, AVCL = +1
0.04
MAX4101, AVCL = +2
0.04
MAX4100, AVCL = +1
0.8
MAX4101, AVCL = +2
0.3
MAX4100, AVCL = +1
-70
MAX4101, AVCL = +2
-65
V/µs
ns
ns
%
degrees
2
Output Resistance
ROUT
f = 10MHz
Spurious-Free Dynamic Range
SFDR
fC = 5MHz,
VOUT = 2Vp-p
Third-Order Intercept
500
MAX4101
MAX4100, AVCL = +1
-1V ≤ VOUT ≤ 1V, RL = 100Ω
ts
MAX4100
fC = 10MHz, AVCL = +2
36
pF
Ω
dBc
dBm
__________________________________________Typical Operating Characteristics
(VCC = 5V, VEE = -5V, TA = +25°C, unless otherwise noted.)
CURRENT NOISE vs. FREQUENCY
VOLTAGE NOISE vs. FREQUENCY
40
30
20
7
6
5
MAX4100
4
MAX4100-03
MAX4100-02
8
VOLTAGE (500mV/div)
MAX4100
50
9
CURRENT NOISE (pA/√Hz)
60
VOLTAGE NOISE (nV/√Hz)
10
MAX4100-01
70
MAX4100
LARGE-SIGNAL PULSE RESPONSE
(AVCL = +1)
3
IN
GND
OUT
GND
2
10
MAX4101
1
MAX4101
0
0
10
100
1k
10k
FREQUENCY (Hz)
100k
1M
10
100
1k
10k
100k
1M
TIME (10ns/div)
FREQUENCY (Hz)
_______________________________________________________________________________________
3
MAX4100/MAX4101
ELECTRICAL CHARACTERISTICS (continued)
____________________________Typical Operating Characteristics (continued)
(VCC = 5V, VEE = -5V, TA = +25°C, unless otherwise noted.)
MAX4100
LARGE-SIGNAL PULSE RESPONSE
(AVCL = +5)
MAX4100-05
100
VOLTAGE (20mV/div)
GND
OUT
RESISTANCE (Ω)
10
MAX4100-06
MAX4100-04
VOLTAGE (500mV/div)
MAX4100
SMALL-SIGNAL PULSE RESPONSE
(AVCL = +1)
MAX4100
OUTPUT RESISTANCE vs. FREQUENCY
GND
IN
1.0
0.1
IN
GND
OUT
GND
0.01
10k
TIME (20ns/div)
100k
1M
10M
100M
1G
TIME (10ns/div)
FREQUENCY (Hz)
MAX4100
SMALL-SIGNAL PULSE RESPONSE
(AVCL = +5)
MAX4101
LARGE-SIGNAL PULSE RESPONSE
(AVCL = +2)
MAX4100-08
100
VOLTAGE (500mV/div)
GND
GND
RESISTANCE (Ω)
VOLTAGE (10mV/div)
10
OUT
MAX4100-09
MAX4101
OUTPUT RESISTANCE vs. FREQUENCY
MAX4100-07
IN
1.0
IN
GND
OUT
GND
0.1
0.01
10k
TIME (50ns/div)
100k
1M
10M
100M
1G
TIME (10ns/div)
FREQUENCY (Hz)
MAX4101
SMALL-SIGNAL PULSE RESPONSE
(AVCL = +2)
GND
TIME (20ns/div)
4
VOLTAGE (10mV/div)
OUT
MAX4100-11b
IN
GND
IN
OUT
GND
TIME (10ns/div)
VOLTAGE (10mV/div)
MAX4100-10
IN
MAX4101
SMALL-SIGNAL PULSE RESPONSE
(AVCL = +10)
MAX4100-11a
MAX4101
LARGE-SIGNAL PULSE RESPONSE
(AVCL = +10)
VOLTAGE (500mV/div)
MAX4100/MAX4101
500MHz, Low-Power Op Amps
OUT
GND
TIME (50ns/div)
_______________________________________________________________________________________
500MHz, Low-Power Op Amps
INPUT BIAS CURRENT
vs. TEMPERATURE
0.5
6
-1.0
-1.5
0.15
CURRENT (µA)
-0.5
4
3
-2.0
-2.5
-3.0
25
0
50
0.05
-0.05
2
-0.15
1
-0.25
0
-75 -50 -25
-0.35
-75 -50 -25
75 100 125
0
25
50
75 100 125
-75 -50 -25
0
25
50
75 100 125
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
POWER-SUPPLY CURRENT
vs. TEMPERATURE
MAX4100
COMMON-MODE REJECTION
vs. FREQUENCY
MAX4100
POWER-SUPPLY REJECTION
vs. FREQUENCY
70
60
60
50
40
50
40
PSR30
30
4
70
PSR (dB)
CMR (dB)
5
20
20
10
10
PSR+
0
3
0
25
50
75 100 125
30k 100k
TEMPERATURE (°C)
1M
100M
10M
3
RL = 100Ω
2
-2
RL = 100Ω
-3
-4
RL = ∞
-5
100M
1G
MAX4100-17
RL = ∞
10M
FREQUENCY (Hz)
3.5
3.0
OUTPUT SWING (Vp-p)
4
1M
OUTPUT SWING
vs. LOAD RESISTANCE
MAX4100 TOC-20A
6
5
0
0.1M
1G
FREQUENCY (Hz)
POSITIVE OUTPUT SWING
vs. TEMPERATURE
POSITIVE OUTPUT SWING (V)
-75 -50 -25
MAX4100 TOC-16
80
6
80
MAX4100 TOC-15
90
MAX4100 TOC-13
7
CURRENT (mA)
0.25
5
CURRENT (µA)
VOLTAGE (mV)
0
0.35
MAX4100 TOC-14A
7
MAX4100 TOC-12
1.0
INPUT OFFSET CURRENT
vs. TEMPERATURE
MAX4100 TOC-14B
INPUT OFFSET VOLTAGE
vs. TEMPERATURE
2.5
2.0
1.5
1.0
0.5
-6
0
-75 -50 -25
0
25
50
75 100 125
TEMPERATURE (°C)
10
22
33
50
75
LOAD RESISTANCE (Ω)
_______________________________________________________________________________________
5
MAX4100/MAX4101
____________________________Typical Operating Characteristics (continued)
(VCC = 5V, VEE = -5V, TA = +25°C, unless otherwise noted.)
____________________________Typical Operating Characteristics (continued)
(VCC = 5V, VEE = -5V, TA = +25°C, unless otherwise noted.)
MAX4101 OPEN-LOOP GAIN
AND PHASE vs. FREQUENCY
90
20
PHASE
10
135
0
100k
1M
10M
100M
MAX4100-19
10
0
-1
-2
-3
-4
135
-5
-6
180
10k
1G
100k
1M
10M
100M
-7
1G
0.1M
10M
1M
100M
1G
FREQUENCY (Hz)
MAX4101 CLOSED-LOOP RESPONSE
(AVCL = +2)
MAX4100
HARMONIC DISTORTION vs. FREQUENCY
MAX4100
HARMONIC DISTORTION vs. FREQUENCY
6
5
4
3
2
1
0
-10
GAIN = +1
VO = 2Vp-p
RL = 100Ω
-20
-30
-40
2nd HARMONIC
-50
-60
-70
3rd HARMONIC
-80
-1
0
HARMONIC DISTORTION (dBc)
7
0
HARMONIC DISTORTION (dBc)
MAX4100 TOC-23
9
10M
1M
100M
1G
GAIN = +2
VO = 2Vp-p
RL = 100Ω
-20
-30
-40
-50
2nd HARMONIC
-60
-70
3rd HARMONIC
-80
-90
-90
0.1M
-10
MAX4100 TOC-25
FREQUENCY (Hz)
MAX4100 TOC-24
FREQUENCY (Hz)
8
0.1
1
10
0.1
100
1
10
100
FREQUENCY (MHz)
MAX4100
HARMONIC DISTORTION vs. FREQUENCY
MAX4101
HARMONIC DISTORTION vs. FREQUENCY
MAX4101
HARMONIC DISTORTION vs. FREQUENCY
-30
-40
-50
2nd HARMONIC
-60
3rd HARMONIC
-70
-10
-20
-30
-40
-50
-60
3rd HARMONIC
-80
-90
-90
1
10
FREQUENCY (MHz)
100
2nd HARMONIC
-70
-80
0.1
GAIN = +2
VO = 2Vp-p
RL = 100Ω
0
HARMONIC DISTORTION (dBc)
-20
0
HARMONIC DISTORTION (dBc)
GAIN = +5
VO = 2Vp-p
RL = 100Ω
-10
MAX4100 TOC-28
FREQUENCY (MHz)
MAX4100 TOC-26
FREQUENCY (Hz)
MAX4100 TOC-27
GAIN (dB)
PHASE
-20
180
10k
6
90
20
1
-10
-20
-10
30
0
-10
0
45
GAIN
2
GAIN (dB)
30
3
0
40
LOOP GAIN (dB)
45
GAIN
PHASE (DEGREES)
MAX4100-18
40
LOOP GAIN (dB)
60
50
0
PHASE (DEGREES)
60
50
MAX4100 CLOSED-LOOP RESPONSE
(AVCL = +1)
MAX4100 TOC-22
MAX4100 OPEN-LOOP GAIN
AND PHASE vs. FREQUENCY
HARMONIC DISTORTION (dBc)
MAX4100/MAX4101
500MHz, Low-Power Op Amps
GAIN = +5
VO = 2Vp-p
RL = 100Ω
-20
-30
-40
-50
2nd HARMONIC
-60
3rd HARMONIC
-70
-80
-90
0.1
1
10
FREQUENCY (MHz)
100
0.1
1
10
FREQUENCY (MHz)
_______________________________________________________________________________________
100
500MHz, Low-Power Op Amps
TWO-TONE THIRD-ORDER
INTERCEPT vs. FREQUENCY
-20
-30
-40
-50
2nd HARMONIC
-60
3rd HARMONIC
-70
40
-80
0.1
1
20
25
20
15
10
5
0.1
100
10
1
10
FREQUENCY (MHz)
MAX4100
DIFFERENTIAL GAIN AND PHASE
MAX4101
DIFFERENTIAL GAIN AND PHASE
0
0.02
-0.00
-0.02
-0.04
-0.06
-0.08
-0.10
100
0
DIFF PHASE (deg)
0.05
0.04
0.03
0.02
0.01
0.00
-0.01
0
100
MAX4100-32
0.02
-0.00
-0.02
-0.04
-0.06
-0.08
DIFF GAIN (%)
FREQUENCY (MHz)
MAX4100-31
DIFF GAIN (%)
35
0
-90
DIFF PHASE (deg)
MAX4100-30
GAIN = +10
VO = 2Vp-p
RL = 100Ω
-10
THIRD-ORDER INTERCEPT (dBm)
HARMONIC DISTORTION (dBc)
0
MAX4100 TOC-29
MAX4101
HARMONIC DISTORTION vs. FREQUENCY
100
0.06
0.04
0.02
0.00
-0.02
100
0
IRE
100
IRE
______________________________________________________________Pin Description
PIN
NAME
FUNCTION
1, 5, 8
N.C.
2
IN-
Inverting Input
3
IN+
Noninverting Input
4
VEE
Negative Power Supply, connected to -5V
6
OUT
Amplifier Output
7
VCC
Positive Power Supply, connected to +5V
No Connection, not internally connected
_______________________________________________________________________________________
7
MAX4100/MAX4101
____________________________Typical Operating Characteristics (continued)
(VCC = 5V, VEE = -5V, TA = +25°C, unless otherwise noted.)
MAX4100/MAX4101
500MHz, Low-Power Op Amps
_______________Detailed Description
The MAX4100/MAX4101 are low-power, high-bandwidth
operational amplifiers optimized for driving back-terminated cables in composite video, RGB, and RF systems.
The MAX4100 is unity-gain stable, and the MAX4101 is
optimized for closed-loop gains greater than or equal to
2V/V (AVCL ≥ 2V/V). While consuming only 5mA (6mA
max) supply current, both devices can drive 50Ω backterminated cables to ±3.1V minimum.
The MAX4100 features a bandwidth in excess of 500MHz
and a 0.1dB gain flatness of 65MHz. It offers differential
gain and phase errors of 0.06%/0.04°, respectively. The
MAX4101 features a -3dB bandwidth of 200MHz, a 0.1dB
bandwidth of 50MHz, and 0.07%/0.04° differential gain
and phase.
Available in small 8-pin SO and µMAX packages, these
ICs are ideally suited for use in portable systems (in
RGB, broadcast, or consumer video applications) that
benefit from low power consumption.
__________Applications Information
Layout and Power-Supply Bypassing
The MAX4100/MAX4101 have an RF bandwidth and,
consequently, require careful board layout. Depending
on the size of the PC board used and the frequency of
operation, it may be desirable to use constant-impedance microstrip or stripline techniques.
To realize the full AC performance of this high-speed
amplifier, 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 multilayer boards, locate the ground
plane on a layer that incorporates no signal or power
traces.
Regardless of whether a constant-impedance board is
used, it is best to observe the following guidelines
when designing the board. Wire-wrap boards are much
too inductive, and breadboards are much too capacitive; neither should be used. IC sockets increase parasitic capacitance and inductance, and should not be
used. In general, surface-mount components give better high-frequency performance than through-hole
components. They have shorter leads and lower parasitic reactances. Keep lines as short and as straight as
possible. Do not make 90° turns; round all corners.
High-frequency bypassing techniques must be observed
to maintain the amplifier accuracy. The bypass capacitors should include a 1000pF ceramic capacitor between
each supply pin and the ground plane, located as close
to the package as possible. Next, place a 0.01µF to
0.1µF ceramic capacitor in parallel with each 1000pF
capacitor, and as close to each as possible. Then place
a 10µF to 15µF low-ESR tantalum at the point of entry (to
the PC board) of the power-supply pins. The power-supply trace should lead directly from the tantalum capacitor
to the VCC and VEE pins. To minimize parasitic inductance, keep PC traces short and use surface-mount
components.
RG
RF
MAX4100
MAX4100
MAX4101
MAX4101
VOUT
VIN
VOUT = [1 + (RF / RG)]VIN
Figure 1b. Noninverting Gain Configuration
VIN
RG
RF
MAX4100
MAX4100
MAX4101
MAX4101
24Ω
VOUT
MAX4100
MAX4100
MAX4101
MAX4101
VIN
VOUT = (RF / RG)VIN
Figure 1a. Inverting Gain Configuration
8
VOUT = VIN
Figure 1c. MAX4100 Unity-Gain Buffer Configuration
_______________________________________________________________________________________
VOUT
500MHz, Low-Power Op Amps
RG
Table 1. Resistor and Bandwidth Values
for Various Gain Configurations
RF
C
MAX4100
MAX4100
MAX4101
VOUT
Figure 2. Effect of Feedback Resistor Values and Parasitic
Capacitance on Bandwidth
Setting Gain
The MAX4100/MAX4101 are voltage-feedback op amps
that can be configured as an inverting or noninverting
gain block, as shown in Figures 1a and 1b. The gain is
determined by the ratio of two resistors and does not
affect amplifier frequency compensation.
In the unity-gain configuration (as shown in Figure 1c),
maximum bandwidth and stability is achieved with the
MAX4100 when a small feedback resistor is included.
This resistor suppresses the negative effects of parasitic inductance and capacitance. A value of 24Ω provides the best combination of wide bandwidth, low
peaking, and fast settling time. In addition, this resistor
reduces the errors from input bias currents.
Choosing Resistor Values
The values of feedback and input resistors used in the
inverting or noninverting gain configurations are not
critical (as is the case with current feedback amplifiers). However, take care when selecting because the
ohmic values need to be kept small and noninductive
for practical reasons.
The input capacitance of the MAX4100/MAX4101 is
approximately 2pF. In either the inverting or noninverting configuration, the bandwidth limit caused by the
package capacitance and resistor time constant is
f3dB = 1 / (2Π RC), where R is the parallel combination
of the input and feedback resistors (R F and R G in
Figure 2) and C is the package and board capacitance
at the inverting input. Table 1 shows the bandwidth limit
for several values of RF and RG, assuming 4pF total
capacitance (2pF for the MAX4100/MAX4101 and 2pF
of PC board parasitics).
GAIN
(V/V)
RG
(Ω)
RF
(Ω)
BANDWIDTH
LIMIT*
(MHz)
+1
∞
24
1659
+2
200
200
398
+5
50
200
995
+10
30
270
1474
-1
200
200
398
-2
75
150
796
-5
50
250
955
-10
50
500
875
* Assuming an infinite bandwidth amplifier.
Resistor Types
Surface-mount resistors are the best choice for highfrequency circuits. They are of similar material to the
metal film resistors, but are deposited using a thick-film
process in a flat, linear manner so that inductance is
minimized. Their small size and lack of leads also minimize parasitic inductance and capacitance, thereby
yielding more predictable performance.
DC and Noise Errors
There are several major error sources to be considered
in any operational amplifier. These apply equally to the
MAX4100/MAX4101. Offset-error terms are given by the
equation below. Voltage and current noise errors are
root-square summed, so are computed separately.
Using the circuit in Figure 3, the total output offset voltage is determined by:
a) The input offset voltage (VOS) times the closed-loop
gain (1 + RF / RG)
b) The positive input bias current (I B+ ) times the
source resistor (RS) minus the negative input bias
current (IB-) times the parallel combination of RG
and R F . I OS (offset current) is the difference
between the two bias currents. If RG | | RF = RS, this
part of the expression becomes IOS x RS.
The equation for total DC error is:
R
VOUT = IOSRS + VOS 1 + F
RG
(
)
_______________________________________________________________________________________
9
MAX4100/MAX4101
VIN
In both DC and noise calculations, errors are dominated by offset voltage and noise voltage (rather than by
input bias current or noise current).
Metal-film resistors with leads are manufactured using
a thin-film process, where resistive material is deposited in a spiral layer around a ceramic rod. Although the
materials used are noninductive, the spiral winding presents a small inductance (about 5nH) that may have an
adverse effect on high-frequency circuits.
RF
IB-
RS
IB+
VOUT
MAX4100
MAX4100
MAX4101
10
Figure 3. Output Offset Voltage
c) Total output-referred noise voltage is shown by the
equation below (en(OUT)):
(2inRS )2 + (eN )2
4
2
0
-2
CL = 5pF
-4
CL = 0pF
-6
-10
0.1M
1M
10M
100M
1G
FREQUENCY (Hz)
Figure 4a. MAX4100 Bandwidth vs. Capacitive Load
R
VOUT = IOSRS + VOS 1 + F
RG
)
10
( )
VOUT = 3 × 10 −6 × 102 + 1 × 10 −3 1 + 1
Calculating total output-referred noise in a similar manner yields:
2
en(OUT) = 1 + 1 2 × 0.8 × 10 −12 × 100 + 8 × 10 −9
CL = 10pF
8
VOUT = 2.6mV
( )
CL = 10pF
-8
The MAX4100/MAX4101, with two high-impedance inputs,
have low 8nV√Hz voltage noise and only 0.8pA√Hz current
noise.
An example of DC error calculations, using the
MAX4100/MAX4101 typical data and the typical operating
circuit with RF = RG = 200Ω (RS = 100Ω), gives:
(
RS = 0Ω
6
2
en(OUT) = 8nV / Hz
6
4
2
0
-2
-4
RS = 22Ω
RS = 10Ω
RS = 4.7Ω
RS = 2.2Ω
-6
-8
-10
0.1M
With a 200MHz system bandwidth, this calculates to
133µVRMS (approximately 679µVp-p).
MAX4100-4b
R
en(OUT) = 1 + F
RG
CLOSED-LOOP GAIN (dB)
8
MAX4100-4a
RI
CLOSED-LOOP GAIN (dB)
MAX4100/MAX4101
500MHz, Low-Power Op Amps
1M
10M
100M
1G
FREQUENCY (Hz)
Figure 4b. MAX4100 Bandwidth vs. Capacitive Load and
Isolation Resistor
10
______________________________________________________________________________________
500MHz, Low-Power Op Amps
MAX4100/MAX4101
Carbon composition resistors with leads are manufactured by pouring the resistor material into a mold. This
process yields a relatively low-inductance resistor that
is very useful in high-frequency applications, although
they tend to cost more and have more thermal noise
than other types. The ability of carbon composition
resistors to self-heal after a large current overload
makes them useful in high-power RF applications.
For general-purpose use, surface-mount metal-film
resistors seem to have the best overall performance for
low cost, low inductance, and low noise.
24Ω
RS
MAX4100
VIN
RL
CL
Driving Capacitive Loads
Figure 5a. Using an Isolation Resistor for High Capacitive
Loads (MAX4100)
MAX4100 FIG05
25
DECOUPLING RESISTOR (Ω)
When driving 50Ω or 75Ω back-terminated transmission
lines, capacitive loading is not an issue; therefore an isolation resistor is not required. For other applications
where the ability to drive capacitive loads is required, the
MAX4100/MAX4101 can typically drive 5pF and 20pF,
respectively. Figure 4a illustrates how a capacitive load
influences the amplifier’s peaking without an isolation
resistor (RS). Figure 4b shows how an isolation resistor
decreases the amplifier’s peaking.
The MAX4100/MAX4101 can drive capacitive loads up to
5pF. By using a small isolation resistor between the
amplifier output and the load, large capacitance values
may be driven without oscillation (Figure 5a). In most
cases, less than 50Ω is sufficient. Use Figure 5b to determine the value needed in your application. Determine the
worst-case maximum capacitive load you may encounter
and select the appropriate resistor from the graph.
20
MAX4100
15
10
MAX4101
5
0
0
20
40
60
80
100
120
CAPACITIVE LOAD (pF)
Figure 5b. Isolation vs. Capacitive Load
______________________________________________________________________________________
11
MAX4100/MAX4101
500MHz, Low-Power Op Amps
________________________________________________________Package Information
DIM
D
0°-8°
A
0.101mm
0.004in.
e
B
A1
E
C
L
Narrow SO
SMALL-OUTLINE
PACKAGE
(0.150 in.)
H
A
A1
B
C
E
e
H
L
INCHES
MAX
MIN
0.069
0.053
0.010
0.004
0.019
0.014
0.010
0.007
0.157
0.150
0.050
0.244
0.228
0.050
0.016
DIM PINS
D
D
D
8
14
16
MILLIMETERS
MIN
MAX
1.35
1.75
0.10
0.25
0.35
0.49
0.19
0.25
3.80
4.00
1.27
5.80
6.20
0.40
1.27
INCHES
MILLIMETERS
MIN MAX
MIN
MAX
0.189 0.197 4.80
5.00
0.337 0.344 8.55
8.75
0.386 0.394 9.80 10.00
21-0041A
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.
12 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600
© 1995 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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