MAX4019ESD-T [MAXIM]
Buffer Amplifier, 3 Func, PDSO14, SO-14;
| 型号： | MAX4019ESD-T |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Buffer Amplifier, 3 Func, PDSO14, SO-14 放大器 光电二极管 |
| 文件： | 总12页 (文件大小：271K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-1284; Rev 2; 8/01
Low-Cost, High-Speed, Single-Supply, Gain of +2
Buffers with Rail-to-Rail Outputs in SOT23
_______________General Description
____________________________Features
ꢀ Internal Precision Resistors for Closed-Loop
The MAX4014/MAX4017/MAX4019/MAX4022 are preci-
sion, closed-loop, gain of +2 (or -1) buffers featuring
high slew rates, high output current drive, and low dif-
ferential gain and phase errors. These single-supply
devices operate from +3.15V to +11V, or from 1.575V
to 5.5V dual supplies. The input voltage range eꢀtends
100mV beyond the negative supply rail and the outputs
swing Rail-to-Rail®.
Gains of +2 or -1
ꢀ High Speed:
200MHz -3dB Bandwidth
30MHz 0.1dB Gain Flatness (6MHz min)
600V/µs Slew Rate
ꢀ Single 3.3V/5.0V Operation
ꢀ Outputs Swing Rail-to-Rail
These devices require only 5.5mA of quiescent supply
current while achieving a 200MHz -3dB bandwidth and
a 600V/µs slew rate. In addition, the MAX4019 has a
disable feature that reduces the supply current to
400µA. Input voltage noise for these parts is only
10nV/√Hz and input current noise is only 1.3pA/√Hz.
This buffer family is ideal for low-power/low-voltage
applications that require wide bandwidth, such as
video, communications, and instrumentation systems.
For space-sensitive applications, the MAX4014 comes
in a tiny 5-pin SOT23 package.
ꢀ Input Voltage Range Extends Beyond V
EE
ꢀ Low Differential Gain/Phase: 0.04%/0.02°
ꢀ Low Distortion at 5MHz:
-78dBc Spurious-Free Dynamic Range
-75dB Total Harmonic Distortion
ꢀ High Output Drive: 120mA
ꢀ Low, 5.5mA Supply Current
ꢀ 400µA Shutdown Supply Current
ꢀ Space-Saving SOT23-5, µMAX, or QSOP Packages
_____________________Selector Guide
______________Ordering Information
NO. OF
AMPS
PART
ENABLE
No
PIN-PACKAGE
5-Pin SOT23
PIN-
SOT
PART
TEMP. RANGE
PACKAGE TOP MARK
MAX4014
MAX4017
MAX4019
MAX4022
1
MAX4014EUK -40°C to +85°C
MAX4017ESA -40°C to +85°C
MAX4017EUA -40°C to +85°C
MAX4019ESD -40°C to +85°C
5 SOT23-5
8 SO
ABZQ
—
2
3
4
No
8-Pin SO/µMAX
8 µMAX
14 SO
—
14-Pin SO,
16-Pin QSOP
Yes
—
MAX4019EEE
MAX4022ESD -40°C to +85°C
MAX4022EEE -40°C to +85°C
-40°C to +85°C
16 QSOP
14 SO
—
14-Pin SO,
16-Pin QSOP
No
—
16 QSOP
—
________________________Applications
__________Typical Operating Circuit
Portable/Battery-Powered Instruments
Video Line Driver
IN+
75Ω
V
Analog-to-Digital Converter Interface
CCD Imaging Systems
OUT
75Ω
Video Routing and Switching Systems
MAX4014
500Ω
500Ω
IN-
Rail-to-Rail is a registered trademark of Nippon Motorola Ltd.
GAIN OF +2 VIDEO/RF CABLE DRIVER
________________________________________________________________ Maxim Integrated Products
1
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.
Low-Cost, High-Speed, Single-Supply, Gain of +2
Buffers with Rail-to-Rail Outputs in SOT23
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V
to V )..................................................12V
8-pin µMAX (derate 4.1mW/°C above +70°C)..............330mW
14-pin SO (derate 8.3mW/°C above +70°C).................667mW
16-pin QSOP (derate 8.3mW/°C above +70°C)............667mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°C
CC
EE
IN_-, IN_+, OUT_, EN_ ....................(V - 0.3V) to (V
+ 0.3V)
EE
CC
Output Short-Circuit Duration to V
or V ..............Continuous
CC
EE
Continuous Power Dissipation (T = +70°C)
A
5-pin SOT23 (derate 7.1mW/°C above+70°C)..............571mW
8-pin SO (derate 5.9mW/°C above +70°C)...................471mW
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 at 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
(V
= +5V, V = 0V, IN_- =0V, EN_ = 5V, R = ∞ to ground, V
= V
/ 2, noninverting configuration, T = T
to T
, unless
MAX
CC
EE
L
CC
A
MIN
OUT
otherwise noted. Typical values are at T = +25°C.) (Note 1)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
IN_+
IN_-
V
EE
V
EE
- 0.1
V
- 2.25
+ 0.1
20
CC
Input Voltage Range
V
V
IN
- 0.1
V
CC
Input Offset Voltage
V
OS
R = 50Ω
L
4
8
mV
Input Offset Voltage Drift
TC
µV/°C
VOS
Any channels for
MAX4017/MAX4019/MAX4022
Input Offset Voltage Matching
1
mV
Input Bias Current
Input Resistance
Voltage Gain
I
IN_+ (Note 2)
5.4
3
20
µA
MΩ
V/V
mΩ
B
R
IN_+, over input voltage range
R ≥ 50Ω, (V + 0.5V) ≤ V
IN
A
≤ (V
CC
- 2.0V)
MAX
1.9
2
2.1
V
L
EE
OUT
Output Resistance
R
f = DC
25
120
OUT
T
T
= +25°C
70
60
A
R = 20Ω to V
or
L
CC
Output Current
I
mA
OUT
V
EE
= T
to T
A
MIN
Short-Circuit Output Current
I
Sinking or sourcing
R = 50Ω
150
1.60
0.04
0.75
0.04
0.06
0.06
57
mA
SC
V
V
V
V
V
V
- V
2.00
0.50
1.50
0.50
CC
OH
L
- V
OL
CC
OL
CC
OL
EE
- V
OH
Output Voltage Swing
V
OUT
R =150Ω
L
V
- V
- V
EE
OH
EE
R = 2kΩ
L
- V
V
CC
V
CC
V
CC
V
CC
= 5V, V = 0V, V
= 2V
46
EE
OUT
Power-Supply Rejection Ratio
(Note 3)
PSRR
= 5V, V = -5V, V
= 0V
OUT
54
66
dB
EE
= 3.3V, V = 0V, V
= 0.9V
OUT
45
EE
Operating Supply-Voltage Range
Disabled Output Resistance
EN_ Logic-Low Threshold
EN_ Logic-High Threshold
to V
3.15
11.0
V
kΩ
V
EE
R
MAX4019, EN_ = 0V, 0V ≤ V
MAX4019
≤ 5V
OUT
1
OUT(OFF)
V
V
- 2.6
IL
CC
V
MAX4019
V
- 1.5
V
IH
CC
(V + 0.2V) ≤ EN_ ≤ V
0.5
200
0.5
5.5
0.4
EE
CC
EN_ Logic Input Low Current
EN_ Logic Input High Current
I
MAX4019
µA
µA
IL
EN_ = V
550
10
EE
I
IH
MAX4019, EN_ = V
CC
Enabled (EN_ = V
8.0
0.7
CC)
Quiescent Supply Current
(per Buffer)
I
mA
CC
MAX4019, disabled (EN_ = V
)
EE
2
_______________________________________________________________________________________
Low-Cost, High-Speed, Single-Supply, Gain of +2
Buffers with Rail-to-Rail Outputs in SOT23
AC ELECTRICAL CHARACTERISTICS
(V
= +5V, V
= 0V, IN_- = 0V, EN_ = 5V, R = 100Ω to ground, noninverting configuration, T = T
to T unless
MAX,
CC
EE
L
A
MIN
otherwise noted. Typical values are at T = +25°C.)
A
PARAMETER
SYMBOL
CONDITIONS
= 20mVp-p
MIN
TYP
200
140
MAX
UNITS
MHz
Small-Signal -3dB Bandwidth
Large-Signal -3dB Bandwidth
BW
BW
V
V
SS
LS
OUT
= 2Vp-p
MHz
OUT
Bandwidth for 0.1dB Gain
Flatness
BW
V
OUT
= 20mVp-p (Note 4)
6
30
MHz
0.1dB
Slew Rate
SR
V
OUT
V
OUT
V
OUT
= 2V step
= 2V step
= 100mVp-p
600
45
1
V/µs
ns
Settling Time to 0.1%
Rise/Fall Time
t
S
t , t
R
ns
F
Spurious-Free Dynamic
Range
SFDR
f
= 5MHz, V
= 2Vp-p
-78
dBc
dBc
C
OUT
Second harmonic
-78
-82
Third harmonic
V
= 2Vp-p,
OUT
Harmonic Distortion
HD
IP3
f
C
= 5MHz
Total harmonic
distortion
-75
Third-Order Intercept
Input 1dB Compression Point
Differential Phase Error
Differential Gain Error
Input Noise Voltage Density
Input Noise Current Density
Input Capacitance
f = 10.0MHz
= 10MHz, A
35
11
0.02
0.04
10
1.3
1
dBm
dBm
degrees
%
f
C
= +2V/V
VCL
DP
NTSC, R = 150Ω
L
DG
NTSC, R = 150Ω
L
e
n
f = 10kHz
f = 10kHz
nV/√Hz
pA/√Hz
pF
i
n
C
IN
OUT(OFF)
Disabled Output Capacitance
Output Impedance
C
MAX4019, EN_ = 0V
f = 10MHz
2
pF
Ω
Z
OUT
6
Buffer Enable Time
t
MAX4019
100
1
ns
ON
Buffer Disable Time
t
MAX4019
µs
OFF
MAX4017/MAX4019/MAX4022,
f = 10MHz, V = 20mVp-p
Buffer Gain Matching
Buffer Crosstalk
0.1
-95
dB
dB
OUT
MAX4017/MAX4019/MAX4022,
f = 10MHz, V = 2Vp-p
X
TALK
OU
T
Note 1: The MAX4014EUK is 100% production tested at T = +25°C. Specifications over temperature limits are guaranteed by
A
design.
Note 2: Tested with V
= +2.5V.
OUT
Note 3: PSRR for single +5V supply tested with V = 0V, V
= +4.5V to +5.5V; for dual 5V supply with V = -4.5V to -5.5V,
EE
EE
CC
V
CC
= +4.5V to +5.5V; and for single +3V supply with V = 0V, V
= +3.15V to +3.45V.
EE
CC
Note 4: Guaranteed by design.
_______________________________________________________________________________________
3
Low-Cost, High-Speed, Single-Supply, Gain of +2
Buffers with Rail-to-Rail Outputs in SOT23
__________________________________________Typical Operating Characteristics
(V
= +5V, V = 0V, A
= +2, R = 150Ω to V / 2, T = +25°C, unless otherwise noted.)
CC
A
CC
EE
VCL
L
SMALL-SIGNAL GAIN vs. FREQUENCY
GAIN FLATNESS vs. FREQUENCY
LARGE-SIGNAL GAIN vs. FREQUENCY
8
6.8
8
7
6
5
4
3
6.7
7
6
5
4
3
2
1
6.6
6.5
6.4
6.3
6.2
6.1
6.0
2
1
5.9
0
100k
1M
10M
100M
1G
100k
1M
10M
100M
1G
100k
1M
10M
100M
1G
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
CLOSED-LOOP OUTPUT IMPEDANCE
vs. FREQUENCY
HARMONIC DISTORTION
vs. FREQUENCY
MAX4017/19/22
CROSSTALK vs. FREQUENCY
1000
100
10
0
50
30
V
= 2Vp-p
OUT
-10
-20
-30
-40
-50
-60
-70
-80
-90
10
-10
-30
-50
-70
2ND HARMONIC
-90
1
-110
-130
3RD HARMONIC
10M
0.1
-100
-150
0.1M
1M
10M
100M
100k
1M
100M
100k
1M
10M
100M
1G
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
MAX4019
OFF ISOLATION vs. FREQUENCY
HARMONIC DISTORTION
vs. LOAD
HARMONIC DISTORTION
vs. OUTPUT SWING
0
0
10
0
f = 5MHz
= 2Vp-p
f = 5MHz
-10
-10
V
OUT
-10
-20
-30
-40
-50
-60
-70
-20
-30
-40
-50
-60
-20
-30
-40
-50
-60
-70
-80
-90
-70
-80
-90
2rd HARMONIC
2ND HARMONIC
3RD HARMONIC
-80
-90
3rd HARMONIC
200
-100
-100
100k
1M
10M
100M
0
400
600
800
1000
0.5
1.0
1.5
2.0
FREQUENCY (Hz)
LOAD (Ω)
OUTPUT SWING (Vp-p)
4
_______________________________________________________________________________________
Low-Cost, High-Speed, Single-Supply, Gain of +2
Buffers with Rail-to-Rail Outputs in SOT23
__________________________________________Typical Operating Characteristics
(V
= +5V, V = 0V, A
= +2, R = 150Ω to V
/ 2, T = +25°C, unless otherwise noted.)
A
CC
EE
VCL
L
CC
POWER-SUPPLY REJECTION
vs. FREQUENCY
CURRENT NOISE DENSITY
vs. FREQUENCY
VOLTAGE NOISE DENSITY
vs. FREQUENCY
20
10
100
10
0
-10
-20
-30
-40
-50
-60
-70
10
-80
1
1
100k
1M
10M
100M
1
10 100 1k 10k 100k 1M 10M
FREQUENCY (Hz)
1
10 100 1k 10k 100k 1M 10M
FREQUENCY (Hz)
FREQUENCY (Hz)
OUTPUT SWING
vs. LOAD RESISTANCE
OUTPUT SWING
vs. LOAD RESISTANCE (R )
BANDWIDTH
vs. LOAD RESISTANCE
L
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
400
350
300
250
200
150
100
50
5
4
3
2
0
10
100
1k
10k
100k
1M
25
50
75
100
125
150
0
100
200
300
400
500
600
LOAD RESISTANCE (Ω)
LOAD RESISTANCE (Ω)
LOAD RESISTANCE (Ω)
POWER-SUPPLY CURRENT (PER AMPLIFIER)
vs. TEMPERATURE
INPUT BIAS CURRENT
vs. TEMPERATURE
INPUT OFFSET CURRENT
vs. TEMPERATURE
7
6.0
5.5
5.0
4.5
4.0
0.20
0.16
0.12
0.08
0.04
0
6
5
4
3
-50
-25
0
25
50
75
100
-50
-25
0
25
50
75
100
-50
-25
0
25
50
75
100
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
5
Low-Cost, High-Speed, Single-Supply, Gain of +2
Buffers with Rail-to-Rail Outputs in SOT23
__________________________________________Typical Operating Characteristics
(V
= +5V, V = 0V, A
= +2, R = 150Ω to V / 2, T = +25°C, unless otherwise noted.)
CC
A
CC
EE
VCL
L
POWER-SUPPLY CURRENT (PER AMPLIFIER)
vs. POWER-SUPPLY VOLTAGE
INPUT OFFSET VOLTAGE
vs. TEMPERATURE
VOLTAGE SWING vs. TEMPERATURE
5.0
10
5
R = 150Ω TO V / 2
L
CC
8
4.8
4.6
4.4
4.2
4.0
4
3
2
1
0
6
4
2
0
-50
-25
0
25
50
75
100
3
4
5
6
7
8
9
10 11
-50
-25
0
25
50
75
100
TEMPERATURE (°C)
POWER-SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
SMALL-SIGNAL PULSE RESPONSE
DIFFERENTIAL GAIN AND PHASE
(C = 5pF)
SMALL-SIGNAL PULSE RESPONSE
L
MAX4014-24
0.01
0.00
-0.01
-0.02
IN
IN
-0.03
-0.04
-0.05
0
100
IRE
0.010
0.005
0.000
OUT
OUT
-0.005
-0.010
-0.015
-0.020
-0.025
TIME (20ns/div)
0
100
TIME (20ns/div)
IRE
V
= 1.25V, R = 100Ω to GROUND
CM L
LARGE-SIGNAL PULSE RESPONSE
LARGE-SIGNAL PULSE RESPONSE
ENABLE RESPONSE TIME
(C = 5pF)
L
MAX4014-25
MAX4014-27
MAX4014-26
5.0V
(ENABLE)
IN
EN_
OUT
IN
0V
(DISABLE)
OUT
1V
0V
OUT
TIME (20ns/div)
TIME (1µs/div)
TIME (20ns/div)
V = 0.5V
IN
V
= 0.9V, R = 100Ω to GROUND
V
= 1.75V, R = 100Ω to GROUND
CM
L
CM
L
6
_______________________________________________________________________________________
Low-Cost, High-Speed, Single-Supply, Gain of +2
Buffers with Rail-to-Rail Outputs in SOT23
______________________________________________________________Pin Description
PIN
MAX4014 MAX4017
MAX4019
QSOP
MAX4022
QSOP
NAME
FUNCTION
SOT23-5
SO/µMAX
SO
—
SO
—
No Connect. Not internally connected. Tie to
ground or leave open.
—
1
—
—
4
8, 9
—
8, 9
—
N.C.
OUT
—
—
Amplifier Output
Negative Power Supply or Ground
(in single-supply operation)
2
11
13
11
13
V
EE
3
—
—
8
—
—
4
—
—
4
—
—
4
—
—
4
IN+
IN-
Noninverting Input
4
Inverting Input
5
V
CC
Positive Power Supply
Amplifier A Output
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
1
7
7
1
1
OUTA
INA-
2
6
6
2
2
Amplifier A Inverting Input
Amplifier A Noninverting Input
Amplifier B Output
3
5
5
3
3
INA+
OUTB
INB-
7
8
10
11
12
16
15
14
—
—
—
1
7
7
6
9
6
6
Amplifier B Inverting Input
Amplifier B Noninverting Input
Amplifier C Output
5
10
14
13
12
—
—
—
1
5
5
INB+
OUTC
INC-
—
—
—
—
—
—
—
—
—
8
10
11
12
16
15
14
—
—
—
9
Amplifier C Inverting Input
Amplifier C Noninverting Input
Amplifier D Output
10
14
13
12
—
—
—
INC+
OUTD
IND-
Amplifier D Inverting Input
Amplifier D Noninverting Input
Enable Input for Amplifier A
Enable Input for Amplifier B
Enable Input for Amplifier C
IND+
ENA
3
3
ENB
2
2
ENC
_______________________________________________________________________________________
7
Low-Cost, High-Speed, Single-Supply, Gain of +2
Buffers with Rail-to-Rail Outputs in SOT23
+2V/V, ground the inverting terminal. Use the noninvert-
_______________Detailed Description
ing terminal as the signal input of the buffer (Figure 1a).
The MAX4014/MAX4017/MAX4019/MAX4022 are sin-
Grounding the noninverting terminal and using the
gle-supply, rail-to-rail output, voltage-feedback, closed-
inverting terminal as the signal input configures the
loop buffers that employ current-feedback techniques
buffer for a gain of -1V/V (Figure 1b).
to achieve 600V/µs slew rates and 200MHz band-
Since the inverting input eꢀhibits a 500Ω input imped-
ance, terminate the input with a 56Ω resistor when the
device is configured for an inverting gain in 50Ω appli-
cations (terminate with 88Ω in 75Ω applications).
Terminate the input with a 49.9Ω resistor in the nonin-
verting case. Output terminating resistors should direct-
ly match cable impedances in either configuration.
widths. These buffers use internal 500Ω resistors to
provide a preset closed-loop gain of +2V/V in the non-
inverting configuration or -1V/V in the inverting configu-
ration. Eꢀcellent harmonic distortion and differential
gain/phase performance make these buffers an ideal
choice for a wide variety of video and RF signal-pro-
cessing applications.
Local feedback around the buffer’ s output stage
ensures low output impedance, which reduces gain
sensitivity to load variations. This feedback also pro-
duces demand-driven current bias to the output tran-
sistors for 120mA drive capability, while constraining
total supply current to less than 7mA.
Layout Techniques
Maꢀim recommends using microstrip and stripline tech-
niques to obtain full bandwidth. To ensure that the PC
board does not degrade the buffer’s performance, design
it for a frequency greater than 1GHz. Pay careful attention
to inputs and outputs to avoid large parasitic capaci-
tance. Whether or not you use a constant-impedance
board, observe the following guidelines when designing
the board:
__________Applications Information
Power Supplies
These devices operate from a single +3.15V to +11V
power supply or from dual supplies of 1.575V to
• Don’t use wire-wrapped boards. They are too inductive.
• Don’t use IC sockets. They increase parasitic capac-
itance and inductance.
5.5V. For single-supply operation, bypass the V
pin
CC
to ground with a 0.1µF capacitor as close to the pin as
possible. If operating with dual supplies, bypass each
supply with a 0.1µF capacitor.
• Use surface-mount instead of through-hole compon-
ents for better high-frequency performance.
• Use a PC board with at least two layers; it should be
as free from voids as possible.
Selecting Gain Configuration
Each buffer in the MAX4014 family can be configured
for a voltage gain of +2V/V or -1V/V. For a gain of
• Keep signal lines as short and as straight as possi-
ble. Do not make 90° turns; round all corners.
IN+
IN+
IN
*R
*R
OUT
OUT
R
OUT
TIN
R
OUT
*R
S
*R
500Ω
IN-
IN
500Ω
500Ω
MAX40_ _
500Ω
IN-
R
TIN
MAX40_ _
*R = 2R
L
*R = 2R
L
Figure 1a. Noninverting Gain Configuration (A = +2V/V)
Figure 1b. Inverting Gain Configuration (A = -1V/V)
V
V
8
_______________________________________________________________________________________
Low-Cost, High-Speed, Single-Supply, Gain of +2
Buffers with Rail-to-Rail Outputs in SOT23
0
-1
20
0
-2
-20
-40
-3
-4
-60
-80
-5
-6
-100
-120
-140
-160
-7
-8
-9
-10
0
100
200
300
400
500
0
100
200
300
400
500
V
IL
(mV ABOVE V
)
EE
V
IL
(mV ABOVE V
)
EE
Figure 2. Enable Logic-Low Input Current vs. Enable Logic-
Low Threshold
Figure 4. Enable Logic-Low Input Current vs. Enable Logic-
Low Threshold with 10kΩ Series Resistor
the output-drive capability, since the buffers have a
fiꢀed voltage gain of +2 or -1.
ENABLE
10k
For eꢀample, a 50Ω load can typically be driven from
40mV above V to 1.6V below V , or 40mV to 3.4V
EE
CC
when operating from a single +5V supply. If the buffer is
operated in the noninverting, gain of +2 configuration
with the inverting input grounded, the effective input
voltage range becomes 20mV to 1.7V, instead of the
-100mV to 2.75V indicated by the Electrical Character-
istics. Beyond the effective input range, the buffer out-
put is a nonlinear function of the input, but it will not
undergo phase reversal or latchup.
IN+
IN-
EN_
MAX40_ _
OUT
500Ω
500Ω
Enable
The MAX4019 has an enable feature (EN_) that allows
the buffer to be placed in a low-power state. When the
buffers are disabled, the supply current will not eꢀceed
550µA per buffer.
Figure 3. Circuit to Reduce Enable Logic-Low Input Current
Input Voltage Range and Output Swing
The input range for the MAX4014 family eꢀtends from
(V - 100mV) to (V
EE
- 2.25V). Input ground sensing
CC
As the voltage at the EN_ pin approaches the negative
supply rail, the EN_ input current rises. Figure 2 shows
a graph of EN_ input current versus EN_ pin voltage.
Figure 3 shows the addition of an optional resistor in
series with the EN pin, to limit the magnitude of the cur-
rent increase. Figure 4 displays the resulting EN pin
input current to voltage relationship.
increases the dynamic range for single-supply applica-
tions. The outputs drive a 2kΩ load to within 60mV of
the power-suply rails. With heavier loads, the output
swing is reduced as shown in the Electrical Character-
istics and the Typical Operating Characteristics. As the
load increases, the input range is effectively limited by
_______________________________________________________________________________________
9
Low-Cost, High-Speed, Single-Supply, Gain of +2
Buffers with Rail-to-Rail Outputs in SOT23
MAX4014
MAX4017
MAX4019
MAX4022
500Ω
500Ω
IN+
R
ISO
OUT
V
OUT
MAX40_ _
V
C
IN
L
R
TIN
50Ω
IN-
500Ω
500Ω
Figure 5. Input Protection Circuit
Figure 7. Driving a Capacitive Load through an Isolation Resistor
conditions, the input protection diodes will be forward
biased, lowering the disabled output resistance to 500Ω.
6
5
4
3
Output Capacitive Loading and Stability
The MAX4014/MAX4017/MAX4019/MAX4022 provide
maꢀimum AC performance with no load capacitance.
This is the case when the load is a properly terminated
transmission line. However, they are designed to drive
up 25pF of load capacitance without oscillating, but
with reduced AC performance.
C = 15pF
L
C = 10pF
L
2
1
0
Driving large capacitive loads increases the chance of
oscillations occurring in most amplifier circuits. This is
especially true for circuits with high loop gains, such as
voltage followers. The buffer’s output resistance and
the load capacitor combine to add a pole and eꢀcess
phase to the loop response. If the frequency of this
pole is low enough to interfere with the loop response
and degrade phase margin sufficiently, oscillations can
occur.
C = 5pF
-1
-2
-3
-4
L
100k
1M
10M
100M
1G
FREQUENCY (Hz)
Figure 6. Small-Signal Gain vs. Frequency with Load
Capacitance and No Isolation Resistor
A second problem when driving capacitive loads
results from the amplifier’s output impedance, which
looks inductive at high frequencies. This inductance
forms an L-C resonant circuit with the capacitive load,
which causes peaking in the frequency response and
degrades the amplifier’s gain margin.
Disabled Output Resistance
The MAX4014/MAX4017/MAX4019/MAX4022 include
internal protection circuitry that prevents damage to the
precision input stage from large differential input volt-
ages, as shown in Figure 5. This protection circuitry con-
sists of five back-to-back Schottky diodes between IN_+
and IN_-. These diodes lower the disabled output resis-
tance from 1kΩ to 500Ω when the output voltage is 3V
greater or less than the voltage at IN_+. Under these
Figure 6 shows the frequency response of the MAX4014/
MAX4017/MAX4019/MAX4022 under different capacitive
loads. To drive loads with greater than 25pF of capaci-
tance or to settle out some of the peaking, the output
requires an isolation resistor like the one shown in
10 ______________________________________________________________________________________
Low-Cost, High-Speed, Single-Supply, Gain of +2
Buffers with Rail-to-Rail Outputs in SOT23
30
25
20
15
10
5
3
2
R
= 27Ω
ISO
C = 47pF
L
1
0
C = 68pF
L
-1
-2
-3
-4
-5
-6
-7
C = 120pF
L
0
100k
1M
10M
100M
1G
0
50
100
150
200
250
FREQUENCY (Hz)
CAPACITIVE LOAD (pF)
Figure 8. Capacitive Load vs. Isolation Resistance
Figure 9. Small-Signal Gain vs. Frequency with Load
Capacitance and 27Ω Isolation Resistor
Figure 7. Figure 8 is a graph of the optimal isolation resis-
tor versus load capacitance. Figure 9 shows the frequen-
cy response of the MAX4014/MAX4017/MAX4019/
MAX4022 when driving capacitive loads with a 27Ω isola-
tion resistor.
Coaꢀial cables and other transmission lines are easily dri-
ven when properly terminated at both ends with their
characteristic impedance. Driving back-terminated trans-
mission lines essentially eliminates the lines’ capacitance.
______________________________________________________________________________________ 11
Low-Cost, High-Speed, Single-Supply, Gain of +2
Buffers with Rail-to-Rail Outputs in SOT23
__________________________________________________________Pin Configurations
TOP VIEW
ENA
ENC
ENB
1
2
3
4
5
6
7
14 OUTC
13 INC-
12 INC+
OUT
1
2
3
5
4
V
CC
OUTA
INA-
1
2
3
4
8
7
6
5
V
CC
OUTB
INB-
MAX4014
MAX4017
MAX4019
V
EE
INA+
V
11
V
EE
CC
V
INB+
INA+
INA-
10 INB+
EE
IN+
IN-
9
8
INB-
SO/µMAX
SOT23-5
OUTA
OUTB
SO
OUTA
INA-
1
2
3
4
5
6
7
14 OUTD
13 IND-
12 IND+
ENA
1
2
3
4
5
6
7
8
16 OUTC
15 INC-
14 INC+
OUTA
INA-
1
2
3
4
5
6
7
8
16 OUTD
15 IND-
14 IND+
ENC
ENB
INA+
INA+
MAX4019
MAX4022
MAX4022
V
11
V
EE
V
13 V
EE
CC
V
CC
13 V
EE
CC
INB+
INB-
10 INC+
INA+
INA-
12 INB+
11 INB-
10 OUTB
INB+
INB-
12 INC+
11 INC-
10 OUTC
9
8
INC-
OUTB
OUTC
OUTA
N.C.
OUTB
N.C.
9
N.C.
9
N.C.
SO
QSOP
QSOP
___________________Chip Information
NO. OF
PART NUMBER
TRANSISTORS
MAX4014
MAX4017
MAX4019
MAX4022
95
190
299
362
SUBSTRATE CONNECTED TO V
EE
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
© 2001 Maꢀim Integrated Products
Printed USA
is a registered trademark of Maꢀim Integrated Products.
相关型号：
MAX4020EEE+
Video Amplifier, 1 Channel(s), 4 Func, PDSO16, 0.150 INCH, 0.025 INCH PITCH, MO-137AB, QSOP-16
MAXIM
MAX4020EEE+T
Video Amplifier, 1 Channel(s), 4 Func, PDSO16, 0.150 INCH, 0.025 INCH PITCH, MO-137AB, QSOP-16
MAXIM
©2020 ICPDF网 联系我们和版权申明