Maxim MAX4217ESA High-speed, single-supply, gain of @, closed-loop, rail-to-rail buffers with enable Datasheet

19-4754; Rev 0; 12/97
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
____________________________Features
The MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
are precision, closed-loop, gain of +2 (or -1) buffers
featuring high slew rates, high output current drive, and
low differential gain and phase error. They operate with
a single +3.15V to +11V supply or with ±1.575V to ±5.5V
dual supplies. The input common-mode voltage range
extends 100mV beyond the negative power-supply rail,
and the output swings Rail-to-Rail®.
These devices require only 5.5mA of quiescent supply
current while achieving a 230MHz -3dB bandwidth and
a 600V/µs slew rate. In addition, the MAX4215/
MAX4219 have a disable feature that reduces the supply current to 400µA per buffer. Input voltage noise is
only 10nV/√Hz, and input current noise is only
1.3pA/√Hz. This buffer family is ideal for low-power/lowvoltage applications requiring wide bandwidth, such as
video, communications, and instrumentation systems.
For space-sensitive applications, the MAX4214 comes
in a miniature 5-pin SOT23 package.
♦ Internal Precision Resistors for Closed-Loop
Gains of +2V/V or -1V/V
_______________Ordering Information
♦ Space-Saving SOT23-5, µMAX, or QSOP Packages
TEMP. RANGE
PINPACKAGE
SOT
TOP MARK
MAX4214EUK-T -40°C to +85°C
5 SOT23-5
ABAH
MAX4215ESA
MAX4215EUA
MAX4217ESA
MAX4217EUA
MAX4219ESD
MAX4219EEE
MAX4222ESD
MAX4222EEE
8 SO
8 µMAX
8 SO
8 µMAX
14 SO
16 QSOP
14 SO
16 QSOP
PART
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
—
—
—
—
—
—
—
—
________________________Applications
Battery-Powered Instruments
Video Line Driver
Analog-to-Digital Converter Interface
CCD Imaging Systems
Video Routing and Switching Systems
Video Multiplexing Applications
♦ High Speed:
230MHz -3dB Bandwidth
90MHz 0.1dB Gain Flatness (MAX4219/22)
600V/µs Slew Rate
♦ Single 3.3V/5.0V Operation
♦ Outputs Swing Rail-to-Rail
♦ Input Common-Mode Range Extends Beyond VEE
♦ Low Differential Gain/Phase Error: 0.03%/0.04°
♦ Low Distortion at 5MHz:
-72dBc SFDR
-71dB Total Harmonic Distortion
♦ High Output Drive: ±120mA
♦ Low 5.5mA Supply Current
♦ 400µA Shutdown Supply Current (MAX4215/19)
______________________Selector Guide
PART
NO. OF
AMPS
MAX4214
1
No
5 SOT23
MAX4215
1
Yes
8 SO/µMAX
MAX4217
2
No
8 SO/µMAX
MAX4219
3
Yes
14 SO, 16 QSOP
MAX4222
4
No
14 SO, 16 QSOP
ENABLE
__________________Pin Configurations
TOP VIEW
OUT 1
VEE 2
Rail-to-Rail is a registered trademark of Nippon Motorola, Inc.
5
VCC
4
IN-
MAX4214
IN+ 3
Typical Application Circuit appears at end of data sheet.
PIN-PACKAGE
SOT23-5
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 408-737-7600 ext. 3468.
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
_________________General Description
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (VCC to VEE) ..................................................12V
IN_-, IN_+, OUT_, EN_ ....................(VEE - 0.3V) to (VCC + 0.3V)
Output Short-Circuit Duration to VCC or VEE ..............Continuous
Continuous Power Dissipation (TA = +70°C)
5-pin SOT23 (derate 7.1mW/°C above +70°C).............571mW
8-pin SO (derate 5.9mW/°C above +70°C)...................471mW
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
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
DC ELECTRICAL CHARACTERISTICS
(VCC = +5V, VEE = 0V, IN_- = 0V, EN_ = 5V, RL = ∞ to 0V, VOUT = VCC/2, noninverting configuration, TA = TMIN to TMAX, unless
otherwise noted. Typical values are at TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
Operating Supply Voltage
Range
VCC to VEE, guaranteed by PSRR tests
Input Voltage Range
VIN
Input Offset Voltage
VOS
Input Offset Voltage Drift
MIN
VCC - 2.25
VCC + 0.1
RL = 50Ω
SO, QSOP
4
10
SOT23-5, µMAX
4
15
IN_+
1
mV
5.4
RL ≥ 50Ω, (VEE + 0.5V) ≤ VOUT ≤ (VCC - 2.0V)
1.9
2
VCC = 5V, VEE = 0V, VOUT = 2.0V
55
58
VCC = 5V, VEE = -5V, VOUT = 0V
60
66
2.1
V/V
dB
ROUT
f = DC
25
mΩ
IOUT
RL = 20Ω to VCC or VEE
±120
mA
±150
mA
ISC
VOUT
±100
Sinking or sourcing
RL = 150Ω
VCC - VOH
1.60
1.90
VOL - VEE
0.04
0.075
VCC - VOH
0.75
1.00
VOL - VEE
0.04
0.075
VCC - VOH
0.06
VOL - VEE
0.06
ROUT(OFF) MAX4215/MAX4219, EN_ = 0V, 0V ≤ VOUT ≤ 5V
EN_ Logic Low Threshold
VIL
MAX4215/MAX4219
EN_ Logic High Threshold
VIH
MAX4215/MAX4219
2
µA
MΩ
45
RL = 2kΩ
Disabled Output
Resistance
12
3
VCC = 3.3V, VEE = 0V, VOUT = 0.90V
RL = 50Ω
Output Voltage Swing
mV
µV/°C
AV
Short-Circuit Output
Current
V
8
Voltage Gain
Output Current
V
VEE - 0.1
IN_+, over input voltage range
Output Resistance
11.0
VEE - 0.1
RIN
PSRR
UNITS
IN_-
Input Resistance
Power-Supply
Rejection Ratio
(Note 2)
MAX
IN_+
Between any two channels for
MAX4217/MAX4219/MAX4222
IB
TYP
3.15
TCVOS
Input Offset Voltage
Matching
Input Bias Current
CONDITIONS
1
V
kΩ
VCC - 2.6
VCC - 1.6
_______________________________________________________________________________________
V
V
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
(VCC = +5V, VEE = 0V, IN_- = 0V, EN_ = 5V, RL = ∞ to 0V, VOUT = VCC/2, noninverting configuration, TA = TMIN to TMAX, unless
otherwise noted. Typical values are at TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
EN_ Logic Input Low
Current
IIL
EN_ Logic Input High
Current
IIH
Quiescent Supply
Current (per Buffer)
ICC
Shutdown Supply Current
ISD
CONDITIONS
MIN
TYP
MAX
UNITS
MAX4215/MAX4219, (VEE + 0.2V) ≤ EN_ ≤ VCC
0.5
MAX4215/MAX4219, EN_ = VEE
200
350
MAX4215/MAX4219, EN_ = VCC
0.5
10
µA
5.5
7.0
mA
400
550
µA
MAX4215/MAX4219, disabled (EN_ = VEE)
µA
Note 1: The MAX421_EU_ is 100% production tested at TA = +25°C. Specifications over temperature limits are guaranteed by design.
Note 2: PSR for single +5V supply tested with VEE = 0V, VCC = +4.5V to +5.5V; for dual ±5V supply with VEE = -4.5V to -5.5V,
VCC = +4.5V to +5.5V; and for single +3V supply with VEE = 0V, VCC = +3.15V to +3.45V.
AC ELECTRICAL CHARACTERISTICS
(VCC = +5V, VEE = 0V, IN_- = 0V, EN_ = 5V, RL = 100Ω to VCC/2, noninverting configuration, TA = TMIN to TMAX, unless otherwise
noted. Typical values are at TA = +25°C.)
PARAMETER
Small-Signal -3dB
Bandwidth
SYMBOL
BW-3dB
Full-Power -3dB
Bandwidth
FPBW
Bandwidth for 0.1dB Gain
Flatness
Slew Rate
Settling Time to 0.1%
BW0.1dB
CONDITIONS
MIN
TYP
VOUT =
100mVp-p
MAX4214/MAX4215/MAX4217
230
MAX4219/MAX4222
200
VOUT =
2Vp-p
MAX4214/MAX4215/MAX4217
220
MAX4219/MAX4222
200
VOUT =
100mVp-p
MAX4214/MAX4215/MAX4217
50
MAX4219/MAX4222
90
MAX
UNITS
MHz
MHz
MHz
SR
VOUT = 2V step
600
V/µs
tS
VOUT = 2V step
45
ns
Rise/Fall Time
tR, tF
VOUT = 100mVp-p
1
ns
Spurious-Free Dynamic
Range
SFDR
fC = 5MHz, VOUT = 2Vp-p
-72
dBc
Harmonic Distortion
Third-Order Intercept
HD
IP3
Input 1dB Compression
Point
VOUT = 2Vp-p,
fC = 5MHz
Second harmonic
-72
Third harmonic
-77
Total harmonic distortion
-71
dBc
f = 10MHz
35
dBm
f = 10MHz
11
dBm
Differential Phase Error
DP
NTSC, RL = 150Ω
0.04
degrees
Differential Gain Error
DG
NTSC, RL = 150Ω
0.03
%
Input Noise-Voltage
Density
en
f = 10kHz
10
nV/√Hz
Input Noise-Current
Density
in
f = 10kHz
1.3
pA/√Hz
Input Capacitance
CIN
1
pF
2
pF
Disabled Output
Capacitance
COUT(OFF) MAX4215/MAX4219, EN_ = 0V
_______________________________________________________________________________________
3
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
DC ELECTRICAL CHARACTERISTICS (continued)
AC ELECTRICAL CHARACTERISTICS (continued)
(VCC = +5V, VEE = 0V, IN_- = 0V, EN_ = 5V, RL = 100Ω to VCC/2, noninverting configuration, TA = TMIN to TMAX, unless otherwise
noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
Output Impedance
CONDITIONS
ZOUT
MIN
TYP
MAX
UNITS
f = 10MHz
200
mΩ
Buffer Enable Time
tON
MAX4215/MAX4219
100
ns
Buffer Disable Time
tOFF
MAX4215/MAX4219
1
µs
MAX4217/MAX4219/MAX4222, f = 10MHz,
VOUT = 100mVp-p
0.1
dB
MAX4217/MAX4219/MAX4222, f = 10MHz,
VOUT = 2Vp-p
-95
dB
Buffer Gain Matching
All-Hostile Crosstalk
XTALK
Note 2: PSR for single +5V supply tested with VEE = 0V, VCC = +4.5V to +5.5V; for dual ±5V supply with VEE = -4.5V to -5.5V,
VCC = +4.5V to +5.5V; and for single +3V supply with VEE = 0V, VCC = +3.15V to +3.45V.
__________________________________________Typical Operating Characteristics
(VCC = +5V, VEE = 0V, AVCL = +2V/V, RL = 100Ω to VCC/2, TA = +25°C, unless otherwise noted.)
MAX4214/MAX4215/MAX4217
GAIN FLATNESS vs. FREQUENCY
VOUT = 100mVp-p
VOUT = 100mVp-p
10
9
6.2
7
6
6.1
6
5
GAIN (dB)
8
7
GAIN (dB)
8
6.3
6.0
5.9
3
5.8
3
2
5.7
2
1
5.6
1
0
5.5
1M
10M
FREQUENCY (Hz)
100M
1G
100k
1M
10M
FREQUENCY (Hz)
100M
1G
VOUT = 2Vp-p
5
4
100k
4
6.4
MAX4214-B
9
6.5
MAX4214-A
10
MAX4214/MAX4215/MAX4217
LARGE-SIGNAL GAIN vs. FREQUENCY
MAX4214-C
MAX4214/MAX4215/MAX4217
SMALL-SIGNAL GAIN vs. FREQUENCY
GAIN (dB)
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
4
0
100k
1M
10M
FREQUENCY (Hz)
_______________________________________________________________________________________
100M
1G
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
MAX4219/MAX4222
GAIN FLATNESS vs. FREQUENCY
8
6.2
7
6
6.1
6
GAIN (dB)
6.3
7
5
6.0
5.9
3
5.8
3
2
5.7
2
1
5.6
1
0
5.5
100M
1M
1G
100k
-40
-50
-60
2ND HARMONIC
3RD HARMONIC
-20
-30
-40
-50
-60
2ND HARMONIC
-70
-80
3RD HARMONIC
-90
-90
10M
0 100 200 300 400 500 600 700 800 900
MAX4214 i
-20
-30
-40
-50
-60
2ND HARMONIC
-70
-80
3RD HARMONIC
-100
1k
0.5
RESISTIVE LOAD (Ω)
FREQUENCY (Hz)
VOLTAGE-NOISE DENSITY
vs. FREQUENCY
1.0
1.5
2.0
2.5
3.0
3.5
VOLTAGE SWING (Vp-p)
MAX4217/MAX4219/MAX4222
CROSSTALK vs. FREQUENCY
CURRENT-NOISE DENSITY
vs. FREQUENCY
MAX4214-12
f = 5MHz
-90
100M
100
1G
0
-10
-100
-100
100M
50
10
MAX4214-04
-30
1M
10M
HARMONIC DISTORTION
vs. VOLTAGE SWING
VOUT = 2Vp-p
f = 5MHz
-10
HARMONIC DISTORTION (dBc)
-20
100k
1M
FREQUENCY (Hz)
0
MAX4214-G
VOUT = 2Vp-p
-80
100M
HARMONIC DISTORTION
vs. RESISTIVE LOAD
0
-70
10M
FREQUENCY (Hz)
HARMONIC DISTORTION
vs. FREQUENCY
-10
4
0
100k
1G
HARMONIC DISTORTION (dBc)
10M
MAX4214-H
1M
FREQUENCY (Hz)
HARMONIC DISTORTION (dBc)
5
4
100k
VOUT = 2Vp-p
RL = 100Ω
9
8
GAIN (dB)
GAIN (dB)
VOUT = 100mVp-p
6.4
10
MAX4214-E
VOUT = 100mVp-p
9
6.5
MAX4214-D
10
MAX4219/MAX4222
LARGE-SIGNAL GAIN vs. FREQUENCY
MAX4214-F
MAX4219/MAX4222
SMALL-SIGNAL GAIN vs. FREQUENCY
30
CROSSTALK (dB)
NOISE (pA/ √Hz)
NOISE (nV/√Hz)
10
10
-10
-30
-50
-70
-90
-110
-130
1
1
10
100
1k
10k 100k
FREQUENCY (Hz)
1M
10M
-150
1
1
10
100
1k
10k 100k
FREQUENCY (Hz)
1M
10M
100k
1M
10M
100M
1G
FREQUENCY (Hz)
_______________________________________________________________________________________
5
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
_____________________________Typical Operating Characteristics (continued)
(VCC = +5V, VEE = 0V, AVCL = +2V/V, RL = 100Ω to VCC/2, TA = +25°C, unless otherwise noted.)
_____________________________Typical Operating Characteristics (continued)
(VCC = +5V, VEE = 0V, AVCL = +2V/V, RL = 100Ω to VCC/2, TA = +25°C, unless otherwise noted.)
POWER-SUPPLY REJECTION
vs. FREQUENCY
MAX4215/MAX4219
OFF ISOLATION vs. FREQUENCY
-10
-30
-40
-50
-60
10
-20
IMPEDANCE (Ω)
OFF ISOLATION (dB)
-20
-30
-40
-50
1
-60
0.1
-70
-80
-90
1M
10M
100M
0.01
100k
1M
FREQUENCY (Hz)
-0.01
100
0
IRE
0.02
0.00
-0.02
-0.06
250
200
150
100
50
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.0
100
200
300
400
LOAD RESISTANCE (Ω)
500
25
LARGE-SIGNAL PULSE RESPONSE
50
75 100 125 150 175 200 225 250
LOAD RESISTANCE (Ω)
ENABLE RESPONSE TIME
MAX4214-T
MAX4214-S
MAX4214-U
5.0V
(ENABLE)
IN
IN
EN_
500mV/div
0V
(DISABLE)
OUT
OUT
1G
1.5
0
SMALL-SIGNAL PULSE RESPONSE
100M
OUTPUT SWING
vs. LOAD RESISTANCE
300
IRE
10M
CLOSED-LOOP BANDWIDTH
vs. LOAD RESISTANCE
VOUT = 100mVp-p
100
1M
FREQUENCY (Hz)
0
0
100k
FREQUENCY (Hz)
350
RL = 150Ω
VCM = 1.35V
-0.04
100M
OUTPUT SWING (Vp-p)
RL = 150Ω
VCM = 1.35V
CLOSED-LOOP BANDWIDTH (MHz)
0.04
0.03
0.02
0.01
0.00
MAX4214-P
DIFFERENTIAL GAIN AND PHASE
10M
MAX4214-24-Q
100k
MAX4214-R
-70
-80
DIFF. GAIN (%)
100
MAX4214-O
0
0
-10
DIFF. PHASE (deg)
CLOSED-LOOP OUTPUT IMPEDANCE
vs. FREQUENCY
MAX4214-N
10
POWER-SUPPLY REJECTION (dB)
10
MAX4214-M
20
25mV/div
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
1V
OUT
0V
20ns/div
VCM = 1.25V, RL = 100Ω to GROUND
6
20ns/div
VCM = 0.9V, RL = 100Ω to GROUND
1µs/div
VIN = 0.5V
_______________________________________________________________________________________
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
LARGE-SIGNAL PULSE RESPONSE
(CL = 5pF)
MAX4214-V
VOLTAGE SWING vs. TEMPERATURE
MAX4214-W
5.0
MAX4214-X
SMALL-SIGNAL PULSE RESPONSE
(CL = 5pF)
RL = 150Ω to 0V
IN
VOLTAGE SWING (Vp-p)
4.8
25mV/div
500mV/div
IN
OUT
OUT
4.6
4.4
4.2
4.0
20ns/div
20ns/div
VCM = 1.25V, RL = 100Ω to 0V
INPUT BIAS CURRENT
vs. TEMPERATURE
3
2
1
0
MAX4214-Z
5.5
5.0
4.5
75
100
-50
-25
0
25
50
TEMPERATURE (°C)
75
POWER-SUPPLY CURRENT (PER AMPLIFIER)
vs. POWER-SUPPLY VOLTAGE
0.12
0.08
0.04
6
4
2
0
-50
-25
0
25
50
TEMPERATURE (°C)
7
POWER-SUPPLY CURRENT (mA)
8
100
75
100
POWER-SUPPLY CURRENT (PER AMPLIFIER)
vs. TEMPERATURE
MAX4214-BB
10
POWER-SUPPLY CURRENT (mA)
0.16
MAX4214-CC
0
25
50
TEMPERATURE (°C)
100
0
4.0
-25
75
0.20
INPUT OFFSET CURRENT (µA)
INPUT BIAS CURRENT (µA)
4
0
25
50
TEMPERATURE (°C)
INPUT OFFSET CURRENT
vs. TEMPERATURE
6.0
MAX4214-Y
5
-50
-25
MAX4214-AA
INPUT OFFSET VOLTAGE
vs. TEMPERATURE
INPUT OFFSET VOLTAGE (mV)
-50
VCM = 1.75V, RL = 100Ω to 0V
6
5
4
3
3
4
5
6
7
8
9
10
POWER-SUPPLY VOLTAGE (V)
11
-50
-25
0
25
50
TEMPERATURE (°C)
75
100
_______________________________________________________________________________________
7
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
_____________________________Typical Operating Characteristics (continued)
(VCC = +5V, VEE = 0V, AVCL = +2V/V, RL = 100Ω to VCC/2, TA = +25°C, unless otherwise noted.)
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
_______________________________________________________________Pin Description
PIN
8
NAME
FUNCTION
8, 9
N.C.
No Connect. Not internally connected.
Tie to ground or leave open.
—
—
OUT
Amplifier Output
13
11
13
VEE
Negative Power Supply or Ground (in
single-supply operation)
—
—
—
—
IN+
Noninverting Input
—
—
—
—
—
IN-
Inverting Input
8
4
4
4
4
VCC
Positive Power Supply
8
—
—
—
—
—
EN
Enable Amplifier
—
—
1
1
—
—
ENA
Enable Amplifier A
—
—
3
3
—
—
ENB
Enable Amplifier B
—
—
—
2
2
—
—
ENC
Enable Amplifier C
—
—
1
7
7
1
1
OUTA
Amplifier A Output
—
—
2
6
6
2
2
INA-
Amplifier A Inverting Input
—
—
3
5
5
3
3
INA+
Amplifier A Noninverting Input
—
—
7
8
10
7
7
OUTB
Amplifier B Output
—
—
6
9
11
6
6
INB-
Amplifier B Inverting Input
—
—
5
10
12
5
5
INB+
Amplifier B Noninverting Input
—
—
—
14
16
8
10
OUTC
Amplifier C Output
—
—
—
13
15
9
11
INC-
Amplifier C Inverting Input
—
—
—
12
14
10
12
INC+
Amplifier C Noninverting Input
—
—
—
—
—
14
16
OUTD
Amplifier D Output
—
—
—
—
—
13
15
IND-
Amplifier D Inverting Input
—
—
—
—
—
12
14
IND+
Amplifier D Noninverting Input
MAX4214
MAX4215
MAX4217
SOT23-5
SO/µMAX
SO/µMAX
SO
MAX4219
QSOP
SO
MAX4222
QSOP
—
1, 5
—
—
8, 9
—
1
6
—
—
—
2
4
4
11
3
3
—
4
2
5
7
—
—
—
_______________________________________________________________________________________
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
The MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
are single-supply, rail-to-rail output, voltage-feedback,
closed-loop buffers that employ current-feedback techniques to achieve 600V/µs slew rates and 230MHz
bandwidths. These buffers use internal 500Ω resistors
to provide a preset closed-loop gain of +2V/V in the
noninverting configuration or -1V/V in the inverting configuration. Excellent harmonic distortion and differential
gain/phase performance make them an ideal choice for
a wide variety of video and RF signal-processing applications.
Local feedback around the buffer’s output stage
ensures low output impedance, which reduces gain
sensitivity to load variations. This feedback also produces demand-driven current bias to the output transistors for ±120mA drive capability, while constraining
total supply current to less than 7mA.
Since the inverting input exhibits a 500Ω input impedance, terminate the input with a 56Ω resistor when configured for an inverting gain in 50Ω applications
(terminate with 88Ω in 75Ω applications). Terminate the
input with a 49.9Ω resistor in the noninverting case.
Output terminating resistors should directly match
cable impedances in either configuration.
Layout Techniques
Maxim recommends using microstrip and stripline techniques to obtain full bandwidth. To ensure 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 capacitance. Whether or not you use a constantimpedance board, observe the following guidelines
when designing the board:
• Don’t use wire-wrapped boards. They are too inductive.
___________Applications Information
• Don’t use IC sockets. They increase parasitic capacitance and inductance.
Power Supplies
• Use surface-mount instead of through-hole components for better high-frequency performance.
These devices operate from a single +3.15V to +11V
power supply or from dual supplies of ±1.575V to
±5.5V. For single-supply operation, bypass the VCC pin
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 a PC board with at least two layers; it should be
as free from voids as possible.
• Keep signal lines as short and as straight as possible. Do not make 90° turns; round all corners.
Selecting Gain Configuration
Input Voltage Range and Output Swing
Each buffer in the MAX4214 family can be configured
for a voltage gain of +2V/V or -1V/V. For a gain of
+2V/V, ground the inverting terminal. Use the noninverting terminal as the signal input of the buffer (Figure 1a).
Grounding the noninverting terminal and using the
inverting terminal as the signal input configures the
buffer for a gain of -1V/V (Figure 1b).
The MAX4214 family’s input range extends from
(VEE - 100mV) to (VCC - 2.25V). Input ground sensing
increases the dynamic range for single-supply applications. The outputs drive a 2kΩ load to within 60mV of
the power-supply rails. With smaller resistive loads, the
output swing is reduced as shown in the Electrical
Characteristics and Typical Operating Characteristics.
IN+
IN
IN+
OUT
RTIN
RTO
OUT
OUT
RS
RTO
RO
OUT
RO
500Ω
500Ω
500Ω
IN
IN-
500Ω
IN-
RTIN
MAX42_ _
Figure 1a. Noninverting Gain Configuration (AV = +2V/V)
MAX42_ _
Figure 1b. Inverting Gain Configuration (AV = -1V/V)
_______________________________________________________________________________________
9
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
________________ Detailed Description
As the load resistance decreases, the useful input range
is effectively limited by the output drive capability, since
the buffers have a fixed voltage gain of +2V/V or -1V/V.
For example, a 50Ω load can typically be driven from
40mV above VEE to 1.6V below VCC, or 40mV to 3.4V
when operating from a single +5V supply. If the buffer
is operated in the noninverting, gain of +2V/V configuration with the inverting input grounded, the useful input
voltage range becomes 20mV to 1.7V instead of the
-100mV to 2.75V indicated by the Electrical Charac
teristics. Beyond the useful input range, the buffer output is a nonlinear function of the input, but it will not
undergo phase reversal or latchup.
Enable
sists of five back-to-back Schottky diodes between
IN_+ and IN_-. These diodes reduce the disabled output resistance from 1kΩ to 500Ω when the output voltage is 3V greater or less than the voltage at IN_+.
Under these conditions, the input protection diodes will
be forward biased, lowering the disabled output resistance to 500Ω.
Output Capacitive Loading and Stability
The MAX4214 family provides maximum AC performance with no load capacitance. This is the case when
the load is a properly terminated transmission line.
These devices are designed to drive up to 20pF of load
capacitance without oscillating, but AC performance
will be reduced under these conditions.
The MAX4215 and MAX4219 have an enable feature
(EN_) that allows the buffer to be placed in a low-power
state. When the buffers are disabled, the supply current
is reduced to 400µA per buffer.
ENABLE
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 current increase. Figure 4 displays the resulting EN pin
input current to voltage relationship.
10k
EN_
IN+
OUT
MAX42_ _
Disabled Output Resistance
The MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
include internal protection circuitry that prevents damage to the precision input stage from large differential
input voltages (Figure 5). This protection circuitry con-
IN500Ω
0
-1
-20
-2
INPUT CURRENT (µA)
0
-40
-60
-80
-100
-3
-4
-5
-6
-7
-120
-8
-140
-9
-10
-160
0
100
200
300
400
500
VIL (mV ABOVE VEE)
Figure 2. Enable Logic-Low Input Current vs. Enable LogicLow Threshold
10
500Ω
Figure 3. Circuit to Reduce Enable Logic-Low Input Current
20
INPUT CURRENT (µA)
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
0
100
200
300
400
500
VIL (mV ABOVE VEE)
Figure 4. Enable Logic-Low Input Current vs. Enable LogicLow Threshold with 10kΩ Series Resistor
______________________________________________________________________________________
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
5
MAX4214
MAX4215
MAX4217
MAX4219
MAX4222
OUT
NORMALIZED GAIN (dB)
IN+
CL = 15pF
4
3
CL = 10pF
2
1
0
CL = 5pF
-1
-2
-3
IN500Ω
-4
500Ω
100k
1M
10M
100M
1G
FREQUENCY (Hz)
Figure 5. Input Protection Circuit
Figure 6. Small-Signal Gain vs. Frequency with Load
Capacitance and No Isolation Resistor
16
14
500Ω
12
500Ω
RISO (Ω)
10
RISO
MAX42_ _
VIN
8
6
VOUT
4
CL
2
RTIN
50Ω
0
0
50
100
150
CLOAD (pF)
200
250
Figure 7. Driving a Capacitive Load Through an Isolation
Resistor
Figure 8. Isolation Resistance vs. Capacitive Load
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 excess 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.
Figure 6 shows the devices’ frequency response under
different capacitive loads. To drive loads with greater
than 20pF of capacitance or to settle out some of the
peaking, the output requires an isolation resistor like
the one shown in Figure 7. Figure 8 is a graph of the
optimal isolation resistor versus load capacitance.
Figure 9 shows the frequency response of the
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
when driving capacitive loads with a 27Ω 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.
Coaxial cables and other transmission lines are easily
driven when properly terminated at both ends with their
characteristic impedance. Driving back-terminated
transmission lines essentially eliminates the lines’
capacitance.
______________________________________________________________________________________
11
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
6
3
2
_________Typical Application Circuit
RISO = 27Ω
CL = 47pF
1
NORMALIZED GAIN (dB)
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
0
IN+
75Ω
CL = 68pF
-1
-2
VOUT
CL = 120pF
-3
75Ω
MAX4214
-4
IN-
-5
500Ω
500Ω
-6
-7
100k
1M
10M
100M
1G
GAIN OF +2 VIDEO/RF CABLE DRIVER
FREQUENCY (Hz)
Figure 9. Small-Signal Gain vs. Frequency with Load
Capacitance and 27Ω Isolation Resistor
____________________Chip Information
PART
NO. OF TRANSISTORS
MAX4214
95
MAX4215
95
MAX4217
190
MAX4219
299
MAX4222
362
SUBSTRATE CONNECTED TO VEE
12
______________________________________________________________________________________
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
TOP VIEW
N.C. 1
IN- 2
8
EN
OUTA 1
7
VCC
INA- 2
MAX4215
8
VCC
7
OUTB
MAX4217
IN+ 3
6
OUT
INA+ 3
6
INB-
VEE 4
5
N.C.
VEE 4
5
INB+
SO/µMAX
SO/µMAX
ENA 1
14 OUTC
ENA 1
16 OUTC
ENC 2
13 INC-
ENC 2
15 INC-
ENB 3
12 INC+
ENB 3
14 INC+
MAX4219
MAX4219
11 VEE
VCC 4
INA+ 5
10 INB+
INA+ 5
12 INB+
INA- 6
9
INB-
INA- 6
11 INB-
OUTA 7
8
OUTB
OUTA 7
10 OUTB
VCC 4
N.C. 8
13 VEE
9
N.C.
SO
QSOP
OUTA 1
14 OUTD
OUTA 1
16 OUTD
INA- 2
13 IND-
INA- 2
15 IND-
12 IND+
INA+ 3
11 VEE
VCC 4
10 INC+
INB+ 5
12 INC+
INA+ 3
VCC 4
MAX4222
INB+ 5
14 IND+
MAX4222
13 VEE
INB- 6
9
INC-
INB- 6
11 INC-
OUTB 7
8
OUTC
OUTB 7
10 OUTC
N.C. 8
9
N.C.
SO
QSOP
______________________________________________________________________________________
13
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
_______________________________________________Pin Configurations (continued)
__________________________________________________Tape-and-Reel Information
D
P0
W
P2
B0
t
D1
F
P
NOTE: DIMENSIONS ARE IN MM.
AND FOLLOW EIA481-1 STANDARD.
K0
A0
P0
3.988
±0.102
A0
3.200
±0.102
E
1.753
±0.102
B0
3.099
±0.102
F
3.505
±0.051
P010
40.005
±0.203
D
1.499
+0.102
+0.000
K0
1.397
±0.102
P2
2.007
±0.051
3.988
±0.102
t
0.254
±0.127
0.991
+0.254
+0.000
P
D1
W
8.001
+0.305
-0.102
5 SOT23-5
E
________________________________________________________Package Information
SOT5L.EPS
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
14
______________________________________________________________________________________
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
8LUMAXD.EPS
SOICN.EPS
______________________________________________________________________________________
15
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
___________________________________________Package Information (continued)
___________________________________________Package Information (continued)
QSOP.EPS
MAX4214/MAX4215/MAX4217/MAX4219/MAX4222
High-Speed, Single-Supply, Gain of +2,
Closed-Loop, Rail-to-Rail Buffers with Enable
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
© 1997 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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