General Description The MAX4385E/MAX4386E op amps are unity-gain sta- ble devices that combine high-speed performance, rail-to-rail outputs, and ±15kV ESD protection. Targeted for applications where an input or an output is exposed to the outside world, such as video and communica- tions, these devices are compliant with International ESD Standards: ±15kV IEC 1000-4-2 Air-Gap Discharge, ±8kV IEC 1000-4-2 Contact Discharge, and the ±15kV Human Body Model. The MAX4385E/MAX4386E operate from a single 5V supply with a common-mode input voltage range that extends beyond V EE . The MAX4385E/MAX4386E con- sume only 5.5mA of quiescent supply current per amplifier while achieving a 230MHz -3dB bandwidth, 30MHz 0.1dB gain flatness and a 450V/μs slew rate. Applications Features ♦ ESD-Protected Inputs and Outputs ±15kV—Human Body Model ±8kV—IEC 1000-4-2 Contact Discharge ±15kV—IEC 1000-4-2 Air-Gap Discharge ♦ Low Cost and High Speed 230MHz -3dB Bandwidth 30MHz 0.1dB Gain Flatness 450V/μs Slew Rate ♦ Rail-to-Rail Outputs ♦ Input Common-Mode Range Extends Beyond V EE ♦ Low Differential Gain/Phase: 0.02%/0.01° ♦ Low Distortion at 5MHz -60dBc SFDR -58dB Total Harmonic Distortion ♦ Ultra-Small 5-Pin SOT23 and 14-Pin TSSOP Packages MAX4385E/MAX4386E Low-Cost, 230MHz, Single/Quad Op Amps with Rail-to-Rail Outputs and ±15kV ESD Protection 220Ω 220Ω 75Ω 75Ω OUT VIDEO LINE DRIVER Z o = 75Ω MAX4385E 5V 2.2µF 75Ω IN Typical Operating Circuit 19-2422; Rev 1; 9/05 Ordering Information ________________________________________________________________ Maxim Integrated Products 1 V EE IN- IN+ 1 5 V CC OUT MAX4385E SOT23 TOP VIEW 2 3 4 Pin Configurations Pin Configurations continued at end of data sheet. PART TEMP RANGE PIN- PACKAGE TOP MARK MAX4385EEUK-T -40°C to +85°C 5 SOT23-5 ADZL MAX4386EESD -40°C to +85°C 14 SO — MAX4386EEUD -40°C to +85°C 14 TSSOP — 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. Set-Top Boxes Surveillance Video Systems Battery-Powered Instruments Analog-to-Digital Converter Interface CCD Imaging Systems Video Routing and Switching Systems Digital Cameras Video-on-Demand Video Line Driver
13
Embed
Low-Cost, 230MHz, Single/Quad Op Amps with Rail-to-Rail Outputs and ±15kV ESD Protection · 2005. 9. 23. · 0.2 VCC -2.25 TA = +25°C 0.2 20 Input Offset Voltage VOS TA = -40°C
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
General DescriptionThe MAX4385E/MAX4386E op amps are unity-gain sta-ble devices that combine high-speed performance, rail-to-rail outputs, and ±15kV ESD protection. Targetedfor applications where an input or an output is exposedto the outside world, such as video and communica-tions, these devices are compliant with InternationalESD Standards: ±15kV IEC 1000-4-2 Air-GapDischarge, ±8kV IEC 1000-4-2 Contact Discharge, andthe ±15kV Human Body Model.
The MAX4385E/MAX4386E operate from a single 5Vsupply with a common-mode input voltage range thatextends beyond VEE. The MAX4385E/MAX4386E con-sume only 5.5mA of quiescent supply current peramplifier while achieving a 230MHz -3dB bandwidth,30MHz 0.1dB gain flatness and a 450V/µs slew rate.
Applications
Features♦ ESD-Protected Inputs and Outputs
±15kV—Human Body Model±8kV—IEC 1000-4-2 Contact Discharge±15kV—IEC 1000-4-2 Air-Gap Discharge
♦ Low Cost and High Speed230MHz -3dB Bandwidth 30MHz 0.1dB Gain Flatness450V/µs Slew Rate
♦ Rail-to-Rail Outputs
♦ Input Common-Mode Range Extends Beyond VEE
♦ Low Differential Gain/Phase: 0.02%/0.01°
♦ Low Distortion at 5MHz-60dBc SFDR-58dB Total Harmonic Distortion
♦ Ultra-Small 5-Pin SOT23 and 14-Pin TSSOPPackages
MA
X4
38
5E
/MA
X4
38
6E
Low-Cost, 230MHz, Single/Quad Op Amps with Rail-to-Rail Outputs and ±15kV ESD Protection
ABSOLUTE MAXIMUM RATINGSPower-Supply Voltage (VCC to VEE) .........................-0.3V to +6V IN_+, IN_-, OUT_,.............................(VEE - 0.3V) to (VCC + 0.3V)Output Short-Circuit Duration to
VCC or VEE.............................................................ContinuousContinuous Power Dissipation (TA = +70°C)
Operating Temperature Range ...........................-40°C to +85°CJunction Temperature ......................................................+150°CStorage Temperature Range .............................-65°C to +150°CLead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and function-al operation of the device at these or at any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposureto absolute maximum rating conditions for extended periods may affect device reliability.
DC ELECTRICAL CHARACTERISTICS (VCC = 5V, VEE = 0, VCM = VCC/2, VOUT = VCC/2, RL = ∞ to VCC/2, CBYPASS = 2.2µF, TA = TMIN to TMAX, unless otherwise noted.Typical values are at TA = +25°C.) (Note 1)
Note 1: All devices are 100% production tested at TA = +25°C. Specifications over temperature limits are guaranteed by design.Note 2: ESD protection is specified for test point A and test point B only (Figure 6).
DC ELECTRICAL CHARACTERISTICS (continued)(VCC = 5V, VEE = 0, VCM = VCC/2, VOUT = VCC/2, RL = ∞ to VCC/2, CBYPASS = 2.2µF, TA = TMIN to TMAX, unless otherwise noted.Typical values are at TA = +25°C.) (Note 1)
Detailed DescriptionThe MAX4385E/MAX4386E are single/quad, 5V, rail-to-rail, voltage-feedback amplifiers that employ current-feedback techniques to achieve 450V/µs slew ratesand 230MHz bandwidths. High ±15kV ESD protectionguards against unexpected discharge. Excellent har-monic distortion and differential gain/phase perfor-mance make these amplifiers an ideal choice for a widevariety of video and RF signal-processing applications.
Applications InformationThe output voltage swings to within 50mV of each sup-ply rail. Local feedback around the output stageensures low open-loop output impedance to reducegain sensitivity to load variations. The input stage per-mits common-mode voltages beyond VEE and to within2.25V of the positive supply rail.
Choosing Resistor ValuesUnity-Gain Configuration
The MAX4385E/MAX4386E are internally compensatedfor unity gain. When configured for unity gain, a 24Ωresistor (RF) in series with the feedback path optimizesAC performance. This resistor improves AC responseby reducing the Q of the parallel LC circuit formed bythe parasitic feedback capacitance and inductance.
Video Line DriverThe MAX4385E/MAX4386E are low-power, voltage-feedback amplif iers featuring bandwidths up to230MHz, 0.1dB gain flatness to 30MHz. They aredesigned to minimize differential-gain error and differ-ential-phase error to 0.02% and 0.01°, respectively.They have a 14ns settling time to 0.1%, 450V/µs slewrates, and output-current-drive capability of up to50mA, making them ideal for driving video loads.
Inverting and Noninverting ConfigurationsSelect the gain-setting feedback (RF) and input (RG)resistor values to fit your application. Large resistor val-ues increase voltage noise and interact with the amplifi-er’s input and PC board capacitance. This cangenerate undesirable poles and zeros and decreasebandwidth or cause oscillations. For example, a nonin-verting gain-of-two configuration (RF = RG) using 1kΩresistors, combined with 8pF of amplifier input capaci-tance and 1pF of PC board capacitance, causes a poleat 35.4MHz. Since this pole is within the amplifier band-width, it jeopardizes stability. Reducing the 1kΩ resis-tors to 100Ω extends the pole frequency to 353.8MHz,but could limit output swing by adding 200Ω in parallelwith the amplif ier’s load resistor (Figures 1a and 1b).
Layout and Power-Supply BypassingThese amplifiers operate from a single 5V power supply.Bypass VCC to ground with 0.1µF and 2.2µF capacitors asclose to the pin as possible.
Maxim recommends using microstrip and stripline tech-niques to obtain full bandwidth. To ensure that the PCboard does not degrade the amplifier’s performance,design it for a frequency greater than 1GHz. Pay care-ful attention to inputs and outputs to avoid large para-sitic capacitance. Regardless of whether you use aconstant-impedance board, observe the followingdesign guidelines:
• Do not use wire-wrap boards; they are too inductive.
• Do not use IC sockets; they increase parasiticcapacitance and inductance.
• Use surface mount instead of through-hole compo-nents for better high-frequency performance.
• Use a PC board with at least two layers; it should beas free from voids as possible.
• Keep signal lines as short and as straight as possi-ble. Do not make 90° turns; round all corners.
INRG
VOUT = -(RF / RG) VIN
RF
VOUTMAX438_E
Figure 1b. Inverting Gain Configuration
IN
RG
VOUT = [1+ (RF / RG)] VIN
RF
VOUTMAX438_E
Figure 1a. Noninverting Gain Configuration
MA
X4
38
5E
/MA
X4
38
6E
Low-Cost, 230MHz, Single/Quad Op Amps with Rail-to-Rail Outputs and ±15kV ESD Protection
The input common-mode range extends from (VEE -200mV) to (VCC - 2.25V) with excellent common-moderejection. Beyond this range, the amplifier output is anonlinear function of the input, but does not undergophase reversal or latchup.
The output swings to within 50mV of either power-sup-ply rail with a 2kΩ load. The input ground sensing andthe rail-to-rail output substantially increase the dynamicrange. The input can swing 2.95VP-P and the outputcan swing 4.9VP-P with minimal distortion.
Output Capacitive Loading and StabilityThe MAX4385E/MAX4386E are optimized for AC perfor-mance and do not drive highly reactive loads, whichdecreases phase margin and may produce excessiveringing and oscillation. Figure 2 shows a circuit thateliminates this problem. Figure 3 is a graph of theOptimal Isolation Resistor (RS) vs. Capacitive Load.Figure 4 shows how a capacitive load causes exces-sive peaking of the amplifier’s frequency response ifthe capacitor is not isolated from the amplifier by aresistor. A small isolation resistor (usually 10Ω to 15Ω)placed before the reactive load prevents ringing andoscillation. At higher capacitive loads, the interaction ofthe load capacitance and the isolation resistor controlsthe AC performance. Figure 5 shows the effect of a15Ω isolation resistor on closed-loop response.
6
-4100k 10M 100M1M 1G
-2
FREQUENCY (Hz)
GAIN
(dB)
0
2
4
5
-3
-1
1
3
CL = 10pF
CL = 15pF
CL = 5pF
Figure 4. Small-Signal Gain vs. Frequency with LoadCapacitance and No Isolation Resistor
Figure 2. Driving a Capacitive Load Through an Isolation Resistor
9
11
10
13
12
15
14
16
0 200100 300 40050 250150 350 450 500
ISOLATION RESISTANCE vs. CAPACITIVE LOAD
CLOAD (pF)
R ISO
(Ω)
Figure 3. Isolation Resistance vs. Capacitive Load
RG RF
RISO
CL
VOUT
VIN
MAX438_E
3
-7100k 10M 100M1M 1G
-5
FREQUENCY (Hz)
GAIN
(dB)
-3
-1
1
2
-6
-4
-2
0
CL = 68pF
RISO = 15Ω
CL = 120pF
CL = 47pF
Figure 5. Small-Signal Gain vs. Frequency with LoadCapacitance and 27Ω Isolation Resistor
MA
X4
38
5E
/MA
X4
38
6E
Low-Cost, 230MHz, Single/Quad Op Amps with Rail-to-Rail Outputs and ±15kV ESD Protection
ESD Protection As with all Maxim devices, ESD protection structuresare incorporated on all pins to protect against ESDencountered during handling and assembly. Input andoutput pins of the MAX4385E/MAX4386E have extraprotection against static electricity. Maxim’s engineershave developed state-of-the-art structures enablingthese pins to withstand ESD up to ±15kV without dam-age when placed in the test circuit (Figure 6). TheMAX4385E/MAX4386E are characterized for protectionto the following limits:
• ±15kV using the Human Body Model
• ±8kV using the Contact Discharge method specifiedin IEC 1000-4-2
• ±15kV using the Air-Gap Discharge method speci-fied in IEC 1000-4-2
Human Body ModelFigure 7 shows the Human Body Model, and Figure 8shows the current waveform it generates when dis-charged into a low impedance. This model consists of a150pF capacitor charged to the ESD voltage of interest,and then discharged into the test device through a1.5kΩ resistor.
IEC 1000-4-2The IEC 1000-4-2 standard covers ESD testing andperformance of finished equipment; it does not specifi-cally refer to ICs. The MAX4385E/MAX4386E enable thedesign of equipment that meets the highest level (Level4) of IEC 1000-4-2 without the need for additional ESDprotection components. The major difference betweentests done using the Human Body Model and IEC 1000-4-2 is higher peak current in IEC 1000-4-2. Becauseseries resistance is lower in the IEC 1000-4-2 model,the ESD-withstand voltage measured to this standard isgenerally lower than that measured using the HumanBody. Figure 10 shows the IEC 1000-4-2 model andFigure 9 shows the current waveform for the ±8kV IEC1000-4-2 Level 4 ESD Contact Discharge test. The Air-Gap test involves approaching the device with acharged probe. The Contact Discharge method con-nects the probe to the device before the probe is ener-gized.
HIGH-VOLTAGE
DCSOURCE
CHARGE CURRENTLIMIT RESISTOR
DISCHARGERESISTANCE
STORAGECAPACITOR
RD = 1.5kΩRC = 1MΩ
CS = 150pF
DEVICEUNDERTEST
Figure 7. Human Body ESD Model
IP 100%90%
36.8%
tRLTIME
tDLCURRENT WAVEFORM
PEAK-TO-PEAK RINGING(NOT DRAWN TO SCALE)
Ir
10%0
0
AMPERES
Figure 8. Human Body Current Waveform
220Ω220Ω
75Ω
MAX438_E
5V
CBYPASS2.2µF
75ΩTEST
POINT B
TEST POINT A
VEE
Figure 6. ESD Test Circuit
MA
X4
38
5E
/MA
X4
38
6E
Low-Cost, 230MHz, Single/Quad Op Amps with Rail-to-Rail Outputs and ±15kV ESD Protection
Package Information(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to www.maxim-ic.com/packages.)
TSS
OP
4.40
mm
.EP
S
PACKAGE OUTLINE, TSSOP 4.40mm BODY
21-0066 11
G
Low-Cost, 230MHz, Single/Quad Op Amps with Rail-to-Rail Outputs and ±15kV ESD Protection
MA
X4
38
5E
/MA
X4
38
6E
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses areimplied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 13
Package Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to www.maxim-ic.com/packages.)