View EL2126CS_574789.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

(R)
EL2126
Data Sheet May 9, 2005 FN7046.2
Ultra-Low Noise, Low Power, Wideband Amplifier
The EL2126 is an ultra-low noise, wideband amplifier that runs on half the supply current of competitive parts. It is intended for use in systems such as ultrasound imaging where a very small signal needs to be amplified by a large amount without adding significant noise. Its low power dissipation enables it to be packaged in the tiny SOT-23 package, which further helps systems where many input channels create both space and power dissipation problems. The EL2126 is stable for gains of 10 and greater and uses traditional voltage feedback. This allows the use of reactive elements in the feedback loop, a common requirement for many filter topologies. It operates from 2.5V to 15V supplies and is available in the 5-pin SOT-23 and 8-pin SO packages. The EL2126 is fabricated in Elantec's proprietary complementary bipolar process, and is specified for operation over the full -40C to +85C temperature range.
Features
* Voltage noise of only 1.3nV/Hz * Current noise of only 1.2pA/Hz * 200V offset voltage * 100MHz -3dB BW for AV = 10 * Very low supply current - 4.7mA * SOT-23 package * 2.5V to 15V operation * Pb-Free available (RoHS compliant)
Applications
* Ultrasound input amplifiers * Wideband instrumentation * Communication equipment * AGC & PLL active filters * Wideband sensors
Pinouts
EL2126 (5-PIN SOT-23) TOP VIEW
OUT 1 VS- 2 + IN+ 3 4 IN5 VS+
Ordering Information
PART NUMBER EL2126CW-T7 EL2126CW-T7A EL2126CS EL2126CS-T7 EL2126CS-T13 PACKAGE 5-Pin SOT-23 5-Pin SOT-23 8-Pin SO 8-Pin SO 8-Pin SO 8-Pin SO (Pb-free) 8-Pin SO (Pb-free) 8-Pin SO (Pb-free) TAPE & REEL PKG. DWG. # 7" (3K pcs) 7" (250 pcs) 7" 13" 7" 13" MDP0038 MDP0038 MDP0027 MDP0027 MDP0027 MDP0027 MDP0027 MDP0027
EL2126 (8-PIN SO) TOP VIEW
NC 1 IN- 2 IN+ 3 VS- 4 8 NC 7 VS+ 6 OUT 5 NC
EL2126CSZ (See Note) EL2126CSZ-T7 (See Note) EL2126CSZ-T13 (See Note)
+
NOTE: Intersil Pb-free products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-352-6832 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2004, 2005. All Rights Reserved All other trademarks mentioned are the property of their respective owners.
EL2126
Absolute Maximum Ratings (TA = 25C)
VS+ to VS- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33V Continuous Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . 40mA Any Input . . . . . . . . . . . . . . . . . . . . . . . . . . VS+ - 0.3V to VS- + 0.3V Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Curves Operating Temperature . . . . . . . . . . . . . . . . . . . . . . .-40C to +85C Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . .-60C to +150C Maximum Die Junction Temperature . . . . . . . . . . . . . . . . . . . +150C
CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA
Electrical Specifications
PARAMETER DC PERFORMANCE VOS
VS+ = +5V, VS- = -5V, TA = 25C, RF = 180, RG = 20, RL = 500 unless otherwise specified. CONDITIONS MIN TYP MAX UNIT
DESCRIPTION
Input Offset Voltage (SO8) Input Offset Voltage (SOT23-5)
0.2
2 3
mV mV V/C A
TCVOS IB IOS TCIB CIN AVOL PSRR CMRR CMIR VOUTH VOUTL VOUTH2 VOUTL2 IOUT ISY
Offset Voltage Temperature Coefficient Input Bias Current Input Bias Current Offset Input Bias Current Temperature Coefficient Input Capacitance Open Loop Gain Power Supply Rejection Ratio (Note 1) Common Mode Rejection Ratio Common Mode Input Range Positive Output Voltage Swing Negative Output Voltage Swing Positive Output Voltage Swing Negative Output Voltage Swing Output Short Circuit Current (Note 2) Supply Current No load, RF = 1k No load, RF = 1k RL = 100 RL = 100 80 3.2 at CMIR VO = -2.5V to +2.5V 80 80 75 -4.6 3.8 -10
17 -7 0.06 0.013 2.2 87 100 106 3.8 3.8 -4 3.45 -3.5 100 4.7 5.5 -3.2 -3.9 0.6
A A/C pF dB dB dB V V V V V mA mA
AC PERFORMANCE - RG = 20, CL = 3pF BW BW 0.1dB BW 1dB Peaking SR OS -3dB Bandwidth, RL = 500 0.1dB Bandwidth, RL = 500 1dB Bandwidth, RL = 500 Peaking, RL = 500 Slew Rate Overshoot, 4Vpk-pk Output Square Wave Settling Time to 0.1% of 1V Pulse Voltage Noise Spectral Density Current Noise Spectral Density VOUT = 2VPP, measured at 20% to 80% Positive Negative 80 100 17 80 0.6 110 2.8 -7 51 1.3 1.2 MHz MHz MHz dB V/s % % ns nV/Hz pA/Hz
tS VN IN
2
EL2126
Electrical Specifications
PARAMETER HD2 HD3 NOTES: 1. Measured by moving the supplies from 4V to 6V 2. Pulse test only and using a 10 load 3. Frequency = 1MHz, VOUT = 2Vpk-pk, into 500 and 5pF load VS+ = +5V, VS- = -5V, TA = 25C, RF = 180, RG = 20, RL = 500 unless otherwise specified. (Continued) CONDITIONS MIN TYP -70 -70 MAX UNIT dBc dBc
DESCRIPTION 2nd Harmonic Distortion (Note 3) 3rd Harmonic Distortion (Note 3)
Electrical Specifications
PARAMETER DC PERFORMANCE VOS
VS+ = +15V, VS- = -15V, TA = 25C, RF = 180, RG = 20, RL = 500 unless otherwise specified.
DESCRIPTION
CONDITIONS
MIN
TYP
MAX
UNIT
Input Offset Voltage (SO8) Input Offset Voltage (SOT23-5)
0.5
3 3
mV mV V/C A
TCVOS IB IOS TCIB CIN AVOL PSRR CMRR CMIR VOUTH VOUTL VOUTH2 VOUTL2 IOUT ISY
Offset Voltage Temperature Coefficient Input Bias Current Input Bias Current Offset Input Bias Current Temperature Coefficient Input Capacitance Open Loop Gain Power Supply Rejection Ratio (Note 1) Common Mode Rejection Ratio Common Mode Input Range Positive Output Voltage Swing Negative Output Voltage Swing Positive Output Voltage Swing Negative Output Voltage Swing Output Short Circuit Current (Note 2) Supply Current No load, RF = 1k No load, RF = 1k RL = 100, RF = 1k RL = 100, RF = 1k 140 10.2 at CMIR 80 65 70 -14.6 13.6 -10
4.5 -7 0.12 0.016 2.2 90 80 85 13.8 13.7 -13.8 11.2 -10.3 220 5 6 -9.5 -13.7 0.7
A A/C pF dB dB dB V V V V V mA mA
AC PERFORMANCE - RG = 20, CL = 3pF BW BW 0.1dB BW 1dB Peaking SR OS -3dB Bandwidth, RL = 500 0.1dB Bandwidth, RL = 500 1dB Bandwidth, RL = 500 Peaking, RL = 500 Slew Rate (2.5V Square Wave, Measured 25%-75%) Overshoot, 4Vpk-pk Output Square Wave Settling Time to 0.1% of 1V Pulse Voltage Noise Spectral Density Positive Negative 130 135 26 60 2.1 150 1.6 -4.4 48 1.4 MHz MHz MHz dB V/S % % ns nV/Hz
TS VN
3
EL2126
Electrical Specifications
PARAMETER IN HD2 HD3 NOTES: 1. Measured by moving the supplies from 13.5V to 16.5V 2. Pulse test only and using a 10 load 3. Frequency = 1MHz, VOUT = 2Vpk-pk, into 500 and 5pF load
VS+ = +15V, VS- = -15V, TA = 25C, RF = 180, RG = 20, RL = 500 unless otherwise specified. (Continued)
DESCRIPTION Current Noise Spectral Density 2nd Harmonic Distortion (Note 3) 3rd Harmonic Distortion (Note 3)
CONDITIONS
MIN
TYP 1.1 -72 -73
MAX
UNIT pA/Hz dBc dBc
4
EL2126 Typical Performance Curves
Non-Inverting Frequency Response for Various RF 10 VS=5V AV=10 CL=5pF RL=500 RF=1k RF=500 Normalized Gain (dB) 10 VS=15V AV=10 CL=5pF RL=500 RF=1k RF=500 Non-Inverting Frequency Response for Various RF
Normalized Gain (dB)
6
6
2
2
-2
RF=180
-2
RF=180 RF=100
-6
RF=100
-6
-10 1M
10M Frequency (Hz)
100M
-10 1M
10M Frequency (Hz)
100M
Inverting Frequency Response for Various RF 8 VS=5V AV=-10 CL=5pF RL=500 RF=500 RF=350 RF=1k Normalized Gain (dB) 4 8
Inverting Frequency Response for Various RF VS=15V AV=-10 CL=5pF RL=500 RF=1k RF=500 RF=350
Normalized Gain (dB)
4
0 RF=200 RF=100 -8
0 RF=200 RF=100 -8
-4
-4
-12 1M
10M Frequency (Hz)
100M
-12 1M
10M Frequency (Hz)
100M
Non-Inverting Frequency Response for Various Gain 10 VS=5V RG=20 RL=500 CL=5pF AV=10 AV=20 AV=50 -6 10
Non-Inverting Frequency Response for Various Gain VS=15V RG=20 RL=500 CL=5pF AV=10 2 AV=20 AV=50 -6
Normalized Gain (dB)
2
-2
Normalized Gain (dB)
6
6
-2
-10 1M
10M Frequency (Hz)
100M
-10 1M
10M Frequency (Hz)
100M
5
EL2126 Typical Performance Curves
(Continued)
Inverting Frequency Response for Various Gain 8 VS=5V CL=5pF RG=35 8
Inverting Frequency Response for Various RF VS=15V CL=5pF RG=20
Normalized Gain (dB)
0
Normalized Gain (dB)
4
4
AV=-10 AV=-50
0 AV=-10 -4 AV=-50 AV=-20
-4
AV=-20
-8
-8
-12 1M
10M Frequency (Hz)
100M
-12 1M
10M Frequency (Hz)
100M
Non-Inverting Frequency Response for Various Output Signal Levels 8 VS=5V CL=5pF RL=500 RF=180 AV=10 VO=500mVPP VO=30mVPP 10
Non-Inverting Frequency Response for Various Output Signal Levels VS=15V CL=5pF RL=500 RF=180 AV=10
Normalized Gain (dB)
Normalized Gain (dB)
4
6
VO=30mVPP VO=500mVPP VO=1VPP
0
2
-4
VO=5VPP VO=2.5VPP VO=1VPP 10M Frequency (Hz) Inverting Frequency Response for Various Output Signal Levels 100M
-2
VO=10VPP VO=5VPP VO=2.5VPP 10M Frequency (Hz) Inverting Frequency Response for Various Output Signal Levels 100M
-8
-6
-12 1M
-10 1M
8 VS=5V CL=5pF RL=500 RF=350 AV=10 VO=500mVPP VO=1VPP VO=30mVPP Normalized Gain (dB)
8 VS=15V CL=5pF RL=500 RF=200 AV=10 VO=500mVPP VO=1VPP VO=30mVPP
Normalized Gain (dB)
4
4
0 VO=3.4VPP
0 VO=3.4VPP
-4
-4
-8
VO=2.5VPP
-8
VO=2.5VPPP VO=2.5V
-12 1M
10M Frequency (Hz)
100M
-12 1M
10M Frequency (Hz)
100M
6
EL2126 Typical Performance Curves
(Continued)
Non-Inverting Frequency Response for Various CL 10 VS=5V RF=150 AV=10 RL=500 CL=11pF 10
Non-Inverting Frequency Response for Various CL VS=15V RF=180 AV=10 RL=500
Normalized Gain (dB)
Normalized Gain (dB)
6
CL=28pF CL=16pF
6
CL=28pF CL=16pF
CL=11pF
2
2 CL=5pF CL=1.2pF -6
-2
CL=5pF CL=1pF
-2
-6
-10 1M
10M Frequency (Hz)
100M
-10 1M
10M Frequency (Hz)
100M
Inverting Frequency Response for Various CL 8 VS=5V RF=350 RL=500 AV=-10 CL=28pF Normalized Gain (dB) CL=16pF 4 8
Inverting Frequency Response for Various CL VS=15V RF=200 RL=500 AV=-10
CL=28pF CL=16pF
Normalized Gain (dB)
4
0 CL=11pF -4 CL=5pF CL=1.2pF -8
0 CL=11pF CL=11p -4 CL=5pF CL=1.2pF
-8
-12 1M
10M Frequency (Hz)
100M
-12 1M
10M Frequency (Hz)
100M
Open Loop Gain/Phase 100 Gain Open Loop Gain (dB) Open Loop Phase () 80 Phase 60 50 150 Supply Current (mA) 250
Supply Current vs Supply Voltage
0.6/div
40
-50
20 VS=5V 0 100k 10k
-150
1M
10M
100M
-250 1G
0 0 1.5/div Supply Voltage (V)
Frequency (Hz)
7
EL2126 Typical Performance Curves
Bandwidth vs Vs 160 140 120 -3dB Bandwidth 100 80 60 40 20 0 0 2 4 6 8 VS (V) Large Signal Step Response RF=180 VS=5V RG=20 VO=2VPP 10 12 AV=-50 AV=50 14 16 AV=-20 AV=-20 VS=5V RG=20 RL=500 CL=5pF AV=-10 AV=10 Peaking (dB) 3.0 2.5 2.0 1.5 1.0 0.5 0 0 2 4 6 8 10 12 14 16 Supply Voltage (V) Small Signal Step Response AV=-10 AV=10 VS=5V RG=20 RL=500 CL=5pF
(Continued)
Peaking vs Vs
0.5V/div
20mV/div RF=180 RG=20 VS=5V VO=100mV 10ns/div 10ns/div
1MHz Harmonic Distortion vs Output Swing -40 Harmonic Distortion (dBc) Harmonic Distortion (dBc) -50 -60 -70 -80 3rd HD -90 -100 0 1 2 3 4 5 6 7 8 VOUT (VP-P) VS=5V VO=2VP-P RF=180 AV=10 RL=500 -30 -40 -50 -60 -70 -80 -90 -100
1MHz Harmonic Distortion vs Output Swing VS=5V VO=2VP-P RF=180 AV=10 RL=500
2nd HD
2nd HD
3rd HD
0
5
10
15
20
25
VOUT (VP-P)
8
EL2126 Typical Performance Curves
(Continued)
Total Harmonic Distortion vs Frequency -20 -30 -40 THD (dBc) -50 -60 -70 -80 -90 1k VS=5V VO=2VP-P IN (pA/Hz), VN (nV/Hz) 10
Noise vs Frequency
IN, VS=5V VN, VS=15V VN, VS=5V
10k
100k
1M
10M
100M
1 10
IN, VS=15V 100 1k Frequency (Hz) 10k 100k
Frequency (Hz) Settling Time vs Accuracy 70 60 Settling Time (ns) 50 40 30 20 10 0 0.1 -4 1M
VS= 5V ,V
VS= 5V , VO= 5V P
Group Delay vs Frequency 16 VS=5V RL=500 AV=10 8
V, V
O=5V P-P
VS=
15 V, V
O=2V P-P
Group Delay (ns)
VS= 15
-P
12
4
AV=-10
O=2V P-P
0
1.0 Accuracy (%)
10.0
10M Frequency (Hz)
100M
400M
CMRR vs Frequency -10 110
PSRR vs Frequency
VS=5V -30 CMRR (dB) PSRR (dB) 90 PSRR-
-50
70
-70
50
PSRR+
-90
30
-110 10
100
1k
10k
100k
1M
10M
100M
10 10k
100k
1M Frequency (Hz)
10M
200M
Frequency (Hz)
9
EL2126 Typical Performance Curves
(Continued)
Closed Loop Output Impedance vs Frequency 120 Closed Loop Output Impedance () 100 VS=5V 100 Bandwidth (MHz) 10 80 60 40
Bandwidth and Peaking vs Temperature 3.5 VS=5V 3 2.5 2 1.5 1 Peaking 20 0.5 0 -0.5 0 40 80 120 160 Temperature Supply Current vs Temperature 5.2 Peaking (dB) Bandwidth
1
0.1
0.01 10k
100k
1M Frequency (Hz)
10M
100M
0 -40
Slew Rate vs Swing 220 200 180 Slew Rate (V/s) 160 140 120 100 80 60 -1 1 3 5 7 9 11 13 15 5VSR5VSR+ 4.9 IS (mA) 15VSR+ 15VSR5.1
VS=15V
5 VS=5V
4.8 -50
0
50 Die Temperature (C)
100
150
VOUT Swing (VPP) Offset Voltage vs Temperature 1 120
CMRR vs Temperature
VS=5V CMRR (dB) 0 VOS (mV) VS=15V -1
110 VS=5V 100
90
-2 -50
0
50 Die Temperature (C)
100
150
80 -50
0
50 Die Temperature (C)
100
150
10
EL2126 Typical Performance Curves
(Continued)
PSRR vs Temperature 110 106 102 PSRR (dB) 98 94 90 VS=15V 86 82 -50 3.85 VS=5V VOUTH (V) 4 4.05
Positive Output Swing vs Temperature
3.95 VS=5V 3.9
0
50 Die Temperature (C)
100
150
3.8 -50
0
50 Die Temperature (C)
100
150
Positive Output Swing vs Temperature 13.85 -3.9 -3.95 13.8 -4 VOUTH (V) 13.75 VS=15V VOUTL (V) -4.05 -4.1 -4.15 13.65 -4.2 13.6 -50
Negative Output Swing vs Temperature
VS=5V
13.7
0
50 Die Temperature (C)
100
150
-4.25 -50
0
50 Die Temperature (C)
100
150
Negative Output Swing vs Temperature -13.76 102 100 Slew Rate (V/s) 98 96 94 92 90 -13.82 -50
Slew Rate vs Temperature
-13.78 VOUTL (V) VS=15V -13.8
VS=5V
0
50 Die Temperature (C)
100
150
88 -50
0
50 Die Temperature (C)
100
150
11
EL2126 Typical Performance Curves
Slew Rate vs Temperature 155 3.52
(Continued)
Positive Loaded Output Swing vs Temperature
150 VOUTH2 (V) SR (V/s) VS=15V 145
3.5 VS=5V 3.48
140 VO=2VPP 0 50 Die Temperature (C) Positive Loaded Output Swing vs Temperature 11.8 11.6 VS=15V VOUTL2 (V) 11.4 SR (V/s) 11.2 11 10.8 10.6 -50 100 150
3.46
135 -50
3.44 -50
0
50 Die Temperature (C)
100
150
Negative Loaded Output Swing vs Temperature -3.35
-3.4
-3.45
-3.5 VS=5V 3.55
0
50 Die Temperature (C)
100
150
-3.6 -50
0
50 Die Temperature (C)
100
150
Negative Loaded Output Swing vs Temperature -9.4 -9.6 Power Dissipation (W) -9.8 -10 -10.2 -10.4 -10.6 -50 VS=15V 1.2 1
Package Power Dissipation vs Ambient Temperature JEDEC JESD51-3 Low Effective Thermal Conductivity Test Board
781mW 0.8 0.6 0.4 0.2 0
J
A =1
VOUTL2 (V)
SO 8 60 W SOT 23J 5 A =25 6C /W C /
488mW
0
50 Die Temperature (C)
100
150
0
25
50
75 85 100
125
150
Ambient Temperature (C)
Package Power Dissipation vs Ambient Temperature JEDEC JESD51-7 High Effective Thermal Conductivity Test Board 1.8 1.6 Power Dissipation (W) 1.4 1.2 1.136W 1 0.8 0.6 543mW 0.4 0.2 0 0 25 50 75 85 100 125 150 Ambient Temperature (C)
J
J
A =1
SO 8 10 C /W
23-5
SOT
A=230
C/W
12
EL2126 Pin Descriptions
EL2126CW (5-PIN SOT-23) 1 EL2126CS (8-PIN SO) 6 PIN NAME VOUT PIN FUNCTION Output EQUIVALENT CIRCUIT
VS+
VOUT
Circuit 1
2 3
4 3
VSVINA+
Supply Input
VS+
VIN+
VIN-
VSCircuit 2
4 5
2 7
VINAVS+
Input Supply
Reference Circuit 2
13
EL2126 Applications Information
Product Description
The EL2126 is an ultra-low noise, wideband monolithic operational amplifier built on Elantec's proprietary high speed complementary bipolar process. It features 1.3nV/Hz input voltage noise, 200V typical offset voltage, and 73dB THD. It is intended for use in systems such as ultrasound imaging where very small signals are needed to be amplified. The EL2126 also has excellent DC specifications: 200V VOS, 22A IB, 0.4A I OS, and 106dB CMRR. These specifications allow the EL2126 to be used in DC-sensitive applications such as difference amplifiers.
Noise Calculations
The primary application for the EL2126 is to amplify very small signals. To maintain the proper signal-to-noise ratio, it is essential to minimize noise contribution from the amplifier. Figure 2 below shows all the noise sources for all the components around the amplifier.
VIN R3 VR3 I N+ VR1 VN + R1 VON
I N-
VR2 R2
Gain-Bandwidth Product
The EL2126 has a gain-bandwidth product of 650MHz at 5V. For gains less than 20, higher-order poles in the amplifier's transfer function contribute to even higher closedloop bandwidths. For example, the EL2126 has a -3dB bandwidth of 100MHz at a gain of 10 and decreases to 33MHz at gain of 20. It is important to note that the extra bandwidth at lower gain does not come at the expenses of stability. Even though the EL2126 is designed for gain 10. With external compensation, the device can also operate at lower gain settings. The RC network shown in Figure 1 reduces the feedback gain at high frequency and thus maintains the amplifier stability. R values must be less than RF divided by 9 and 1 divided by 2RC must be less than 200MHz.
RF R C VIN + VOUT
FIGURE 2.
VN is the amplifier input voltage noise IN+ is the amplifier positive input current noise IN- is the amplifier negative input current noise VRX is the thermal noise associated with each resistor:
V RX = 4kTRx
where: k is Boltzmann's constant = 1.380658 x 10-23 T is temperature in degrees Kelvin (273+ C) The total noise due to the amplifier seen at the output of the amplifier can be calculated by using the following equation (Figure 3). As the equation shows, to keep noise at a minimum, small resistor values should be used. At higher amplifier gain configuration where R2 is reduced, the noise due to IN-, R2, and R1 decreases and the noise caused by IN+, VN, and R3 starts to dominate. Because noise is summed in a rootmean-squares method, noise sources smaller than 25% of the largest noise source can be ignored. This can greatly simplify the formula and make noise calculation much easier to calculate.
FIGURE 1.
Choice of Feedback Resistor, RF
The feedback resistor forms a pole with the input capacitance. As this pole becomes larger, phase margin is reduced. This increases ringing in the time domain and peaking in the frequency domain. Therefore, RF has some maximum value which should not be exceeded for optimum performance. If a large value of RF must be used, a small capacitor in the few pF range in parallel with RF can help to reduce this ringing and peaking at the expense of reducing the bandwidth. Frequency response curves for various RF values are shown in the typical performance curves section of this data sheet.
Output Drive Capability
The EL2126 is designed to drive low impedance load. It can easily drive 6VP-P signal into a 100 load. This high output drive capability makes the EL2126 an ideal choice for RF, IF,
V ON =
R 1 2 R 1 2 R 1 2 R 1 2 2 2 2 2 2 BW x VN x 1 + ------ + IN- x R 1 + IN+ x R 3 x 1 + ------ + 4 x K x T x R 1 + 4 x K x T x R 2 x ------ + 4 x K x T x R 3 x 1 + ------ R 2 R 2 R 2 R 2
FIGURE 3.
14
EL2126
and video applications. Furthermore, the EL2126 is currentlimited at the output, allowing it to withstand momentary short to ground. However, the power dissipation with outputshorted cannot exceed the power dissipation capability of the package. where pin 4 (VS-) is connected to the ground plane, a single 4.7F tantalum capacitor in parallel with a 0.1F ceramic capacitor across pins 7 (VS+) and pin 4 (VS-) will suffice. For good AC performance, parasitic capacitance should be kept to a minimum. Ground plane construction again should be used. Small chip resistors are recommended to minimize series inductance. Use of sockets should be avoided since they add parasitic inductance and capacitance which will result in additional peaking and overshoot.
Driving Cables and Capacitive Loads
Although the EL2126 is designed to drive low impedance load, capacitive loads will decreases the amplifier's phase margin. As shown in the performance curves, capacitive load can result in peaking, overshoot and possible oscillation. For optimum AC performance, capacitive loads should be reduced as much as possible or isolated with a series resistor between 5 to 20. When driving coaxial cables, double termination is always recommended for reflectionfree performance. When properly terminated, the capacitance of the coaxial cable will not add to the capacitive load seen by the amplifier.
Supply Voltage Range and Single Supply Operation
The EL2126 has been designed to operate with supply voltage range of 2.5V to 15V. With a single supply, the EL2126 will operate from +5V to +30V. Pins 4 and 7 are the power supply pins. The positive power supply is connected to pin 7. When used in single supply mode, pin 4 is connected to ground. When used in dual supply mode, the negative power supply is connected to pin 4. As the power supply voltage decreases from +30V to +5V, it becomes necessary to pay special attention to the input voltage range. The EL2126 has an input voltage range of 0.4V from the negative supply to 1.2V from the positive supply. So, for example, on a single +5V supply, the EL2126 has an input voltage range which spans from 0.4V to 3.8V. The output range of the EL2126 is also quite large, on a +5V supply, it swings from 0.4V to 3.8V.
Power Supply Bypassing And Printed Circuit Board Layout
As with any high frequency devices, good printed circuit board layout is essential for optimum performance. Ground plane construction is highly recommended. Lead lengths should be kept as short as possible. The power supply pins must be closely bypassed to reduce the risk of oscillation. The combination of a 4.7F tantalum capacitor in parallel with 0.1F ceramic capacitor has been proven to work well when placed at each supply pin. For single supply operation,
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems. Intersil Corporation's quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com 15

▲Up To Search▲

Price & Availability of EL2126CS

	To Download EL2126CS Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .