Datasheet EL2070CS, EL2070CN Datasheet (ELANT)

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Page 1

EL2070C

200MHz Current Feedback Amplifier

EL2070C

Features

• 200MHz -3dB bandwidth, AV=2

• Disable/enable

• 12ns settling to 0.05%

• VS = ±5V @ 15mA

• Low distortion: HD2, HD3 @ -----

-60dBc at 20MHz

• Differential gain 0.02% at NTSC, PAL

• Differential phase 0.01° at NTSC, PAL

• Overload/short-circuit protected

• ±1 to ±8 closed-loop gain range

• Low cost

Applications

• Video gain block

• Video distribution

• HDTV amplifier

• Analog multiplexing (using disable)

• Power-down mode (using disable)

• High-speed A/D conversion

• D/A I-V conversion

• Photodiode, CCD preamps

• IF processors

• High-speed communications

General Description

The EL2070C is a wide bandwidth, fast settling monolithic amplifier incorporating a disable/enable feature. Built using an advanced complementary bipolar process, this amplifier uses current-mode feedback to achieve more bandwidth at a given gain than conventional operational amplifiers. Designed for closed-loop gains of ±1 to ±8, the EL2070C has a 200MHz -3dB bandwidth (AV = +2), and 12ns settling to 0.05% while consuming only 15mA of supply current. Furthermore, the fast disable/enable times of 200ns/100ns allow rapid analog multiplexing.

The EL2070C is an obvious high-performance solution for video distribution and line-driving applications, especially when its disable feature can be used for fast analog multiplexing. Furthermore, the low 15mA supply current, and the very low 5mA of supply current when disabled suggest use in systems where power is critical. With differential gain/phase of 0.02%/0.01°, guaranteed video specifications, and a minimum 50mA output drive, performance in these areas is assured.

The EL2070C's settling to 0.05% in 12ns, low distortion, and ability to drive capacitive loads make it an ideal flash A/D driver. The wide 200MHz bandwidth and extremely linear phase allow unmatched signal fidelity. D/A systems can also benefit from the EL2070C, especially if linearity and drive levels are important.

Ordering Information

Part No. Temp. Range Package Outline #

EL2070CN -40°C to +85°C 8-Pin P-DIP MDP0031

EL2070CS -40°C to +85°C 8-Lead SO MDP0027

Note: All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication; however, this data sheet cannot be a “controlled document”. Current revisions, if any, to these specifications are maintained at the factory and are available upon your request. We recommend checking the revision level before finalization of your design documentation.

Connection Diagrams

DIP and SO Package - Top VIew

Manufactured under U.S. Patent No. 4,893,091

September 26, 2001

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EL2070C

200MHz Current Feedback Amplifier

EL2070C

Absolute Maximum Ratings (T

Supply Voltage (VS) ±7V

Output Current 70mA

(Output is short-circuit protected to ground, however, maximum reliability is obtained if I

Common-Mode Input Voltage ±V

Differential Input Voltage 5V

Disable Input Voltage +VS, -1V Thermal Resistance θ

does not exceed 70mA)

OUT

= 25°C)

= 95°C/W P-DIP

Applied Output Voltage (Disabled) ±V

Power Dissipation See Curves

Operating Temperature

EL2070C -40C to +85C

Lead Temperature (Soldering, 5 Seconds) 300°C

Junction Temperature 175°C

Storage Temperature-60°C to +150°C

= 175°C/W SO-8

Important Note:

All parameters having Min/Max specifications are guaranteed. Typ values are for information purposes only. Unless otherwise noted, all tests are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA.

Open Loop DC Electrical Characteristics

VS = ±5V, R

d(VOS)/dT Average Offset

d(+IIN)/dT Average +Input

-I

d(-IIN)/dT Average -Input

PSRR Power Supply

CMRR Common-Mode

CMIR Common-Mode

OUT

= 100Ω unless otherwise specified

Parameter Description Test Conditions Temp Min Typ Max Unit

Input Offset Voltage 25°C 2 5.5 mV

MIN

[1]

MAX

All 10.0 40.0 µV/°C

8.2 mV

9.0 mV

Voltage Drift

+Input Current 25°C, T

[1]

All 50.0 200.0 nA/°C

MAX

MIN

10 25.0 µA

36.0 µA

Current Drift

-Input Current 25.0°C 10 30 µA

, T

MIN

[1]

MAX

All 50.0 200.0 nA/°C

46 µA

Current Drift

All 45.0 50.0 dB

Rejection Ratio

All 40.0 50.0 dB

Rejection Ratio

Supply Current—Quiescent No Load All 16.0 20.0 mA

OFF

OUT

D Output Resistance (DC) Disabled All 100.0 200.0 kΩ

OUT

D Output Capacitance (DC) Disabled All 0.5 2.0 pF

OUT

Supply Current—Disabled

+Input Resistance 25°C, T

Input Capacitance All 0.5 2.0 pF Output Impedance (DC) All 0.1 0.2 Ω

Input Range

Output Current 25°C, T

OUT

L Output Voltage Swing 100Ω 25°C 3.0 3.4 V

OUT

Output Voltage Swing No Load All 3.3 3.5 V

[2]

[3]

All 4.0 7.0 mA

100.0 200.0 kΩ

50.0 kΩ

2.0 2.1 V

1.2 V

50.0 70.0 mA

35.0 mA

25°C, T

MAX

MIN

MAX

MIN

MAX

MIN

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EL2070C

200MHz Current Feedback Amplifier

Open Loop DC Electrical Characteristics (Continued)

VS = ±5V, R

-ICMR Input Current Common

+IPSR +Input Current Power

-IPSR -Input Current Power

LOGIC

DIS

1. Measured from T

2. Supply current when disabled is measured at the negative supply.

3. Common-mode input range for rated performance.

= 100Ω unless otherwise specified

Parameter Description Test Conditions Temp Min Typ Max Unit

25°C 8.0 33.0 µA/V

Mode Rejection

25°C 1.0 3.6 µA/V

Supply Rejection

25°C 20 24 µA/V

Supply Rejection

Transimpedance 25°C 30.0 125.0 V/mA

MIN

MAX

80.0 V/mA

140.0 V/mA

Pin 8 Current @ 0V All 0.8 1.2 mA

DIS

Maximum Pin 8

All 0.5 V

V to Disable

Minimum Pin 8

All 3.5 V

V to Enable

Minimum Pin 8

All 350.0 µA

I to Disable

Maximum Pin 8

All 60.0 µA

I to Enable

to T

MAX

MIN

EL2070C

Closed-Loop AC Electrical Characteristics

VS = ±5V, R

Parameter Description Test Conditions Temp Min Typ Max Unit

FREQUENCY RESPONSE

SSBW -3dB Bandwidth

LSBW -3dB Bandwidth

GAIN FLATNESS

GFPL Peaking

GFPH Peaking

GFR Rolloff

LPD Linear Phase Deviation

TIME-DOMAIN RESPONSE

tr1, t

tr2, t

= 250Ω, A

= +2, R

= 100Ω unless otherwise specified

25°C 150.0 200.0 MHz

< 0.5VPP)

OUT

MIN

MAX

150.0 MHz

120.0 MHz

AV = +5 All 35.0 50.0 MHz

< 5.0VPP)

OUT

<40MHz 25°C 0.0 0.3 dB

< 0.5V

OUT

, T

MIN

MAX

>40MHz 25°C 0.0 0.5 dB

< 0.5V

OUT

, T

MIN

MAX

<75MHz 25°C 0.6 1.0 dB

< 0.5V

OUT

Rise Time, Fall Time 0.5V Step All 1.6 2.4 ns

Rise Time, Fall Time 5.0V Step All 6.5 10.0 ns

< 0.5V

<75MHz 25°C, T

MIN

MAX

MIN

0.2 1.0 °

0.4 dB

0.7 dB

1.0 dB

1.3 dB

1.2 °

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EL2070C

200MHz Current Feedback Amplifier

EL2070C

Closed-Loop AC Electrical Characteristics

VS = ±5V, R

Parameter Description Test Conditions Temp Min Typ Max Unit

OS Overshoot 0.5V Step 25°C, T

SR Slew Rate AV = +2 All 430.0 700.0 V/µs

DISTORTION

HD2 2nd Harmonic Distortion

HD3 3rd Harmonic Distortion

EQUIVALENT INPUT NOISE

NF Noise Floor

INV Integrated Noise

DISABLE/ENABLE PERFORMANCE

OFFIso Off Isolation 10MHz All 55.0 59.0 dB

VIDEO PERFORMANCE

VBW -0.1dB Bandwidth

= 250Ω, A

= +2, R

= 100Ω unless otherwise specified

Settling Time to 0.1% 2.0V Step All 10.0 13.0 ns

Settling Time to 0.05% 2.0V Step All 12.0 15.0 ns

AV = - 2 All 1600.0 V/µs

at 20MHz

[1]

>100kHz

[1]

100kHz to 200MHz

OFF

Disable Time to >50dB 10MHz All 1000.0 IV ns

Enable Time All 200.0 ns

Differential Gain

Differential Phase

Differential Gain

Differential Phase

[2]

NTSC/PAL 25°C 0.02 0.08 % pp

NTSC/PAL 25°C 0.01 0.08 ° pp

30MHz 25°C 0.05 0.18 % pp

30MHz 25°C 0.05 0.18 ° pp

1. Noise Tests are performed from 5MHz to 200MHz.

2. Differential gain/phase tests are with R

= 100Ω. For other values of R

, see curves.

MAX

MIN

0.0 10.0 %

15.0 %

25°C -60.0 -45.0 dBc

MIN

MAX

-40.0 dBc

-45.0 dBc

25°C -60.0 -50.0 dBc

MIN

, T

MAX

-50.0 dBc

25°C -157.0 -154.0 dBm (1Hz)

MIN

MAX

-154.0 dBm (1Hz)

-153.0IV dBm (1Hz)

25°C 40.0 57.0 µV

MIN

MAX

57.0 µV

63.0 µV

25°C 30.0 60.0 MHz

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Typical Performance Curves

EL2070C

200MHz Current Feedback Amplifier

Non-Inverting Frequency Response

Open-Loop Transimpedance Gain and Phase

Equivalent Input Noise Power-Supply

Inverting Frequency Response

2nd and 3rd Harmonic Distortion

Rejection Ratio

Frequency Response for Various RLs

2-Tone 3rd Order Intermodulation Intercept

Common-Mode Rejection Ratio

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EL2070C

200MHz Current Feedback Amplifier

EL2070C

Settling Time Long-Term Settling Time Settling Time vs

Recommended RS vs Load Capacitance

Pulse Response AV = +2

Load Capacitance

Pulse Response AV = +2

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EL2070C

200MHz Current Feedback Amplifier

EL2070C

Differential Gain and Phase (3.58MHz)

Forward and Reverse Gain during Disable

Differential Gain and Phase (4.43MHz)

Enable/Disable Response

Differential Gain and Phase (30MHz)

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EL2070C

200MHz Current Feedback Amplifier

EL2070C

Equivalent Circuit

Burn-In Circuit

ALL PACKAGES USE THE SAME SCHEMATIC.

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Applications Information

EL2070C

200MHz Current Feedback Amplifier

Theory of Operation

The EL2070C has a unity gain buffer from the noninverting input to the inverting input. The error signal of the EL2070C is a current flowing into (or out of) the inverting input. A very small change in current flowing through the inverting input will cause a large change in the output voltage. This current amplification is called the transimpedance (ROL) of the EL2070C [V

=(ROL) * (-IIN)]. Since ROL is very large, the cur-

OUT

rent flowing into the inverting input in the steady-state (non-slewing) condition is very small.

Therefore we can still use op-amp assumptions as a firstorder approximation for circuit analysis, namely that:

1.The voltage across the inputs is approximately 0V.

2.The current into the inputs is approximately 0mA.

Resistor Value Selection and Optimization

The value of the feedback resistor (and an internal capacitor) sets the AC dynamics of the EL2070C. The

nominal value for the feedback resistor is 250Ω, which

is the value used for production testing. This value guarantees stability. For a given closed-loop gain the bandwidth may be increased by decreasing the feedback resistor and, conversely, the bandwidth may be decreased by increasing the feedback resistor.

Reducing the feedback resistor too much will result in overshoot and ringing and eventually oscillations. Increasing the feedback resistor results in a lower -3dB frequency. Attenuation at high frequency is limited by a zero in the closed-loop transfer function which results from stray capacitance between the inverting input and ground. Consequently, it is very important to keep stray capacitance to a minimum at the inverting input.

Differential Gain/Phase

An industry-standard method of measuring the distortion of a video component is to measure the amount of differential gain and phase error it introduces. To measure these, a 40 IREPP reference signal is applied to the device with 0V DC offset (0 IRE) at 3.58MHz for NTSC, 4.43MHz for PAL, and 30MHz for HDTV. A

second measurement is then made with a 0.714V DC offset (100 IRE). Differential Gain is a measure of the change in amplitude of the sine wave, and is measured in percent. Differential Phase is a measure of the change in phase, and is measured in degrees. Typically, the maximum positive and negative deviations are summed to give peak values.

In general, a back terminated cable (75Ω in series at the drive end and 75Ω to ground at the receiving end) is pre-

ferred since the impedance match at both ends will absorb any reflections. However, when double-termination is used, the received signal is reduced by half; therefore a gain of 2 configuration is typically used to compensate for the attenuation. In a gain of 2 configuration, with output swing of 2VPP, with each back-

terminated load at 150Ω. The EL2070C is capable of

driving up to 4 back-terminated loads with excellent video performance. Please refer to the typical curves for more information on video performance with respect to frequency, gain, and loading.

Capacitive Feedback

The EL2070C relies on its feedback resistor for proper compensation. A reduction of the impedance of the feedback element results in less stability, eventually resulting in oscillation. Therefore, circuit implementations which have capacitive feedback should not be used because of the capacitor's impedance reduction with frequency. Similarly, oscillations can occur when using the technique of placing a capacitor in parallel with the feedback resistor to compensate for shunt capacitances from the inverting input to ground.

Offset Adjustment Pin

Output offset voltage of the EL2070C can be nulled by tying a 10k potentiometer between +VS and -VS with the slider attached to pin 1. A full-range variation of the voltage at pin 1 to ±5V results in an offset voltage adjustment of at least ±10mV. For best settling performance pin 1 should be bypassed to ground with a ceramic capacitor located near to the package, even if the offset voltage adjustment feature is not being used.

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EL2070C

200MHz Current Feedback Amplifier

EL2070C

Printed Circuit Layout

As with any high frequency device, good PCB layout is necessary for optimum performance. Ground plane construction is a requirement, as is good power-supply and Offset Adjust bypassing close to the package. The inverting input is sensitive to stray capacitance, therefore connections at the inverting input should be minimal, close to the package, and constructed with as little coupling to the ground plane as possible.

Capacitance at the output node will reduce stability, eventually resulting in peaking, and finally oscillation if the capacitance is large enough. The design of the EL2070C allows a larger capacitive load than comparable products, yet there are occasions when a series resistor before the capacitance may be needed. Please refer to the graphs to determine the proper resistor value needed.

Disable/Enable Operation

The EL2070C has a disable/enable control input at pin 8. The device is enabled and operates normally when pin 8 is left open or tied to pin 7. When more than 350µA is pulled from pin 8, the EL2070C is disabled. The output becomes a high impedance, the inverting input is no longer driven to the positive input voltage, and the supply current is reduced by 2/3. To make it easy to use this feature, there is an internal resistor to limit the current to a safe level (0.8mA) if pin 8 is grounded.

To draw current out of pin 8 an open-collector TTL output, a 5V CMOS output, or an NPN transistor can be used.

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EL2070C Macromodel

* Revision A. March 1992 * Enhancements include PSRR, CMRR, and Slew Rate Limiting * Connections: +input * | -input * | | +Vsupply * | | | -Vsupply * | | | | output * | | | | | .subckt M2070C 3 2 7 4 6 * * Input Stage * e1 10 0 3 0 1.0 vis 10 9 0V h2 9 12 vxx 1.0 r1 2 11 50 l1 11 12 48nH iinp 3 0 8µA iinm 2 0 8µA * * Slew Rate Limiting * h1 13 0 vis 600 r2 13 14 1K d1 14 0 dclamp d2 0 14 dclamp * * High Frequency Pole * e2 30 0 14 0 0.00166666666 l3 30 17 0.1µH c5 17 0 0.1pF r5 17 0 500 * * Transimpedance Stage * g1 0 18 17 0 1.0 rol 18 0 150K cdp 18 0 2.8pF * * Output Stage * q1 4 18 19 qp q2 7 18 20 qn q3 7 19 21 qn q4 4 20 22 qp r7 21 6 2 r8 22 6 2

ios1 7 19 2.5mA ios2 20 4 2.5mA * * Supply Current * ips 7 4 9mA * * Error Terms * ivos 0 23 5mA vxx 23 0 0V e4 24 0 3 0 1.0 e5 25 0 7 0 1.0

EL2070C

200MHz Current Feedback Amplifier

Page 12

EL2070C

200MHz Current Feedback Amplifier

EL2070C

e6 26 0 4 0 1.0 r9 24 23 3K r10 25 23 1K r11 26 23 1K * * Models * .model qn npn (is=5e-15 bf=200 tf=0.05nS) .model qp pnp (is=5e-15 bf=200 tf=0.05nS) .model dclamp d(is=1e-30 ibv=0.266 bv=1.3 n=4) .ends

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EL2070C Macromodel

EL2070C

200MHz Current Feedback Amplifier

Page 14

EL2070C

200MHz Current Feedback Amplifier

EL2070C

General Disclaimer

Specifications contained in this data sheet are in effect as of the publication date shown. Elantec, Inc. reserves the right to make changes in the circuitry or specifications contained herein at any time without notice. Elantec, Inc. assumes no responsibility for the use of any circuits described herein and makes no representations that they are free from patent infringement.

WARNING - Life Support Policy

Elantec, Inc. products are not authorized for and should not be used within Life Support Systems without the specific written consent of Elantec, Inc. Life Support systems are equipment intended to sup-

Elantec Semiconductor, Inc.

675 Trade Zone Blvd. Milpitas, CA 95035 Telephone: (408) 945-1323

(888) ELANTEC Fax: (408) 945-9305 European Office: +44-118-977-6020 Japan Technical Center: +81-45-682-5820

port or sustain life and whose failure to perform when properly used in accordance with instructions provided can be reasonably expected to result in significant personal injury or death. Users contemplating application of Elantec, Inc. Products in Life Support Systems are requested to contact Elantec, Inc. factory headquarters to establish suitable terms & conditions for these applications. Elantec, Inc.’s warranty is limited to replacement of defective components and does not cover injury to persons or property or other consequential damages.

September 26, 2001

Printed in U.S.A.