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OPA683

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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

SBOS221E – NOVEMBER 2001 – REVISED JULY 2008

Very Low-Power, Current Feedback

OPERATIONAL AMPLIFIER With Disable

FEATURES

● REDUCED BANDWIDTH CHANGE VERSUS GAIN

● 150MHz BANDWIDTH G = +2

● > 90MHz BANDWIDTH TO GAIN > +10

● LOW DISTORTION: < –69dBc at 5MHz

● HIGH OUTPUT CURRENT: 110mA

● SINGLE +5V TO +12V SUPPLY OPERATION

● DUAL ±2.5V TO ±6V SUPPLY OPERATION

● LOW SUPPLY CURRENT: 0.94mA

● LOW SHUTDOWN CURRENT: 100µA

V+

V–

ERR

U.S. Patent No. 6,724,260

(S)

ERR

Low-Power Amplifier

–3

–6

–9

–12

–15

–18

–21

Normalized Gain (dB)

1 10 200100

= 1.2kΩ

Frequency (MHz)

OPA683 BANDWIDTH vs GAIN

G = 10

G = 20

G = 50

G = 100

G = 2

G = 5

DESCRIPTION

The OPA683 provides a new level of performance in very low-

power, wideband, current feedback amplifiers. This CFB

plus

ampli-

fier is among the first to use an internally closed-loop input buffer

stage that enhances performance significantly over earlier low-

power CFB amplifiers. While retaining the benefits of very low

power operation, this new architecture provides many of the

advantages of a more ideal CFB amplifier. The closed-loop input

stage buffer gives a very low and linearized impedance path at the

inverting input to sense the feedback error current. This improved

inverting input impedance gives exceptional bandwidth retention to

much higher gains and improved harmonic distortion over earlier

solutions limited by inverting input linearity. Beyond simple high

gain applications, the OPA683 CFB

plus

amplifier can allow the gain

setting element to be set with considerable freedom from amplifier

bandwidth interaction. This allows frequency response peaking

elements to be added, multiple input inverting summing circuits to

APPLICATIONS

● LOW POWER BROADCAST VIDEO DRIVERS

● EQUALIZING FILTERS

● SAW FILTER HIGH GAIN POST AMPLIFIERS

● SHORT LOOP ADSL CO DRIVERS

● MULTICHANNEL SUMMING AMPLIFIERS

● PROFESSIONAL CAMERAS

● ADC INPUT DRIVERS

have greater bandwidth, and low-power line drivers to meet the

demanding requirements of studio cameras and broadcast video.

The output capability for the OPA683 also sets a new mark in

performance for very low-power current feedback amplifiers. De-

livering a full ±4V

swing on ±5V supplies, the OPA683 also has

the output current to support this swing into a 100Ω load. This

minimal output headroom requirement is complemented by a

similar 1.2V input stage headroom giving exceptional capability for

single +5V operation.

The OPA683’s low 0.94mA supply current is precisely trimmed at

25°C. This trim, along with low shift over temperature and supply

voltage, gives a very robust design over a wide range of operating

conditions. System power may be further reduced by using the

optional disable control pin. Leaving this disable pin open, or holding

it HIGH, gives normal operation. If pulled LOW, the OPA683 supply

current drops to less than 100µA while the I/O pins go to a high

impedance state.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

All trademarks are the property of their respective owners.

Summary of content (31 pages)

PAGE 1
OPA683 OPA 683 OPA68 3 SBOS221E – NOVEMBER 2001 – REVISED JULY 2008 www.ti.com Very Low-Power, Current Feedback OPERATIONAL AMPLIFIER With Disable FEATURES APPLICATIONS ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● REDUCED BANDWIDTH CHANGE VERSUS GAIN 150MHz BANDWIDTH G = +2 > 90MHz BANDWIDTH TO GAIN > +10 LOW DISTORTION: < –69dBc at 5MHz HIGH OUTPUT CURRENT: 110mA SINGLE +5V TO +12V SUPPLY OPERATION DUAL ±2.5V TO ±6V SUPPLY OPERATION LOW SUPPLY CURRENT: 0.
PAGE 2
ELECTROSTATIC DISCHARGE SENSITIVITY ABSOLUTE MAXIMUM RATINGS(1) Power Supply ............................................................................... ±6.5VDC Internal Power Dissipation ................................. See Thermal Information Differential Input Voltage .................................................................. ±1.2V Input Voltage Range ............................................................................ ±VS Storage Temperature Range: ID, IDBV ........................
PAGE 3
ELECTRICAL CHARACTERISTICS: VS = ±5V Boldface limits are tested at +25°C. RF = 1.2kΩ, RL = 1kΩ, and G = +2 (see Figure 1 for AC performance only), unless otherwise noted. OPA683ID, IDBV TYP PARAMETER AC PERFORMANCE (See Figure 1) Small-Signal Bandwidth (VO = 0.5VPP) Bandwidth for 0.
PAGE 4
ELECTRICAL CHARACTERISTICS: VS = +5V Boldface limits are tested at +25°C. RF = 1.4kΩ, RL = 1kΩ, and G = +2 (see Figure 3 for AC performance only), unless otherwise noted. OPA683ID, IDBV TYP PARAMETER AC PERFORMANCE (See Figure 3) Small-Signal Bandwidth (VO = 0.2VPP) Bandwidth for 0.
PAGE 5
TYPICAL CHARACTERISTICS: VS = ±5V TA = 25°C, RF = 1.2kΩ, RL = 1kΩ, and G = +2 (see Figure 1 for AC performance only), unless otherwise noted. NONINVERTING SMALL-SIGNAL FREQUENCY RESPONSE VO = 0.5VPP RF = 1.2kΩ 3 INVERTING SMALL-SIGNAL FREQUENCY RESPONSE 3 G = 100 G=1 0 G=2 –3 –6 G = 10 G=5 –9 0 –6 G = –2 –9 See Figure 2 –12 1 10 100 200 1 10 NONINVERTING LARGE-SIGNAL FREQUENCY RESPONSE VO = 0.5VPP 0 VO = 1VPP VO = 1VPP Gain (dB) Gain (dB) G = –1 RL = 1kΩ VO = 0.
PAGE 6
TYPICAL CHARACTERISTICS: VS = ±5V (Cont.) TA = 25°C, RF = 1.2kΩ, RL = 1kΩ, and G = +2 (see Figure 1 for AC performance only), unless otherwise noted. HARMONIC DISTORTION vs LOAD RESISTANCE HARMONIC DISTORTION vs FREQUENCY –50 –50 VO = 2VPP f = 5MHz G = +2 –60 VO = 2VPP RL = 1kΩ 2nd-Harmonic Harmonic Distortion (dBc) Harmonic Distortion (dBc) –55 –65 –70 –75 –80 –85 –60 2nd-Harmonic –70 3rd-Harmonic –80 3rd-Harmonic See Figure 1 –90 See Figure 1 –90 100 0.
PAGE 7
TYPICAL CHARACTERISTICS: VS = ±5V (Cont.) TA = 25°C, RF = 1.2kΩ, RL = 1kΩ, and G = +2 (see Figure 1 for AC performance only), unless otherwise noted. 2-TONE, 3RD-ORDER INTERMODULATION DISTORTION INPUT VOLTAGE AND CURRENT NOISE DENSITY –45 Inverting Current Noise 11.6pA/√Hz Noninverting Current Noise 5.2pA/√Hz 10 Voltage Noise 4.4nV/√Hz 3rd-Order Spurious Level (dBc) Voltage Noise (nV/√Hz) Current Noise (pA/√Hz) 100 20MHz –55 10MHz +5V –65 PI 1kΩ –5V 1.2kΩ –75 1.
PAGE 8
TYPICAL CHARACTERISTICS: VS = ±5V (Cont.) TA = 25°C, RF = 1.2kΩ, RL = 1kΩ, and G = +2 (see Figure 1 for AC performance only), unless otherwise noted.
PAGE 9
TYPICAL CHARACTERISTICS: VS = ±5V (Cont.) TA = 25°C, RF = 1.2kΩ, RL = 1kΩ, and G = +2 (see Figure 1 for AC performance only), unless otherwise noted. SETTLING TIME DISABLED SUPPLY CURRENT vs TEMPERATURE 0.05 110 0.03 0.02 0.01 0 –0.01 –0.02 –0.03 100 90 80 70 –0.04 +VS Current –0.05 60 0 10 20 30 Time (ns) 40 50 60 –50 0 25 50 75 Ambient Temperature (°C) 125 8.0 3.2 6.4 6.4 6.4 2.4 4.8 4.8 4.8 1.6 3.2 0.8 1.6 0 0 Output Voltage Right Scale –0.8 –1.6 See Figure 1 –1.
PAGE 10
TYPICAL CHARACTERISTICS: VS = +5V TA = 25°C, RF = 1.4kΩ, RL = 1kΩ, and G = +2 (see Figure 3 for AC performance only), unless otherwise noted. NONINVERTING SMALL-SIGNAL FREQUENCY RESPONSE 3 Normalized Gain (dB) 0 INVERTING SMALL-SIGNAL FREQUENCY RESPONSE 3 G = 50 RF = 1.4kΩ VO = 0.2VPP RL = 1kΩ G=1 Normalized Gain (3dB/div) 6 G=2 –3 –6 G=5 –9 G = 10 –12 –15 0 –3 RF = 1.4kΩ VO = 0.2VPP RL = 1kΩ –6 G = 20 See Figure 3 –18 See Figure 4 –12 1 10 100 200 1 10 Frequency (MHz) 0.
PAGE 11
TYPICAL CHARACTERISTICS: VS = +5V (Cont.) TA = 25°C, RF = 1.4kΩ, RL = 1kΩ, and G = +2 (see Figure 3 for AC performance only), unless otherwise noted. HARMONIC DISTORTION vs FREQUENCY HARMONIC DISTORTION vs LOAD RESISTANCE –50 –50 3rd-Harmonic Harmonic Distortion (dBc) Harmonic Distortion (dBc) VO = 2VPP RL = 1kΩ VO = 2VPP f = 5MHz –55 –60 –65 –70 2nd-Harmonic –75 –80 3rd-Harmonic –60 2nd-Harmonic –70 –80 –85 See Figure 3 See Figure 3 –90 –90 100 0.
PAGE 12
APPLICATIONS INFORMATION VERY LOW POWER CURRENT-FEEDBACK OPERATION The OPA683 gives a new level of performance in very low power current-feedback op amps. Using a new input stage buffer architecture, the OPA683 CFBplus amplifier gives improved bandwidth to higher gains than previous < 1mA supply current amplifiers. This closed-loop internal buffer gives a very low and linearized impedance at the inverting node—isolating the amplifier’s AC performance from gain element variations.
PAGE 13
+5V 0.1µF 50Ω Source + +5V 6.8µF 12.5kΩ 0.1µF 0.1µF 2.5V VI 0.1µF 50Ω 12.5kΩ OPA683 DIS RF 1.4kΩ + 6.8µF 12.5kΩ 2.5V VO 0.1µF 0.1µF 1kΩ 50Ω Source 0.1µF 12.5kΩ OPA683 DIS RF 1.4kΩ RG 1.4kΩ VO 1kΩ VI RG 1.4kΩ 52.3Ω 0.1µF FIGURE 3. AC-Coupled, G = +2V/V, Single-Supply, Specification and Test Circuit. into this midpoint voltage bias. The input voltage can swing to within 1.25V of either supply pin, giving a 2.5VPP input signal range centered between the supply pins.
PAGE 14
VERY LOW POWER ACTIVE FILTER HIGH GAIN HF AMPLIFIER The OPA683 provides an exceptionally capable gain block for implementing Sallen-Key type filters. Typically, the bandwidth interaction with gain setting for low power amplifiers, constrain these filters to using unity-gain amplifiers. Since the OPA683 CFBplus design holds very high bandwidth to high gains, implementations that provide signal gain, as well as the desired filter shape, are easily implemented.
PAGE 15
RI 1.4kΩ +5V DIS RG 2.5VDC VI 60Ω OPA683 VO IN ADS820 10-Bit 20MSPS 22pF VO = – 1.4kΩ RG VI 2VPP Max 50Ω IN +2.5V CM 0.1µF FIGURE 9. Low Power, Single-Supply, ADC Driver. DESIGN-IN TOOLS DEMONSTRATION FIXTURES VI Two printed circuit boards (PCBs) are available to assist in the initial evaluation of circuit performance using the OPA683 in its two package options. Both of these are offered free of charge as unpopulated PCBs, delivered with a user's guide.
PAGE 16
 R  α 1 + F  R  VO α NG G = = VI  RF  1 + RF + RI NG RF + RI 1 +  Z (S )  RG  1+ Z (S )   R  NG = 1 + F    R G    This is written in a loop-gain analysis format where the errors arising from a non-infinite open-loop gain are shown in the denominator. If Z(s) was infinite over all frequencies, the denominator of Equation 1 would reduce to 1 and the ideal desired signal gain shown in the numerator would be achieved.
PAGE 17
OUTPUT CURRENT AND VOLTAGE The OPA683 provides output voltage and current capabilities that can support the needs of driving doubly-terminated 50Ω lines. Changing the 1kΩ load in Figure 1 to a 100Ω will give a total load that is the parallel combination of the 100Ω load and the 2.4kΩ total feedback network impedance. This 96Ω load will require no more than 36mA output current to support a ±3.5V output voltage swing.
PAGE 18
cludes the feedback network—in the noninverting configuration (see Figure 1) this is the sum of RF + RG, while in the inverting configuration it is just RF. Also, providing an additional supply decoupling capacitor (0.1µF) between the supply pins (for bipolar operation) improves the 2nd-order distortion slightly (3dB to 6dB). In most op amps, increasing the output voltage swing increases harmonic distortion directly.
PAGE 19
the two input bias currents, gives a worst case output offset range equal to: ±(NG • VOS(MAX)) ± (IBN • RS/2 • NG) ± (IBI • RF) where NG = noninverting signal gain = ±(2 • 3.5mV) ± (4µA • 25Ω • 2) ± (1.2kΩ • 10µA) = ±7mV ± 0.1mV ± 12mV = ±19.1mV While the last term, the inverting bias current error, is dominant in this low-gain circuit, the input offset voltage will become the dominant DC error term as the gain exceeds 4V/V.
PAGE 20
BOARD LAYOUT GUIDELINES is a good starting point for design. Note that a 1.2kΩ feedback resistor, rather than a direct short, is required for the unity-gain follower application. A current-feedback op amp requires a feedback resistor even in the unity-gain follower configuration to control stability. Achieving optimum performance with a high frequency amplifier like the OPA683 requires careful attention to board layout parasitics and external component types.
PAGE 21
INPUT AND ESD PROTECTION The OPA683 is built using a very high speed complementary bipolar process. The internal junction breakdown voltages are relatively low for these very small geometry devices. These breakdowns are reflected in the Absolute Maximum Ratings table where an absolute maximum 13V across the supply pins is reported. All device pins have limited ESD protection using internal diodes to the power supplies as shown in Figure 15.
PAGE 22
Revision History DATE REVISION 7/08 E 3/06 D PAGE SECTION 2 Abs Max Ratings 3, 4 Electrical Characteristics, Power Supply 15 Design-In Tools DESCRIPTION Changed Storage Temperature Range from −40°C to +125C to −65°C to +125C. Added minimum supply voltage. Board part number changed. NOTE: Page numbers for previous revisions may differ from page numbers in the current version. OPA683 22 www.ti.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com 11-Apr-2013 (4) Multiple Top-Side Markings will be inside parentheses. Only one Top-Side Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Top-Side Marking for that device. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided.
PAGE 25
PACKAGE MATERIALS INFORMATION www.ti.com 26-Jan-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) OPA683IDBVR SOT-23 DBV 6 3000 180.0 OPA683IDBVT SOT-23 DBV 6 250 OPA683IDR SOIC D 8 2500 B0 (mm) K0 (mm) P1 (mm) 8.4 3.2 3.1 1.39 4.0 180.0 8.4 3.2 3.1 1.39 330.0 12.4 6.4 5.2 2.1 Pack Materials-Page 1 W Pin1 (mm) Quadrant 8.0 Q3 4.0 8.0 Q3 8.0 12.
PAGE 26
PACKAGE MATERIALS INFORMATION www.ti.com 26-Jan-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) OPA683IDBVR SOT-23 DBV 6 3000 210.0 185.0 35.0 OPA683IDBVT SOT-23 DBV 6 250 210.0 185.0 35.0 OPA683IDR SOIC D 8 2500 367.0 367.0 35.
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IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.