® OPA349 OPA2349 OPA 349 OPA 349 OPA 234 9 For most current data sheet and other product information, visit www.burr-brown.com 1µA, Rail-to-Rail, CMOS OPERATIONAL AMPLIFIERS FEATURES DESCRIPTION ● ● ● ● ● ● ● ● ● ● The OPA349 and OPA2349 are ultra-low power operational amplifiers that provide 70kHz bandwidth with only 1µA quiescent current. These rail-to-rail input and output amplifiers are specifically designed for battery powered applications. Unlike some micropower op amps, these parts are unity-gain stable and require no external compensation. The OPA349’s low input bias current allows the use of large source and feedback resistors. The input common-mode voltage range extends 200mV beyond the power supply rails and the output swings to within 150mV of the rails, maintaining wide dynamic range. LOW SUPPLY CURRENT: 1µA GAIN-BANDWIDTH: 70kHz UNITY GAIN STABLE LOW INPUT BIAS CURRENT: 10pA WIDE SUPPLY RANGE: 1.8V to 5.5V INPUT RANGE 200mV BEYOND RAILS OUTPUT SWINGS TO 150mV OF RAILS OUTPUT DRIVE CURRENT: 20mA OPEN-LOOP GAIN: 90dB SOT23 MicroPACKAGES APPLICATIONS ● ● ● ● ● ● ● ● BATTERY PACKS AND POWER SUPPLIES PORTABLE PHONES/PAGERS/CAMERAS SOLAR-POWERED SYSTEMS SMOKE/GAS/FIRE DETECTION SYSTEMS REMOTE SENSORS PCMCIA CARDS DRIVING A/D CONVERTERS MicroPOWER FILTERS OPA349 can be operated with power supplies from 1.8V to 5.5V with little change in performance, guaranteeing continuing superior performance even in low battery situations. OPA349 comes in the miniature SOT23-5, SO-8 surface mount and PDIP-8(1) packages. OPA2349 dual is also available in the SOT23 (8-lead SOT23-8), as well as the SO-8 surface mount packages. These tiny packages are ideal for use in high-density applications, such as PCMCIA cards, battery packs and portable instruments. All models are specified for the commercial temperature range, 0°C to +70°C. OPA349 OPA349 Out 1 V– 2 +In 3 5 4 V+ –In OPA2349 NC 1 8 NC Out A 1 8 V+ –In 2 7 V+ –In A 2 7 Out B +In 3 6 Out +In A 3 6 –In B V– 4 5 NC V– 4 5 +In B SOT23-5 SO-8, PDIP-8(1) SOT23-8, SO-8 NOTE: (1) Available Q4 2000. International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 Twx: 910-952-1111 • Internet: http://www.burr-brown.com/ • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132 © 2000 Burr-Brown Corporation PDS-1568A Printed in U.S.A. June, 2000 SPECIFICATIONS: VS = +1.8V to +5.5V Boldface limits apply over the specified temperature range, TA = 0°C to +70°C At TA = +25°C, RL = 1MΩ connected to VS /2, unless otherwise noted. OPA349NA, UA, PA OPA2349EA, UA PARAMETER CONDITION OFFSET VOLTAGE Input Offset Voltage VOS Drift dVOS /dT vs Power Supply PSRR Channel Separation, dc (Dual version) INPUT VOLTAGE RANGE Common-Mode Voltage Range Common-Mode Rejection Ratio INPUT BIAS CURRENT Input Bias Current Input Offset Current VCM CMRR MIN VS = 5V, VCM = 2.5V (V–) – 0.2 52 48 OPEN-LOOP GAIN Open-Loop Voltage Gain Open-Loop Voltage Gain en in AOL OUTPUT Voltage Output Swing from Rail Output Current Short-Circuit Current FREQUENCY RESPONSE Gain-Bandwidth Product Slew Rate Settling Time, 0.1% 0.01% Overload Recovery Time POWER SUPPLY Specified Voltage Range Operating Voltage Range Quiescent Current (per amplifier) TEMPERATURE RANGE Specified Range Storage Range Thermal Resistance SOT23-5 Surface Mount SOT23-8 Surface Mount SO-8 Surface Mount PDIP-8 RL = 1MΩ, VS = +5.5V, +0.3V < VO < +5.2V R L = 10kΩ, VS = +5.5V, +0.35V < VO < +5.15V 74 74 RL = 1MΩ, VS = +5.5V, AOL > 74dB RL = 10kΩ, V S = +5.5V, AOL > 74dB CL = 10pF G = +1 VS = +5V, G = +1 VS = 5V, 1V Step VS = 5V, 1V Step VIN • Gain = VS ±10 350 10 1000 mV µV/°C µV/V µV/V (V+) + 0.2 V dB dB ±10 ±10 pA pA 72 60 1013 || 2 1013 || 4 Ω || pF Ω || pF 8 300 4 µVp-p nV/√Hz fA/√Hz 90 90 dB dB 300 350 70 0.02 65 80 5 1.8 1.8 VS IQ ±2 150 200 ±8 ±25 I SC GBW SR tS UNITS ±1 ±1 IB IOS INPUT IMPEDANCE Differential Common-Mode NOISE Input Voltage Noise, f = 0.1Hz to 10Hz Input Voltage Noise Density, f = 1kHz Current Noise Density, f = 1kHz MAX ±10 VS = 1.8V to 5.5V, VCM = (V–) + 0.3V RL = 100kΩ VS = +5V, –0.2V < VCM < 3.5V VS = +5V, –0.2V < VCM < 5.2V TYP IO = 0 1 0 –65 θJA 200 200 150 100 mV mV mA mA kHz V/µs µs µs µs 5.5 5.5 2 V V µA +70 +150 °C °C °C/W °C/W °C/W °C/W °C/W The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant any BURR-BROWN product for use in life support devices and/or systems. ® OPA349 2 ABSOLUTE MAXIMUM RATINGS(1) ELECTROSTATIC DISCHARGE SENSITIVITY Supply Voltage, V+ to V– ................................................................... 5.5V Signal Input Terminals, Voltage(2) .................. (V–) – 0.5V to (V+) + 0.5V Current(2) .................................................... 10mA Output Short Circuit(3) .............................................................. Continuous Operating Temperature .................................................. –55°C to +125°C Storage Temperature ..................................................... –65°C to +150°C Junction Temperature ...................................................................... 150°C Lead Temperature (soldering, 3s) ................................................... 300°C This integrated circuit can be damaged by ESD. Burr-Brown recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. NOTES: (1) Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these, or any other conditions beyond those specified, is not implied. (2) Input terminals are diode-clamped to the power supply rails. Input signals that can swing more than 0.5V beyond the supply rails should be current-limited to 10mA or less. (3) Short circuit to ground, one amplifier per package. PACKAGE/ORDERING INFORMATION PRODUCT PACKAGE PACKAGE DRAWING NUMBER Single OPA349NA SOT23-5 331 0°C to +70°C A49 " " " " OPA349UA " OPA349UA SPECIFIED TEMPERATURE RANGE PACKAGE MARKING ORDERING NUMBER(1) TRANSPORT MEDIA OPA349NA/250 OPA349NA/3K OPA349UA OPA349UA/2K5 OPA349PA Tape and Reel Tape and Reel Rails Tape and Reel Rails OPA2349EA/250 OPA2349EA/3K OPA2349UA OPA2349UA/2K5 Tape and Reel Tape and Reel Rails Tape and Reel SO-8 182 0°C to +70°C " " " " " OPA349PA(2) PDIP-8 006 0°C to +70°C OPA349PA Dual OPA2349EA SOT23-8 348 0°C to +70°C C49 " " " " " OPA2349UA SO-8 182 0°C to +70°C OPA2349UA " " " " " NOTE: (1) Models with a slash (/) are available only in Tape and Reel in the quantities indicated (e.g., /3K indicates 3000 devices per reel). Ordering 3000 pieces of “OPA2349EA/3K” will get a single 3000-piece Tape and Reel. (2) OPA349PA (DIP) available Q4 2000. ® 3 OPA349 TYPICAL PERFORMANCE CURVES At TA = +25°C, VS = 5V, unless otherwise noted. COMMON-MODE REJECTION RATIO vs FREQUENCY OPEN-LOOP GAIN AND PHASE vs FREQUENCY 70 100 90 0 60 80 50 60 50 90 40 30 CMRR (dB) 45 Phase (°) Gain (dB) 70 135 40 30 20 20 10 10 180 0 0 0.1 1 10 100 1k Frequency (Hz) 10k 100k 10 1M 90 90 80 80 Channel Separation (dB) 100 PSRR (dB) 70 60 +PSRR –PSRR 1k Frequency (Hz) 10k 100k CHANNEL SEPARATION vs FREQUENCY POWER SUPPLY REJECTION RATIO vs FREQUENCY 100 50 100 40 30 20 70 60 50 40 30 20 10 10 0 0 10 100 1k Frequency (Hz) 10k 10 100k 100 1k Frequency (Hz) 10k 100k OFFSET VOLTAGE DRIFT PRODUCTION DISTRIBUTION INPUT VOLTAGE NOISE DENSITY 400 Population Voltage Noise (nV/√Hz) 1000 100 10 100 1k 10k –30 –25 –20 –15 –10 –5 Frequency (Hz) ® OPA349 0 5 10 15 20 25 30 35 40 Offset Voltage Drift 4 TYPICAL PERFORMANCE CURVES (Cont.) At TA = +25°C, unless otherwise noted. QUIESCENT CURRENT vs TEMPERATURE OUTPUT VOLTAGE vs OUTPUT CURRENT 16 V+ 0°C to +70°C (V+)–1 12 Output Voltage (V) Quiescent Current (µA) 14 OPA2349 (per channel) 10 8 6 4 Sourcing Current (V+)–2 (V+)+2 Sinking Current (V–)+1 2 0°C to +70°C OPA349 V– 0 –75 –50 –25 0 25 50 Temperature (°C) 75 100 125 0 1 2 3 4 5 Output Current (mA) 6 7 8 LARGE-SIGNAL STEP RESPONSE G = 1, RL = 1MΩ MAXIMUM OUTPUT VOLTAGE vs FREQUENCY 6 VS = +5.5V VS = +5V 1V/div 4 3 VS = +2.5V 2 VS = +1.8V 1 0 100 1k 10k 100k 100µs/div Frequency (Hz) SMALL-SIGNAL STEP RESPONSE G = 1, RL = 1MΩ, CL = 500pF 50mV/div SMALL-SIGNAL STEP RESPONSE G = 1, RL = 1MΩ, CL = 20pF 50mV/div Output Voltage (Vp-p) 5 100µs/div 40µs/div ® 5 OPA349 APPLICATIONS INFORMATION value reacts with input capacitance and stray capacitance to produce a pole in the feedback network. A feedback capacitor may be required to assure stability and limit overshoot or gain peaking. Check circuit performance carefully to assure that biasing and feedback techniques meet your signal and quiescent current requirements. OPA349 series op amps are unity gain stable and can operate on a single supply, making them highly versatile and easy to use. Power supply pins should be by passed with 0.01µF ceramic capacitors. OPA349 series op amps are fully specified and guaranteed from +1.8V to +5.5V. Parameters that vary significantly with operating voltages or temperature are shown in the Typical Performance Curves. RAIL-TO-RAIL INPUT The input common-mode voltage range of the OPA349 series extends 200mV beyond the supply rails. This is achieved with a complementary input stage—an N-channel input differential pair in parallel with a P-channel differential pair (see Figure 2). The N-channel pair is active for input voltages close to the positive rail, typically (V+) – 1.3V to 200mV above the positive supply, while the P-channel pair is on for inputs from 200mV below the negative supply to approximately (V+) – 1.3V. There is a small transition region, typically (V+) – 1.5V to (V+) – 1.1V, in which both pairs are on. This 400mV transition region can vary 300mV with process variation. Thus, the transition region (both stages on) can range from (V+) – 1.8V to (V+) – 1.4V on the low end, up to (V+) – 1.2V to (V+) – 0.8V on the high end. Within the 400mV transition region PSRR, CMRR, offset voltage, offset drift, and THD may be degraded compared to operation outside this region. For more information on designing with rail-to-rail input op amps, see Figure 3 “Design Optimization with Rail-to-Rail Input Op Amps.” The ultra low quiescent current of the OPA349 requires careful applications circuit techniques to achieve low overall current consumption. Figure 1 shows an ac-coupled amplifier biased with a voltage divider. Resistor values must be very large to minimize current. The large feedback resistor +1.8 to 5.5V CF 3pF R3 2M R1 10M R5 10M CF may be required for best stability or to reduce frequency peaking—see text. G = 11 10nF OPA349 R2 10M VOUT R4 2M FIGURE 1. AC-Coupled Amplifier. V+ Reference Current VIN+ VIN– VBIAS1 VBIAS2 V– (Ground) FIGURE 2. Simplified Schematic. ® OPA349 6 Class AB Control Circuitry VO DESIGN OPTIMIZATION WITH RAIL-TO-RAIL INPUT OP AMPS swing is required. A design option would be to configure the op amp as a unity-gain inverter as shown below and hold the noninverting input at a set common-mode voltage outside the transition region. This can be accomplished with a voltage divider from the supply. The voltage divider should be designed such that the biasing point for the noninverting input is outside the transition the region. In most applications, operation is within the range of only one differential pair. However, some applications can subject the amplifier to a common-mode signal in the transition region. Under this condition, the inherent mismatch between the two differential pairs may lead to degradation of the CMRR and THD. The unity-gain buffer configuration is the most problematic—it will traverse through the transition region if a sufficiently wide input R R VOUT VIN VCM FIGURE 3. Design Optimization. COMMON-MODE REJECTION The CMRR for the OPA349 is specified in two ways so the best match for a given application may be used. First, the CMRR of the device in the common-mode range below the transition region (VCM < (V+) – 1.5V) is given. This specification is the best indicator of the capability of the device when the application requires use of one of the differential input pairs. Second, the CMRR at VS = 5V over the entire commonmode range is specified. is driven to the low limit (Figure 4). Similarly, loads that can cause current to flow out of the output pin when the output voltage is near V– can cause oscillations. The op amp will recover to normal operation a few milliseconds after the output is driven positively out of the rail. Some op amp applications can produce this condition even without a load connected to V– The integrator in Figure 4a shows an example. Assume that the output ramps negatively, and saturates near 0V. Any negative-going step at VIN will produce a positive output current pulse through R1 and C1. This may incite the oscillation. Diode, D1, prevents the input step from pulling output current when the output is saturated at the rail, thus preventing the oscillation. RAIL-TO-RAIL OUTPUT A class AB output stage with common-source transistors is used to achieve rail-to-rail output. Loads that connect to single supply ground (or the V- supply pin) can cause the op amp to oscillate if the output voltage a) V+ b) V+ R1 1M C1 1nF VIN 2V VO OPA349 VIN 0V D1 1N4148 OPA349 (No Load) 0V RL 1V 0V FIGURE 4. Output Driven to Negative Rail. ® 7 OPA349