MAX4490AXK+

19-1525; Rev 2; 4/01 Low-Cost, High-Slew-Rate, Rail-to-Rail I/O Op Amps in SC70 Features ♦ 2.7V to 5.5V Single-Supply Operation ♦ 10V/µs Slew Rate ♦ Rail-to-Rail Input Common-Mode Voltage Range ♦ Rail-to-Rail Output Voltage Swing ♦ 10MHz Gain-Bandwidth Product ♦ Unity-Gain Stable with Capacitive Loads Up to 300pF ♦ 50pA Input Bias Current ♦ Ultra-Small, 5-Pin SC70 Package (MAX4490) Ordering Information Applications PART Battery-Powered Instruments TEMP RANGE PINPACKAGE Portable Equipment MAX4490AXK-T -40°C to +125°C 5 SC70-5 Audio Signal Conditioning MAX4490AUK-T MAX4491AKA-T MAX4491AUA MAX4492AUD MAX4492ASD 5 SOT23-5 8 SOT23-5 8 µMAX 14 TSSOP 14 SO Low-Power/Low-Voltage Applications Sensor Amplifiers RF Power Amplifier Control -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C TOP MARK AAB ADKQ AADB — — — High-Side/Low-Side Current Sensors Pin Configurations/ Functional Diagrams Capacitive-Load Stability 6000 TOP VIEW IN+ 4000 3000 1 VSS 2 MAX4490 5 VDD 4 OUT + - CAPACITIVE LOAD (pF) 5000 UNSTABLE 2000 IN- 3 1000 STABLE SOT23-5/SC70-5 0 100 1k 10k 100k RESISTIVE LOAD (Ω) Pin Configurations continued at end of data sheet. Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd. ________________________________________________________________ Maxim Integrated Products 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. 1 MAX4490/MAX4491/MAX4492 General Description The MAX4490/MAX4491/MAX4492 single/dual/quad, low-cost CMOS op amps feature Rail-to-Rail® input and output capability from either a single 2.7V to 5.5V supply or dual ±1.35V to ±2.75V supplies. These amplifiers exhibit a high slew rate of 10V/µs and a gain-bandwidth product of 10MHz. They can drive 2kΩ resistive loads to within 55mV of either supply rail and remain unitygain stable with capacitive loads up to 300pF. The MAX4490 is offered in the ultra-small, 5-pin SC70 package, which is 50% smaller than the standard 5-pin SOT23 package. Specifications for all parts are guaranteed over the automotive (-40°C to +125°C) temperature range. MAX4490/MAX4491/MAX4492 Low-Cost, High-Slew-Rate, Rail-to-Rail I/O Op Amps in SC70 ABSOLUTE MAXIMUM RATINGS Supply Voltage (VDD to VSS) ....................................................6V All Other Pins ...................................(VSS - 0.3V) to (VDD + 0.3V) Output Short-Circuit Duration .................................................10s Continuous Power Dissipation (TA = +70°C) 5-Pin SC70 (derate 2.5mW/°C above +70°C) ............ 200mW 5-Pin SOT23 (derate 7.1mW/°C above +70°C).......... 571mW 8-Pin SOT23 (derate 5.26mW/°C above +70°C)........421 mW 8-Pin µMAX (derate 4.1mW/°C above +70°C) ........... 330mW 14-Pin TSSOP (derate 8.3mW/°C above +70°C) ....... 667mW 14-Pin SO (derate 8.3mW/°C above +70°C).............. 667mW Operating Temperature Range ........................ -40°C to +125°C Junction Temperature ..................................................... +150°C Storage Temperature Range ............................ -65°C to +150°C Lead 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 functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VDD = 5V, VSS = 0, VCM = 0, VOUT = VDD/2, RL = 100kΩ connected to VDD/2, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Supply Voltage Range Supply Current (per amplifier) Input Offset Voltage Input Bias Current Input Offset Current SYMBOL VDD CONDITIONS (Note 2) MIN TYP 2.7 IS TA = +25°C 5.5 V 0.8 2 mA ±1.5 ±10 (Note 3) IB (Note 3) ±0.05 ±2.5 nA IOS (Note 3) ±0.05 ±2.5 nA RIN Input Common-Mode Range VCM TA = TMIN to TMAX 16 VSS 54 CMRR VSS ≤ VCM ≤ VDD Power-Supply Rejection Ratio PSRR 2.7V ≤ VDD ≤ 5.5V 65 (VSS + 0.25V) ≤ VOUT ≤ (VDD - 0.25V) RL = 100kΩ VDD dB 100 dB 110 AV Output-Voltage Swing High VOH Specified as VDD - VOH RL = 100kΩ 1.5 RL = 2kΩ 55 Output-Voltage Swing Low VOL Specified as VOL - VSS RL = 100kΩ 1.5 RL = 2kΩ 35 Input Capacitance IOUT(SC) GBWP Sourcing or sinking CL = 10pF CIN 65 V 75 Large-Signal Voltage Gain RL = 2kΩ mV MΩ 1000 Inferred from CMRR test Common-Mode Rejection Ratio Gain-Bandwidth Product UNITS VOS Input Resistance Output Short-Circuit Current MAX dB 85 200 150 mV mV ±50 mA 10 MHz 5 pF degrees Phase Margin CL = 10pF 60 Gain Margin CL = 10pF 10 dB Slew Rate SR Measured from 10% to 90% of 4VP-P step 10 V/µs Voltage-Noise Density en ƒ = 10kHz 12 nV/√Hz Current-Noise Density in ƒ = 10kHz 1 fA√Hz 300 pF Capacitive-Load Drive AV(CL) = 1, no sustained oscillations Note 1: All units production tested at TA = +25°C. Limits over temperature guaranteed by design. Note 2: Guaranteed by the Power-Supply Rejection Ratio (PSRR) test. Note 3: Input Offset Voltage, Input Bias Current, and Input Offset Current are all tested and guaranteed at both ends of the commonmode range. 2 _______________________________________________________________________________________ Low-Cost, High-Slew-Rate, Rail-to-Rail I/O Op Amps in SC70 650 VDD = 2.7V 600 700 600 500 400 300 -0.8 -1.0 -1.2 -1.4 200 -1.6 100 -1.8 -2.0 2.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 3.0 3.5 4.0 4.5 5.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 5.5 SUPPLY VOLTAGE (V) TEMPERATURE (°C) OUTPUT SWING HIGH vs. TEMPERATURE OUTPUT SWING LOW vs. TEMPERATURE OP AMP GAIN AND PHASE vs. FREQUENCY 70 VDD = 2.7V RL = 2kΩ 40 30 50 10 0 90 GAIN 40 20 VDD = 5V OR 2.7V RL = 100kΩ 135 40 VDD = 5V RL = 2kΩ 30 45 30 0 20 PHASE -45 10 VDD = 2.7V RL = 2kΩ -90 0 VDD = 5V OR 2.7V RL = 100kΩ AV = 1000 CL = 10pF -10 0 -135 -180 10M -20 10k -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) TEMPERATURE (°C) FREQUENCY (Hz) LARGE-SIGNAL GAIN vs. TEMPERATURE POWER-SUPPLY REJECTION RATIO vs. FREQUENCY 180 130 VDD = 5V GAIN 90 30 45 20 0 10 -45 -90 PHASE 0 AV = 1000 CLOAD = 200pF -10 1k 120 10k 100k FREQUENCY (Hz) 1M -180 10M 100k 1M 0 AV = 1 -10 -20 -30 110 100 -40 -50 -60 -70 90 -80 80 -100 -135 -20 100 PHASE (DEGREES) 40 LARGE-SIGNAL GAIN (dB) 135 50 1k MAX4490 toc09 60 PSSR (dB) MAX4490 toc07 100 MAX4490 toc08 GAIN AND PHASE vs. FREQUENCY (WITH CLOAD) 180 50 GAIN (dB) 60 50 VOUT - VSS (mV) 60 MAX4490 toc06 60 MAX4490 toc05 70 80 MAX4490 toc04 VDD = 5V RL = 2kΩ 10 2.5 TEMPERATURE (°C) 80 20 MAX4490 toc03 -0.6 0 500 VDD - VOUT (mV) -0.4 -90 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) _______________________________________________________________________________________ 3 PHASE (DEGREES) 700 550 GAIN (dB) MAX4490 toc02 800 750 0 -0.2 OFFSET VOLTAGE (mV) VDD = 5V 900 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) 1000 MAX4490 toc 01 850 800 INPUT OFFSET VOLTAGE vs. TEMPERATURE SUPPLY CURRENT PER AMPLIFIER vs. SUPPLY VOLTAGE SUPPLY CURRENT PER AMPLIFIER vs. TEMPERATURE MAX4490/MAX4491/MAX4492 Typical Operating Characteristics (VDD = 5V, VSS = 0, VCM = VDD/2, RL = 100kΩ to VDD/2, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VDD = 5V, VSS = 0, VCM = VDD/2, RL = 100kΩ to VDD/2, TA = +25°C, unless otherwise noted.) 100 AV = 1V/V 2Vp-p SIGNAL 500kHz LOWPASS FILTER 0.035 0.030 THD + NOISE (%) RL = 2kΩ 10 1 MAX4490toc12 AV = 1 MAX4490 toc11 0.040 MAX4490 toc10 1k LARGE-SIGNAL TRANSIENT RESPONSE (NONINVERTING) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY OUTPUT IMPEDANCE vs. FREQUENCY IN V/div 0.025 0.020 0.015 RL = 10kΩ 0.010 0.1 OUT V/div 0.005 0.01 0 1k 10k 100k 1M 10 10M 100 1k 10k 40µs/div 100k FREQUENCY (Hz) LARGE-SIGNAL TRANSIENT RESPONSE (INVERTING) SMALL-SIGNAL TRANSIENT RESPONSE (NONINVERTING) SMALL-SIGNAL TRANSIENT RESPONSE (INVERTING) MAX4490toc13 MAX4490toc14 FREQUENCY (Hz) AV = 1 MAX4490toc15 100 IN IN IN 2V/div 50mV/div 50mV/div OUT OUT 2V/div 50mV/div AV = -1 OUT 50mV/div 40µs/div 40µs/div 4 -20 -40 8 6 4 AV = 1 10% TO 90% STEP 2 4µs/div AV = 1, VIN CONNECTED TO VDD/2, RL = 2kΩ 0 CROSSTALK (dB) SLEW RATE (V/µS) 10 OUT 1V/div MAX4491/MAX4492 CROSSTALK vs. FREQUENCY MAX4490 toc17 12 MAX4490toc16 VDD AV = -1 SLEW RATE vs. SUPPLY VOLTAGE POWER-UP TRANSIENT RESPONSE 2V/div 40µs/div AV = 1 MAX4492toc18 OUTPUT IMPEDANCE (Ω) MAX4490/MAX4491/MAX4492 Low-Cost, High-Slew-Rate, Rail-to-Rail I/O Op Amps in SC70 3.0 3.5 -80 -100 0 2.5 -60 4.0 4.5 SUPPLY VOLTAGE (V) 5.0 5.5 -120 0.001 0.01 0.1 1 10 FREQUENCY (MHz) _______________________________________________________________________________________ 100 1000 Low-Cost, High-Slew-Rate, Rail-to-Rail I/O Op Amps in SC70 PIN NAME FUNCTION MAX4490 MAX4491 MAX4492 1 — — IN+ Noninverting Input 2 4 11 VSS Negative Supply Input. Connect to ground for single-supply operation. 3 — — IN- Inverting Input 4 — — OUT Amplifier Output 5 8 4 VDD Positive Supply Input — 3 3 INA+ Noninverting Input to Amplifier A — 2 2 INA- Inverting Input to Amplifier A — 1 1 OUTA Amplifier A Output — 5 5 INB+ Noninverting Input to Amplifier B — 6 6 INB- Inverting Input to Amplifier B — 7 7 OUTB — — 10, 12 INC+, IND+ Noninverting Inputs to Amplifiers C and D — — 9, 13 INC-, IND- Inverting Inputs to Amplifiers C and D — — 8, 14 OUTC, OUTD Amplifier B Output Amplifiers C and D Outputs Detailed Description Rail-to-Rail Input Stage The MAX4490/MAX4491/MAX4492 CMOS operational amplifiers have parallel-connected N- and P-channel differential input stages that combine to accept a common-mode range extending to both supply rails. The Nchannel stage is active for common-mode input voltages typically greater than (VSS + 1.2V), and the Pchannel stage is active for common-mode input voltages typically less than (VDD - 1.2V). Rail-to-Rail Output Stage The MAX4490/MAX4491/MAX4492 CMOS operational amplifiers feature class-AB push-pull output stages that can drive a 100kΩ load to within 1.5mV of either supply rail. Short-circuit output current is typically ±50mA. Figures 1a and 1b show the typical temperature dependence of output source and sink currents, respectively, for three fixed values of (VDD - VOH) and (VOL - VSS). For example, at VDD = 5.0V, the load currents that maintain (VDD - VOH) = 100mV and (VOL - VSS) = 100mV at TA = +25°C are 2.2mA and 3.3mA, respectively, when the load is connected to VDD/2. Consistent resistivedrive capability is (2.5 - 0.1) / 2.2 = 1.1kΩ. For the same application, resistive-drive capability is 2.2kΩ when the load is connected to VDD or VSS. Applications Information Power-Supply Considerations The MAX4490/MAX4491/MAX4492 operate from a single 2.7V to 5.5V supply or from dual ±1.35V to ±2.75V supplies with typically 800µA supply current per amplifier. A high power-supply rejection ratio of 100dB allows for extended operation from a decaying battery voltage, thereby simplifying designs for portable applications. For single-supply operation, bypass the power supply with a 0.1µF ceramic capacitor placed close to the VDD pin. For dual-supply operation, bypass each supply to ground. Input Capacitance One consequence of the parallel-connected differential input stages for rail-to-rail operation is a relatively large input capacitance CIN (typically 5pF). This introduces a _______________________________________________________________________________________ 5 MAX4490/MAX4491/MAX4492 Pin Description pole at frequency (2πR′CIN)-1, where R′ is the parallel combination of the gain-setting resistors for the inverting or noninverting amplifier configuration (Figure 2). If the pole frequency is less than or comparable to the unity-gain bandwidth (10MHz), the phase margin will be reduced, and the amplifier will exhibit degraded AC performance through either ringing in the step response or sustained oscillations. The pole frequency is 10MHz when R′ = 3.2kΩ. To maximize stability, R′ 3kΩ. To improve step response under these conditions, connect a small OUTPUT SOURCE CURRENT (mA) 6 VDD - VOH = 200mV VDD - VOH = 100mV VDD - VOH = 50mV VDD = 5V 5 4 capacitor Cf between the inverting input and output. Choose Cf as follows: Cf = 5(R / Rf) [pf] where Rf is the feedback resistor and R is the gain-setting resistor (Figure 2). Figure 3 shows the step response for a noninverting amplifier subject to R′ = 4kΩ with and without the Cf feedback capacitor. INVERTING Cf Rf VDD = 2.7V VIN 3 R VOUT 2 MAX4490 1 R′ = R || Rf RfCf = RCIN 0 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) Figure 1a. Output Source Current vs. Temperature NONINVERTING VIN 9 7 6 VOUT VDD - VOH = 200mV VDD - VOH = 100mV VDD - VOH = 50mV 8 OUTPUT SINK CURRENT (mA) MAX4490/MAX4491/MAX4492 Low-Cost, High-Slew-Rate, Rail-to-Rail I/O Op Amps in SC70 VDD = 2.7V MAX4490 VDD = 5V Rf 5 Cf 4 3 R 2 R′ = R || Rf RfCf = RCIN 1 0 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) Figure 2. Inverting and Noninverting Amplifier with Feedback Compensation Figure 1b. Output Sink Current vs. Temperature 6 _______________________________________________________________________________________ Low-Cost, High-Slew-Rate, Rail-to-Rail I/O Op Amps in SC70 Improve stability for large capacitive loads by adding an isolation resistor (typically 10Ω) in series with the output (Figure 5). Note that the isolation resistor forms a voltage divider with potential for gain error. Chip Information MAX4490 TRANSISTOR COUNT: 60 MAX4491 TRANSISTOR COUNT: 120 MAX4492 TRANSISTOR COUNT: 240 SUBSTRATE CONNECTED TO VSS 4a) 3a) WITHOUT CAPACITIVE LOADING WITHOUT FEEDBACK COMPENSATION AV = +1, RL = 100kΩ, CL = 0 AV = -1, RL = 4kΩ, Cf = 0 4b) 3b) WITH FEEDBACK COMPENSATION AV = -1, RL = 4kΩ, Cf = 5pF Figure 3. Step Response With and Without Feedback Compensation WITH CAPACITIVE LOADING AV = +1, RL = 100kΩ, CL = 300pF Figure 4. Step Response With and Without Capacitive Loading _______________________________________________________________________________________ 7 MAX4490/MAX4491/MAX4492 Driving Capacitive Loads In conjunction with op amp output resistance, capacitive loads introduce a pole frequency that can reduce phase margin and lead to unstable operation. The MAX4490/MAX4491/MAX4492 drive capacitive loads up to 300pF without significant degradation of step response and slew rate (Figure 4). Capacitive-Load Stability (page 1) shows regions of stable and marginally stable (step overshoot