MIC921 Micrel MIC921 45MHz Low-Power SC-70 Op Amp Final Information General Description Features The MIC921 is a high-speed operational amplifier with a gainbandwidth product of 45MHz. The part is unity gain stable. It has a very low 300µA supply current, and features the IttyBitty™ SC-70 and SOT-23-5 package. Supply voltage range is from ±2.5V to ±9V, allowing the MIC921 to be used in low-voltage circuits or applications requiring large dynamic range. The MIC921 is stable driving any capacitative load and achieves excellent PSRR and CMRR, making it much easier to use than most conventional high-speed devices. Low supply voltage, low power consumption, and small packing make the MIC921 ideal for portable equipment. The ability to drive capacitative loads also makes it possible to drive long coaxial cables. • • • • • • • • 45MHz gain bandwidth product 61MHz –3dB bandwidth 300µA supply current SC-70 or SOT-23-5 packages 3200V/µs slew rate Drives any capacitive load 112dB CMRR Unity gain stable Applications • • • • • Video Imaging Ultrasound Portable equipment Line drivers Ordering Information Part Number Junction Temp. Range Package MIC921BM5 –40°C to +85°C SOT-23-5* MIC921BC5 –40°C to +85°C SC-70 *Contact factory for availability of SOT-23-5 package. Pin Configuration Functional Pinout IN– V– IN+ 3 2 1 Part Identification IN– V– IN+ 3 2 1 A38 4 5 4 5 OUT V+ OUT V+ SOT-23-5 or SC-70 SOT-23-5 or SC-70 Pin Description Pin Number Pin Name Pin Function 1 IN+ Noninverting Input 2 V– Negative Supply (Input) 3 IN– Inverting Input 4 OUT Output: Amplifier Output 5 V+ Positive Supply (Input) Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com December 2001 1 MIC921 MIC921 Micrel Absolute Maximum Ratings (Note 1) Operating Ratings (Note 2) Supply Voltage (VV+ – VV–) ........................................... 20V Differentail Input Voltage (VIN+ – VIN–) .......... 4V, Note 3 Input Common-Mode Range (VIN+, VIN–) .......... VV+ to VV– Lead Temperature (soldering, 5 sec.) ....................... 260°C Storage Temperature (TS) ........................................ 150°C ESD Rating, Note 4 ................................................... 1.5kV Supply Voltage (VS) ....................................... ±2.5V to ±9V Junction Temperature (TJ) ......................... –40°C to +85°C Package Thermal Resistance SC70-5 .............................................................. 450°C/W SOT23-5 ............................................................ 260°C/W Electrical Characteristics (±5V) V+ = +5V, V– = –5V, VCM = 0V, RL = 10MΩ; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +85°C; unless noted. Symbol Parameter Condition Min VOS Input Offset Voltage VOS VOS Temperature Coefficient IB Input Bias Current 0.13 0.6 µA IOS Input Offset Current 0.06 0.3 µA VCM Input Common-Mode Range CMRR > 72dB +3.25 V CMRR Common-Mode Rejection Ratio –2.5V < VCM < +2.5V 75 87 dB PSRR Power Supply Rejection Ratio ±3.5V < VS < ±9V 95 105 dB AVOL Large-Signal Voltage Gain RL = 2k, VOUT = ±2V 70 84 dB 85 dB 3.7 V Maximum Output Voltage Swing Units 0.43 5 mV –3.25 positive, RL = 2kΩ +3.0 negative, RL = 2kΩ positive, RL = 200Ω –3.7 +1.5 negative, RL = 200Ω, Note 5 GBW Unity Gain-Bandwidth Product PM Phase Margin BW –3dB Bandwidth AV = 1, RL = 1kΩ, CL = 1.7pF SR Slew Rate C=1.7pF, Gain=1, VOUT=5V, peak to peak, negative SR = 1300V/µs ISC Short-Circuit Output Current source sink IS Max µV/°C 1 RL = 100Ω, VOUT = ±1V VOUT Typ 3.0 –2.5 AV = 1, CL = 1.7pF –3.0 V V –1.0 V 37 MHz 46 ° 53 MHz 1500 V/µs 45 57 mA 20 40 mA Supply Current No Load 0.30 0.50 mA Input Voltage Noise f = 10kHz 12 nV√Hz Input Current Noise f = 10kHz 0.7 pA√Hz Electrical Characteristics V+ = +9V, V– = –9V, VCM = 0V, RL = 10MΩ; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +85°C; unless noted Symbol Parameter VOS Input Offset Voltage VOS Input Offset Voltage Temperature Coefficient IB Input Bias Current 0.13 0.6 µA IOS Input Offset Current 0.06 0.3 µA VCM Input Common-Mode Range CMRR > 75dB +7.25 V CMRR Common-Mode Rejection Ratio –2.5V < VCM < +2.5V MIC921 Condition Min Typ Max Units 0.4 5 mV µV/°C 1 2 –7.25 75 87 dB December 2001 MIC921 Micrel Symbol Parameter Condition Min Typ PSRR Power Supply Rejection Ratio AVOL Large-Signal Voltage Gain ±3.5V < VS < ±9V 95 105 dB RL = 2k, VOUT = ±3V 75 86 dB 92 dB 7.6 V RL = 100Ω, VOUT = ±1V VOUT Maximum Output Voltage Swing positive, RL = 2kΩ +6.5 Max –6.2 Units negative, RL = 2kΩ –7.6 V AV = 1, CL = 1.7pF 45 MHz 40 ° 61 MHz 3200 V/µs GBW Unity Gain-Bandwidth Product PM Phase Margin BW –3dB Bandwidth AV = 1, RL = 1kΩ, CL = 1.7pF SR Slew Rate C=1.7pF, Gain=1, VOUT=5V, peak to peak, negative SR = 2500V/µs ISC Short-Circuit Output Current source 40 59 mA sink 25 45 mA IS Supply Current No Load 0.36 0.6 mA Input Voltage Noise f = 10kHz 12 nV√Hz Input Current Noise f = 10kHz 0.7 pA√Hz Note 1. Exceeding the absolute maximum rating may damage the device. Note 2. The device is not guaranteed to function outside its operating rating. Note 3. Exceeding the maximum differential input voltage will damage the input stage and degrade performance (in particular, input bias current is likely to change). Note 4. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF. Note 5. Output swing limited by the maximum output sink capability, refer to the short-circuit current vs. temperature graph in “Typical Characteristics.” December 2001 3 MIC921 MIC921 Micrel Test Circuits V+ 10µF V+ 0.1µF 50Ω R2 BNC 5k Input 10µF 0.1µF 10k 10k 10k 2k 3 BNC R1 5k Input 5 MIC921 BNC 4 3 1 2 50Ω 2 Output 0.1µF R6 5k R3 200k Input 50Ω All resistors: 1% metal film R5 5k 10µF V– All resistors 1% 0.1µF R4 250Ω R2 R2 + R 5 + R4 VOUT = VERROR 1 + + R1 R7 10µF V– CMRR vs. Frequency PSRR vs. Frequency 100pF BNC 4 1 0.1µF BNC 0.1µF MIC921 R7c 2k R7b 200Ω R7a 100Ω Output 5 V+ V+ 10µF 10pF R1 20Ω 10µF 3 R3 27k S1 S2 R5 20Ω R2 4k 3 5 0.1µF MIC921 4 1 2 R4 27k 0.1µF 10pF 10µF BNC MIC921 To Dynamic Analyzer VIN 300Ω 4 1 2 0.1µF 1k 50Ω VOUT FET Probe CL 10µF V– V– Closed Loop Frequency Response Measurement Noise Measurement MIC921 0.1µF 5 4 December 2001 MIC921 Micrel Typical Characteristics Supply Current vs. Temperature -4.5 0 -13.5 -9.0 -22.5 -18.0 -27.0 -36.0 -31.5 85°C –40°C 3.8 5.1 6.4 7.7 SUPPLY VOLTAGE (V) 9 V± = ±9V –40°C 7.40 4.44 5.92 +85°C 1.48 2.96 -7.40 -5.92 +25°C +85°C OFFSET VOLTAGE (mV) –40°C -3.4 -2.7 OUTPUT VOLTAGE (V) 25°C -45.0 -40.5 OUTPUT VOLTAGE (V) –40°C V± = ±5V COMMON-MODE VOLTAGE (V) Output Voltage vs. Output Current (Sourcing) Output Voltage vs. Output Current (Sinking) V± = ±5V +25°C 2.2 2 1.8 1.6 1.4 1.2 +25°C 1 0.8 0.6 0.4 0.2 0 COMMON-MODE VOLTAGE (V) Output Voltage vs. Output Current (Sinking) 0.5 0 -0.5 -1.0 -1.5 -2.0 -2.5 -3.0 -3.5 -4.0 -4.5 -5.0 2.2 2 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 +85°C Offset Voltage vs. Common-Mode Voltage Offset Voltage vs. Common-Mode Voltage OFFSET VOLTAGE (mV) OFFSET VOLTAGE (mV) Offset Voltage vs. Common-Mode Voltage 2.20 2.00 V± = ±2.5V 1.80 –40°C 1.60 1.40 +25°C 1.20 1.00 +85°C 0.80 0.60 0.40 0.20 0 -900 -540 -180 180 540 900 COMMON-MODE VOLTAGE (V) SUPPLY CURRENT (mA) 0.10 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) 0.9 V± = ±9V 0 -0.9 -1.8 -2.7 25°C -3.6 -4.5 85°C –40°C -5.4 -6.3 -7.2 -8.1 -9.0 -50-45-40-35-30-25-20-15-10 -5 0 OUTPUT CURRENT (mA) OUTPUT VOLTAGE (V) 0.55 0.5 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) 0.15 0.42 0.40 0.38 0.36 0.34 0.32 0.30 0.28 0.26 0.24 0.22 0.20 2.5 3 V± = ±9V 0.20 2.0 2.7 V± = ±5V 0.65 0.6 V± = ±2.5V 0.25 0.7 1.4 0.75 0.7 -0.7 0.0 V± = ±2.5V V± = ±5V 0.30 -2.0 -1.4 0.85 0.8 V± = ±9V -1.48 0 0.35 SUPPLY CURRENT (mA) OFFSET VOLTAGE (mV) 1 0.95 0.9 Supply Current vs. Supply Voltage -4.44 -2.96 Offset Voltage vs. Temperature 5.5 V± = ±5V 5.0 4.5 4.0 85°C 25°C 3.5 3.0 2.5 –40°C 2.0 1.5 1.0 0.5 0 0 8 16 24 32 40 48 56 64 72 80 OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) Short Circuit Current vs. Supply Voltage (Sinking) 7 0 –40°C -7 25°C -14 -21 -28 -35 85°C -42 -49 -56 -63 -70 2.0 3.4 4.8 Short-Circuit Current vs. Supply Voltage (Sourcing) OUTPUT CURRENT (mA) 0.5 V± = ±9V 0 85°C -0.5 25°C -1.0 -1.5 –40°C -2.0 -2.5 -3.0 -3.5 -4.0 -4.5 -5.0 0 8 16 24 32 40 48 56 64 72 80 SHORT CIRCUIT CURRENT (mA) OUTPUT VOLTAGE (V) Output Voltage vs. Output Current (Sourcing) 6.2 7.6 SUPPLY VOLTAGE (V) 9.0 110 100 90 80 70 60 50 40 30 20 10 0 –40°C 25°C 85°C 2 3.4 4.8 6.2 7.6 SUPPLY VOLTAGE (±V) 9 OUTPUT CURRENT (mA) December 2001 5 MIC921 MIC921 Micrel Bias Current vs. Temperature Closed-Loop Gain vs. Frequency 50 40 0.04 100pF -10 -20 200pF 400pF 600pF 800pF 1000pF -30 -40 0.02 0.00 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) -50 100k Open-Loop Gain vs. Frequency 50 40 100pF 1.7pF 200pF Open-Loop Frequency Response 10 1000pF 400pF -180 -225 35 30 Phase Margin 25 30 20 20 10 700 800 500 600 0 100 200 300 400 Gain Bandwidth 5 10 0 900 1000 15 0 40 NOISE VOLTAGE (nV/Hz1/2) 50 35 10 60 50 30 25 40 Phase Margin 20 30 15 20 10 Gain Bandwidth 5 10 0 CAPACITIVE LOAD (pF) Current Noise Density vs. Frequency 2.5 60 50 40 30 20 10 0 10 V± = ±5V 35 0 2 4 6 8 SUPPLY VOLTAGE (V) 70 60 PHASE MARGIN (°) V± = ±9V Gain Bandwidth and Phase Margin vs. Load Voltage Noise Density vs. Frequency Gain Bandwidth and Phase Margin vs. Load 40 Gain Bandwidth 25 20 0 -225 1M 10M 100M FREQUENCY (Hz) 40 40 FREQUENCY (Hz) 45 -135 -180 -100 100k Phase Margin 45 30 -45 -90 Gain 0 100 200 -80 -100 1000pF 100M 10M 1M FREQUENCY (Hz) GAIN BANDWIDTH (MHz) -90 -135 45 0 (100Ω) -20 -40 NOISE CURRENT (pA/Hz1/2) Gain GAIN BANDWIDTH (MHz) 0 -45 (100Ω) PHASE (°) 90 45 (no load) (no load) 20 0 -60 -80 600pF 50 180 135 (100Ω) -40 -60 200pF 135 90 (100Ω) Gain Bandwidth and Phase Margin vs. Supply Voltage 225 Phase 40 20 0 -20 1.7pF -50 100k 100M 10M 1M FREQUENCY (Hz) V± = ±9V 80 60 100pF 0 -10 Open-Loop Frequency Response 100 50pF 225 180 Phase 60 40 -30 -40 600pF 100M 10M 1M FREQUENCY (Hz) 100 V± = ±5V 80 V± = ±9V -20 400pF -50 100k GAIN (dB) -50 100k GAIN (dB) 50pF -30 -40 GAIN BANDWIDTH (MHz) -30 -40 20 GAIN (dB) GAIN (dB) 30 20 -10 -20 200pF 400pF 600pF 800pF 1000pF Open-Loop Gain vs. Frequency 40 30 1.7pF 100pF 0 -10 -20 100M 10M 1M FREQUENCY (Hz) 50 V± = ±5V 10 0 50pF 10 PHASE (°) 0.06 1.7pF PHASE MARGIN (°) V± = ±9V 0.08 20 50pF 10 0 900 1000 V± = ±5V 0.10 V± = ±9V 40 30 GAIN (dB) 0.14 0.12 50 V± = ±5V 30 20 GAIN (dB) BIAS CURRENT (µA) 0.16 300 400 500 600 700 800 0.18 Closed-Loop Gain vs. Frequency 100 1000 10000 100000 FREQUENCY (Hz) 2.0 1.5 1.0 0.5 0 10 100 1000 10000 100000 FREQUENCY (Hz) CAPACITIVE LOAD (pF) MIC921 6 December 2001 MIC921 Micrel Positive Slew Rate vs. Supply Voltage Negative Slew Rate vs. Supply Voltage 100 0 2 3 4 5 6 7 8 600 400 800 600 400 200 0 9 200 0 POSITIVE VOLTAGE (±V) 1 2 3 4 5 6 7 8 0 9 POSITIVE VOLTAGE (±V) 1000 200 800 1000 800 900 300 1000 600 700 400 V± = ±5V 1200 1200 400 500 500 1400 200 300 600 1400 0 100 700 Negative Slew Rate 1600 SLEW RATE (V/µs) NEGATIVE SLEW RATE (V/µs) POSITIVE SLEW RATE (V/µs) 800 LOAD CAPACITANCE (pF) 400 1000 1500 1000 0 1000 800 900 500 600 700 300 400 0 900 1000 100 200 0 700 800 0 500 600 0 300 400 500 0 500 100 200 200 LOAD CAPACITANCE (pF) LOAD CAPACITANCE (pF) LOAD CAPACITANCE (pF) Positive Power Supply Rejection Ratio Negative Power Supply Rejection Ratio Positive Power Supply Rejection Ratio 120 120 V± = ±5V 120 V± = ±5V 100 100 80 80 80 60 40 20 60 40 20 10k 100k 1k FREQUENCY (Hz) 0 100 1M Negative Power Supply Rejection Ratio 120 80 70 60 CMRR (dB) 90 80 60 40 20 10k 100k 1k FREQUENCY (Hz) December 2001 1M 60 40 0 100 1M Common-Mode Rejection Ratio 100 0 100 10k 100k 1k FREQUENCY (Hz) 100 V± = ±9V V± = ±9V 20 90 80 50 40 10 0 100 10 0 100 7 V± = ±9V 50 40 30 20 10M 1M 70 60 30 20 1k 10k 100k 1M FREQUENCY (Hz) 10k 100k 1k FREQUENCY (Hz) Common-Mode Rejection Ratio 100 V± = ±5V CMRR (dB) 0 100 PSRR (dB) 100 PSRR (dB) PSRR (dB) 1500 2000 1000 600 2000 800 900 800 2500 500 600 700 1000 V± = ±9V 2500 SLEW RATE (V/µs) SLEW RATE (V/µs) 3000 1200 PSRR (dB) Negative Slew Rate 3000 V± = ±9V 300 400 1400 SLEW RATE (V/µs) Positive Slew Rate 3500 V± = ±5V 100 200 Positive Slew Rate 1600 1k 10k 100k 1M FREQUENCY (Hz) 10M MIC921 MIC921 Micrel Functional Characteristics Small Signal Reponse Small Signal Reponse OUTPUT (50mV/div) OUTPUT (50mV/div) INPUT (50mV/div) V± = ±9V Av = 1 CL = 1.7pF INPUT (50mV/div) V± = ±5V Av = 1 CL = 1.7pF TIME (100ns/div) TIME (100ns/div) Small Signal Reponse Small Signal Reponse OUTPUT (50mV/div) OUTPUT (50mV/div) INPUT (50mV/div) V± = ±9V Av = 1 CL = 100pF INPUT (50mV/div) V± = ±5V Av = 1 CL = 100pF TIME (500ns/div) TIME (500ns/div) Small Signal Reponse Small Signal Reponse OUTPUT (50mV/div) OUTPUT (50mV/div) INPUT (50mV/div) V± = ±9V Av = 1 CL = 1000pF INPUT (50mV/div) V± = ±5V Av = 1 CL = 1000pF TIME (1µs/div) MIC921 TIME (1µs/div) 8 December 2001 MIC921 Micrel Large Signal Response Large Signal Response OUTPUT (2V/div) V± = ±9V Av = 1 CL = 1.7pF OUTPUT (2V/div) V± = ±5V Av = 1 CL = 1.7pF Positive Slew Rate = 3230V/µs Negative Slew Rate = 2950V/µs Positive Slew Rate = 1520V/µs Negative Slew Rate = 1312V/µs TIME (25ns/div) TIME (25ns/div) Large Signal Response Large Signal Response OUTPUT (2V/div) V± = ±9V Av = 1 CL = 100pF OUTPUT (2V/div) V± = ±5V Av = 1 CL = 100pF Positive Slew Rate = 349V/µs Negative Slew Rate = 181V/µs Positive Slew Rate = 615V/µs Negative Slew Rate = 447V/µs TIME (50ns/div) TIME (25ns/div) Large Signal Response Large Signal Response OUTPUT (2V/div) V± = ±9V Av = 1 CL = 1000pF OUTPUT (2V/div) V± = ±5V Av = 1 CL = 1000pF Positive Slew Rate = 63V/µs Negative Slew Rate = 44V/µs Positive Slew Rate = 85V/µs Negative Slew Rate = 57V/µs TIME (250ns/div) December 2001 TIME (250ns/div) 9 MIC921 MIC921 Micrel Power Supply Bypassing Regular supply bypassing techniques are recommended. A 10µF capacitor in parallel with a 0.1µF capacitor on both the positive and negative supplies are ideal. For best performance all bypassing capacitors should be located as close to the op amp as possible and all capacitors should be low ESL (equivalent series inductance), ESR (equivalent series resistance). Surface-mount ceramic capacitors are ideal. Thermal Considerations The SC70-5 package, like all small packages, has a high thermal resistance. It is important to ensure the IC does not exceed the maximum operating junction (die) temperature of 85°C. The part can be operated up to the absolute maximum temperature rating of 125°C, but between 85°C and 125°C performance will degrade, in particular CMRR will reduce. An MIC921 with no load, dissipates power equal to the quiescent supply current * supply voltage Applications Information The MIC921 is a high-speed, voltage-feedback operational amplifier featuring very low supply current and excellent stability. This device is unity gain stable, capable of driving high capacitance loads. Driving High Capacitance The MIC921 is stable when driving high capacitance, making it ideal for driving long coaxial cables or other high-capacitance loads. Most high-speed op amps are only able to drive limited capacitance. Note: increasing load capacitance does reduce the speed of the device. In applications where the load capacitance reduces the speed of the op amp to an unacceptable level, the effect of the load capacitance can be reduced by adding a small resistor (<100Ω) in series with the output. Feedback Resistor Selection ( MIC921 ) PD(no load) = VV + − VV − IS Conventional op amp gain configurations and resistor selection apply, the MIC921 is NOT a current feedback device. Also, for minimum peaking, the feedback resistor should have low parasitic capacitance, usually 470Ω is ideal. To use the part as a follower, the output should be connected to input via a short wire. Layout Considerations All high speed devices require careful PCB layout. The following guidelines should be observed: Capacitance, particularly on the two inputs pins will degrade performance; avoid large copper traces to the inputs. Keep the output signal away from the inputs and use a ground plane. It is important to ensure adequate supply bypassing capacitors are located close to the device. When a load is added, the additional power is dissipated in the output stage of the op amp. The power dissipated in the device is a function of supply voltage, output voltage and output current. ( ) PD(output stage) = VV + − VOUT IOUT Total Power Dissipation = PD(no load) + PD(output stage) Ensure the total power dissipated in the device is no greater than the thermal capacity of the package. The SC70-5 package has a thermal resistance of 450°C/W. Max. AllowablePowerDissipation = 10 TJ(max) − TA(max) 450°C / W December 2001 MIC921 Micrel Package Information 1.90 (0.075) REF 0.95 (0.037) REF 1.75 (0.069) 1.50 (0.059) 3.00 (0.118) 2.60 (0.102) DIMENSIONS: MM (INCH) 1.30 (0.051) 0.90 (0.035) 3.02 (0.119) 2.80 (0.110) 0.20 (0.008) 0.09 (0.004) 10° 0° 0.15 (0.006) 0.00 (0.000) 0.50 (0.020) 0.35 (0.014) 0.60 (0.024) 0.10 (0.004) SOT-23-5 (M5) 0.65 (0.0256) BSC 1.35 (0.053) 2.40 (0.094) 1.15 (0.045) 1.80 (0.071) 2.20 (0.087) 1.80 (0.071) DIMENSIONS: MM (INCH) 1.00 (0.039) 1.10 (0.043) 0.80 (0.032) 0.80 (0.032) 0.10 (0.004) 0.00 (0.000) 0.30 (0.012) 0.15 (0.006) 0.18 (0.007) 0.10 (0.004) 0.30 (0.012) 0.10 (0.004) SC-70 (C5) MICREL INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB USA http://www.micrel.com This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc. © 2001 Micrel Incorporated December 2001 11 MIC921