MD1322

MD1321/2 1MHz, 40μA, Rail-to-Rail I/O CMOS Operational Amplifiers MINGDA MICROELECTRONICS FEATURES PRODUCT DESCRIPTION   Low Cost Rail-to-Rail Input and Output 0.8mV Typical VOS      Unity Gain Stable Gain-Bandwidth Product: 1MHz Very Low Input Bias Current: 10pA Supply Voltage Range: 2.1V to 5.5V Input Voltage Range: -0.1V to +5.6V with (VDD - VSS) = 5.5V Low Supply Current: 40μA/Amplifier Small Packaging MD1321 Available in SOT-23-5 MD1322 Available in SOIC-8 The MD1321 (single), MD1322 (dual) are low cost, rail-to-rail input and output voltage feedback amplifiers. They have a wide input common mode voltage range and output voltage swing, and take the minimum operating supply voltage down to 2.1V. The maximum recommended supply voltage is 5.5V. It is specified over the extended -40℃ to +85℃ temperature range.   The MD1321/2 provide 1MHz bandwidth at a low current consumption of 40μA per amplifier. Very low input bias currents of 10pA enable MD1321/2 to be used for integrators, photodiode amplifiers, and piezoelectric sensors. Rail-to-rail input and output are useful to designers for buffering ASIC in single-supply systems. APPLICATIONS  ASIC Input or Output Amplifier  Sensor Interface  Piezoelectric Transducer Amplifier  Medical Instrumentation  Mobile Communication  Audio Output  Portable Systems  Smoke Detectors  Notebook PC  PCMCIA Cards  Battery-Powered Equipment  DSP Interface Applications for this series of amplifiers include safety monitoring, portable equipment, battery and power supply control, and signal conditioning and interfacing for transducers in very low power systems. The MD1321 is available in the Green SOT-23-5 Package. The MD1322 comes in the Green SOIC-8 package. PIN CONFIGURATIONS (TOP VIEW) MD1322 MD1321 VIN+ 1 VSS 2 VIN- 3 5 VDD 4 VOUT SOT-23-5 VOUTA 1 8 VDD VINA- 2 7 VOUTB VINA+ 3 VSS 4 6 VINB5 VINB+ SOIC-8 REV. A. 1.0 MD Micro Corp www.md-ic.com.cn 1 1MHz, 40μA, Rail-to-Rail I/O CMOS Operational Amplifiers MD1321/2 ORDER INFORMATION PACKAGE MODEL ORDER NUMBER MARKING PACKAGE OPTION DESCRIPTION INFORMATION MD1321 -- SOT23-5 Tape and Reel, 2500 -- MD1322 -- SOIC-8 Tape and Reel, 2500 -- ABSOLUTE MAXIMUM RATINGS Supply Voltage, VDD to VSS...............................................................6V Common Mode Input Voltage…...................VSS - 0.3V to VDD + 0.3V Storage Temperature Range.......................................-65℃ to +150℃ Junction Temperature...................................................................150℃ Operating Temperature Range......................................-40℃ to +85℃ Package Thermal Resistance @ TA = +25℃ SOIC-8, θJA....................................................................125℃/W Lead Temperature (Soldering 10sec)................................260℃ NOTE: 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. ESD, Electrostatic Discharge Protection Symbol 2 Parameter HBM Human Body Model ESD MM Machine Model ESD Condition Minimum Level Unit 4 kV 300 V MD Micro Corp www.md-ic.com.cn 1MHz, 40μA, Rail-to-Rail I/O CMOS Operational Amplifiers MD1321/2 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are At TA=25℃, VDD = +5V, VSS = GND, RL = 100kΩ connected to VDD/2, and VOUT = VDD/2. PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS INPUT CHARACTERISTICS VCM = VDD/2 Input Offset Voltage VOS VCM = VDD/2 0.8 ● 5 mV 6.6 Input Bias Current IB 10 pA Input Offset Current IOS 10 pA ΔVOS/ΔT 2 μV/℃ -0.1-5.6 V VDD = 5.5V, VCM = -0.1V to 4V 76 dB RL = 100kΩ, VOUT = 2.5V 95 dB RL = 100kΩ, VOUT = +0.2V to +4.8V 93 dB Input Offset Voltage Drift Input Common Mode Voltage Range Common Mode Rejection Ratio VCM CMRR Open-Loop Voltage Gain AOL VDD = 5.5V OUTPUT CHARACTERISTICS VOH RL = 100kΩ 4.980 4.995 V VOL RL = 100kΩ 25 5 mV VOH RL = 10kΩ 4.970 4.994 V VOL RL = 10kΩ 35 6 mV Output Voltage Swing from Rail ISOURCE Output Current ISINK 40 RL = 10Ω to VDD/2 mA 40 POWER SUPPLY 2.1 Operating Voltage Range Power Supply Rejection Ratio ● PSRR V 2.5 VDD = +2.5V to +5.5V, VCM = +0.5V 5.5 85 dB 40 Quiescent Current/Amplifier IQ ● 35 V 80 μA DYNAMIC PERFORMANCE (CL = 100pF) Gain-Bandwidth Product GBP 1 MHz Phase Margin PM RL = 100kΩ, CL = 100pF 45 ° HD2 f = 10kHz, G = +1, RL=100k,VOUT=2VPP >80 HD3 f = 10kHz, G = +1, RL=100k,VOUT=2VPP >80 Harmonic Distortion dBc Slew Rate SR G = +1, 2V Output Step 0.64 V/μs Settling Time to 0.1% ts G = +1, 2V Output Step 6 μs VIN·G = VDD 2.5 μs f = 1kHz 30 f = 10kHz 20 nV/√Hz Overload Recovery Time NOISE PERFORMANCE Voltage Noise Density MD Micro Corp www.md-ic.com.cn en nV/√Hz 3 1MHz, 40μA, Rail-to-Rail I/O CMOS Operational Amplifiers MD1321/2 TYPICAL PERFORMANCE CHARACTERISTICS 45 80 40 75 35 70 30 Supply Current (μA) Supply Current (μA) At TA = +25℃, VDD = +5V, VSS = GND, and RL = 100kΩ connected to VDD/2, unless otherwise specified. VCM=VDD/2 25 20 15 10 5 65 60 55 50 45 40 35 30 0 0 1 2 3 Supply Voltage (V) 4 -50 5 60 120 50 110 40 30 Sink 20 Source 10 100 125 150 90 80 70 60 0 1 2 3 Supply Voltage (V) 4 -50 5 Figure 3. Output Short Circuit Current vs. Supply Voltage -25 0 25 50 75 Temperature (℃) 100 125 150 Figure 4. Open-Loop Gain vs. Temperature 120 120 VDD=5.5V 110 110 0V≤VCM≤4V PSRR (dB) CMRR (dB) 25 50 75 Temperature (℃) 100 0 100 90 100 90 80 80 70 70 60 60 -50 -25 0 25 50 75 Temperature (℃) 100 Figure 5. CMRR vs. Temperature 4 0 Figure 2. Supply Current vs. Temperature Open-Loop Gain (dB) Output Short Circuit Current (mA) Figure 1. Supply Current vs. Supply Voltage -25 125 150 -50 -25 0 25 50 75 Temperature (℃) 100 125 150 Figure 6. PSRR vs. Temperature MD Micro Corp www.md-ic.com.cn 1MHz, 40μA, Rail-to-Rail I/O CMOS Operational Amplifiers MD1321/2 TYPICAL PERFORMANCE CHARACTERISTICS At TA = +25℃, VDD = +5V, VSS = GND, and RL = 100kΩ connected to VDD/2, unless otherwise specified. 50% 80% G=+1 70% 40% Small-Signal Overshoot Small-Signal Overshoot 45% 35% 30% -OS 25% 20% 15% 10% +OS 5% 60% -OS 50% 40% +OS 30% 20% 10% 0% 0% 1 10 100 CL (pF) 1000 10000 1 Figure 7. Small-Signal Overshoot vs. Load Capacitance 10 100 CL (pF) 1000 10000 Figure 8. Small-Signal Overshoot vs. Load Capacitance 5 2.5 4.5 Source Source 4 2 Output Voltage (V) Output Voltage (V) G=-1 RFB=20kΩ 3.5 3 VDD=+5V 2.5 2 1.5 Sink 1 1.5 VDD=+2.5V 1 0.5 Sink 0.5 0 0 0 10 20 30 Output Current (mA) 40 50 0 Figure 9. Output Voltage vs. Output Current 20 6 Maximum Outputt Voltage (VPP) Voltage Noise （nV/√Hz） 10 15 Output Current (mA) Figure 10. Output Voltage vs. Output Current 1000 100 10 1 0.01 5 VDD=+5.5V 5 VDD=+5V 4 3 2 VDD=+2.5V 1 0 0.1 1 10 Frequency (kHz) 100 Figure 11. Input Voltage Noise Spectral Density vs. Frequency MD Micro Corp www.md-ic.com.cn 1 10 100 1000 Frequency (kHz) 10000 Figure 12. Maximum Output Voltage vs. Frequency 5 1MHz, 40μA, Rail-to-Rail I/O CMOS Operational Amplifiers MD1321/2 TYPICAL PERFORMANCE CHARACTERISTICS At TA = +25℃, VDD = +5V, VSS = GND, and RL = 100kΩ connected to VDD/2, unless otherwise specified G=-5 G=-5 2.5V 5V 0V 2.5V 2.5V 3.5V 2.5V 1.5V Time (2μs/div) Time (2μs/div) Figure 13. Positive Overload Recovery Time Figure 14. Negative Overload Recovery Time Voltage (1V/div) Voltage (500mV/div) G=+ 2.5V Time (2μs/div) Time (200μs/div) Figure 15. Phase Reversal Figure 16. Large-Signal Step Response G=+1 RFB=20kΩ G=+1 Voltage (20mV/div) Voltage (20mV/div) G=+1 Time (2μs/div) Figure 17. Small-Signal Step Response 6 G=-1 Time (2μs/div) Figure 18. Small-Signal Step Response MD Micro Corp www.md-ic.com.cn 1MHz, 40μA, Rail-to-Rail I/O CMOS Operational Amplifiers MD1321/2 TYPICAL PERFORMANCE CHARACTERISTICS At TA = +25℃, VDD = +5V, VSS = GND, and RL = 100kΩ connected to VDD/2, unless otherwise specified. 80 160 80 140 70 60 120 40 100 20 80 60 0 40 -20 PSRR（dB） 90 Open-Loop Phase (°) 180 Open-Loop Gain (dB) 100 0.01 0.1 1 10 100 Frequency (kHz) CMRR 60 50 40 30 20 10 20 -40 PSRR 0 0 1000 0.01 Figure 19. Gain and Phase vs. Frequency 1 10 Frequency (kHz) 100 1000 Figure 20. CMRR and PSRR vs. Frequency 120 1000 100 100 80 Zol（ohms） Channel Separation（dB） 0.1 60 40 10 1 0.1 20 0 0.01 0.01 0.1 1 10 Frequency (kHz) 100 1000 Figure 21. Channel Separation vs. Frequency MD Micro Corp www.md-ic.com.cn 0.01 0.1 1 10 Frequency (kHz) 100 1000 Figure 22. Zol vs. Frequency 7 1MHz, 40μA, Rail-to-Rail I/O CMOS Operational Amplifiers MD1321/2 APPLICATION INFORMATION MD1321/2 are CMOS, rail-to-rail input and output voltage VDD feedback amplifiers designed for general purpose applications. RISO VOUT Operating Voltage VP The MD1321/2 are specified over a power-supply range of MD1322 CL +2.1V to +5.5V (±1.05V to ±2.75V), Supply voltages higher than 6V (absolute maximum) can permanently damage the Figure 23. Driving Large Capacitive Loads amplifier. loop’s phase margin (stability) by making the output load Parameters that vary over supply voltage or temperature are resistive at higher frequencies. shown in the typical characteristics section of this datasheet. PCB Surface Leakage Rail-to-Rail Input In Applications where low input bias current is critical, PC The input stage of the amplifiers is a true rail-to-rail board surface leakage effects need to be considered. Surface architecture, allowing the input common-mode voltage range leakage is caused by humidity, dust or other contamination on of the op amp to extend to both positive and negative supply the board. Under low humidity conditions, a typical resistance rails. This maximizes the usable voltage range of the amplifier, between nearby traces is 1012Ω. A 5V difference would cause an important feature for single-supply and low voltage 5pA of current to flow; which is similar to the MD1321/2 op applications. This rail-to-rail input range is achieved with a amps’ bias current at +25℃ (±10pA, typical). complementary input stage—an NMOS input differential pair The best way to reduce surface leakage is to use a guard ring in parallel with a PMOS differential pair. The NMOS pair is around sensitive pins (or traces). The guard ring is biased at active at the upper end of the common-mode voltage range, the same voltage as the sensitive pin. An example of this type typically VDD – 1.2V to 100mV above the positive supply, of layout is shown in Figure 24. while the PMOS pair is active for inputs from 100mV below 1. Non-inverting Gain and Unity-Gain Buffer: a) the negative supply to approximately VDD – 1.2V. Rail-to-Rail Output Connect the non-inverting pin (VIN+) to the input with a wire that does not touch the PCB surface. A class AB output stage with common-source transistors is b) Connect the guard ring to the inverting input pin used to achieve rail-to-rail output. The maximum output (VIN-). This biases the guard ring to the Common voltage swing is proportional to the output current, and larger Mode input voltage. currents will limit how close the output voltage can get to the proximity of the output voltage to the supply rail. This is a characteristic of all rail-to-rail output amplifiers. See the 2. Inverting Gain and Transimpedance Gain Amplifiers (convert current to voltage, such as photo detectors): a) Connect the guard ring to the non-inverting input typical performance characteristic Figure 9, Output Voltage pin (VIN+). This biases the guard ring to the same Swing vs. Output Current. reference voltage as the op amp (e.g., VDD/2 or Capacitive Loads ground). The MD1321/2 op amps can directly drive large capacitive b) Connect the inverting pin (VIN-) to the input with a loads. As the load capacitance increases, the feedback loop’s wire that does not touch the PCB surface. phase margin decreases and the closed-loop’s bandwidth is Guard Ring reduced. This produces gain peaking in the frequency VIN- VIN+ VSS response, with overshoot and ringing in the step response. While a op amp in unity gain configuration (G = +1 V/V) is most susceptible to the effects of capacitive loading. When driving large capacitive loads with the MD1321/2 amplifiers (e.g., > 100pF when G = +1 V/V), a small series resistor at the output (RISO in Figure 23) improves the feedback 8 Figure 24. Example Guard Ring Layout for Inverting Gain MD Micro Corp www.md-ic.com.cn 1MHz, 40μA, Rail-to-Rail I/O CMOS Operational Amplifiers MD1321/2 TYPICAL APPLICATION Differential Amplifier excessive output offset. In addition, a resistor is not needed on The circuit shown in Figure 25 performs the difference function. the noninverting input to cancel bias current offset because If the resistor ratios are equal to (R4 / R3 = R2 / R1), then VOUT = the bias current-related output offset is not significant when (VP - VN) × R2 / R1 + VREF. compared to the voltage offset contribution. For best performance, follow the standard high impedance layout R2 VN VP techniques, which include the following: VDD R1 VOUT MD1322 R3 R4 2.5VREF  Shielding the circuit.  Cleaning the circuit board.  Putting a trace connected to the noninverting input around the inverting input.  Using separate analog and digital power supplies. C Figure 25. Differential Amplifier 100pF Photodiode Application R 10MΩ The MD1321/2 have very high impedance with an input bias current typically around 10 pA. This characteristic allows the OR VDD VOUT MD1321/2 op amp to be used in photodiode applications and MD1322 other applications that require high input impedance. Note that the MD1321/2 have significant voltage offset that can be removed by capacitive coupling or software calibration. Figure 26 illustrates a photodiode or current measurement application. The feedback resistor is limited to 10 MΩ to avoid MD Micro Corp www.md-ic.com.cn 2.5VREF 2.5VREF Figure 26. High Input Impedance Application—Photodiode Amplifier 9 1MHz, 40μA, Rail-to-Rail I/O CMOS Operational Amplifiers MD1321/2 PACKAGE OUTLINE DIMENSIONS COMPLIANT TO JEDEC STANDARD MS-012-AA Figure 27 8-Lead Small Outline Package [SOIC] Dimensions shown in millimeters 10 MD Micro Corp www.md-ic.com.cn 1MHz, 40μA, Rail-to-Rail I/O CMOS Operational Amplifiers MD1321/2 PACKAGE OUTLINE DIMENSIONS COMPLIANT TO JEDEC STANDARD MO-178-AA Figure 28 5-Lead Small Outline Transistor Package [SOT-23] Dimensions shown in millimeters MD Micro Corp www.md-ic.com.cn 11