MIC864 Dual 350kHz Rail-to-Rail Operational Amplifier General Description Features The MIC864 is a dual operational amplifier offering smallsize, low-power consumption (33µA/channel typical), ‘greater-than-the-rails’ input capability, and output range to within 15mV of the supply rails. The MIC864 can be operated with a single supply of +2.5V to +5.5V or a dualsupply of ±1.25V to ±2.75V, and features an excellent speed/power ratio with a gain bandwidth product of 350kHz. The MIC864 was designed with input stage transconductance normalization, making it immune to common-mode rejection ratio (CMRR) and power supply rejection ratio (PSRR) degradation across the input voltage range. This feature makes the MIC864 superior to some earlier operational amplifiers, in which a region of the input voltage range was subject to degraded performance. The MIC864 is available with an industry standard pin configuration in an 8-pin SOIC package, and is specified to operate from −40°C to +125°C junction temperature. Data sheets and support documentation can be found on Micrel’s web site at: www.micrel.com. • 2.5V to 5.5V single or ±1.25V to ±2.75V dual supply voltage • 33µA per channel quiescent current • 350kHz gain bandwidth product • 0.2V/µs slew rate • 18mA output drive capability (sink or source) • 200mV greater-than-the-rails input capability • Rail-to-rail output (within 15mV) • 80dB common mode rejection ratio (CMRR) • 80dB power supply rejection ratio (PSRR) • 8-pin SOIC Package Applications • • • • Battery-powered equipment Cellular phone PA biasing circuits Carbon monoxide detectors Smoke detectors _________________________________________________________________________________________________________________________ Pin Configuration MIC864 8-Pin SOIC (M) (Top View) Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com March 2012 M9999-032612-A Micrel, Inc. MIC864 Ordering Information Part Number MIC864YM Junction Temperature Range Package –40°C to +125°C 8-Pin SOIC Pin Configuration MIC864 8-Pin SOIC (M) (Top View) Pin Description Pin Number Pin Name 1 OUTA Output of operational amplifier A. 2 −INA Inverting input of operational amplifier A. 3 +INA Non-inverting input of operational amplifier A. 4 V− 5 +INB Non-inverting input of operational amplifier B. 6 −INB Inverting input of operational amplifier B. 7 OUTB Output of operational amplifier B. 8 V+ March 2012 Pin Function Negative Power Supply Connection. Connect to GND for single supply operation. Positive Power Supply Input. Connect a 0.1µF ceramic bypass capacitor from V+ to V−, placed within 0.2in (5mm) of the MIC864. 2 M9999-032612-A Micrel, Inc. MIC864 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (V+ to V−)...........................................+6.0V Differential Input Voltage (|V+IN − V-IN|)........................+6.0V Input Voltage (V+IN, V−IN) ............... (V+) + 0.2V, (V−) − 0.2V Output Short-Circuit Duration............................. Continuous Lead Temperature (soldering, 10s)............................ 260°C Storage Temperature (TS).........................−65°C to +150°C Junction Temperature (TJ) ........................−40°C to +150°C ESD Rating(3) ................................................. ESD Sensitive Supply Voltage (V+ to V−)............................ +2.5V to +5.5V Differential Input Voltage (|V+IN − V-IN_|)........ +2.5V to +5.5V Input Voltage (V+IN, V−IN) .................(V+) + 0.2V, (V−) − 0.2V Ambient Temperature (TA) ........................ –40°C to +125°C Package Thermal Resistance SOIC-8 (θJA).......................................................99°C/W Electrical Characteristics(4) V+ = +2.5V, V− = −2.5V, VCM = ((V+) – (V-))/2; RL = 100kΩ connected to ((V+) – (V−))/2; TJ = +25°C, unless otherwise noted. Bold values indicate –40°C ≤ TJ ≤ +125°C. Symbol VOS Parameter Condition Min. Typ. Max. Units Input Offset Voltage 2 8 mV Input Offset Voltage Temperature Coefficient 4 µV/°C IB Input Bias Current ±2.5 ±20 pA IOS Input Offset Current ±0.5 ±15 pA VCM Input Voltage Range (V+) + 0.2 V (V−) − 0.2 CMRR Common-Mode Rejection Ratio (V−) − 0.2V < VCM < (V+) + 0.2V PSRR Power Supply Rejection Ratio AVOL VOUT 80 dB 2.5 < VS < 5.25V 80 dB Large-Signal Voltage Gain CL = 100pF, RL = 100kΩ 80 dB Maximum Output Voltage Swing RL = 100kΩ (V−) + 0.015 (V+) − 0.015 RL = 5kΩ (V−) + 0.125 (V+) − 0.125 Gain-Bandwidth Product CL = 100pF, RL = 100kΩ 350 kHz SR Slew Rate AV = 1, CL = 100pF, RL = 100kΩ 0.2 V/µs ISC Short-Circuit Output Current Source, RL connected to V− 23 Sink, RL connected to V+ 15 IS Supply Current per Amplifier No Load 33 GBW 54 V mA 50 µA Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function outside its operating rating. 3. Devices are ESD Sensitive. Handling precautions recommended. Human body model, 1.5kΩ in series with 100pF. 4. Specification for packaged product only. March 2012 3 M9999-032612-A Micrel, Inc. MIC864 Typical Characteristics V+ = VS/2 = 2.5V, V− = −VS/2 = −2.5V, RL = 100kΩ , RL and CL connected in parallel to GND; TA = +25°C, unless otherwise noted. 100 45 80 80 80 0 60 60 60 -45 40 -90 20 -135 20 40 20 100k 100000 1M 1000000 10 10 100 100 10k 10000 100 0 60 -45 60 -45 40 -90 40 -90 20 -135 20 -135 -180 0 -180 0 -225 -20 -225 -20 20 -135 GAIN (dB) -90 PHASE (Degrees) 40 10k 10000 100k 1000000 1M 100000 1 1 10 10 FREQUENCY (Hz) 1k 1000 10k 10000 90 80 SUPPLY CURRENT (µA) 5 4 3.5 3 2.5 2 1.5 =+IN 0V, Sinking, R RLTO to V+ +IN == 0V, SINKING, V+ L +IN L TO +IN == 5V, 5V, SOURCING, Sourcing, RLRto V- V10 15 20 OUTPUT CURRENT (mA) March 2012 100 100 1k 1000 10k 10000 -225 100k 1M 100000 1000000 FREQUENCY (Hz) Short Circuit Current vs. Supply Voltage 30 NO LOAD +IN = 0V, Sinking, RRL to V+ +IN = 0V, SINKING, L TO DUAL OP AMP 70 60 50 +IN == 5V, RLto TOV-V+IN 5V,SOURCING, Sourcing, RL 25 SINGLE OP AMP 40 30 20 20 15 10 5 0 0 5 10 10 10 0 0 -180 Gain (5kΩ GAIN (5k Ω ||II 100pF) 100pF) PHASE (5k Ω|| II100pF) 100pF) Phase (5kΩ 1 100k 1000000 1M 100000 Supply Current vs. Supply Voltage 4.5 1 100 100 PHASE Phase (5k (5kΩ) Ω) FREQUENCY (Hz) Output Voltage Swing vs. Output Current 0.5 Open-Loop Gain and Phase vs. Frequency 80 -45 1k 1000 FREQUENCY (Hz) 0 60 100 100 -225 10k 1M 10000 100k 100000 1000000 80 0 10 10 1k 1000 45 80 1 1 100 100 100 GAIN (5k Ω) Gain (5kΩ) -20 10 10 45 45 Gain (100kΩ & 100pF) GAIN (100k Ω AND 100pF) PHASE (100k Ω||II100pF) 100pF) Phase (100kΩ 11 1M 1000000 Open-Loop Gain and Phase vs. Frequency Open-Loop Gain and Phase vs. Frequency 0 100k 100000 FREQUENCY (Hz) FREQUENCY (Hz) 100 1k 1000 GAIN (dB) 10k 10000 CURRENT (mA) 1k 1000 PHASE (Degrees) 100 100 PHASE Phase (100k (100kΩ) Ω) -20 -20 -20 1010 -180 GAIN Gain (100k (100kΩ) Ω) CMRR (100kΩ || 100pF) PSRR (100kΩ || 100pF) GAIN (dB) 0 CMRR (100kΩ) 0 PSRR (100kΩ) PHASE (Degrees) 40 PHASE (Degrees) 100 GAIN (dB) 100 0 OUTPUT VOLTAGE (V) Open-Loop Gain and Phase vs. Frequency CMRR vs. Frequency CMRR (dB) PSRR (dB) PSRR vs. Frequency 25 30 2 2.5 3 3.5 4 4.5 SUPPLY VOLTAGE (V) 4 5 5.5 2 2.5 3 3.5 4 4.5 5 5.5 SUPPLY VOLTAGE (V) M9999-032612-A Micrel, Inc. MIC864 Functional Characteristics V+ = VS/2 = 2.5V, V− = -VS/2 = 2.5V, RL = 100kΩ , RL and CL connected in parallel to GND; TA = +25°C, unless otherwise noted. March 2012 5 M9999-032612-A Micrel, Inc. MIC864 Functional Characteristics (Continued) V+ = VS/2 = 2.5V, V− = -VS/2 = 2.5V, RL = 100kΩ , RL and CL connected in parallel to GND; TA = +25°C, unless otherwise noted. March 2012 6 M9999-032612-A Micrel, Inc. MIC864 Functional Description The MIC864 is a dual-operational amplifier with an input range 0.2V greater than the supply rails and an output range to within 15mV of the supply rails (100kΩ load). The MIC864 can be operated from a single from 2.5V to 5.5V supply or a dual ±1.25V to ±2.75V supply. It features a low 33µA quiescent current per channel with a gain bandwidth product of 350kHz. Compared with other operational amplifiers in its class, the MIC864 offers dependable CMRR and PSRR. This is achieved through transconductance normalization, which ensures consistent performance across the entire input voltage range. This feature eliminates a region of the input voltage range where some earlier operational amplifiers were subject to degraded CMRR and PSRR. Transconductance Normalization Hand-off between the NFET and PFET differential pairs is managed by the transconductance normalization circuit block. As the common-mode input voltage transitions between high and low voltages, this circuit block ensures smooth, consistent, and continuous operation. Class AB Output Stage Low output impedance is achieved by driving the common-emitter output stage with a class AB control circuit. In contrast with the common collector output stages of earlier operational amplifiers, this allows an output range very close to the supply rails. Input Stage The MIC864 uses parallel NFET and PFET differential input transistor pairs for a common-mode input voltage range beyond the supply rails. When input voltages are high, the NFET differential input pair operates. When input voltages are low, the PFET differential input pair operates. Functional Diagram MIC864 Block Diagram March 2012 7 M9999-032612-A Micrel, Inc. MIC864 Application Information The MIC864 operational amplifier is optimized for portable applications such as cell phones, computer pads, media players, mobile chemical sensors, carbon monoxide detectors, and smoke detectors. A 2.5V to 5.5V supply voltage range allows operation from the regulated output of a lithium-ion battery. No-load supply current is 33µA per channel for long battery life. An input range 0.2V beyond the supply rails and an output range to within 15mV of the supply rails (100kΩ load) maximize dynamic range for improved signal to noise ratios in the application. High, consistent CMRR and PSRR minimize power supply noise coupling from adjacent circuitry. Power Supply Bypassing For single supply operation, connect a 0.1µF ceramic capacitor between the V+ and V− power supply pins. For dual supply operation, connect 0.1µF capacitors from V+ to GND and from GND to V−. Place these capacitors within 0.2in (5mm) of the MIC864. If no large-value capacitors are nearby then also include 10uF capacitors connected in similar fashion. Capacitive and Resistive Loads The MIC864 is internally compensated for unity-gain stability with load resistances between 5kΩ and 100kΩ, and a 100pF load capacitance. A 68pF minimum load capacitance is required to ensure unity-gain stability across production and temperature variations. Care should be taken to observe the minimum load capacitance requirement in circuits with a gain less than 2, and in circuits with a capacitor connected between the IN- and OUT pins. Input protection The IN- and IN+ inputs of the MIC864 are clamped to the V+ and V− pins using ESD protection diodes. Operation of IN+ or IN− beyond (V+) + 0.2V and (V−) − 0.2V is not recommended as this would turn on the ESD protection diodes and violates the Absolute Maximum Ratings. Driving ADCs ADCs (analog-to-digital converters) typically include either a capacitive sample-and-hold or a capacitive DAC at their inputs. During operation, they periodically connect those capacitors to their inputs while sampling the input signal. General practice is to place a RC lowpass filter between the operational amplifier supplying the input signal and the ADC. The series resistor between the operational amplifier output and ADC input limits capacitive loading on the operational amplifier to prevent instability. The capacitor between the ADC input and GND minimizes glitches by supplying charge to the internal ADC capacitors. Feedback Feedback resistors in the 5kΩ and 100kΩ range are recommended. Load resistance and capacitance requirements must be considered when designing the feedback network, especially in unity-gain and low-gain circuits (see “Capacitive and Resistive Loads” section for further information). When using high-value feedback resistors, place a lowvalue capacitor in parallel with the resistor connected between IN- and OUT. This capacitor counteracts the effects of the parasitic capacitance at the IN- pin which forms a pole that may otherwise degrade stability. However, a 68pF minimum load capacitance must be included to ensure stability. When AC-coupling signals to the MIC864 through a capacitor, provide a DC-bias current path using a resistor. Otherwise, there will be no source for supplying the input bias current and the circuit will stop working. March 2012 8 M9999-032612-A Micrel, Inc. MIC864 Package Information 8-Pin SOIC (M) MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry, specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2012 Micrel, Incorporated. March 2012 9 M9999-032612-A