TC911ACOA

1 TC911A TC911B AUTO-ZEROED OPERATIONAL AMPLIFIERS FEATURES s s s s s s s s s s s s First Monolithic Chopper-Stabilized Amplifier With On-Chip Nulling Capacitors Offset Voltage .................................................... 5µV Offset Voltage Drift .................................. 0.05µV/°C Low Supply Current ...................................... 350µA High Common-Mode Rejection .................... 116dB Single Supply Operation ....................... 4.5V to 16V High Slew Rate ............................................. 2.5V/µs Wide Bandwidth ............................................1.5MHz High Open-Loop Voltage Gain (RL = 10 kΩ) .................................................... 120dB Low Input Voltage Noise (0.1 Hz to 1 Hz) .......................................... 0.65µVP-P Pin Compatible With ICL7650 Lower System Parts Count GENERAL DESCRIPTION The TC911 CMOS auto-zeroed operational amplifier is the first complete monolithic chopper-stabilized amplifier. Chopper operational amplifiers like the ICL7650/7652 and LTC1052 require user-supplied, external offset compensation storage capacitors. External capacitors are not required with the TC911. Just as easy to use as the conventional OP07 type amplifier, the TC911 significantly reduces offset voltage errors. Pinout matches the OP07/741/7650 8-pin mini-DIP configuration. Several system benefits arise by eliminating the external chopper capacitors: lower system parts count, reduced assembly time and cost, greater system reliability, reduced PC board layout effort and greater board area utilization. Space savings can be significant in multiple-amplifier designs. Electrical specifications include 15µV maximum offset voltage, 0.15µV/°C maximum offset voltage temperature coefficient. Offset voltage error is five times lower than the premium OP07E bipolar device. The TC911 improves offset drift performance by eight times. The TC911 operates from dual or single power supplies. Supply current is typically 350µA. Single 4.5V to 16V supply operation is possible, making single 9V battery operation possible. The TC911 is available in 2 package types: 8-pin plastic DIP and SOIC. PIN CONFIGURATION (SOIC and DIP) NC 1 – INPUT 2 + INPUT 3 VSS 4 TC911ACPA TC911BCPA 8 NC 7 VDD 6 OUTPUT 5 NC NC 1 – INPUT 2 + INPUT 3 VSS 4 8 NC 7 VDD TC911ACOA 6 OUTPUT TC911BCOA 5 NC 2 3 4 5 6 7 ORDERING INFORMATION Temperature Range 0°C to +70°C 0°C to +70°C 0°C to +70°C 0°C to +70°C Part No. TC911ACOA TC911ACPA TC911BCOA TC911BCPA Package 8-Pin SOIC 8-Pin Plastic DIP 8-Pin SOIC 8-Pin Plastic DIP Maximum Offset Voltage 15µV 15µV 30µV 30µV FUNCTIONAL BLOCK DIAGRAM VDD 4 VSS 7 V CORRECTION AMPLIFIER OS A – B B INTERNAL OSCILLATOR (fOSC ≈ 200 Hz) NC = NO INTERNAL CONNECTION –INPUT 2 + * * A +INPUT 3 + TC911 LOW IMPEDANCE OUTPUT BUFFER + – MAIN AMPLIFIER – 6 OUTPUT *NOTE: Internal capacitors. No external capacitors required. TC911/A/B-7 9/11/96 8 3-263 TELCOM SEMICONDUCTOR, INC. AUTO-ZEROED MONOLITHIC OPERATIONAL AMPLIFIERS TC911A TC911B ABSOLUTE MAXIMUM RATINGS* Total Supply Voltage (VDD to VSS) ........................... +18V Input Voltage ........................ (VDD + 0.3V) to (VSS – 0.3V) Current into Any Pin .................................................10mA While Operating ................................................100µA Storage Temperature Range ................ – 65°C to +150°C Lead Temperature (Soldering, 10 sec) ................. +300°C Operating Temperature Range C Device ................................................ 0°C to +70°C Package Power Dissipation (TA = ≤ 70°C) Plastic DIP ...................................................... 730mW Plastic SOIC ................................................... 470mW *Static-sensitive device. Unused devices should be stored in conductive material. Stresses above 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 above those indicated in the operational sections of the specifications is not implied. ELECTRICAL CHARACTERISTICS: VS = ±5V, TA = +25°C, unless otherwise indicated. Symbol Parameter VOS TCVOS Input Offset Voltage Average Temperature Coefficient of Input Offset Voltage Average Input Bias Current Average Input Offset Current Input Voltage Noise Common-Mode Rejection Ratio Common-Mode Voltage Range Open-Loop Voltage Gain Output Voltage Swing Closed Loop Bandwidth Slew Rate Power Supply Rejection Ratio Operating Supply Voltage Range Quiescent Supply Current Test Conditions TA = +25°C 0°C ≤ TA ≤ +70°C –25°C ≤ TA ≤ +85°C (Note 1) TA = +25°C 0°C ≤ TA ≤ +70°C –25°C ≤ TA ≤ +85°C TA = +25°C TA = +85°C 0.1 to 1 Hz, RS ≤ 100Ω 0.1 to 10 Hz, RS ≤ 100Ω VSS ≤ VCM ≤ VDD – 2.2 Min — — — — — — — — — — 110 VSS TC911A Typ 5 0.05 0.05 — — — 5 — 0.65 11 116 — 120 — 1.5 2.5 — — — 350 Max 15 0.15 0.15 70 3 4 20 1 — — — VDD – 2 — VDD – 0.9 — — — ±8 16 600 Min — — — — — — — — — — 105 VSS 110 VSS + 0 .3 — — 105 ±3.3 6.5 — TC911B Typ 15 0.1 0.1 — — — 10 — 0.65 11 110 — 120 — 1.5 2.5 — — — — Max 30 0.25 0.25 120 4 6 40 1 — — — VDD – 2 — VDD – 0.9 — — — ±8 16 800 Unit µV µV/°C µV/°C pA nA nA pA nA µVP-P µVP-P dB V dB V MHz V/µs dB V V µA IB IOS eN CMRR CMVR AOL VOUT BW SR PSRR VS IS RL = 10 kΩ, VOUT = ±4V 115 RL = 10 kΩ VSS + 0 .3 Closed Loop Gain = +1 — RL = 10 kΩ, CL = 50 pF ±3.3V to ±5.5V Split Supply Single Supply VS = ±5V — 112 ±3.3 6.5 — NOTES: 1. Characterized; not 100% tested. 3-264 TELCOM SEMICONDUCTOR, INC. AUTO-ZEROED MONOLITHIC OPERATIONAL AMPLIFIERS TC911A TC911B TYPICAL CHARACTERISTICS Supply Current vs. ± Supply Voltage 700 600 TA = +25°C 450 1 Supply Current vs. Temperature VS = ±5V 35 Input Offset Voltage vs. Common-Mode Voltage VS = ±5V 2 3 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) 400 INPUT OFFSET VOLTAGE (µV) 30 25 20 15 10 5 0 TA = +25°C 500 400 300 200 100 0 2 3 4 5 6 7 ± SUPPLY VOLTAGE (V) 8 350 300 250 200 –100 –50 0 50 100 AMBIENT TEMPERATURE (°C) 150 –6 –5 –4 –3 –2 –1 0 1 2 3 4 INPUT COMMON-MODE VOLTAGE (V) Gain and Phase vs. Frequency 50 40 PHASE GAIN VS = ±5V TA = +25°C RL = 10 kΩ 225 180 135 Large Signal Output Switching Waveform RL = 10 kΩ TA = +25°C OUTPUT VERTICAL SCALE = 1 V/DIV 0V 5.8 5.0 Output Voltage Swing vs. Load Resistance TA = +25°C VS = ±5V –SWING 4 5 CLOSED-LOOP GAIN (dB) ± OUTPUT VOLTAGE (V) 30 20 10 0 INPUT VERTICAL SCALE = 2 V/DIV PHASE (deg) 90 45 0 4.2 3.4 2.6 1.8 1.0 100 +SWING –10 –20 –45 –90 –135 100k 1M FREQUENCY (Hz) –180 10M HORIZONTAL SCALE = 2 µs/DIV –30 –40 10k 1k 10k 100k 1M LOAD RESISTANCE (Ω) 6 7 8 TELCOM SEMICONDUCTOR, INC. 3-265 AUTO-ZEROED MONOLITHIC OPERATIONAL AMPLIFIERS TC911A TC911B Pin Compatibility The CMOS TC911 is pin compatible with the industry standard ICL7650 chopper-stabilized amplifier. The ICL7650 must use external 0.1µF capacitors connected at pins 1 and 8. With the TC911, external offset voltage error canceling capacitors are not required. On the TC911 pins 1, 8 and 5 are not connected internally. The ICL7650 uses pin 5 as an optional output clamp connection. External chopper capacitors and clamp connections are not necessary with the TC911. External circuits connected to pins 1, 8 and 5 will have no effect. The TC911 can be quickly evaluated in existing ICL7650 designs. Since external capacitors are not required, system part count, assembly time, and total system cost are reduced. Reliability is increased and PC board layout eased by having the error storage capacitors integrated on the TC911 chip. The TC911 pinout matches many existing op amps: 741, LM101, LM108, OP05–OP08, OP-20, OP-21, ICL7650 and ICL7652. In many applications operating from +5V supplies the TC911 offers superior electrical performance and can be a functional pin-compatible replacement. Offset voltage correction potentiometers, compensation capacitors, and chopper-stabilization capacitors can be removed when retrofitting existing equipment designs. (Seebeck voltage) can be measured. Junction temperature and metal type determine the magnitude. Typical values are 0.1µV/°C to 10µV/°C. Thermal-induced voltages can be many times larger than the TC911 offset voltage drift. Unless unwanted thermocouple potentials can be controlled, system performance will be less than optimum. Unwanted thermocouple junctions are created when leads are soldered or sockets/connectors are used. Low thermo-electric coefficient solder can reduce errors. A 60% Sn/36% Pb solder has 1/10 the thermal voltage of common 64% Sn/36% Pb solder at a copper junction. The number and type of dissimilar metallic junctions in the input circuit loop should be balanced. If the junctions are kept at the same temperature, their summation will add to zero-canceling errors (Figure 1). Shielding precision analog circuits from air currents — especially those caused by power dissipating components and fans — will minimize temperature gradients and thermocouple-induced errors. Avoiding Latch-Up Junction-isolated CMOS circuits inherently contain a parasitic p-n-p-n transistor circuit. Voltages exceeding the supplies by 0.3V should not be applied to the device pins. Larger voltages can turn the p-n-p-n device on, causing excessive device power supply current and excessive power dissipation. TC911 power supplies should be established at the same time or before input signals are applied. If this is not possible input current should be limited to 0.1mA to avoid triggering the p-n-p-n structure. Thermocouple Errors Heating one joint of a loop made from two different metallic wires causes current flow. This is known as the Seebeck effect. By breaking the loop, an open circuit voltage J3 = J4 J2 = J5 NO TEMPERATURE DIFFERENTIAL AND SAME METALLIC CONNECTION J1 = J6 J2 J1 J3 Overload Recovery PACKAGE PIN The TC911 recovers quickly from the output saturation. Typical recovery time from positive output saturation is 20msec. Negative output saturation recovery time is typically 5msec. J4 J5 J2 V2 J6 + – J3 V3 + – + J1 V1 – VT = V1 + V2 + V3 – V4 – V5 – V6 = 0 + J4 V 4 – VT = 0 + V5 J5 – + V6 J6 – Figure 1. Unwanted Thermocouple Errors Eliminated by Reducing Thermal Gradients and Balancing Junctions 3-266 TELCOM SEMICONDUCTOR, INC. AUTO-ZEROED MONOLITHIC OPERATIONAL AMPLIFIERS TC911A TC911B TYPICAL APPLICATIONS 10-Volt Precision Reference Thermometer Circuit +9V TC911 REF02 ADJ R2 1 2 3 18 kΩ +15V TC911 3+ 2 – 7 6 4 0.1 µF VOUT = 10V TEMP OUT V REF R1 – + VOUT 6.4V 3.6 kΩ R3 6.4 kΩ R3 + R1 V OUT = VTEMP 1 + R2 R X R 1 3 [( )] [ dT R2 – VREF R 1 ] 4 5 dV OUT dT K=1+ = [( 1 + R2 R2 R +R 3 1 R3 X R 1 )] d (VTEMP ) ≈ K (2.1 mV/°C) R3X R1 Programmable Gain Amplifier With Input Multiplexer +5V –5V GND +5V –5V IN1 IN2 IN3 IN4 IC1b IC1b + – +5V –5V TC911 VOUT X1 X 10 18 k Ω X 100 99 k Ω X 1000 999 kΩ 6 7 A1 A2 A3 A4 WR INPUT CHANNEL SELECT 68HC11 GAIN SELECT WR LATCH A1 A2 A3 A4 GND 2 kΩ 1 kΩ 1 kΩ IC1a, b, = Quad Analog Switch 8 3-267 TELCOM SEMICONDUCTOR, INC.