1 TC901 MONOLITHIC, AUTO-ZEROED OPERATIONAL AMPLIFIER 2 FEATURES GENERAL DESCRIPTION ■ Second-Generation Monolithic, Chopper-Stabilized Op Amp ■ No External Capacitors Required ■ Single-Supply Operation ........... ±15V or 5V to 32V ■ Supply Current ............................ 450µA at 15V, Typ ■ Input Offset Voltage ................................... 7µV, Typ ■ Common-Mode Rejection Ratio ............ 140dB, Typ ■ Open-Loop Gain ............ 140dB Into 10k Load, Typ ■ Input Noise ......................... 5µV at 10Hz Bandwidth ■ Pinout Compatible With ICL7650 ■ Lowest Parts Count Chopper Op Amp The TC901 is a monolithic, auto-zeroed operational amplifier. It is a second-generation design of the TC91X CMOS chopper-stabilized op amps with on-chip capacitors. Elimination of the external capacitors allows the designer to increase reliability, lower cost, and simplify design by lowering parts count. Since the TC901 is an auto-zeroing op amp, input offset voltage is very low. More important, there is almost zero drift with time. This eliminates production line adjustments, as well as periodic calibration. Notable electrical characteristics are low supply current (450µA, typical), single-supply operation (5V to 32V), low input offset voltage (7µV, typical), low noise (<5µVP-P, typical, for a 10Hz bandwidth), and fast recovery from saturation without the use of external clamp circuitry. This device is supplied in 8-pin plastic DIP and plastic SOIC packages. It is pin compatible with bipolar, CMOS, JFET and other chopper-stabilized op amps using the industry-standard 741 pinout. PIN CONFIGURATION (DIP and SOIC) TC901CPA +INPUT 3 VSS 4 NC 1 8 NC NC 1 –INPUT 2 TC901COA – + 7 VDD 6 OUTPUT 5 NC –INPUT 2 +INPUT 3 VSS 4 8 NC – 7 VDD + 6 OUTPUT ORDERING INFORMATION 5 NC Temperature Range NC = NO INTERNAL CONNECTION Part No. Package TC901COA TC901CPA 8-Pin SOIC 8-Pin Plastic DIP 3 4 5 0°C to +70°C 0°C to +70°C FUNCTIONAL BLOCK DIAGRAM –INPUT 2 VDD VSS 4 7 + 6 VOS CORRECTION AMPLIFIER TC901 – A INTERNAL OSCILLATOR (fOSC ≈ 200 Hz) B * B 7 * A +INPUT 3 + + – MAIN AMPLIFIER LOW IMPEDANCE OUTPUT BUFFER 6 OUTPUT – 8 NOTE: Internal capacitors. No external capacitors required. TC901- 7 9/5/96 TELCOM SEMICONDUCTOR, INC. 3-259 MONOLITHIC, AUTO-ZEROED OPERATIONAL AMPLIFIER TC901 ABSOLUTE MAXIMUM RATINGS* Total Supply Voltage (VDD to VSS) ........................... +36V 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. Appropriate precautions should be taken when handling, shipping, or storing these devices. Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the devices. 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 ±15V, TA = +25°C, unless otherwise indicated. Symbol Parameter Test Conditions VOS Input Offset Voltage (Figure 2) Average Temperature Coefficient of Input Offset Voltage Average Input Bias Current TCVOS IBIAS IOS eN eN CMRR CMVR AOL VOUT BW SR PSRR VS IS Average Input Offset Current Input Voltage Noise (Figure 1B) Input Voltage Noise (Figure 1A) Common-Mode Rejection Ratio Common-Mode Voltage Range Open-Loop Voltage Gain Output Voltage Swing Closed-Loop Bandwidth (Figure 7) Slew Rate Power Supply Rejection Ratio Operating Supply Voltage Range Quiescent Supply (Figure 2) Min Typ Max TA = +25°C — 7 15 0°C ≤ TA ≤ +70°C (Note 1) — 0.05 0.15 µV/°C 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 — — — — — — 30 0.2 0.2 50 — 1.2 50 10 10 100 1 — pA nA nA pA nA µVP-P 0.1 to 10 Hz, RS ≤ 100Ω — 5 — µVP-P VSS ≤ VCM ≤ VDD –2V 120 140 — dB VS = ±5V to ±15V VSS — VDD –2 V RL = 10 kΩ, VS = ±15V RL = 10 kΩ Closed-Loop Gain = +1 120 VSS + 1 — 140 — 0.8 — VDD –1.2 — RL = 10 kW, CL = 50 pF VS = ±5V to ±15V Note 2 — 120 ±3 2 140 — — — ±16 V/µsec dB V — 0.45 0.6 mA VS = ±15V Units µV dB V MHz NOTES: 1. Characterized; not 100% tested. 2. Single supply operation: VDD = +5V to +32V. 3-260 TELCOM SEMICONDUCTOR, INC. MONOLITHIC, AUTO-ZEROED OPERATIONAL AMPLIFIER 1 TC901 Overload Recovery The TC901 recovers quickly from output saturation. Typical recovery time from positive output saturation is 20 msec. Negative output saturation recovery time is typically 5 msec. Larger voltages can turn the p-n-p-n device on, causing excessive device power supply current and excessive power dissipation. TC901's power supply should be established at the same time (or before) input signals are applied. If this is not possible, input current should be limited to 100µA to avoid triggering the p-n-p-n structure. Thermocouple Errors Pin Compatibility Heating a junction made from two different metallic wires causes current flow. This is known as the Seebeck effect. An open-circuit voltage (Seebeck voltage) can be measured across the junction. 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 TC901's 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 thermoelectric coefficient solder can reduce errors. A 60% Cd/40% Sn Pb solder has one-tenth 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 7). Shielding precision analog circuits from air currents — especially those caused by power dissipating components and fans — will minimize temperature gradients and minimize thermocouple-induced errors. The CMOS TC901 is pin compatible with other chopperstabilized amplifiers, such as the 7650, 7652 and 1052. Amplifiers such as the 7650 require 0.1µF external capacitors connected to pins 1 and 8. The TC901 includes the chopper capacitors on-chip, so external capacitors are not required. Since pins 1, 5 and 8 of the TC901 are not connected, the TC901 can directly replace other chopperstabilized amplifiers in existing circuits. The TC901 pinout also matches many popular bipolar and JFET op amps, such as the OP-07, OP-20, LM101, LM108, 356 and 741. In many applications that operate from ±15V power supplies, the TC901 offers superior electrical performance and is a functional pin-compatible replacement. Offset voltage correction potentiometers, compensation capacitors, and chopper-stabilization capacitors can be removed when retrofitting existing equipment designs. System parts count, assembly time, and system cost are reduced, while reliability and performance are improved. J3 = J4 J2 = J5 NO TEMPERATURE DIFFERENTIAL AND SAME METALLIC CONNECTION J1 = J6 J2 J1 J3 Overload Recovery 2 3 4 5 The TSC90X Series recovers quickly from output saturation. Typical recovery time from positive output saturation is 20 msec. Negative output saturation recovery time is typically 5 msec. PACKAGE PIN 6 VT = 0 7 J6 J4 J5 + – J2 V2 – + J1 V1 – J3 V3 + VT = V1 + V2 + V3 – V4 – V5 – V6 = 0 + J4 V4 – V + 5 – J5 V + 6 – J6 Figure 7. Unwanted Thermocouple Errors Eliminated by Reducing Thermal Gradients and Balancing Junctions 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. TELCOM SEMICONDUCTOR, INC. 8 3-261 MONOLITHIC, AUTO-ZEROED OPERATIONAL AMPLIFIER (A) 0.1 TO 1.0 Hz 1 µV/DIV TC901 2V INPUT 2 V/DIV 0V (B) 0.1 TO1.0 Hz 1 µV/DIV 0V OUTPUT 5 V/DIV –15V 0 1 2 3 4 5 6 7 8 9 10 5 msec/DIV 1 sec/DIV Figure 1. Figure 3. Recovery From Negative Saturation Input Voltage Noise VOS (µV) 4 VDD (µA) 450 2V 400 6 9 OUTPUT 5 V/DIV 350 VOS 10 300 12 250 14 200 16 150 18 100 20 50 0V OUTPUT 0V 5 V/DIV –2V 0 22 0 2 4 6 8 10 12 14 16 18 20 msec/DIV 20 ±VS (V) Figure 2. VOS and IDD vs Supply Voltage Figure 4. Recovery From Positive Saturation +50 R2 +15V – + –15V OUTPUT GAIN (dB) R1 +240 +40 +30 +180 +20 +120 +10 +60 0 0°C –10 PHASE MARGIN 10kΩ with 50 pF LOAD 36° at 700 kHz at 70°C 40° at 800 kHz at 25°C –20 GAIN = 40 R1= 1kΩ R2= 40kΩ –30 –120 –180 –40 0 10 100 1k 10k 100k 1M FREQUENCY (Hz) Figure 5. Saturation Test Circuit 3-262 Figure 6. Phase-Gain TELCOM SEMICONDUCTOR, INC.