TL064CDR

The TL064CDR is a quad low-power JFET-input operational amplifier from Texas Instruments in a 14-pin SOIC package, providing four independent op-amp channels in a single device. Each amplifier features 200 uA typical supply current, 1 MHz gain-bandwidth product, and 3.5 V/us slew rate. The JFET input stage provides extremely high input impedance (10^12 Ohm), low input bias current (30 pA typical), and a common-mode input voltage range that includes the positive supply rail. With internal frequency compensation, output short-circuit protection, and EMI filtering, the TL064CDR is the low-power variant of the industry-standard TL074 and TL084 families.

The TL064CDR uses a JFET-input differential pair as the first gain stage, which provides very high input impedance and very low input bias current compared to bipolar-input op-amps. The differential input stage amplifies the voltage difference between the inverting and non-inverting inputs, converting it to a single-ended signal. A high-gain voltage amplifier stage further amplifies this signal, and a class-AB output buffer provides low-impedance output drive capability with short-circuit protection. Internal frequency compensation (a dominant pole capacitor) ensures stability in unity-gain configurations without external components. The JFET input allows the common-mode input voltage to extend to the positive supply rail, enabling single-supply operation in many applications. The trade-off for the low 200 uA per-amplifier quiescent current (compared to 1.4 mA for the TL074) is a slightly lower gain-bandwidth product (1 MHz versus 3 MHz) and slower slew rate (3.5 V/us versus 13 V/us). The integrated EMI filter on the input pins rejects high-frequency interference, improving robustness in electrically noisy environments.

TL064CDR uses the SOIC-14 (D) surface-mount package with standard quad op-amp pinout: Pin 1 = Output 1, Pin 2 = Inverting Input 1 (-), Pin 3 = Non-inverting Input 1 (+), Pin 4 = VCC+, Pin 5 = Non-inverting Input 2 (+), Pin 6 = Inverting Input 2 (-), Pin 7 = Output 2, Pin 8 = Output 3, Pin 9 = Inverting Input 3 (-), Pin 10 = Non-inverting Input 3 (+), Pin 11 = VCC-, Pin 12 = Non-inverting Input 4 (+), Pin 13 = Inverting Input 4 (-), Pin 14 = Output 4. This 14-pin quad op-amp pinout is shared by TL064, TL074, TL084, LM324, LM348, and LF347. The JFET inputs provide 30pA typical input bias current. For through-hole, TL064CN provides the same pinout in PDIP-14.

• Active Filters: Multiple second-order filter stages in a single package for audio and instrumentation signal conditioning
• Instrumentation Amplifiers: Three-amplifier instrumentation amp topology with the fourth channel for gain or filtering
• Signal Conditioning: Low-power sensor interface amplifiers in battery-powered data acquisition systems
• Audio Preamplifiers: Low-noise JFET-input microphone and instrument preamplifier circuits
• Oscillators and Waveform Generators: Wien-bridge and state-variable oscillators requiring multiple op-amp channels

TL064CDR is a quad JFET-input op-amp from TI in SOIC-14. The TL074CDR provides higher 3V/µs slew rate with similar pinout. The TL084CDR offers 13V/µs slew rate for faster signal processing. The LF347DR from TI provides similar JFET performance. For CMOS rail-to-rail, TLC274 offers quad CMOS op-amps in the same DIP-14/SOIC-14 pinout. The OPA4134 from TI/Burr-Brown provides FET-input audiophile-grade performance. The LM324 remains the lowest-cost alternative for general-purpose applications.