OPA1678IDRGR

Due to market price fluctuations,if you need to purchase or consult the price.You can contact us or emial to us:   sales@allicdata.com

1. Describe

The single-channel OPA1677, dual-channel OPA1678IDRGR, and quad-channel OPA1679 (OPA167x) op amps provide higher system-level performance than conventional op amps commonly used in audio circuits. The OPA1678IDRGR amplifier achieves a low noise density of 4.5nV/√Hz and low distortion of 0.0001% at 1 kHz, improving audio signal fidelity. These devices also provide rail-to-rail output swings in the 800mV range into a 2kΩ load, increasing headroom and maximizing dynamic range. To accommodate the power supply constraints of many audio products, the OPA1678IDRGR operates over a very wide supply range of ±2.25 V to ±18 V (or 4.5 V to 36 V) with a supply current of only 2 mA. These op amps are unity gain stable and have excellent dynamic behavior under various load conditions, so the OPA167x can be used in many audio circuits. The OPA167x amplifiers use completely independent internal circuitry, so even under overload or overload conditions, crosstalk and channel-to-channel interaction are not affected.

2. Feature

    1. Low noise: 4.5 nV/√Hz at 1 kHz

    2. Low distortion: 0.0001% at 1 kHz

    3. High open loop gain: 114 dB

    4. High Common Mode Rejection: 110 dB

    5. Low quiescent current:

        – 2 mA per channel

    6. Low input bias current: 10 pA (typ)

    7. Slew rate: 9 V/μs

    8. Wide Gain Bandwidth: 16 MHz (G = 1)

    9. Unity gain stable

  10. Rail-to-rail output

  11. Wide range of supply:

        – ±2.25 V to ±18 V, or 4.5 V to 36 V

  12. Single, dual and quad versions

  13. Available packages:

        – Singles: SOIC-8 (preview), SOT-23

        – Dual: SOIC-8, Small SON-8, VSSOP-8

        – Quad: Small QFN-16, SO-14, TSSOP-14

  14. Temperature range: –40°C to +85°C

3. Application

    1. Professional microphone and wireless system

    2. Professional audio mixer/control surface

    3. Guitar amplifiers and other instrument amplifiers

    4. A/V receiver

    5. Automotive external amplifier

4. Pin configuration

5. Pin Description

6. Function description

    1. Typical application

        Contact microphones can be used to amplify the sound of instruments that do not contain electronic pickups, such as acoustic guitars and violins. Most contact microphones use piezoelectric elements to convert vibrations in the body of the instrument into voltages that can be amplified or recorded. The low noise and low input bias current of the OPA1678IDRGR make this device an excellent choice for high impedance preamplifiers for piezoelectric elements. This preamplifier circuit provides high input impedance for piezoelectric elements, but low output impedance for driving long cable runs. The circuit is also designed to be powered by the 48V phantom power commonly found in professional microphone preamps and recording consoles.

    2. Reverse phase protection

        The OPA1678IDRGR family has internal reverse phase protection. Many op amps exhibit phase inversion when the input is driven beyond the linear common-mode range. This occurs most often in non-inverting circuits when the input is driven beyond the specified common-mode voltage range, causing the output to reverse into the opposite supply rail. The inputs of the OPA167x are protected against phase reversal due to excessive common-mode voltage. Conversely, proper power rails limit the output voltage.

    3. Electrical overstress

        Designers often ask questions about an op amp's ability to withstand electrical overstress. These questions tend to focus on device inputs, but may involve supply voltage pins or even output pins. Each of these different pin functions has electrical stress limits determined by the specific semiconductor fabrication process and the voltage breakdown characteristics of the specific circuit connected to the pin. Additionally, these circuits have built-in internal electrostatic discharge (ESD) protection to protect them from accidental ESD events before and during product assembly. It is helpful to have a good understanding of this basic ESD circuit and its correlation to electrical overstress events. The ESD protection circuit consists of several current control diodes connected from the input and output pins and back to the internal power supply lines, where the diodes meet at the sink device inside the op amp. This protection circuit is designed to remain inactive during normal circuit operation.

7. Application Information

The dynamic characteristics of the OPA1678IDRGR family are suitable for common gain, load and operating conditions. The combination of low closed-loop gain and high capacitive loading reduces the headroom of the phase amplifier and can cause gain peaking or ringing. Therefore, large capacitive loads must be isolated from the output. The easiest way to achieve this isolation is to place a small resistor in series with the output. This small series resistance also prevents excessive power dissipation if the output of the device is shorted.