How to Use LE11: Examples, Pinouts, and Specs

The LE11 is a low-power, high-speed operational amplifier (op-amp) designed for precision signal processing applications. It offers a wide bandwidth and low noise performance, making it ideal for use in analog circuits requiring high accuracy and stability. The LE11 is commonly used in audio processing, sensor signal conditioning, active filters, and instrumentation amplifiers.

• Audio signal amplification
• Sensor signal conditioning
• Active filters (low-pass, high-pass, band-pass)
• Precision instrumentation amplifiers
• Analog-to-digital converter (ADC) buffering

• Supply Voltage (Vcc): ±2.5V to ±15V
• Input Offset Voltage: 0.5 mV (typical)
• Input Bias Current: 10 nA (typical)
• Gain Bandwidth Product (GBP): 10 MHz
• Slew Rate: 5 V/µs
• Output Voltage Swing: ±13.5V (at ±15V supply)
• Quiescent Current: 1.2 mA (typical)
• Noise Density: 4 nV/√Hz (at 1 kHz)
• Operating Temperature Range: -40°C to +85°C
• Package Options: 8-pin DIP, SOIC

The LE11 is typically available in an 8-pin package. Below is the pinout and description:

1. Power Supply:

   • Connect the positive supply voltage (V+) to Pin 7 and the negative supply voltage (V-) to Pin 4.
   • Ensure the supply voltage is within the specified range (e.g., ±2.5V to ±15V).

2. Input Connections:

   • Connect the signal to be amplified to either the inverting input (Pin 2) or the non-inverting input (Pin 3), depending on the desired configuration (inverting or non-inverting amplifier).

3. Output Connection:

   • The amplified signal will be available at the output terminal (Pin 6). Connect this pin to the next stage of your circuit.

4. Offset Adjustment (Optional):

   • If precise offset voltage adjustment is required, connect a 10 kΩ potentiometer between Pins 1 and 5, with the wiper connected to V+.

5. Bypass Capacitors:

   • Place decoupling capacitors (e.g., 0.1 µF ceramic and 10 µF electrolytic) close to the power supply pins to reduce noise and improve stability.

Below is an example of using the LE11 as a non-inverting amplifier with a gain of 11.

// Non-inverting amplifier circuit with LE11
// Gain = 1 + (R2 / R1)

#include <Arduino.h>

// Define pin for input signal (e.g., from a sensor)
const int inputPin = A0;  // Analog input pin
const int outputPin = 9;  // PWM output pin (for testing purposes)

void setup() {
  pinMode(inputPin, INPUT);  // Set input pin as input
  pinMode(outputPin, OUTPUT); // Set output pin as output
}

void loop() {
  int sensorValue = analogRead(inputPin); // Read input signal
  int outputValue = map(sensorValue, 0, 1023, 0, 255); 
  // Map input to PWM range (0-255)
  
  analogWrite(outputPin, outputValue); // Output amplified signal
  delay(10); // Small delay for stability
}

• Stability: Use proper bypass capacitors near the power supply pins to ensure stable operation.
• Input Impedance: The LE11 has a high input impedance, making it suitable for interfacing with high-impedance sources.
• Thermal Management: Ensure the operating temperature does not exceed the specified range to avoid performance degradation.

1. No Output Signal:

   • Cause: Incorrect power supply connections.
   • Solution: Verify that V+ and V- are connected to the correct pins and within the specified voltage range.

2. Output Signal is Distorted:

   • Cause: Insufficient power supply decoupling or incorrect gain configuration.
   • Solution: Add bypass capacitors near the power supply pins and verify the resistor values in the gain configuration.

3. High Noise in Output:

   • Cause: Poor grounding or external interference.
   • Solution: Ensure a proper ground connection and minimize noise sources near the circuit.

4. Offset Voltage Too High:

   • Cause: Offset adjustment not performed.
   • Solution: Use a potentiometer between Pins 1 and 5 to fine-tune the offset voltage.

Q1: Can the LE11 be used with a single power supply?
A1: Yes, the LE11 can operate with a single supply voltage. In this case, connect V- to ground and ensure the input signal is biased within the op-amp's input range.

Q2: What is the maximum gain I can achieve with the LE11?
A2: The maximum gain depends on the external resistor values and the op-amp's bandwidth. For high gains, ensure the gain-bandwidth product (GBP) is not exceeded.

Q3: Can the LE11 drive capacitive loads?
A3: Yes, but for large capacitive loads, use a small series resistor (e.g., 10 Ω) at the output to improve stability.

Q4: Is the LE11 suitable for audio applications?
A4: Absolutely! The LE11's low noise and wide bandwidth make it an excellent choice for audio signal processing.

By following this documentation, you can effectively integrate the LE11 into your analog circuit designs and troubleshoot common issues with ease.