LM388N 1

LM388N-1 Audio Power Amplifier

Overview

The LM388N-1 is a medium-power audio amplifier IC designed for consumer applications requiring reliable performance with minimal external components. Its internally fixed gain of 20 simplifies circuit design while remaining flexible enough for adjustable gain configurations. The device operates across a wide voltage range, making it suitable for battery-powered and mains-operated systems. Housed in a 14-pin dual-in-line package (DIP), the LM388N-1 delivers low distortion and excellent power supply rejection, ensuring high-quality audio reproduction.

Key Features

• Minimal External Components: Internally set gain of 20 reduces BOM count
• Wide Supply Voltage Range: Operates from 4V to 22V for versatile applications
• Excellent Power Supply Rejection: 60dB typical minimizes noise interference
• Ground-Referenced Input: Simplifies signal interface design
• Self-Centering Output: Automatic quiescent voltage stabilization
• Adjustable Gain: External resistor/capacitor network allows gain modification
• Low THD: <0.2% typical at 1W output
• Robust Package: 14-pin DIP (N14A) for reliable mechanical mounting

Applications

The LM388N-1 is ideal for various audio and power control applications:

• Consumer Audio:
  • AM/FM radio power amplifiers
  • Portable tape player audio stages
  • Television sound systems
• Communication Systems:
  • Intercom amplifiers
  • Line drivers for telephone equipment
• Industrial/Control:
  • Ultrasonic transducer drivers
  • Small servo motor controllers
  • Lamp drivers for indicator systems
• Power Conversion:
  • DC-AC inverters
  • Voltage converter control circuits

Electrical Characteristics

(TA = 25°C, VCC = 12V, RL = 8Ω unless otherwise specified)

DC Characteristics

• Supply Voltage Range: 4V to 22V
• Quiescent Current: 8mA typical (14mA maximum)
• Output Voltage Swing: VCC-2V typical (RL = 8Ω)
• Input Bias Current: 100nA maximum

AC Characteristics

• Bandwidth: 100kHz (AV = 20)
• Slew Rate: 0.5V/μs typical
• THD+N: 0.2% at 1W, 1kHz
• PSRR: 60dB at 120Hz

Power Characteristics

• Output Power: 2W continuous (8Ω load at 12V)
• Efficiency: 65% typical at maximum output

Absolute Maximum Ratings

(Stresses beyond these may cause permanent damage)

• Supply Voltage (VCC): 26V
• Input Voltage: ±15V
• Output Current: 1.5A peak
• Power Dissipation: Internally limited
• Operating Temperature Range: 0°C to +70°C
• Storage Temperature Range: -65°C to +150°C
• Lead Temperature (Soldering, 10 sec): 260°C

Package Information

N14A - 14-Pin Dual-In-Line Package

• Package Dimensions: 19.3mm x 6.35mm x 4.57mm
• Pin Spacing: 2.54mm (0.1") row-to-row, 7.62mm (0.3") between rows
• Lead Material: Copper alloy
• Finish: Matte tin plating
• Mounting: Through-hole, wave or reflow solderable
• Thermal Resistance: 80°C/W junction-to-ambient

Pin Configuration

• Pin 1: Output A
• Pin 2: Inverting Input A
• Pin 3: Non-Inverting Input A
• Pin 4: VCC-
• Pin 5: Non-Inverting Input B
• Pin 6: Inverting Input B
• Pin 7: Output B
• Pin 8: NC (No Connection)
• Pin 9: VCC+
• Pins 10-14: NC (No Connection)

Design Considerations

For optimal performance with the LM388N-1:

• Use 0.1μF ceramic decoupling capacitors near supply pins
• Maintain short lead lengths for input signals
• For adjustable gain: R = 20kΩ/(Desired Gain - 1) between pins 2-6
• Heat sinking may be required for continuous high-power operation
• Keep ground returns separate for input and output stages

Reliability Data

• MTBF: >100,000 hours at 25°C
• ESD Protection: 1kV Human Body Model
• Moisture Sensitivity: Level 1 (unlimited floor life)

Ordering Information

• Base Part Number: LM388N-1
• Package Code: N14A
• Temperature Grade: Commercial (0°C to +70°C)
• Shipping Format: Tube (25 pieces) or Tape & Reel (1000 pieces)