February 1999
LM1875
20W Audio Power Amplifier
General Description
The LM1875 is a monolithic power amplifier offering very low
distortion and high quality performance for consumer audio
applications.
Features
n Up to 30 watts output power
n AVO typically 90 dB
n Low distortion: 0.015%, 1 kHz, 20 W
n Wide power bandwidth: 70 kHz
±
The LM1875 delivers 20 watts into a 4Ω or 8Ω load on 25V
±
supplies. Using an 8Ω load and 30V supplies, over 30
n Protection for AC and DC short circuits to ground
n Thermal protection with parole circuit
n High current capability: 4A
n Wide supply range 16V-60V
n Internal output protection diodes
n 94 dB ripple rejection
watts of power may be delivered. The amplifier is designed
to operate with a minimum of external components. Device
overload protection consists of both internal current limit and
thermal shutdown.
The LM1875 design takes advantage of advanced circuit
techniques and processing to achieve extremely low distor-
tion levels even at high output power levels. Other outstand-
ing features include high gain, fast slew rate and a wide
power bandwidth, large output voltage swing, high current
capability, and a very wide supply range. The amplifier is in-
ternally compensated and stable for gains of 10 or greater.
n Plastic power package TO-220
Applications
n High performance audio systems
n Bridge amplifiers
n Stereo phonographs
n Servo amplifiers
n Instrument systems
Connection Diagram
Typical Applications
DS005030-1
Front View
NSC Package
Package
Ordering Info
Number
For Straight Leads
LM1875T
SL108949
T05A
For Stagger Bend
LM1875T
LB03
T05D
T05E
For 90˚ Stagger Bend
For 90˚ Stagger Bend
LM1875T
LB05
LM1875T
LB02
TA05B
DS005030-2
© 1999 National Semiconductor Corporation
DS005030
www.national.com