LME49720NA/NOPB National Semiconductor, LME49720NA/NOPB Datasheet - Page 23

• Manufacturer Part Number: LME49720NA/NOPB
• Description: IC AMP AUDIO STER AB HIFI 8DIP
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LME49720NA/NOPB

• Amplifier Type: Audio
• Number Of Circuits: 2
• Slew Rate: 20 V/µs
• Gain Bandwidth Product: 55MHz
• Current - Input Bias: 10nA
• Voltage - Input Offset: 100µV
• Current - Supply: 10mA
• Current - Output / Channel: 26mA
• Voltage - Supply, Single/dual (±): ±2.5 V ~ 17 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 8-DIP (0.300", 7.62mm)
• Bandwidth: 55 MHz
• Channel Separation: 118
• Common Mode Rejection Ratio: 120
• Current, Input Bias: 10 nA
• Current, Input Offset: 11 nA
• Current, Output: ±26 mA
• Current, Supply: 10 mA
• Harmonic Distortion: 0.00003 %
• Impedance, Thermal: 102 °C/W
• Number Of Amplifiers: Dual
• Package Type: DIP-8
• Resistance, Input: 30 Kilohms (Differential), 1000 Megohms (Common-Mode)
• Temperature, Operating, Range: -40 to +85 °C
• Voltage, Gain: 140 dB
• Voltage, Input: 5 to 34 V
• Voltage, Noise: 2.7 nV/sqrt Hz
• Voltage, Offset: ±0.1 mV
• Voltage, Output, High: 14.1 V
• Voltage, Output, Low: -14.1 V
• Voltage, Supply: ±15 V
• Amplifier Class: AB
• No. Of Channels: 2
• Supply Voltage Range: ± 2.5V To ± 17V
• Load Impedance: 2kohm
• Operating Temperature Range: -40°C To +85°C
• Amplifier Case Style: DIP
• No. Of Pins: 8
• Rohs Compliant: Yes
• Number Of Channels: 2
• Voltage Gain Db: 140 dB
• Common Mode Rejection Ratio (min): 110 dB
• Input Voltage Range (max): 34 V
• Input Voltage Range (min): 5 V
• Input Offset Voltage: 0.7 mV at +/- 15 V
• Supply Current: 5.0 mA
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• Maximum Dual Supply Voltage: +/- 17 V
• Minimum Operating Temperature: - 40 C
• For Use With: LME49720NABD - BOARD EVALUATION LME49720NA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Output Type: -
• -3db Bandwidth: -
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device
• Other names: LME49720NA

Application Information
DISTORTION MEASUREMENTS
The vanishingly low residual distortion produced by
LME49720 is below the capabilities of all commercially avail-
able equipment. This makes distortion measurements just
slightly more difficult than simply connecting a distortion me-
ter to the amplifier’s inputs and outputs. The solution, how-
ever, is quite simple: an additional resistor. Adding this
resistor extends the resolution of the distortion measurement
equipment.
The LME49720’s low residual distortion is an input referred
internal error. As shown in Figure 1, adding the 10Ω resistor
connected between the amplifier’s inverting and non-inverting
FIGURE 1. THD+N and IMD Distortion Test Circuit
23
inputs changes the amplifier’s noise gain. The result is that
the error signal (distortion) is amplified by a factor of 101. Al-
though the amplifier’s closed-loop gain is unaltered, the feed-
back available to correct distortion errors is reduced by 101,
which means that measurement resolution increases by 101.
To ensure minimum effects on distortion measurements,
keep the value of R1 low as shown in Figure 1.
This technique is verified by duplicating the measurements
with high closed loop gain and/or making the measurements
at high frequencies. Doing so produces distortion compo-
nents that are within the measurement equipment’s capabili-
ties. This datasheet’s THD+N and IMD values were generat-
ed using the above described circuit connected to an Audio
Precision System Two Cascade.
300038k4
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