- 3W Output to 8Ω at 5V with THD + N = 1%
- Selectable spread spectrum mode reduces EMI
- 80% efficiency
- Independent voltage regulator and amplifier shutdown control
- Dynamically selectable regulator output voltage
- Class D without filtering
- 3.0V - 5.5V operation
- Low shutdown current
- Click-inhibition
illustrate
The LM48511 integrates a high efficiency Class D audio power amplifier boost converter that delivers 3W of continuous power to an 8Ω speaker while operating from a 5V supply. When operating from a 4V 3V supply, the LM48511 can be configured to drive an 8Ω load into less than 1% distortion (THD+N) of 1 to 2.5W. Class D amplifiers feature a low-noise PWM architecture that eliminates output filters, reduces external component count, board area consumption, system cost, and simplifies design. An optional spread-spectrum modulation technique rejects RF emissions, further reducing the need for output filters.
The LM48511's switching regulator is a current mode boost to 1MHz fixed-frequency converter operation. Two optional feedback networks enable the LM48511 switching regulator to dynamically improve efficiency by optimizing the amplifier's supply voltage, battery voltage, and output power requirements.
The LM48511 is designed for use in portable devices such as GPS, mobile phones and MP3 players. High, 80% efficiency at 5V, extending battery life compared to boosting Class AB amplifiers. Independent voltage regulators and amplifier shutdown control regulators save power by disabling high output power without optimization.
The LM48511 gain is set by an external resistor, allowing independent gain control by summarizing signals from multiple sources. Output short-circuit protection and thermal overload protection prevent damage to the device under fault conditions. Superior click-and-pop suppression eliminates power-up and power-down sound transients.
Main specifications
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■ Quiescent supply current
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VDD= 3V VDD= 5V
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9 mA (typical) 13.5 mA (typical)
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■ PO in VDD= 5V，PV1 = 7.8V RL =8Ω，THD + N = 1％
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3.0W (typical)
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■ PO in VDD= 3V，PV1 = 4.8V RL =8Ω，THD + N = 1％
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1W (typical)
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■ PO in VDD= 5V，PV1 = 7.8V RL =4Ω，THD + N = 1％
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5.4W (typical)
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■ The shutdown current is in VDD= 3V
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0.01μA (typical)
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apply
- GPS
- Portable media
- camera
- mobile phone
- Handheld game consoles
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