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LM49150 -
Mono Class D Audio Subsystem with Earpiece Driver and Stereo Ground Referenced Headphone Amplifiers
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Features
| • | E
2S class D amplifier
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| • | Ground referenced headphone outputs — eliminates output coupling capacitors |
| • | I
2C volume and mode control
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| • | Mono earpiece amplifier |
| • | Flexible output for speaker and headphone output |
| • | 20–bump micro SMD package |
| • | Soft enable function |
| • | “Click and Pop” suppression circuitry |
| • | Thermal shutdown protection |
| • | Low supply current |
| • | Micro-power shutdown |
Key Specification
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Output power at VDD = 5V:
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| Speaker:
RL = 8Ω BTL, THD+N
≤ 1%
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1.25W (typ)
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| Headphone:
RL = 32Ω SE, THD+N
≤ 1%
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42mW (typ)
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| Earpiece:
RL = 8Ω SE, THD+N
≤ 1%
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135mW (typ)
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Output power at VDD = 3.3V:
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| Speaker:
RL = 8Ω BTL, THD+N
≤ 1%
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520mW (typ)
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| Headphone:
RL = 32Ω BTL, THD+N
≤ 1%
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42mW (typ)
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| Earpiece:
RL = 8Ω SE, THD+N
≤ 1%
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35mW (typ)
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Output Offset
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| LS Mode
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9mV (typ)
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| HP Mode
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1mV (typ)
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| Earpiece
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1mV (typ)
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Single Supply Operation (VDD)
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2.7 to 5.5V
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I
2C Single Supply Operation
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1.7 to 5.5V
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General Description
The LM49150 is a fully integrated audio subsystem designed for portable handheld applications such as cellular phones. More...
Applications
| • | Mobile Phones |
| • | PDAs |
| • | Portable Electronics |
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Typical Application
click for larger image
| Parameters | Values |
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| Power@ 4Ohms, 1% THD |
0.845 Watt |
| Power@ 8Ohms, 1% THD |
2.1 Watt |
| THD |
0.01 % |
| PSRR |
91 dB |
| SNR |
101 dB |
| Channels |
3 Channels |
| THD Conditions |
VDD=5V, HP Pout = 20mW, RL=32ohms |
| PSRR Conditions |
Vripple = 200mVpp, f=217Hz, RL = 32ohms, CB=2.2uF, HP Attenuation = 0dB |
| SNR Conditions |
HP mode 4, A-weighted, Output referred |
| User Supply |
5 Volt |
| Audio Mux |
Yes |
| Capless Headphone |
Yes |
| ClassD Driver |
Yes |
| Interface |
I2C |
| Stereo Inputs |
Single Ended |
| National 3D |
No |
| Digital Volume Control Max |
18 dB |
| Digital Volume Control Min |
-80 dB |
| Output Modes |
16 |
| Supply Range |
+2.7 - +5.5 V |
| Mono Inputs |
Differential |
| Temperature Min |
-40 deg C |
| Temperature Max |
85 deg C |
| Loudspeaker Type |
Class D |
| Headphone Type |
True Ground |
Typical Performance
click for larger image
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Also Recommended
| LM49151▲ | Class D With ALC, Ground Reference Headphone |
Additional Resources
Application Notes
Connection Diagram
click for larger image
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Datasheet
RoHS Compliance Information
| Size in Kbytes | Date |
 |
| LM49150 Mono Class D Audio Subsystem with Earpiece Driver and Stereo Ground Referenced Headphone Amplifiers |
764
Kbytes |
4-Mar-09 |
Download |
Package Availability, Models, Samples & Pricing
General Description
The LM49150 is a fully integrated audio subsystem designed for portable handheld applications such as cellular phones. Part
of National's Power Wise® product family, the LM49150 consumes very low power in the various modes of operation and still
providing great audio performance. The LM49150 combines a 1.25W mono E
2S (Enhanced Emission Suppression) class D amplifier, 135mW Class AB earpiece amplifier, 42mW/channel stereo ground reference
headphone amplifiers, volume control, and mixing circuitry into a single device.
The filterless class D amplifier delivers 1.25W into an 8Ω load with <1% THD+N with a 5V supply. The E
2S class D amplifier features a patented, ultra low EMI PWM architecture that significantly reduces RF emissions while preserving
audio quality. The 42mW/channel headphone drivers feature National’s ground referenced architecture that creates a ground-referenced
output from a single supply, eliminating the need for bulky and expensive DC-blocking capacitors, saving space and minimizing
cost.
The LM49150 features a fully differential mono input, and two single-ended stereo inputs. The three inputs can be mixed/multiplexed
to either the speaker or headphone amplifiers. Each input channel has an independent, 32-step digital volume control. The
headphone output stage features an additional, 8-step gain control, while the speaker output stage has a selectable 6dB or
12dB gain. The mixer, volume control and device mode select are controlled through an I
2C compatible serial interface.
The LM49150’s superior click and pop suppression eliminates audible transients on power-up/down and during shutdown. The
LM49150 is available in a ultra-small 20-bump micro SMD package (2.225mm X 2.644mm).
More Application Notes
| Title | Size in Kbytes |
Date |
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| AN-1964: Application Note 1964 LM49151 Demonstration Board and Software Guide |
1605
Kbytes |
13-May-09 |
Download |
[Information as of 7-Nov-2009]
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