JM2020 True Fidelity

JM2020 True Fidelity®
8W Stereo Sub-ranging Digital Audio Amplifier
Features
Product Overview
• Sub-ranging PWM architecture delivers 100dB true
dynamic range for faithful small signal reproduction
• Direct digital Synchronous Bi-modulation eliminates
distortion and noise inherent with D/A conversion
- Stereo SPDIF or I2S input formats
- Supports audio sample rates from 32KHz-192kH
• Operates from 10-13.2V output power supply
• 8W per channel into 8Ω Load from 12V supply
• 100 dB Signal to Noise
• 80% power efficiency
• Silent power on/off (no clicks or pops)
• Digital volume control via pins or I2C serial bus
• Low EMI with 192kHz PRF
• Low current shutdown and mute modes
• Available in 9mm x 9mm 64-pin QFN package
The JM2020 True Fidelity® sub-ranging PWM digital
power amplifier is a monolithic IC integrating the
modulator and power stage for two channels of True
Fidelity stereo.
The patented sub-ranging PWM
architecture provides the efficiency of Class D, fidelity of
analog, and robustness of digital. With direct digital
Synchronous Bi-modulation™, the JM2020 directly
converts digital audio data into analog power for driving
speakers without the distortion and noise inherent with
D/A conversion.
Applications
•
•
•
•
Flat Panel TVs
Compact Audio
Powered Speakers
PMP Docking Stations
The JM2020 delivers premium 16 bit audio quality with a
range of linearity greater than 96dB, enabling consumer
audio equipment to achieve True Fidelity sound even at
low signal levels. The open-loop design delivers full
resolution over a wide dynamic range without using
Delta-Sigma modulation, linearizing feedback loops,
DSP error-correction or predictive error-compensating
circuitry..
With the JM2020, true 16 bit audio can be transmitted
digitally over any medium to distributed speaker systems
providing unprecedented all-digital performance.
System Diagram
VCR
Video
Front A/V
Tuner
DVD
Video
Display
Driver
Audio
And
Video
Processor
Audio
JM2020
Digital
Digital
audio
amplifier
Audio
Amplifier
Speaker
Interface
I2S
Or
SPDIF
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JM2020
Functional descriptions
Digital Audio Input
Silent power-on/power off
The JM2020 features silent power-on and power-off
operation to avoid clicks and pops during reset and
power up. For correct operation the digital power
supply must be valid prior to the application of the
output supply.
2
The JM2020 supports I S and SPDIF digital audio
inputs. The part will automatically detect the audio
2
format and auto-configure itself to accept either I S
audio format or SPDIF format.
The JM2020 supports audio sample rates ranging
from 32 Khz to 196 Khz via the I2S and SPDIF digital
audio interface, including the 44.1 KHz, 48 KHz and
192 KHz standard rates.
The data clock is not
required to be synchronized with the internally
generated master chip clock.
Thermal Protection
Thermal protection prevents damage to the device
when the internal die temperature exceeds 150 ºC.
There is a +/-25 ºC tolerance on the trip point and 45
ºC hysteresis. Over-temperature is indicated via the
2
I C registers. When over-temperature is indicated the
device should then be disabled using the SHDNB
input to prevent damage to the device. Once the
temperature is reduced beneath the hysteresis point
the device can be enabled to resume normal
operation.
Volume control
Volume can be controlled via the I2C registers or the
volume up and volume down pins. The volume
2
control will be set to the I C register value whenever
the register is written. The external
VOLUPB/VOLDNB pins will increase/decrease the
volume from the register value. If the volume is to be
2
controlled via the I C bus the volume inputs should
be tied high.
Chip Clock
The master chip clock can either be internally
generated or supplied from an external source with
low phase noise to the CLKIN pin.
Mute
EMI Suppression
The Mute pin will disable the output of the amplifier.
2
Mute can also be enabled via the I C volume control
registers.
To reduce potential EMI, the output pulse repetition
rate is designed to be 192kHz.
Shutdown operation
The shutdown mode can be used to conserve power
during periods of nonuse. The I2C bus will not
function during shutdown mode.
C
Control Port
Reference
Generator
CLKOUT
FREQ
CLKIN
SHDNB
RESETB
VREF
VREF
MUTEB
VOLUPB
VOLDNB
I2CCLK
I2CAD1
I2CDAT
I2CAD0
Block Diagram
Oscillator
Left Speaker
Output stage
LRCLK
SCLK
SDAT
I2S
Or
S/PDIF
I/F
Gain/Mute
control
Modulator
Right Speaker
Output stage
I2S
Or
S/PDIF
Jam Technologies Singapore Pte Ltd
159 Kampong Ampat
#05-02 KA Place
Singapore 368328
Tel : +(65) 6285.1200
Email: sales@jam-tech.com
Jam Technologies, Inc.
6500 River Place Boulevard
Building II, Suite 100
Austin, TX 78730
+1.512.372.9950
www.jamtech.com
Copyright © 2006, Jam Technologies, Inc.; E-Bridge and True Fidelity are registered trademarks and Synchronous Bi-Modulation is a trademark of
Jam Technologies, Inc. All other company and product names mentioned in this document are the property of their respective owners.
PB01026-02 V1
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