EB-2100 Datasheet, PDF (2/11 Pages) List of Unclassifed Manufacturers – DDX All-Digital, High Efficiency Evaluation Amplifier

_______________
__ EB-2100x
DESIGN OVERVIEW
The EB-2100x is an all-digital amplifier
evaluation board that demonstrates Apogee’s
DDX-2000/2100 chip set solution. The board
features coaxial and optical S/PDIF digital
interfaces, volume and balance controls,
expansion headers for off-board processing, and
local power regulation enabling single supply
operation from 10 to 36VDC. The all-digital
amplifier board may be configured as either 2 x
50W into 8Ω or 1 x 100W into 4Ω.
INL[1:2]
INR[1:2]
VL
PWRDN
TRI-STATE
FAULT
TWARN
Logic I/F
and Decode
Left
H-Bridge
Protection
Circuitry
Regulators
Right
H-Bridge
OUTPL
OUTNL
OUTPR
OUTNR
DDX-2000/2100 OVERVIEW
The DDX-2000 Controller is a 3.3V digital
integrated circuit that converts serial PCM digital
audio signals into Apogee's patented damped
ternary outputs. The device supports two
modes of digital volume control, muting and anti-
clipping functions. A block diagram of the
device is shown in Figure 1.
ACE MUTE
SCLK
SDATA
LRCLK
VMODE
VCLK/UP
VDATA/DN
SERIAL
INTERFACE
VOLUME/
GAIN
ANTI-
CLIPPING
SYSTEM
CLOCKING
PWM
GENERATION
OUTL[1:2]
OUTR[1:2]
XI XO LPIN LPOUT
Figure 1 - DDX-2000 Functional Diagram
The DDX-2100 Power Device is a dual channel
H-Bridge that can deliver over 50 watts per
channel of audio output power. The DDX-2100
includes; a logic interface, integrated bridge
drivers, high efficiency MOSFET outputs and
protection circuitry. Two logic level signals per
channel are used to control high-speed
MOSFET switches to connect the speaker load
to the input supply or to ground in a bridge
configuration, according to Apogee's patented
damped ternary PWM. The DDX-2100 includes
over-current and thermal protection, and under-
voltage lockout with automatic recovery. A
thermal warning status is also provided.
Figure 2 - DDX-2100 Block Diagram
SCHEMATIC DESCRIPTION
S/PDIF INPUT INTERFACE (FIG. 3A)
The EB-2100x accommodates either a coaxial
or an optical S/PDIF digital audio interface.
Either input may be selected by moving jumper
J2. Connect J2 pins 1-2 for coaxial or J2 pins 2-
3 for optical S/PDIF. A Crystal CS8415A digital
audio interface receiver is utilized to convert the
incoming S/PDIF signal to serial I²S used by the
DDX-2000. The receiver also recovers a 256*Fs
clock synchronized to the incoming signal which
is used as the master clock to the DDX-2000.
The design will support sample rates from below
32kHz to above 48kHz. The receiver PLL out-
of-lock signal is used to mute the amplifier’s
output when a valid S/PDIF signal is not present.
Zero ohm jumpers R6,R9,R10,R11,R42 are
provided to disconnect the outputs of the S/PDIF
receiver from the inputs to the DDX-2000 so that
external signals may be applied via the
expansion header J7 (see Fig. 3D).
DIGITAL SIGNAL PROCESSING (FIG. 3B)
The DDX-2000 converts serial I²S digital audio
signals into pulse-width-modulated digital
signals output at 8*Fs, according to Apogee’s
patented damped ternary architecture. Signals
from the S/PDIF receiver are applied as inputs
to the DDX processor and signals from the DDX
processor are applied to the inputs of the DDX
power stage.
A low-cost microcontroller with an ADC is used
to implement the volume and balance controls.
The amplifier’s volume and balance levels are
2
Details are subject to change without notice.