AD AD8393

Adaptive Linear Power™
12 V ADSL-CO Line Driver
AD8393
APPLICATIONS
ADSL DSLAMs, DLC
xDSL Line Cards using DMT Signals
Other Application Signals with Occasional Peaks
GENERAL DESCRIPTION
The AD8393 is a low power, high output current, single-supply,
ADSL-CO line driver that features ADI’s patent pending
Adaptive Linear Power (ALP) architecture. The AD8393 ALP
architecture offers increased port density in ADSL Central Office
(CO) line card designs through improved line driver efficiency
and simplified system design by operating from a single 12 V
supply. The AD8393 ALP amplifier can provide 20.4 dBm of
line power from a single 12 V dc supply, surpassing the efficiency
of typical class AB line drivers. ADSL signals applied to the inputs
of the AD8393 modulate internal driver supplies coincidentally
with the peak voltages contained in Discrete Multitone (DMT)
signals. The internal supplies modulated by the ALP circuit
allow the AD8393 to operate from a lower supply voltage that
improves efficiency and simplifies CO line card designs. Crest
factors (CF) up to 6.5 can be accommodated by the AD8393.
C02885–0–12/02(SpA)
–20
–30
–40
–50
–73dBc
FEATURES
Low 600 mW Total Power Consumption
Includes 19.8 dBm Line Power
MTPR –73 dBc, 12 V Supply
Requires Only a Single 12 V Power Supply
Can Achieve over 36 V p-p Differential Output while
Processing Signals with Occasional Peaks (Such as
Discrete Multitone)
Analog Devices’ Adaptive Linear Power Architecture
Enables High Port Density Central Office Line Cards
Current Feedback Amplifier (CFB)
Greater than 500 mA Peak Output Drive Current Capability
4 Power Modes Controlled by 2 Logic Pins
AD8393-1 Input Range of 0.75 V to 1.2 V
AD8393-2 Input Range of 0.3 V to 0.75 V
–60
–70
–80
–90
–100
–110
–120
CENTER 513kHz
1kHz/DIV
SPAN 10kHz
Figure 1. AD8393-1 MTPR Performance
(DMT Waveform, 5.5 CF, Line Power = 19.8 dBm)
+12V
INTERNALLY
GENERATED
PUMPED SUPPLY
VOUT1
GND
VOUT2
INTERNALLY
GENERATED
PUMPED SUPPLY
Figure 2. Typical Output and Pumped Supplies
Processing a 5.5 CF Waveform
PRINTED IN U.S.A.
Potentially useful in non-DSL applications, the ALP architecture dramatically improves power efficiency when processing
signals with occasional peaks by responding to these signal
peaks and instantaneously raising the internal supply voltage
when peak power is needed. The AD8393 is capable of delivering
over 36 V p–p of signal to a differential load, while operating
on a single 12 V supply.
To inquire about AD8393 samples and an evaluation board, contact
Analog Devices via email at: [email protected]
REV. SpA
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective companies.
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© 2002 Analog Devices, Inc. All rights reserved.