
Audio Switching Amplifier
AD1990
FEATURES
Integrated stereo modulator and power stage
<0.002% THD + N
101 dB dynamic range (A-weighted)
2 × 5 W output power (4 Ω, <0.01% THD + N)
R
DS-ON
< 0.3 Ω (per transistor)
PSRR > 65 dB
On-off-mute pop noise suppression
EMI optimized modulator
Short-circuit protection
Overtemperature protection
Low cost DMOS process
APPLICATIONS
Advanced televisions
Compact multimedia systems
Minicomponents
Rev. 0
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. Specifications subject to change without notice. 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 owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
2006 Analog Devices, Inc. All rights reserved.
www.analog.com
GENERAL DESCRIPTION
The AD1990 is a 2-channel, bridge tied load (BTL), switching
audio power amplifier with integrated Σ-Δ modulator. The
modulator accepts a single-ended, analog input signal and
converts it to a switching waveform to drive speakers directly. A
digital, microprocessor-compatible interface provides control of
reset, mute, and PGA gain, as well as feedback signals for thermal
and overcurrent error conditions. The output stage can operate
over a power supply voltages range of 8 V to 12 V. The analog
modulator and digital logic operate from a 5 V supply.
FUNCTIONAL BLOCK DIAGRAM
B2
B1
A2
A1
OUTL+
LEVEL
DEAND
CONTROL
H-BRIDGE
PGND
OUTL–
OUTR+
D
D
D
OUTR–
D2
D1
C2
C1
N
N
N
N
M
R
E
E
E
-
Δ
MODΣ
-
Δ
MODΣ
PGA
PGA
OSCILLATOR
RVOLTAGE
MODE CONTROL
POP/CLICK
SUPPRESSION
AGND
CLKI
CLKO
REF_FILT
AINR
AINL
PV
DD
AV
DD
DV
DD
PGA1
PGA0
NETWORK
NETWORK
AD1990
0
Figure 1.