Class-D Audio Power Amplifier
Preliminary Technical Data
AD1990/AD1992/AD1994/AD1996


Rev. PrA – 1/20/05
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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
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FEATURES
Integrated Stereo Modulator & Power Stage
0.005% THD+N
101.5dB Dynamic Range
PSRR > 65 dB
RDS-ON < 0.3 Ω (per transistor)
Efficiency > 80% @ 5W/6 Ω
EMI Optimized Modulator
On-Off-Mute Pop Noise Suppression
Short Circuit Protection
Over-Temperature Protection
Low Cost DMOS Process
APPLICATIONS
Flat Panel Televisions
Automotive Amplifiers
PC Audio Systems
Mini Components

GENERAL DESCRIPTION
The AD199x is a two channel Bridge Tied Load (BTL)
switching audio power amplifier with integrated ∑∆ modulator.
The modulator accepts a 1Vrms input signal (maximum power)
and generates a switching waveform to drive speakers directly.
One of the two modulators can control both output stages
providing twice the current for single-channel applications. A
digital, microcontroller-compatible interface provides control of
reset, mute and PGA gain as well as output signals for thermal
and over-current error conditions. The output stage can operate
from supply voltages ranging from 8V to 20V. The analog
modulator and digital logic operate from a 5V supply.

AD1990: 5Wx2 (10Wx1)
AD1992: 10Wx2 (20Wx1)
AD1994: 25Wx2 (50Wx1)
AD1996: 40Wx2 (80Wx1)
PGND1
Σ∆
MODULATOR
PGA
LEFT CHANNEL
VOLTAGE
REFERENCE
OSCILLATOR MODE CONTROL LOGIC
MUTE/
POP
CONTROL
TEMPERATURE
SENSE &
OVER-CURRENT
PROTECTION
19
E
R
R
0
29
M
U
T
E
17
E
R
R
2
30
R
S
T
/
P
W
D
N
49
M
O
N
O
18
E
R
R
1
7,8
4,5,6
1,2,3
9,10
11,12,13
14,15,16
55
27 28 22 21 20
41,42
43,44,45
46,47,48
39,40
36,37,38
33,34,35
50 5160 53313262 63
PVDD
OUTL+
PGND1
PVDD1
OUTL-
PGND1
REF_FILT
CLKI CLKO
D
C
T
R
L
0
D
C
T
R
L
1
D
C
T
R
L
2
PVDD2
OUTR+
PGND2
PVDD2
OUTR-
PGND2
N
F
R
+
N
F
R
-
N
F
L
+
N
F
L
-
P
G
A
0
P
G
A
1
A
I
N
L
A
I
N
R
AVDD
AGND
DVDD
DGND
57
56
24,25
23,26
Ø1 Ø2 Ø1 Ø2
PGND2
PVDD2
PVDD2
PGND2
LEVEL
SHIFT
+
DEAD
TIME
CONTROL
Σ∆
MODULATOR
PGA
RIGHT CHANNEL
DRIVER
HIGH SIDE
DRIVER
LOW SIDE
DRIVER
HIGH SIDE
DRIVER
LOW SIDE
DRIVER
HIGH SIDE
DRIVER
LOW SIDE
LEVEL
SHIFT
+
DEAD
TIME
CONTROL

Figure 1. Block Diagram