ssm2211z-eval Analog Devices, Inc., ssm2211z-eval Datasheet - Page 14

• Manufacturer Part Number: ssm2211z-eval
• Description: Low Distortion 1.5 Watt Audio Power Amplifier
• Manufacturer: Analog Devices, Inc.

SSM2211
PRODUCT OVERVIEW
The SSM2211 is a low distortion speaker amplifier that can run
from a 2.7 V to 5.5 V supply. It consists of a rail-to-rail input
and a differential output that can be driven within 400 mV of
either supply rail while supplying a sustained output current of
350 mA. The SSM2211 is unity-gain stable, requiring no
external compensation capacitors, and can be configured for
gains of up to 40 dB. Figure 41 shows the simplified schematic.
V
IN
20kΩ
0.1μF
4
3
2
Figure 41. Simplified Schematic
20kΩ
A1
50kΩ
50kΩ
V
DD
6
7
50kΩ
SSM2211
SHUTDOWN
CONTROL
A2
BIAS
50kΩ
1
5
8
V
V
O1
O2
Rev. D | Page 14 of 24
Pin 4 and Pin 3 are the inverting and noninverting terminals
to A1. An offset voltage is provided at Pin 2, which should be
connected to Pin 3 for use in single-supply applications. The
output of A1 appears at Pin 5. A second operational amplifier,
A2, is configured with a fixed gain of A
inverted replica of Pin 5 at Pin 8. The SSM2211 outputs at Pin 5
and Pin 8 produce a bridged configuration output to which a
speaker can be connected. This bridge configuration offers the
advantage of a more efficient power transfer from the input to
the speaker. Because both outputs are symmetric, the dc bias at
Pin 5 and Pin 8 are exactly equal, resulting in zero dc differ-
ential voltage across the outputs. This eliminates the need for a
coupling capacitor at the output.
THERMAL PERFORMANCE—LFCSP
The addition of the LFCSP to the Analog Devices, Inc., package
portfolio offers the SSM2211 user even greater choice when
considering thermal performance criteria. For the 8-lead,
3 mm × 3 mm LFCSP, the θ
performance improvement over most other packaging options.
JA
is 50°C/W. This is a significant
V
= −1 and produces an