Low Distortion, 1.5 W Audio
Power Amplifier
SSM2211
Data Sheet
FEATURES
FUNCTIONAL BLOCK DIAGRAM
1.5 W output with THD + N < 1%
Differential bridge-tied load output
Single-supply operation: 2.7 V to 5.5 V
Functions down to 1.75 V
Wide bandwidth: 4 MHz
Highly stable phase margin: >80°
Low distortion: 0.2% THD + N at 1 W output
Excellent power supply rejection
IN–
VOUTA
IN+
VOUTB
BYPASS
SHUTDOWN
Portable computers
Personal wireless communicators
Hands-free telephones
Speaker phones
Intercoms
Musical toys and talking games
BIAS
SSM2211
V– (GND)
00358-001
APPLICATIONS
Figure 1.
GENERAL DESCRIPTION
The SSM22111 is a high performance audio amplifier that
delivers 1 W rms of low distortion audio power into a bridgeconnected 8 Ω speaker load (or 1.5 W rms into a 4 Ω load).
The SSM2211 operates over a wide temperature range and is
specified for single-supply voltages between 2.7 V and 5.5 V.
When operating from batteries, it continues to operate down to
1.75 V. This makes the SSM2211 the best choice for unregulated
applications, such as toys and games.
Featuring a 4 MHz bandwidth and distortion below 0.2% total
harmonic distortion plus noise (THD + N) at 1 W, superior
performance is delivered at higher power or lower speaker load
impedance than competitive units. Furthermore, when the
ambient temperature is at 25°C, THD + N < 1%, and VS = 5 V
on a 4-layer printed circuit board (PCB), the SSM2211 delivers
a 1.5 W output.
1
The low differential dc output voltage results in negligible
losses in the speaker winding and makes high value dc blocking
capacitors unnecessary. The battery life is extended by using
shutdown mode, which typically reduces quiescent current
drain to 100 nA.
The SSM2211 is designed to operate over the −40°C to +85°C
temperature range. The SSM2211 is available in 8-lead SOIC
(narrow body) and LFCSP (lead frame chip scale) surfacemount packages. The advanced mechanical packaging of the
LFCSP models ensures lower chip temperature and enhanced
performance relative to standard packaging options.
Applications include personal portable computers, hands-free
telephones and transceivers, talking toys, intercom systems, and
other low voltage audio systems requiring 1 W output power.
Protected by U.S. Patent No. 5,519,576.
Rev. G
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Tel: 781.329.4700 ©2002–2016 Analog Devices, Inc. All rights reserved.
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SSM2211
Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1
Bridged Output vs. Single-Ended Output Configurations ... 16
Applications ....................................................................................... 1
Speaker Efficiency and Loudness ............................................. 16
Functional Block Diagram .............................................................. 1
Power Dissipation....................................................................... 16
General Description ......................................................................... 1
Output Voltage Headroom........................................................ 18
Revision History ............................................................................... 2
Automatic Shutdown-Sensing Circuit ..................................... 18
Specifications..................................................................................... 4
Shutdown-Circuit Design Example ......................................... 19
Absolute Maximum Ratings ............................................................ 6
Start-Up Popping Noise............................................................. 19
Thermal Resistance ...................................................................... 6
SSM2211 Amplifier Design Example .................................. 19
ESD Caution .................................................................................. 6
Single-Ended Applications ........................................................ 20
Pin Configurations and Function Descriptions ........................... 7
Driving Two Speakers Single-Endedly .................................... 20
Typical Performance Characteristics ............................................. 8
LFCSP PCB Considerations ...................................................... 21
Theory of Operation ...................................................................... 15
Outline Dimensions ....................................................................... 22
Thermal Performance—LFCSP ................................................ 15
Ordering Guide .......................................................................... 22
Applications Information .............................................................. 16
REVISION HISTORY
5/16—Rev. F to Rev. G
Changed Electrical Characteristics Section Heading to
Specifications Section Heading....................................................... 4
Changes to Table 5 ............................................................................ 6
Changes to Figure 3 .......................................................................... 7
Changed Product Overview Section Heading to Theory of
Operation Section Heading ........................................................... 15
Changed Typical Applications Section Heading to Applications
Information Section Heading ....................................................... 16
Updated Outline Dimensions ....................................................... 22
Changes to Ordering Guide .......................................................... 22
Changes to Driving Two Speakers Single Endedly Section ...... 20
Changes to Figure 50...................................................................... 20
Changes to Evaluation Board Section.......................................... 20
Changes to Figure 51...................................................................... 20
Changes to Ordering Guide .......................................................... 22
12/13—Rev. E to Rev. F
Changes to Table 5 ............................................................................ 5
Added Exposed Pad Notation, Pin Configurations and Function
Descriptions Section ........................................................................ 6
Deleted Evaluation Board Section ................................................ 20
Updated Outline Dimensions ....................................................... 21
Changes to Ordering Guide .......................................................... 22
11/06—Rev. C to Rev. D
Updated Format .................................................................. Universal
Changes to General Description .....................................................1
Changes to Electrical Characteristics .............................................3
Changes to Absolute Maximum Ratings ........................................5
Added Table 6 ....................................................................................6
Changes to Figure 32...................................................................... 11
Changes to the Product Overview Section ................................. 14
Changes to the Output Voltage Headroom Section................... 17
Changes to the Start-Up Popping Noise Section........................ 18
Changes to the Evaluation Board Section ................................... 20
Updated Outline Dimensions ....................................................... 21
Changes to Ordering Guide .......................................................... 21
4/08—Rev. D to Rev. E
Changes to Features.......................................................................... 1
Changes to General Description .................................................... 1
Changes to Supply Current in Table 1 and Table 2 ...................... 3
Changes to Supply Current in Table 3 ........................................... 4
Changes to Absolute Maximum Ratings ....................................... 5
Changes to Figure 41 ...................................................................... 14
Changes to Equation 7, Equation 8, and Equation 10 ............... 16
Changes to Figure 47 ...................................................................... 17
Changes to Automatic Shutdown-Sensing Circuit Section ...... 18
Changes to SSM2211Amplifier Design Example Section ......... 19
10/04—Rev. B to Rev. C
Updated Format .................................................................. Universal
Changes to General Description .....................................................1
Changes to Table 5.............................................................................4
Deleted Thermal Performance—SOIC Section ...........................8
Changes to Figure 31...................................................................... 10
Changes to Figure 40...................................................................... 12
Changes to Thermal Performance—LFCSP Section ................. 13
Deleted Figure 52, Renumbered Successive Figures .................. 14
Deleted Printed Circuit Board Layout—SOIC Section ............. 14
Changes to Output Voltage Headroom Section ......................... 16
Rev. G | Page 2 of 24
Data Sheet
SSM2211
Changes to Start-Up Popping Noise Section ...............................17
Changes to Ordering Guide ...........................................................20
10/02—Rev. A to Rev. B
Deleted 8-Lead PDIP ......................................................... Universal
Updated Outline Dimensions ........................................................15
5/02—Rev. 0 to Rev. A
Edits to General Description ........................................................... 1
Edits to Package Type ....................................................................... 3
Edits to Ordering Guide ................................................................... 3
Edits to Product Overview............................................................... 8
Edits to Printed Circuit Board Layout Considerations .............. 13
Added section Printed Circuit Board Layout
Considerations—LFCSP ................................................................ 14
Rev. G | Page 3 of 24
SSM2211
Data Sheet
SPECIFICATIONS
VDD = 5.0 V, TA = 25°C, RL = 8 Ω, CB = 0.1 µF, VCM = VDD/2, unless otherwise noted.
Table 1.
Parameter
GENERAL CHARACTERISTICS
Differential Output Offset Voltage
Output Impedance
SHUTDOWN CONTROL
Input Voltage High
Input Voltage Low
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current
Supply Current, Shutdown Mode
DYNAMIC PERFORMANCE
Gain Bandwidth Product
Phase Margin
AUDIO PERFORMANCE
Total Harmonic Distortion
Total Harmonic Distortion
Voltage Noise Density
Symbol
Conditions
VOOS
ZOUT
AVD = 2, −40°C ≤ TA ≤ +85°C
VIH
VIL
ISY =
(2.2 μF)(20 kΩ)
25 kΩ
= 1.76 μF
20kΩ
AUDIO
INPUT
4
1µF
+
–
LEFT
SPEAKER
(8Ω)
5
SSM2211
3
1
+
7
2
0.1µF
(19)
8
470µF
+
RIGHT
SPEAKER
(8Ω)
–
Figure 49. SSM2211 Used as a Dual-Speaker Amplifier
Each speaker is driven by a single-ended output. The trade-off
is that only 250 mW of sustained power can be put into each
speaker. In addition, a coupling capacitor must be connected in
series with each of the speakers to prevent large dc currents from
flowing through the 8 Ω speakers. These coupling capacitors
produce a high-pass filter with a corner frequency given by
Equation 4. For a speaker load of 8 Ω and a coupling capacitor
of 470 µF, this results in a −3 dB frequency of 42 Hz.
Selecting CB to be 2.2 µF for a practical value of capacitor
minimizes start-up popping noise.
To summarize the final design,
•
•
•
•
•
•
6
–
00358-049
CC >
It is not necessary to connect a dummy load to the unused
output to help stabilize the output. The 470 µF coupling capacitor creates a high-pass frequency cutoff of 42 Hz, as given in
Equation 4, which is acceptable for most computer speaker
applications. The overall gain for a single-ended output configuration is AV = RF/R1, which for this example is equal to 1.
VDD = 5 V
R1 = 20 kΩ
RF = 28 kΩ
CC = 2.2 µF
CB = 2.2 µF
TA, MAX = 85°C
SINGLE-ENDED APPLICATIONS
Because the power of a single-ended output is one-quarter that
of a BTL, both speakers together are still half as loud (−6 dB SPL) as
a single speaker driven with a BTL.
There are applications in which driving a speaker differentially
is not practical, for example, a pair of stereo speakers where the
negative terminal of both speakers is connected to ground.
Figure 48 shows how this application can be accomplished.
The polarity of the speakers is important because each output is
180° out of phase with the other. By connecting the negative
terminal of Speaker 1 to Pin 5 and the positive terminal of
Speaker 2 to Pin 8, proper speaker phase can be established.
10kΩ
5V
6
10kΩ
4
0.47µF
–
5
SSM2211
3
1
+
7
2
0.1µF
8
470µF
+
250mW
SPEAKER
(8Ω)
–
00358-048
AUDIO
INPUT
The maximum power dissipation of the device, assuming both
loads are equal, can be found by doubling Equation 11. If the
loads are different, use Equation 11 to find the power dissipation caused by each load, and then take the sum to find the total
power dissipated by the SSM2211.
Figure 48. Single-Ended Output Application
Rev. G | Page 20 of 24
Data Sheet
SSM2211
LFCSP PCB CONSIDERATIONS
The LFCSP is a plastic encapsulated package with a copper lead
frame substrate. The LFCSP is a leadless package with solder lands
on the bottom surface of the package, instead of conventional
formed perimeter leads. A key feature that allows the user to
reach the quoted θJA performance is the exposed die attach
paddle (DAP) on the bottom surface of the package. When
soldered to the PCB, the DAP can provide efficient conduction
of heat from the die to the PCB. To achieve optimum package
performance, consideration must be given to the PCB pad
design for both the solder lands and the DAP. For further
information, see the AN-772 Application Note.
Rev. G | Page 21 of 24
SSM2211
Data Sheet
OUTLINE DIMENSIONS
5.00 (0.1968)
4.80 (0.1890)
8
4.00 (0.1574)
3.80 (0.1497)
1
5
6.20 (0.2441)
5.80 (0.2284)
4
1.27 (0.0500)
BSC
0.25 (0.0098)
0.10 (0.0040)
COPLANARITY
0.10
SEATING
PLANE
1.75 (0.0688)
1.35 (0.0532)
0.51 (0.0201)
0.31 (0.0122)
0.50 (0.0196)
0.25 (0.0099)
45°
8°
0°
0.25 (0.0098)
0.17 (0.0067)
1.27 (0.0500)
0.40 (0.0157)
012407-A
COMPLIANT TO JEDEC STANDARDS MS-012-AA
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.
Figure 50. 8-Lead Standard Small Outline Package [SOIC_N]
Narrow Body, S-Suffix
(R-8)
Dimensions shown in millimeters and (inches)
1.84
1.74
1.64
3.10
3.00 SQ
2.90
1.55
1.45
1.35
EXPOSED
PAD
0.50
0.40
0.30
0.80
0.75
0.70
0.30
0.25
0.20
1
4
BOTTOM VIEW
TOP VIEW
0.05 MAX
0.02 NOM
COPLANARITY
0.08
0.203 REF
PIN 1
INDICATOR
(R 0.15)
FOR PROPER CONNECTION OF
THE EXPOSED PAD, REFER TO
THE PIN CONFIGURATION AND
FUNCTION DESCRIPTIONS
SECTION OF THIS DATA SHEET.
COMPLIANT TO JEDEC STANDARDS MO-229-WEED
12-07-2010-A
PIN 1 INDEX
AREA
SEATING
PLANE
0.50 BSC
8
5
Figure 51. 8-Lead Lead Frame Chip Scale Package [LFCSP]
3 mm × 3 mm Body and 0.75 mm Package Height
(CP-8-13)
Dimensions shown in millimeters
ORDERING GUIDE
Model 1
SSM2211CPZ-REEL
SSM2211CPZ-REEL7
SSM2211SZ
SSM2211SZ-REEL
SSM2211SZ-REEL7
1
Temperature Range
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
Package Description
8-Lead LFCSP
8-Lead LFCSP
8-Lead SOIC_N
8-Lead SOIC_N
8-Lead SOIC_N
Z = RoHS Compliant Part; # denotes RoHS compliant product may be top or bottom marked.
Rev. G | Page 22 of 24
Package Option
CP-8-13
CP-8-13
R-8 (S-Suffix)
R-8 (S-Suffix)
R-8 (S-Suffix)
Branding
B5A#
B5A#
Data Sheet
SSM2211
NOTES
Rev. G | Page 23 of 24
SSM2211
Data Sheet
NOTES
©2002–2016 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D00358-0-5/16(G)
Rev. G | Page 24 of 24