SSM2211CPZ-REEL7 Analog Devices Inc, SSM2211CPZ-REEL7 Datasheet - Page 19

• Manufacturer Part Number: SSM2211CPZ-REEL7
• Description: IC,Audio Amplifier,SINGLE,CMOS,LLCC,8PIN,PLASTIC
• Manufacturer: Analog Devices Inc
• Type: Class ABr

Specifications of SSM2211CPZ-REEL7

• Output Type: 1-Channel (Mono)
• Max Output Power X Channels @ Load: 1.5W x 1 @ 4 Ohm
• Voltage - Supply: 2.7 V ~ 5.5 V
• Features: Differential Inputs, Shutdown
• Mounting Type: Surface Mount
• Package / Case: 8-LFCSP
• Operational Class: Class-AB
• Audio Amplifier Output Configuration: 1-Channel Mono
• Audio Amplifier Function: Speaker
• Total Harmonic Distortion: 0.2%%
• Single Supply Voltage (typ): 3/5V
• Dual Supply Voltage (typ): Not RequiredV
• Supply Current (max): 20@5V@-40C TO 85CmA
• Power Supply Requirement: Single
• Unity Gain Bandwidth Product (typ): 4MHz
• Rail/rail I/o Type: Rail to Rail Input
• Power Supply Rejection Ratio: 66dB
• Single Supply Voltage (min): 2.7V
• Single Supply Voltage (max): 5.5V
• Dual Supply Voltage (min): Not RequiredV
• Dual Supply Voltage (max): Not RequiredV
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 8
• Package Type: LFCSP EP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: SSM2211CPZ-REEL7

voltage reference. The extra supply voltage also allows the
SSM2211 to reproduce peaks in excess of 1 W without clipping
the signal. With V
the maximum power dissipation for the SSM2211 is 633 mW.
From the power derating curve in Figure 31, the ambient
temperature must be less than 50°C for the SOIC and 121°C for
the LFCSP.
The required gain of the amplifier can be determined from
Equation 17 as
From Equation 1
or R
R
The final design step is to select the input capacitor. When
adding an input capacitor, C
corner frequency needs to be far enough away for the design to
meet the bandwidth criteria. For a first-order filter to achieve a
pass-band response within 0.25 dB, the corner frequency must
be at least 4.14× away from the pass-band frequency. Therefore,
(4.14 × f
input capacitor can be found.
Therefore, C
The gain bandwidth product for each internal amplifier in the
SSM2211 is 4 MHz. Because 4 MHz is much greater than 4.14 ×
20 kHz, the design meets the upper frequency bandwidth criteria.
The SSM2211 can also be configured for higher differential
gains without running into bandwidth limitations. Equation 16
shows an appropriate value for C
noise.
Selecting C
minimizes start-up popping noise.
To summarize the final design
V
R1 = 20 kΩ
R
C
C
T
A, MAX
I
F
C
B
DD
= 20 kΩ and R2 = 28 kΩ.
= 28 kΩ
= 2.2 μF
= 2.2 μF
F
= 5 V
C
C
A
R
= 1.4 × R
R
C
V
F
B
= 85°C
I
HP
=
>
>
=
) < 20 Hz. Using Equation 2, the minimum size of an
B
(
A
π 2
C
2
2
to be 2.2 μF for a practical value of capacitor
V
V
> 1.65 μF. Using a 2.2 μF is a practical choice for C
.
P
2
I
L
IN,
. Because the desired input impedance is 20 kΩ,
×
μF
25
×
20
rms
DD
)(
R
kΩ
20
kΩ
= 5 V and R
L
1
kΩ
=
⎛
⎜ ⎜
⎝
2
20
)
4
8 .
.
=
C
14
Hz
, to create a high-pass filter, the
1
.
76
⎞
⎟ ⎟
⎠
B
L
= 8 Ω, Equation 9 shows that
to reduce start-up popping
μF
(17)
(18)
(19)
Rev. E | Page 19 of 24
C
.
SINGLE-ENDED APPLICATIONS
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 can be accomplished.
It is not necessary to connect a dummy load to the unused
output to help stabilize the output. The 470 μF coupling capa-
citor 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 config-
uration is A
DRIVING TWO SPEAKERS SINGLE ENDEDLY
It is possible to drive two speakers single endedly with both
outputs of the SSM2211.
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.
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.
AUDIO
AUDIO
AUDIO
INPUT
INPUT
INPUT
Figure 49. SSM2211 Used as a Dual-Speaker Amplifier
0.47μF
0.47μF
V
1μF
= R
Figure 48. Single-Ended Output Application
20kΩ
10kΩ
10kΩ
0.1μF
0.1μF
0.1μF
F
/R
1
, which for this example is equal to 1.
4
4
3
3
4
3
–
+
–
–
+
+
SSM2211
SSM2211
SSM2211
2
2
2
20kΩ
10kΩ
10kΩ
6
6
6
5V
5V
5V
7
7
7
1
1
1
5
8
5
5
8
8
470μF
470μF
470μF
470μF
–
+
+
–
+
+
–
–
SSM2211
LEFT
SPEAKER
(8Ω)
RIGHT
SPEAKER
(8Ω)
250mW
250mW
SPEAKER
SPEAKER
(8Ω)
(8Ω)