SSM2301CPZ-REEL7 Analog Devices Inc, SSM2301CPZ-REEL7 Datasheet - Page 12

• Manufacturer Part Number: SSM2301CPZ-REEL7
• Description: IC,Audio Amplifier,SINGLE,LLCC,16PIN,PLASTIC
• Manufacturer: Analog Devices Inc
• Type: Class Dr

Specifications of SSM2301CPZ-REEL7

• Output Type: 1-Channel (Mono)
• Max Output Power X Channels @ Load: 1.52W x 1 @ 8 Ohm
• Voltage - Supply: 2.5 V ~ 5 V
• Features: Depop, Differential Inputs, Short-Circuit and Thermal Protection, Shutdown
• Mounting Type: Surface Mount
• Package / Case: 8-LFCSP
• Operational Class: Class-D
• Audio Amplifier Output Configuration: 1-Channel Mono
• Output Power (typ): 1.52x1@8OhmW
• Audio Amplifier Function: Speaker
• Single Supply Voltage (typ): 3V
• Dual Supply Voltage (typ): Not RequiredV
• Power Supply Requirement: Single
• Rail/rail I/o Type: No
• Power Supply Rejection Ratio: 85dB
• Single Supply Voltage (min): 2.5V
• Single Supply Voltage (max): 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
• For Use With: SSM2301-MINI-EVALZ - BOARD EVAL MINI SSM2301SSM2301-EVALZ - BOARD EVAL FOR SSM2301
• Lead Free Status / Rohs Status: Compliant
• Other names: SSM2301CPZ-REEL7TR

SSM2301
APPLICATIONS INFORMATION
OVERVIEW
The SSM2301 mono Class-D audio amplifier features a filterless
modulation scheme that greatly reduces external component count,
conserving board space and, thus, reducing system cost. The
SSM2301 does not require an output filter but, instead, relies
on the inherent inductance of the speaker coil and the natural
filtering of the speaker and human ear to fully recover the audio
component of the square-wave output. While most Class-D ampli-
fiers use some variation of pulse-width modulation (PWM), the
SSM2301 uses a Σ-Δ modulation to determine the switching
pattern of the output devices. This provides a number of important
benefits. Σ-Δ modulators do not produce a sharp peak with many
harmonics in the AM frequency band, as pulse-width modulators
often do. Σ-Δ modulation reduces the amplitude of spectral
components at high frequencies, thereby reducing EMI emission
that might otherwise be radiated by speakers and long cable traces.
The SSM2301 also offers protection circuitry for output short-
circuit and high temperature conditions. When the fault-inducing
condition is removed, the SSM2301 automatically recovers
without the need for a hard reset.
GAIN SELECTION
Pulling the GAIN pin of the SSM2301 high sets the gain of the
speaker amplifier to 12 dB; pulling it low sets the gain of the
speaker amplifier to 6 dB.
It is possible to adjust the SSM2301 gain by using external resistors
at the input. To set a gain lower than 12 dB, see Figure 26 for
differential input configuration and Figure 27 for single-ended
configuration. For external gain configuration from a fixed 12 dB
gain, use the following formula:
To set a gain lower than 6 dB, see Figure 28 for differential input
configuration and Figure 29 for single-ended configuration. For
external gain configuration from a fixed 6 dB gain, use the
following formula:
POP-AND-CLICK SUPPRESSION
Voltage transients at the output of audio amplifiers may occur
when shutdown is activated or deactivated. Voltage transients
as low as 10 mV can be heard as an audio pop in the speaker.
Clicks and pops can also be classified as undesirable audible
transients generated by the amplifier system and, therefore,
as not coming from the system input signal. Such transients may
be generated when the amplifier system changes its operating
mode. For example, the following can be sources of audible
transients: system power-up/power-down, mute/unmute, input
source change, and sample rate change. The SSM2301 has a pop-
and-click suppression architecture that reduces these output
transients, resulting in noiseless activation and deactivation.
External Gain Settings = 20 log[4/(1 + R/150 kΩ)]
External Gain Settings = 20 log[2/(1 + R/150 kΩ)]
Rev. A | Page 12 of 16
LAYOUT
As output power continues to increase, care must be taken to
lay out PCB traces and wires properly between the amplifier,
load, and power supply. A good practice is to use short, wide
PCB tracks to decrease voltage drops and minimize inductance.
Make track widths at least 200 mil for every inch of track length
for lowest DCR, and use 1 oz or 2 oz of copper PCB traces to
further reduce IR drops and inductance.
Poor layout increases voltage drops, consequently affecting
efficiency. Use large traces for the power supply inputs and
amplifier outputs to minimize losses due to parasitic trace
resistance. Proper grounding guidelines help improve audio
performance, minimize crosstalk between channels, and prevent
switching noise from coupling into the audio signal. To maintain
high output swing and high peak output power, PCB traces that
connect the output pins to the load and supply pins should be
as wide as possible to maintain the minimum trace resistances.
It is also recommended that a large-area ground plane be used for
minimum impedances. Good PCB layouts also isolate critical
analog paths from sources of high interference. High frequency
circuits (analog and digital) should be separated from low
frequency circuits. Properly designed multilayer printed circuit
boards can reduce EMI emission and increase immunity to the
RF field by a factor of 10 or more compared with double-sided
boards. A multilayer board allows a complete layer to be used
for the ground plane, whereas the ground plane side of a double-
side board is often disrupted with signal crossover. If the system
has separate analog and digital ground and power planes, the
analog ground plane should be underneath the analog power plane,
and, similarly, the digital ground plane should be underneath the
digital power plane. There should be no overlap between analog
and digital ground planes or analog and digital power planes.
INPUT CAPACITOR SELECTION
The SSM2301 does not require input coupling capacitors if the
input signal is biased from 1.0 V to V
are required if the input signal is not biased within this recom-
mended input dc common-mode voltage range, if high-pass
filtering is needed (see Figure 24) or if using a single-ended
source (see Figure 25). If high-pass filtering is needed at the input,
the input capacitor, along with the input resistor of the SSM2301,
forms a high-pass filter whose corner frequency is determined
by the following equation:
The input capacitor can have very important effects on the
circuit performance. Not using input capacitors degrades the
output offset of the amplifier as well as the PSRR performance.
f
C
= 1/(2π × R
IN
× C
IN
)
DD
− 1.0 V. Input capacitors