LM49153TMEVAL National Semiconductor, LM49153TMEVAL Datasheet - Page 22

• Manufacturer Part Number: LM49153TMEVAL
• Description: EVAL BOARD LM49153
• Manufacturer: National Semiconductor
• Series: Boomer®r

Specifications of LM49153TMEVAL

• Amplifier Type: Class D
• Output Type: 1-Channel (Mono) with Stereo Headphones
• Max Output Power X Channels @ Load: 145mW x 2 @ 16 Ohm
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Board Type: Fully Populated
• Utilized Ic / Part: LM49153
• Lead Free Status / Rohs Status: Lead free by exemption / RoHS compliant by exemption

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Charge Pump Flying Capacitor (C1)
The flying capacitor (C1) affects the load regulation and out-
put impedance of the charge pump. A C1 value that is too low
results in a loss of current drive, leading to a loss of amplifier
headroom. A higher valued C1 improves load regulation and
lowers charge pump output impedance to an extent. Above
2.2μF, the R
of C1 and C2 dominate the output impedance. A lower value
capacitor can be used in systems with low maximum output
power requirements.
Charge Pump Hold Capacitor (C2)
The value and ESR of the hold capacitor (C2) directly affects
the ripple on CPV
put ripple. Decreasing the ESR of C2 reduces both output
ripple and charge pump output impedance. A lower value ca-
pacitor can be used in systems with low maximum output
power requirements.
Input Capacitor Selection
Input capacitors may be required for some applications, or
when the audio source is single-ended. Input capacitors block
the DC component of the audio signal, eliminating any conflict
between the DC component of the audio source and the bias
voltage of the LM49153. The input capacitors create a high-
pass filter with the input resistors R
high-pass filter is found using Equation (1) below.
Where the value of R
tics Table.
High-pass filtering the audio signal helps protect the speak-
ers. When the LM49153 is using a single-ended source,
power supply noise on the ground is seen as an input signal.
Setting the high-pass filter point above the power supply noise
frequencies, 217Hz in a GSM phone, for example, filters out
the noise such that it is not amplified and heard on the output.
Capacitors with a tolerance of 10% or better are recommend-
ed for impedance matching and improved CMRR and PSRR.
Connections
INM+/INL1 and INM-/INR1
LSOUT- and LSOUT+
Headers/Jumpers
HPV
INL2 and INR2
HPL and HPR
V
EP+ and EP-
Description
DD
DD
and GND
JU1
and GND7
DS(ON)
J1
f = 1 / 2
SS
of the charge pump switches and the ESR
. Increasing the value of C2 reduces out-
IN
π
is given in the Electrical Characteris-
R
IN
Power supply connection. Connect an external power supply's positive voltage source to V
supply's ground source to GND header pins respectively.
Headphone power supply connection. Connect an external power supply's positive voltage source to
HPV
These header pins provide a connection to a mono differential or stereo left and right single-ended
input.
These header pins provide a connection to stereo left and right single-ended input.
These header pins provide a connection to the input of the earpiece bypass switch.
These header pins provide a connection to Class D loudspeaker outputs. Apply a load greater than
4Ω. A low pass filter may be required for measurements.
These header pins provide a connection to headphone outputs. Apply a load greater than 16Ω.
J1 provides a USB connection to control the LM49153.
Stereo headphone jack
C
IN
DD
(Hz)
IN
and the supply's ground source to GND7 header pins respectively.
. The -3dB point of the
(4)
22
DEMO BOARD GUIDELINES
Introduction
The LM49153 demoboard is shown in Figure TBD.
Quick Start Guide:
be used to control the demo board and the other end to J1 of
the LM49153 demo board.
a ground connection to the header labeled GND above C5.
ply a ground connection to the header labeled GND7.
nal to headers labeled INM-/INR1 and INM+/INL1. Then,
apply a single-ended signal to headers labeled INL2 and
INR2.
(> = 4Ω) to LSOUT- and LSOUT+ header pins (a low pass
filter may be required for measurements).
phone output jack or HPR and HPL header pins.
mode, set 0dB volume gain, and Power on options from the
GUI.
Board Features
The LM49153 demonstration board has all of the necessary
connections, using 100mil headers, to apply the power supply
voltage and the audio input signals. The Class D amplifier’s
output is available on 100mil headers. The Class AB
headphone’s amplified audio signal is available on both a
stereo headphone jack and 100 mil headers. The input and
output of the earpiece analog switch are also available on
100mil headers. On-board I
troller allows for a convenient connection via USB jack.
1. Connect the one end of the USB cable to the PC that will
2. Install the LM49153 I
3. Apply 2.7V to 5.5V to the header labeled V
4. Apply 1.7V to 2.0V to the header labeled HPV
5. Apply a mono differential signal or two single-ended sig-
6. A) For class D speaker output, connect a speaker or load
7. Run the LM49153 I
Function/Use
B) For headphone output, connect either through head-
2
C interface software, select desired
2
C interface software.
2
C signal generation microcon-
DD
DD
DD
and apply
and the
and ap-