FAN7033MPX Fairchild Semiconductor, FAN7033MPX Datasheet - Page 16

• Manufacturer Part Number: FAN7033MPX
• Description: Audio Amplifiers 2W CMOS Stereo Power Amplifier wtih Fixed
• Manufacturer: Fairchild Semiconductor

Specifications of FAN7033MPX

• Product: Class-AB
• Output Power: 1.9 W
• Thd Plus Noise: 0.6 %
• Operating Supply Voltage: 3 V, 5 V
• Maximum Power Dissipation: Internally Limited
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Audio Load Resistance: 8 Ohms
• Input Signal Type: Differential
• Minimum Operating Temperature: - 40 C
• Output Signal Type: Differential
• Supply Type: Single
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Output Type: 2-Channel Stereo
• Package / Case: MLP-14
• Operational Class: Class-AB
• Audio Amplifier Output Configuration: 2-Channel Stereo
• Output Power (typ): 1.9x2@4OhmW
• Audio Amplifier Function: Speaker
• Total Harmonic Distortion: 0.6@4Ohm@1W%
• Single Supply Voltage (typ): 3/5V
• Dual Supply Voltage (typ): Not RequiredV
• Power Supply Requirement: Single
• Rail/rail I/o Type: No
• Power Supply Rejection Ratio: 68dB
• 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: 14
• Package Type: MLP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

FAN7033MP
affect the output power. In order to obtain the maximum power depicted in the performance characteristics figures,
outputs, power, and ground lines need wide metal trace. The parasitic resistance of the power line increases ripple
noise and degrades the THD and PSRR performance. To reduce such unwanted effect, a large capacitor must be
connected between V
use a capacitor with low ESR.
Power Supply Bypassing
Selection of a proper power supply bypassing capacitor is critical to obtaining lower noise as well as higher power
supply rejection. Larger capacitors may help to increase immunity to the supply noise. However, considering eco-
nomical design, attaching 10µF electrolytic capacitor or tantalum capacitor with 0.1µF ceramic capacitor as close
as possible to the VDD pins are enough to get a good supply noise rejection.
Selection of Input Capacitor
The input capacitors CINN and CINP block the DC voltage also low frequency input signal. Thus, these capacitors
act as a high pass filter. When there are DC level differences between input source and the amplifier, these capac-
itors block DC voltage and make easy connection. However, these capacitors limit the low frequency input signal.
Thus to cover the full audio frequency range, the values of these are very important. The input impedance and the
capacitance of these capacitors stand for the low frequency characteristics and -3dB frequency is
Where Zin is the input equivalent impedance and C is the capacitance of the input capacitor.
For FAN7033MP, the input has several resistors and these resistors determine the input impedance. In the normal
condition, (-) input of the amplifier looks like a voltage source since the negative feedback topology makes (-) input
virtually be the AC ground. Thus, resistance between the negative input of the amplifier and input pin is 15kΩ. The
resistance toward (+) input is the summation of 15kΩ and 90kΩ. Thus total input impedance is
Considering f
from equation(2) and (3) as follow:
Thus, Cin must be higher than 0.606uF. In the application note, 1uF is chosen by considering input impedance vari-
ation during the chip fabrication.
When using a capacitor which has the polarity, customers must carefully connect the capacitor. The input DC level
of the FAN7033MP is a half of VDD. Thus, if the DC level of a source is higher than VDD/2, the positive lead of the
capacitor must be faced toward the source.
Shutdown Mode
In order to reduce power consumption while not in use, the FAN7033MP contains a shutdown pin to externally turn-
off bias circuitry. This shutdown feature turns the amplifier off when a logic low is placed on the shutdown pin. The
trigger point between a logic low and logic high level is typically half-supply. It is best to switch between ground and
supply to provide maximum device performance. By switching the shutdown pin to VDD , the FAN7033MP supply
current draw will be minimized in idle mode. In either case, the shutdown pin should be tied to a definite voltages to
avoid unwanted state changes.
In many appplications, a microcontroller or microprocessor output is used to control the shutdown circuitry which
provides a quick, smooth transition into shutdown. Another solution is to use a single-pole, single-throw switch in
conjunction with an external pull-down resistor. When the switch is closed, the shutdown pin is connected to VDD
and enables the amplifier. If the switch is open, then the external pull-down resistor will disable the FAN7033MP.
This scheme guarantees that the shutdown pin will not float thus preventing unwanted state changes.
16
L
=20Hz(the lowest frequency of the audio freqeuncy range), it is possible to get the capacitance value
DD
pin and GND pin as close as possible. To improve power supply regulation performance,
Zin
=
15kΩ
Cin
f
L
=
||
=
---------------------------- -
2π Zin f
(
15kΩ
---------------------------- -
2π Zin C
⋅
1
⋅
1
+
⋅
90kΩ
L
⋅
=
0.606uF
)
=
13.125kΩ
(2)
(3)
(4)