LPA4873-00
Preliminary Datasheet LPA4873
LPA4873–00 Ver. 1.0 Datasheet Sep.-2010 https://www.wendangku.net/doc/3f11122292.html, Page 1 of 6
Preliminary Datasheet LPA4873
LPA4873–00 Ver. 1.0 Datasheet Sep.-2010 https://www.wendangku.net/doc/3f11122292.html, Page 2 of 6
Functional Pin Description
P a c k a g e Ty p e
P i n C o n f i g u r a t i o n s
SOP-8
Pin Description Pin No.
Pin Name
PIN I/O DESCRIPTION
1
SHDN
C3 I The device enters in shutdown mode when a low level is applied on this pin 2 BYPASS C1 I Bypass capacitor pin which provides the common mode voltage
3 +IN A3
I Positive input of the first amplifier, receives the common mode voltage
4 -IN A1 I Negative input of the first amplifier, receives the audio input signal. Connected to the
5 VO1 A2 O Negative output of the LPA4873. Connected to the load and to the feedback resistor Rf
6 VDD B3 I Analog VDD input supply.
7 GND B1/B2 Ground connection for circuitry. 8
VO2
C2 O Positive output of the LPA4873.
Absolute Maximum Ratings
Input V oltage to GND (V INA, V INB) ---------------------------------------------------------------------------- 6V
Adapter V oltage to GND (V ADP) ----------------------------------------------------------------------
0.3V to 6V Supply Voltage, V DD
------------------------------------------------------------------------------------- -0.3 V to 6V Voltage at Any Input Pin ------------------------------------------------------------------------- -0.3 V to V DD
+0.3 Junction Temperature, T JMAX --------------------------------------------------------------------------------------- 150°C Storage Temperature Rang, T stg
--------------------------------------------------------------------- -65°C to 150°C ESD Susceptibility -------------------------------------------------------------------------------------------- 2 kV Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds ----------------------------------------- 260°C
Thermal Resistance θJA
(WCSP) ----------------------------------------------------------------------------- 57°C/W
Preliminary
Datasheet LPA4873
LPA4873–00 Ver. 1.0 Datasheet Sep.-2010 https://www.wendangku.net/doc/3f11122292.html, Page 3 of 6
Electrical Characteristics
Symbol Parameter Conditions
LPA4873
Unit Min. Typ. Max.
V OS Output offset voltage
(measured differentially)
Vi=0V ,Av=2V/V ,VDD=2.5V to 5.5V 5 25
mV
PSRR
Power supply rejection ration V DD =2.5V to 5.5V -70 -55 dB
I Q Quiescent current V DD =5.5V , no load
2.5 mA V DD =
3.6V , no load 1.40 V DD =2.5V , no load
1.06 I SHDN Shutdown Current V SHDN =0.35V , V DD =
2.5V to 5.5V 0.1
2.0
μA
PO Output Power VDD=5V ,THD=1%,F=1KHz,RL=4Ω 3.1 W VDD=5V ,THD=1%,F=1KHz,RL=8Ω 1.8 W VDD=5V ,THD=10%,F=1KHz,RL=4Ω 3.6 W
VDD=5V ,THD=10%,F=1KHz,RL=8Ω 2.1 W
I LIM P-Channel Current Limit
1
A R DS(ON) Static drain-source on-state resistance V DD =5.5V , no load 400 m V DD =3.6V , no load 500 V DD =2.5V , no load 700 F (SW)
Switching frequency V DD =2.5V to 5.5V 200
250
300 KHz
THD+N
Total harmonic distortion plus noise
V DD =5V ,,Po=1W,RL=8f =
1KHz 0.123 %
V DD =3.6V ,,Po=0.5W,RL=8f =
1KHz 0.130 V DD =2.5V ,,Po=0.2W,RL=8
f =1KHz 0.163
kSVR Supply ripple rejection ratio
V DD =3.6V ,Inputs ac-grounded with Ci=2uF F=217Hz,Vripple)=
200mVpp
-68 dB
CMRR Common mode rejection ratio VDD=3.6V , Vic=1Vpp F =217Hz -58 dB
Zt
Start-up time from shutdown
VDD=3.6V
45
mS
Preliminary
Datasheet LPA4873
LPA4873–00 Ver. 1.0 Datasheet Sep.-2010 https://www.wendangku.net/doc/3f11122292.html, Page 4 of 6
Typical Operating Characteristics
Preliminary
Datasheet LPA4873
LPA4873–00 Ver. 1.0 Datasheet Sep.-2010 https://www.wendangku.net/doc/3f11122292.html, Page 5 of 6
Layout Considerations
As output power increases, interconnect resistance (PCB traces and wires) between the amplifier, load and power supply create a voltage drop. The voltage loss on the traces between the LP A4873 and the load results is lower output power and decreased efficiency. Higher trace resistance between the supply and the LPA4873 has the same effect as a poorly regulated supply, increase ripple on the supply line also reducing the peak output power. The effects of residual trace resistance increases as output current increases due to higher output power, decreased load impedance or both. To maintain the highest output voltage swing and corresponding peak output power, the PCB traces that connect the output pins to the load and the supply pins to the power supply should be as wide as possible to minimize trace resistance.
The use of power and ground planes will give the best THD+N performance. While reducing trace resistance, the use of power planes also creates parasite capacitors that help to filter the power supply line.
The inductive nature of the transducer load can also result in overshoot on one or both edges, clamped by the parasitic diodes to GND and VDD in each case. From an EMI stand- point, this is an aggressive waveform that can radiate or conduct to other components in the system and cause interference. It is essential to keep the power and output traces short and well shielded if possible. Use of ground planes, beads, and micro-strip layout techniques are all useful in preventing unwanted interference.
As the distance from the LPA4873 and the speaker increase, the amount of EMI radiation will increase since the output wires or traces acting as antenna become more efficient with length. What is acceptable EMI is highly application specific. Ferrite chip inductors placed close to the LPA4873 may be needed to reduce EMI radiation. The value of the ferrite chip is very application specific.
Ferrite chip inductors placed close to the LPA4873 may be needed to reduce EMI radiation. The value of the ferrite chip is very application specific.
Preliminary
Datasheet LPA4873
LPA4873–00 Ver. 1.0 Datasheet Sep.-2010 https://www.wendangku.net/doc/3f11122292.html, Page 6 of 6
Packaging Information