LM4857SPBD National Semiconductor, LM4857SPBD Datasheet - Page 11

• Manufacturer Part Number: LM4857SPBD
• Description: BOARD EVALUATION LM4857SP
• Manufacturer: National Semiconductor
• Series: Boomer®r

Specifications of LM4857SPBD

• Amplifier Type: Class AB
• Output Type: 2-Channel (Stereo) with Stereo Headphones
• Max Output Power X Channels @ Load: 1.6W x 2 @ 4 Ohm; 75mW x 2 @ 32 Ohm
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Board Type: Fully Populated
• Utilized Ic / Part: LM4857
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

External Components Description
Typical Performance Characteristics
1.
2.
3.
4.
5.
6.
Components
V
C
LM4857SP THD+N vs Frequency
R
C
DD
C
C
C
OUT
3D
3D
IN
S
B
R
= 5V; LLS, RLS; P
L
= 4Ω; Mode 7; 0dB Gain
This is the input coupling capacitor. It blocks the DC voltage and couples the input signal to the
amplifier’s input terminals. C
Impedance) at f
This is the supply bypass capacitor. It filters the supply voltage applied to the V
reduce the noise at the V
This is the BYPASS pin capacitor. It filters the V
PSRR.
This is the output coupling capacitor. It blocks the DC voltage and couples the output signal to the
speaker load R
This resistor sets the gain of the National 3D effect. Please refer to the National 3D Enhancement
section for information on selecting the value of R
This capacitor sets the frequency at which the National 3D effect starts to occur. Please refer to the
National 3D Enhancement section for information on selecting the value of C
O
= 400mW;
L
c
. C
= 1/(2πR
OUT
also creates a high pass filter with R
DD
i
20079755
C
IN
IN
pin.
).
also creates a highpass filter with the internal resistor R
(Note 11)
11
Functional Description
DD
3D
/ 2 voltage and helps maintain the LM4857’s
.
V
LM4857SP THD+N vs Frequency
DD
R
= 3V; LLS, RLS; P
L
= 4Ω; Mode 7; 0dB Gain
L
at f
O
= 1/(2πR
L
O
C
3D
OUT
= 200mW;
DD
.
).
pin and helps
i
(Input
www.national.com
20079756