LM4857SP/NOPB National Semiconductor, LM4857SP/NOPB Datasheet - Page 11

• Manufacturer Part Number: LM4857SP/NOPB
• Description: IC AUDIO SUBSYSTEM W/3D AB 28LLP
• Manufacturer: National Semiconductor
• Series: Boomer®r
• Type: Class ABr

Specifications of LM4857SP/NOPB

• Output Type: 2-Channel (Stereo) with Mono and 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
• Features: 3D, Depop, I²C, Mute, Shutdown, Thermal Protection, Volume Control
• Mounting Type: Surface Mount
• Package / Case: 28-LLP
• Operational Class: Class-AB
• Input Offset Voltage: 40@5VmV
• Single Supply Voltage (typ): Not RequiredV
• Dual Supply Voltage (typ): 3/5V
• Supply Current (max): 21@5VmA
• Power Supply Requirement: Dual
• Rail/rail I/o Type: No
• Power Supply Rejection Ratio: 86dB
• Single Supply Voltage (min): Not RequiredV
• Single Supply Voltage (max): Not RequiredV
• Dual Supply Voltage (min): 2.5/2.7V
• Dual Supply Voltage (max): 5.5V
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 28
• For Use With: LM4857SPBD - BOARD EVALUATION LM4857SP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LM4857SP; LM4857SPTR

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
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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