LM4912MM National Semiconductor, LM4912MM Datasheet - Page 4

• Manufacturer Part Number: LM4912MM
• Description: Stereo 40mW Low Noise Headphone Amplifier
• Manufacturer: National Semiconductor

www.national.com
I
I
I
P
V
PSRR
T
V
T
A
DD
SD
M
WU
UM
O
NO
OSD
M
Electrical Characteristics V
The following specifications apply for V
apply to T
Note 1: All voltages are measured with respect to the GND pin unless otherwise specified.
Note 2: : Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional but do not guarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which
guarantee specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not guaranteed for parameters where no limit
is given, however, the typical value is a good indication of device performance.
Note 3: : The maximum power dissipation must be derated at elevated temperatures and is dictated by TJMAX, θ
maximum allowable power dissipation is P
power derating currents for more information.
Note 4: Human body model, 100pF discharged through a 1.5kΩ resistor.
Note 5: Machine Model, 220pF-240pF discharged through all pins.
Note 6: Typicals are measured at 25˚C and represent the parametric norm.
Note 7: Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level).
Note 8: Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis.
Note 9: 10Ω Terminated input.
External Components Description
Components
1.
2.
3.
4.
5.
6.
Symbol
A
C
C
C
R
C
R
= 25˚C.
S
B
o
I
I
f
Quiescent Power Supply Current
Shutdown Current
Mute Current
Output Power
Output Noise Voltage
Power Supply Rejection Ratio
Wake Up Time from Shutdown
Output Voltage Change on
Release from Shutdown
Time to Un-Mute
Mute Attenuation
Inverting input resistance which sets the closed-loop gain in conjunction with R
high-pass filter with C
Input coupling capacitor which blocks the DC voltage at the amplifier’s input terminals. Also creates a
high-pass filter with R
an explanation of how to determine the value of C
Feedback resistance which sets the closed-loop gain in conjunction with R
Supply bypass capacitor which provides power supply filtering. Refer to the Power Supply Bypassing
section for information concerning proper placement and selection of the supply bypass capacitor.
Bypass pin capacitor which provides half-supply filtering. Refer to the section, Proper Selection of Proper
Components, for information concerning proper placement and selection of C
Output coupling capacitor which blocks the DC voltage at the amplifier’s output. Forms a high pass filter with
R
L
at f
o
= 1/(2πR
Parameter
DMAX
L
C
o
= (T
)
DD
i
i
at f
at f
JMAX
= 2.4V, R
c
c
DD
- T
= 1/(2πR
= 1/(2πR
A
)/ θ
= 2.4V
JA
L
V
V
V
THD = 1%; f = 1kHz
BW = 20 Hz to 20kHz, A-weighted
V
f = 1kHz
IN
SHUTDOWN
MUTE
RIPPLE
or the number given in Absolute Maximum Ratings, whichever is lower. For the LM4912, see
= 16Ω, C
i
i
C
C
= 0V, I
i
i
).
). Refer to the section Proper Selection of External Components, for
See (Figure 1)
= V
= 200mV sine p-p
Functional Description
(Notes 1, 2)
4
O
DD
O
= GND
= 0A
= 100µF, and C
Conditions
R = 16Ω
R = 32Ω
i
.
B
= 4.7µF unless otherwise specified. Limits
i
JA
.
, and the ambient temperature, T
(Note 6)
B
0.01
Typ
f
1.5
0.1
1.5
25
12
10
65
80
. This resistor also forms a
2
LM4912
(Note 7)
Limit
0.02
2.0
3
3
1
mA (max)
mA (max)
mV (max)
µA (max)
(Limits)
s (max)
Units
mW
A
µV
dB
db
. The
s