LM4879 Datasheet, PDF (5/25 Pages) National Semiconductor (TI) – 1.1 Watt Audio Power Amplifier

Electrical Characteristics V_DD = 3.0V (Notes 1, 2)
The following specifications apply for the circuit shown in Figure 1 unless otherwise specified. Limits apply for T_A =
25˚C. (Continued)
Symbol
Parameter
N_OUT
Output Noise
Conditions
A-Weighted; Measured across 8Ω
BTL
Input terminated with 10Ω to
ground
LM4879
Typical
Limit
(Note 6) (Notes 7, 8)
Units
(Limits)
26
µV_RMS
Electrical Characteristics V_DD = 2.6V (Notes 1, 2)
The following specifications apply for the circuit shown in Figure 1 unless otherwise specified. Limits apply for T_A = 25˚C.
Symbol
Parameter
Conditions
I_DD
I_SD
V_OS
P_o
THD+N
PSRR
Quiescent Power Supply Current
Shutdown Current
Output Offset Voltage
Output Power
Total Harmonic Distortion+Noise
Power Supply Rejection Ratio
V_IN = 0V, 8Ω BTL
V_shutdown = GND
THD+N = 1% (max); f = 1kHz
R_L = 8Ω
R_L = 4Ω
P_o = 0.1Wrms; f = 1kHz
V_ripple = 200mVsine p-p, C_B =
1.0µF
Input terminated with 10Ω to
ground
LM4879
Typical
Limit
(Note 6) (Notes 7, 8)
3.5
0.1
5
Units
(Limits)
mA
µA
mV
250
mW
350
0.1
%
55 (f = 1kHz)
55 (f =
dB
217Hz)
Note 1: All voltages are measured with respect to the ground 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 T_JMAX, θ_JA, and the ambient temperature T_A. The maximum
allowable power dissipation is P_DMAX = (T_JMAX–T_A)/θ_JA or the number given in Absolute Maximum Ratings, whichever is lower. For the LM4879, see power derating
curves for additional 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: For micro SMD only, shutdown current is measured in a Normal Room Environment. Exposure to direct sunlight will increase I_SD by a maximum of 2µA.
Note 9: If the product is in shutdown mode, and V_DD exceeds 6V (to a max of 8V V_DD), then most of the excess current will flow through the ESD protection circuits.
If the source impedance limits the current to a max of 10ma, then the part will be protected. If the part is enabled when V_DD is above 6V, circuit performance will
be curtailed or the part may be permanently damaged.
Note 10: All bumps have the same thermal resistance and contribute equally when used to lower thermal resistance.
Note 11: Maximum power dissipation (P_DMAX) in the device occurs at an output power level significantly below full output power. P_DMAX can be calculated using
Equation 1 shown in the Application section. It may also be obtained from the power dissipation graphs.
Note 12: The stated θ_JA is achieved when the LLP package’s DAP is soldered to a 4in² copper heatsink plain.
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