Datasheet

LM4938
www.ti.com SNAS245B –FEBRUARY 2005–REVISED MAY 2013
Electrical Characteristics for Bridged Mode Operation
(1)(2)
The following specifications apply for V
DD
= 5V, unless otherwise noted. Limits apply for T
A
= 25°C.
LM4938
Units
Symbol Parameter Conditions
(Limits)
Typical
(3)
Limit
(4)
V
OS
Output Offset Voltage V
IN
= 0V, No Load 5 ±50 mV (max)
P
O
Output Power THD + N = 1.0%; f = 1kHz
2.2 W
R
L
= 3Ω
(5)
THD + N = 1.0%; f = 1kHz
2 W
R
L
= 4Ω
(6)
THD = 1% (max); f = 1kHz
1.3 1.0 W (min)
R
L
= 8Ω
THD+N = 10%; f = 1 kHz; R
L
= 8Ω 1.5 W
THD+N Total Harmonic Distortion + Noise P
O
= 0.4W, f = 1kHz,
0.05 %
R
L
= 8Ω, A
VD
= 2
C
B
= 1.0 µF, f = 120 Hz,
V
RIPPLE
= 200 mVrms; R
L
= 8Ω, 78 dB
Floating
PSRR Power Supply Rejection Ratio
C
B
= 1.0 µF, f = 120 Hz,
V
RIPPLE
= 200 mVrms; R
L
= 8Ω, 60 dB
Terminated
SNR Signal to Noise Ratio V
DD
= 5V, P
OUT
= 1.2W, R
L
= 8Ω, A-
100 dB
Wtd Filter, 1kHz
X
talk
Channel Separation f = 1kHz, C
B
= 1.0μF, 1W 76 dB
(1) All voltages are measured with respect to the ground pins, unless otherwise specified. All specifications are tested using the typical
application as shown in Figure 1.
(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 ensure specific performance limits. Electrical Characteristics state DC and AC electrical
specifications under particular test conditions which ensure specific performance limits. This assumes that the device is within the
Operating Ratings. Specifications are not ensured for parameters where no limit is given, however, the typical value is a good indication
of device performance.
(3) Typicals are measured at 25°C and represent the parametric norm.
(4) Limits are specified to Texas Instruments' AOQL (Average Outgoing Quality Level). Datasheet min/max specification limits are specified
by design, test, or statistical analysis.
(5) When driving 3Ω loads from a 5V supply the LM4938MH must be mounted to the circuit board and forced-air cooled.
(6) When driving 4Ω loads from a 5V supply the LM4938MH must be mounted to the circuit board.
Electrical Characteristics for Single-Ended Mode Operation
(1)(2)
The following specifications apply for V
DD
= 5V. Limits apply for T
A
= 25°C.
LM4938
Units
Symbol Parameter Conditions
(Limits)
Typical
(3)
Limit
(4)
P
O
Output Power THD = 1.0%; f = 1kHz; R
L
= 32Ω 92 mW
THD+N Total Harmonic Distortion + Noise V
OUT
= 1V
RMS
, f = 1kHz,
0.065 %
R
L
= 10kΩ, A
VD
= 1
C
B
= 1.0 μF, f = 120 Hz, V
RIPPLE
= 200
63 dB
mVrms, Floating
PSRR Power Supply Rejection Ratio
C
B
= 1.0 μF, f = 120 Hz, V
RIPPLE
= 200
59 dB
mVrms, Terminated
SNR Signal to Noise Ratio P
OUT
= 75mW, R
L
= 32Ω,
100 dB
A-Wtd Filter
X
talk
Channel Separation f = 1kHz, C
B
= 1.0 μF 73 dB
(1) All voltages are measured with respect to the ground pins, unless otherwise specified. All specifications are tested using the typical
application as shown in Figure 1.
(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 ensure specific performance limits. Electrical Characteristics state DC and AC electrical
specifications under particular test conditions which ensure specific performance limits. This assumes that the device is within the
Operating Ratings. Specifications are not ensured for parameters where no limit is given, however, the typical value is a good indication
of device performance.
(3) Typicals are measured at 25°C and represent the parametric norm.
(4) Limits are specified to Texas Instruments' AOQL (Average Outgoing Quality Level). Datasheet min/max specification limits are specified
by design, test, or statistical analysis.
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