Datasheet

LM48820
www.ti.com SNAS370B –MAY 2007–REVISED MAY 2013
Electrical Characteristics V
DD
= 3V
(1)(2)
(continued)
The following specifications apply for V
DD
= 3V, 16Ω load, and the conditions shown in “Typical Audio Amplifier Application
Circuit” (see Figure 1) unless otherwise specified. Limits apply to T
A
= 25°C.
LM48820
Units
Symbol Parameter Conditions
Typical Limit
(Limits)
(3) (4) (5)
15 kΩ (min)
R
IN
Input Resistance 20
25 kΩ (max)
THD+N = 1% (max); f = 1kHz,
95 mW
one channel
THD+N = 1% (max); f = 1kHz,
80 mW
R
L
= 32Ω, one channel
P
O
Output Power
THD+N = 1% (max); f = 1kHz,
50 40 mW (min)
two channels in phase
THD+N = 1% (max); f = 1kHz,
55 45 mW (min)
R
L
= 32Ω, two channels in phase
P
O
= 60mW, f = 1kHz,
0.01 %
single channel
THD+N Total Harmonic Distortion + Noise
P
O
= 50mW, f = 1kHz, R
L
= 32Ω
0.007 %
single channel
V
RIPPLE
= 200mV
P-P
, Input Referred
Power Supply Rejection Ratio f = 217Hz 80 dB
PSRR
Full Power Mode f = 1kHz 75 dB
f = 20kHz 58 dB
R
L
= 32Ω, P
O
= 20mW,
SNR Signal-to-Noise Ratio (A-weighted) 100 dB
f = 1kHz, BW = 20Hz to 22kHz
V
IH
Shutdown Input Voltage High V
DD
= 1.8V to 4.2V 1.2 V (min)
V
IL
Shutdown Input Voltage Low V
DD
= 1.8V to 4.2V 0.45 V (max)
X
TALK
Crosstalk P
O
= 1.6mW, f = 1kHz 70 dB
SD_LC = SD_RC = GND
Z
OUT
Output Impedance Input Terminated 30 25 kΩ (min)
Input not terminated 30
SD_LC = SD_RC = GND
Z
OUT
Output Impedance –500mV ≤ V
OUT
≤ V
DD
+500mV 8 2 kΩ (min)
(6)
I
L
Input Leakage ±0.1 nA
(6) V
OUT
refers to signal applied to the LM48820 outputs.
External Components Description
(Figure 1)
Components Functional Description
Input coupling capacitor which blocks the DC voltage at the amplifier's input terminals. Also creates a high-pass filter
1. C
INR/INL
with R
i
at f
C
= 1/(2πR
i
C
IN
). Refer to the section SELECTING PROPER EXTERNAL COMPONENTS, for an explanation
of how to determine the value of C
i
.
2 C
C
Flying capacitor. Low ESR ceramic capacitor (≤100mΩ)
3. C
SS
Output capacitor. Low ESR ceramic capacitor (≤100mΩ)
Tantalum capacitor. Supply bypass capacitor which provides power supply filtering. Refer to the POWER SUPPLY
4. C
S1
BYPASSING section for information concerning proper placement and selection of the supply bypass capacitor.
Ceramic capacitor. Supply bypass capacitor which provides power supply filtering. Refer to the POWER SUPPLY
5. C
S2
BYPASSING section for information concerning proper placement and selection of the supply bypass capacitor.
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