Electrical Characteristics VDD = 3V (Note 1) (Continued)
The following specifications apply for VDD = 3V and 16Ω load unless otherwise specified. Limits apply to TA = 25˚C.
Symbol
Parameter
Conditions
LM4920
Units
(Limits)
Typ
Limit
(Note 6)
(Notes 7, 8)
VSD-LC = VSD-RC = GND
–500mV ≤ VOUT ≤ +500mV
(Note 12)
ZOUT
IL
Output Impedance
Input Leakage
8
2
kΩ (min)
0.1
nA
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 that
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
, θ , and the ambient temperature, T . The maximum
A
JMAX JA
allowable power dissipation is P
= (T
- T ) / θ or the number given in Absolute Maximum Ratings, whichever is lower. For the LM4920, see power
DMAX
JMAX A JA
de-rating 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: If the product is in shutdown mode and V
exceeds 4.2V (to a max of 4.5V V ), then most of the excess current will flow through the ESD protection
DD
DD
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
performance will be curtailed or the part may be permanently damaged.
is above 4.5V, circuit
DD
Note 10: Human body model, 100pF discharged through a 1.5kΩ resistor.
Note 11: θ value is measured with the device mounted on a PCB with a 3” x 1.5”, 1oz copper heatsink.
JA
Note 12: V
refers to signal applied to the LM4920 outputs.
OUT
External Components Description (Figure 1)
Components
Functional Description
1.
Ci
Input coupling capacitor which blocks the DC voltage at the amplifier’s input terminals. Also creates a
high-pass filter with Ri at fC = 1/(2πRiCi). Refer to the section Proper Selection of External Components, for
an explanation of how to determine the value of Ci.
2.
3.
4.
C1
C2
C3
Flying capacitor. Low ESR ceramic capacitor (≤100mΩ)
Output capacitor. Low ESR ceramic capacitor (≤100mΩ)
Tantalum capacitor. 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.
Ceramic capacitor. 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.
5.
C4
5
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