LM4666SD National Semiconductor, LM4666SD Datasheet - Page 11

• Manufacturer Part Number: LM4666SD
• Description: IC AMP AUDIO 1.2W STER D 14LLP
• Manufacturer: National Semiconductor
• Series: Boomer®r
• Type: Class Dr

Specifications of LM4666SD

• Output Type: 2-Channel (Stereo)
• Max Output Power X Channels @ Load: 1.2W x 2 @ 8 Ohm
• Voltage - Supply: 2.8 V ~ 5.5 V
• Features: Depop, Differential Inputs, Short-Circuit Protection, Shutdown
• Mounting Type: Surface Mount
• Package / Case: 14-LLP
• For Use With: LM4666SDBD - BOARD EVALUATION LM4666SD
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LM4666SD/NOPB; LM4666SDTR

Application Information
typical value. Increased THD may also be observed with
voltages less than V
mode.
The LM4666 has an internal resistor connected between
GND and Shutdown pins. The purpose of this resistor is to
eliminate any unwanted state changes when the Shutdown
pin is floating. The LM4666 will enter the shutdown state
when the Shutdown pin is left floating or if not floating, when
the shutdown voltage has crossed the threshold. To mini-
mize the supply current while in the shutdown state, the
Shutdown pin should be driven to GND or left floating. If the
Shutdown pin is not driven to GND, the amount of additional
resistor current due to the internal shutdown resistor can be
found by Equation (1) below.
(V
DD
SD
on the Shutdown pin when in PLAY
- GND) / 60kΩ
(Continued)
(1)
11
With only a 0.5V difference, an additional 8.3µA of current
will be drawn while in the shutdown state.
GAIN SELECTION FUNCTION
The LM4666 has fixed selectable gain to minimize external
components, increase flexibility and simplify design. For a
differential gain of 6dB, the Gain Select pin should be per-
manently connected to V
For a differential gain of 12dB, the Gain Select pin should be
permanently connected to GND or driven to a logic low level.
The gain of the LM4666 can be switched while the amplifier
is in PLAY mode driving a load with a signal without damage
to the IC. The voltage on the Gain Select pin should be
switched quickly between GND (logic low) and V
high) to eliminate any possible audible artifacts from appear-
ing at the output. For typical threshold voltages for the Gain
Select function, refer to the Gain Threshold Voltages graph
in the Typical Performance Characteristics section.
DD
or driven to a logic high level.
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DD
(logic