LM1971N/NOPB National Semiconductor, LM1971N/NOPB Datasheet - Page 4

• Manufacturer Part Number: LM1971N/NOPB
• Description: IC ATTENUATOR AUDIO W/MUTE 8-DIP
• Manufacturer: National Semiconductor
• Series: Overture™r
• Type: Audio Attenuatorr

Specifications of LM1971N/NOPB

• Applications: Cell Phones, PC, MIDI
• Mounting Type: Through Hole
• Package / Case: 8-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *LM1971N; *LM1971N/NOPB; LM1971N

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Pin Descriptions
V
analog input signal. This pin should be biased at half of the
supply voltage, V
OUT (2): The attenuated analog output signal comes from
this pin.
GND (3): The GND pin references the digital input signals
and is the lower voltage reference for the IC. Typically this
pin would be labeled “V
digital logic input control is tied to this same point. With a
higher pin-count there would generally be separate pins for
these functions; V
the LM1971 always be operated using a single voltage sup-
ply configuration, for which pin 3 (GND) should always be at
system ground. If a bipolar or split-supply configuration are
desired, level shifting circuitry is needed for the digital logic
control pins as they would be referenced through pin 3 which
would be at the negative supply. It is highly recommended,
however, that the LM1971 be used in a unipolar or
single-supply configuration.
Typical Performance Characteristics
REF
IN (1): The V
DD
SS
REF
Analog Measurement
, as shown in Figure 1 and Figure 6.
Supply Current vs
and Logic Ground. It is intended that
IN pin provides the reference for the
Supply Voltage
SS
Noise Floor
” but the ground reference for the
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LOAD (4): The LOAD input accepts a TTL or CMOS level
signal. This is the enable pin of the device, allowing data to
be clocked in while this input is low (0V). The GND pin is the
reference for this signal.
DATA (5): The DATA input accepts a TTL or CMOS level
signal. This pin is used to accept serial data from a micro-
controller that will be latched and decoded to change the
channel’s attenuation level. The GND pin is the reference for
this signal.
CLOCK (6): The CLOCK input accepts a TTL or CMOS level
signal. The clock input is used to load data into the internal
shift register on the rising edge of the input clock waveform.
The GND pin is the reference for this signal.
V
pin.
IN (8): The analog input signal should be placed to this pin.
DD
(7): The positive voltage supply should be placed to this
THD + N vs Freq and Amp
Supply Current vs
Temperature
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