Features: ·3-wire serial interface
·Daisy-chain capability
·104dB mute attenuation
·Pop and click free attenuation changesApplication·Automated studio mixing consoles
·Music reproduction systems
·Sound reinforcement systems
·Electronic music (MIDI)
·Personal computer audio controlPinout
Specifications
| THD |
0.0008 % |
| SNR |
120 dB |
| Special Features |
2 Channels, Digitally controlled audio attenuator |
| Supply Min |
4.5 Volt |
| Supply Max |
15 Volt |
| Equivalent Input Noise |
13 uV/root(Hz) |
| Separation |
110 dB |
| Interface Type |
Serial |
| Temperature Min |
0 deg C |
| Temperature Max |
70 deg C |
| View Using Catalog |
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (VDDVSS) .....................................15V
Voltage at Any Pin VSS ................− 0.2V to VDD + 0.2V
Power Dissipation (Note 3) ..............................150 mW
ESD SusceptabiIity (Note 4)................................ 2000V
Junction Temperature ........................................150°C
Soldering Information
N Package (10 sec.) .........................................+260°C
Storage Temperature ......................−65°C to +150°CDescriptionThe LM1972 is a digitally controlled 2-channel 78dB audio attenuator fabricated on a CMOS process. Each channel has attenuation steps of 0.5dB from 0dB47.5dB, 1.0dB steps from 48dB78dB, with a mute function attenuating 104dB. Its logarithmic attenuation curve can be customized through software to fit the desired application.
The performance of a Pot is demonstrated through its excellent Signal-to-Noise Ratio, extremely low (THD+N), and high channel separation. Each Pot contains a mute function that disconnects the input signal from the output, providing a minimum attenuation of 96dB. Transitions between any attenuation settings are pop free.
The LM1972's 3-wire serial digital interface is TTL and CMOS compatible; receiving data that selects a channel and the desired attenuation level. The Data-Out pin of the LM1972 allows multiple Pots to be daisy-chained together, reducing the number of enable and data lines to be routed for a given application.
Reliability Metrics
| Part Number |
Process |
EFR Reject |
EFR Sample Size |
PPM |
LTA Rejects |
LTA Device Hours |
FITS |
MTTF (Hours) |
| LM1972M |
P2CMOS |
0 |
48295 |
0 |
1 |
4172500 |
2 |
536440139 |
| LM1972MX |
P2CMOS |
0 |
48295 |
0 |
1 |
4172500 |
2 |
536440139 |
Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.For more information on Reliability Metrics, please click here.
LM1972 Data Sheet
