|
|
PDF LM4546A Data sheet ( Hoja de datos )
| Número de pieza | LM4546A | |
| Descripción | 2 Multi-Channel Audio Codec | |
| Fabricantes | National Semiconductor | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LM4546A (archivo pdf) en la parte inferior de esta página. Total 28 Páginas | ||
|
No Preview Available !
LM4546A
OBSOLETE
July 15, 2009
AC '97 Rev 2 Multi-Channel Audio Codec with Sample Rate
Conversion and National 3D Sound
General Description
The LM4546A is an audio codec for PC systems which is fully
PC98 compliant and performs the analog intensive functions
of the AC '97 Rev 2 architecture. Using 18-bit Sigma-Delta
ADCs and DACs, the LM4546A provides 90 dB of Dynamic
Range.
The LM4546A was designed specifically to provide a high
quality audio path and provide all analog functionality in a PC
audio system. It features full duplex stereo ADCs and DACs
and analog mixers with access to 2 stereo and 2 mono inputs.
Each mixer input has separate gain, attenuation and mute
control and the mixers drive 1 mono and 1 stereo output, each
with attenuation and mute control. The LM4546A supports
National's 3D Sound stereo enhancement and a comprehen-
sive sample rate conversion capability. The sample rate for
the ADCs and DACs can be programmed separately with a
resolution of 1 Hz to convert any rate in the range 4 kHz –
48 kHz. Sample timing from the ADCs and sample request
timing for the DACs are completely deterministic to ease task
scheduling and application software development. These fea-
tures together with an extended temperature range also make
the LM4546A suitable for non-PC codec applications.
The LM4546A features the ability to connect several codecs
together using the Extended AC Link configuration of one
dedicated serial data signal to the Controller per codec.
LM4546A systems support up to 8 simultaneous channels of
streaming data on Input Frames (Codec to Controller) while
Output Frames (Controller to Codec) carry 2 streams to mul-
tiple codecs. The LM4546A may also be used in systems with
the National LM4550 to support up to 6 simultaneous chan-
nels of streaming data on Output Frames.
The AC '97 architecture separates the analog and digital
functions of the PC audio system allowing both for system
design flexibility and increased performance.
Key Specifications
■ Analog Mixer Dynamic Range
■ DAC Dynamic Range
■ ADC Dynamic Range
97 dB (typ)
89 dB (typ)
90 dB (typ)
Features
■ AC '97 Rev 2 compliant
■ High quality Sample Rate Conversion from 4 kHz to 48
kHz in 1 Hz increments
■ Multiple codec support
■ National's 3D Sound stereo enhancement circuitry
■ Advanced power management support
■ Digital 3.3V and 5V supply options
■ Extended Temperature: −40°C ≤ TA ≤ 85°C
Applications
■ Desktop PC audio systems on PCI cards, AMR cards, or
with motherboard chips sets featuring AC Link
■ Portable PC systems as on MDC cards, or with a chipset
or accelerator featuring AC Link
■ General and Multi-channel audio frequency systems
© 2009 National Semiconductor Corporation 200308
200308 Version 5 Revision 1 Print Date/Time: 2009/07/15 15:26:52
www.national.com
1 page  
Symbol
TFALL
TRST_LOW
TRST2CLK
TSH
TSYNC2CLK
TS2_PDOWN
TSUPPLY2RST
TSU2RST
TRST2HZ
Parameter
Conditions
Fall Time
BIT_CLK, SYNC, SDATA_IN or
SDATA_OUT
RESET# active low pulse width
For Cold Reset
RESET# inactive to BIT_CLK start up For Cold Reset
SYNC active high pulse width
For Warm Reset
SYNC inactive to BIT_CLK start up For Warm Reset
AC Link Power Down Delay
Delay from end of Slot 2 to BIT_CLK,
SDATA_IN low
Power On Reset
Time from minimum valid supply levels to
end of Reset
Setup to trailing edge of RESET#
For ATE Test Mode
Rising edge of RESET# to Hi-Z
For ATE Test Mode
LM4546A
Typical Limit
(Note 6) (Note 7)
Units
(Limits)
6 ns (max)
TBD
1.3
TBD
1.0
162.8
TBD
162.8
µs (min)
ns (min)
µs (min)
ns (min)
1 µs (max)
1 µs (min)
15 ns (min)
25 ns (max)
Note 1: 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
which 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 2: Human body model, 100 pF discharged through a 1.5 kΩ resistor.
Note 3: Machine Model, 220 pF – 240 pF discharged through all pins.
Note 4: The maximum power dissipation must be derated at elevated temperatures and is dictated by TJMAX, θJA, and the ambient temperature TA. The maximum
allowable power dissipation is PDMAX = (TJMAX– TA)/θJA or the number given in Absolute Maximum Ratings, whichever is lower. For the LM4546A, TJMAX = 150°
C. The typical junction-to-ambient thermal resistance is 74°C/W for package number VBH48A.
Note 5: All voltages are measured with respect to the ground pin, unless otherwise specified.
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: Loopthrough mode describes a path from an analog input through the analog mixers to an analog output.
Note 9: These specifications are guaranteed by design and characterization; they are not production tested.
Note 10: Out of band energy is measured from 28.8 kHz to 100 kHz relative to a 1 Vrms DAC output.
5
200308 Version 5 Revision 1 Print Date/Time: 2009/07/15 15:26:52
www.national.com
5 Page 
Name
Pin I / O
Functional Description
LINE_OUT_R 36
Right Stereo Channel Output
O
This line level output (1 Vrms nominal) is fed from the right channel of the Stereo Mix signal from
MIX2 via the Master Volume register, 02h. The LINE_OUT_R amplitude can be muted (along with
LINE_OUT_L) or adjusted from 0 dB to -46.5 dB in 1.5 dB steps.
MONO_OUT
37
Mono Output
This mono line level output (1 Vrms nominal) is fed from either a microphone input (MIC1 or MIC2,
after boost amplifier) or from the mono sum of the left and right Stereo Mix 3D channels from MIX1.
O The optional National 3D Sound enhancement can be disabled (default) by the 3D bit (bit D13) in
the General Purpose register, 20h. Choice of input is by the MIX bit (D9) in the same register.
MIX=0 selects a microphone input. Output level can be muted or adjusted from 0 dB to -46.5 dB
in 1.5 dB steps via the Mono Volume register, 06h.
Name
Pin
XTL_IN
2
XTL_OUT
3
SDATA_OUT 5
BIT_CLK
6
SDATA_IN
8
SYNC
10
DIGITAL I/O AND CLOCKING
I / O Functional Description
24.576 MHz crystal or oscillator input
To complete the oscillator circuit use a fundamental mode crystal operating in parallel resonance
and connect a 1MΩ resistor across pins 2 and 3. Choose the load capacitors (Figure 2, C1, C2) to
suit the load capacitance required by the crystal (e.g. C1 = C2 = 33 pF for a 20 pF crystal Assumes
I that each 'Input + trace' capacitance = 7 pF).
This pin may also be used as the input for an external oscillator (24.576 MHz nominal) at standard
logic levels (VIH, VIL).
This pin is only used when the codec is in Primary mode. It may be left open (NC) for any Secondary
mode.
24.576 MHz crystal output
O
Used with XTAL_IN to configure a crystal oscillator.
When the codec is used with an external oscillator this pin should be left open (NC).
When the codec is configured in a Secondary mode this pin is not used and may be left open (NC).
Input to codec
I
This is the input for AC Link Output Frames from an AC '97 Digital Audio Controller to the LM4546A
codec. These frames can contain both control data and DAC PCM audio data. This input is sampled
by the LM4546A on the falling edge of BIT_CLK.
AC Link clock
An OUTPUT when in Primary Codec mode. This pin provides a 12.288 MHz clock for the AC Link.
I/O
The clock is derived (internally divided by two) from the 24.576 MHz signal at the crystal input
(XTL_IN).
This pin is an INPUT when the codec is configured in any of the Secondary Codec modes and
would normally use the AC Link clock generated by a Primary Codec.
Output from codec
O
This is the output for AC Link Input Frames from the LM4546A codec to an AC '97 Digital Audio
Controller. These frames can contain both codec status data and PCM audio data from the ADCs.
The LM4546A clocks data from this output on the rising edge of BIT_CLK.
AC Link frame marker and Warm Reset
This input defines the boundaries of AC Link frames. Each frame lasts 256 periods of BIT_CLK. In
normal operation SYNC is a 48 kHz positive pulse with a duty cycle of 6.25% (16/256). SYNC is
I sampled on the rising edge of BIT_CLK and the codec takes the first positive sample of SYNC as
defining the start of a new AC Link frame. If a subsequent SYNC pulse occurs within 255 BIT_CLK
periods of the frame start it will be ignored.
SYNC is also used as an active high input to perform an (asynchronous) Warm Reset. Warm Reset
is used to clear a power down state on the codec AC Link interface.
11
200308 Version 5 Revision 1 Print Date/Time: 2009/07/15 15:26:52
www.national.com
11 Page | ||
| Páginas | Total 28 Páginas | |
| PDF Descargar | [ Datasheet LM4546A.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LM4546 | AC 97 Rev 2 Codec with Sample Rate Conversion and National 3D Sound | National Semiconductor |
| LM4546 | LM4546 AC97 Rev 2 Codec w/Samp Rate Convrsn and TI 3D Sound (Rev. D) |  Texas Instruments |
| LM4546A | LM4546A AC97 Multi-Chan Audio Codec w/Samp Rate Conver w/National 3D Sound (Rev. E) | Texas Instruments |
| LM4546A | 2 Multi-Channel Audio Codec | National Semiconductor |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |