SNAS598 Data sheet

SNAS598B July 2012 – July 2015 LM4549B

PRODUCTION DATA.

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Mechanical Data (Package|Pins)

PT|48
- MTQF003C

Thermal pad, mechanical data (Package|Pins)

Orderable Information

6 Pin Configuration and Functions

PT Package

48-Pin LQFP

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Pin Functions

PIN		I/O	DESCRIPTION
NAME	NO.	I/O	DESCRIPTION
AUX_L	14	I	Left Stereo Channel Input This line level input (1 Vrms nominal) is selectable at the left channel of the stereo Record Select Mux for conversion by the left channel ADC. It can also be mixed into the left channel of the Stereo Mix 3D signal at MIX1 under the control of the Aux Volume register, 16h. The AUX_L level can be muted (along with AUX_R) or adjusted from +12 dB to -34.5 dB in 1.5 -dB steps. Stereo Mix 3D is combined into the Stereo Mix signal at MIX2 for access to the stereo outputs Line Out and Line Level Out.
AUX_R	15	I	Right Stereo Channel Input This line level input (1 Vrms nominal) is selectable at the right channel of the stereo Record Select Mux for conversion by the right channel ADC. It can also be mixed into the right channel of the Stereo Mix 3D signal at MIX1 under the control of the Aux Volume register, 16h. The AUX_R level can be muted (along with AUX_L) or adjusted from +12 dB to -34.5 dB in 1.5-dB steps. Stereo Mix 3D is combined into the Stereo Mix signal at MIX2 for access to the stereo outputs Line Out and Line Level Out.
CD_GND	19	I	AC Ground Reference This input is the reference for the signals on both CD_L and CD_R. CD_GND is not a DC ground and should be AC-coupled to the stereo source ground common to both CD_L and CD_R. The three inputs, CD_GND, CD_L and CD_R act together as a quasi-differential stereo input with CD_GND providing AC common-mode feedback to reject ground noise. This can improve the input SNR for a stereo source with a good common ground but precision resistors may be needed in any external attenuators to achieve the necessary balance between the two channels.
CD_L	18	I	Left Stereo Channel Input This line level input (1 Vrms nominal) is selectable at the left channel of the stereo Input Mux for conversion by the left channel ADC. It can also be mixed into the left channel of the Stereo Mix 3D signal at MIX1 under the control of the CD Volume register, 12h. The CD_L level can be muted (along with CD_R) or adjusted from +12 dB to -34.5 dB in 1.5-dB steps. Stereo Mix 3D is mixed into the Stereo Mix signal at MIX2 for access to the stereo outputs Line Out and Line Level Out.
CD_R	20	I	Right Stereo Channel Input This line level input (1 Vrms nominal) is selectable at the right channel of the stereo Input Mux for conversion by the right channel ADC. It can also be mixed into the right channel of the Stereo Mix 3D signal at MIX1 under the control of the CD Volume register, 12h. The CD_R level can be muted (along with CD_L) or adjusted from +12 dB to -34.5 dB in 1.5-dB steps. Stereo Mix 3D is combined into the Stereo Mix signal at MIX2 for access to the stereo outputs Line Out and Line Level Out.
LINE_IN_L	23	I	Left Stereo Channel Input This line level input (1 Vrms nominal) is selectable at the left channel of the stereo Record Select Mux for conversion by the left channel ADC. It can also be mixed into the left channel of the Stereo Mix 3D signal at MIX1 under the control of the Line In Volume register, 10h. The LINE_IN_L level can be muted (along with LINE_IN_R) or adjusted from +12 dB to -34.5 dB in 1.5-dB steps. Stereo Mix 3D is combined into the Stereo Mix signal at MIX2 for access to the stereo outputs Line Out and Line Level Out.
LINE_IN_R	24	I	Right Stereo Channel Input This line level input (1 Vrms nominal) is selectable at the right channel of the stereo Input Mux for conversion by the right channel ADC. It can also be mixed into the right channel of the Stereo Mix 3D signal at MIX1 under the control of the Line In Volume register, 10h. The LINE_IN_R level can be muted (along with LINE_IN_L) or adjusted from +12 dB to -34.5 dB in 1.5 dB steps. Stereo Mix 3D is combined into the Stereo Mix signal at MIX2 for access to the stereo outputs Line Out and Line Level Out.
LINE_OUT_L	35	O	Left Stereo Channel Output This line level output (1 Vrms nominal) is fed from the left channel of the Stereo Mix signal from MIX2 via the Master Volume register, 02h. The LINE_OUT_L amplitude can be muted (along with LINE_OUT_R) or adjusted from 0 dB to -46.5 dB in 1.5-dB steps.
LINE_OUT_R	36	O	Right Stereo Channel Output 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.
LNLVL_OUT_L	39	O	Left Stereo Channel Output This line level output (1 Vrms nominal) is fed from the left channel of the Stereo Mix signal from MIX2 via the Line Level Volume register, 04h. The LNLVL_OUT_L amplitude can be muted (along with LNLVL_OUT_R) or adjusted from 0 dB to - 46.5 dB in 1.5-dB steps
LNLVL_OUT_R	41	O	Right Stereo Channel Output This line level output (1 Vrms nominal) is fed from the right channel of the Stereo Mix signal from MIX2 via the Line Level Volume register, 04h. The LNLVL_OUT_R amplitude can be muted (along with LNLVL_OUT_L) or adjusted from 0 dB to - 46.5 dB in 1.5-dB steps
MIC1	21	I	Mono microphone input Either MIC1 or MIC2 can be muxed to a programmable boost amplifier with selection by the MS bit (bit D8) in the General Purpose register, 20h. The boost amplifier gain (0 dB or 20 dB) is set by the 20dB bit (D6) in the Mic Volume register, 0Eh. Nominal input levels at the two gain settings are 1 Vrms and 0.1 Vrms respectively. The amplifier output is selectable (Record Select register, 1Ah) by either the right or left channels of the Record Select Mux for conversion on either or both channels of the stereo ADCs. The amplifier output can also be accessed at the stereo mixer MIX1 (muting and mixing adjustments via Mic Volume register, 0Eh) where it is mixed equally into both left and right channels of Stereo Mix 3D for access to the stereo outputs Line Out and Line Level Out. Access to the Mono analog output is selected by a mux controlled by the MIX bit (D9) in General Purpose register, 20h.
MIC2	22	I	Mono microphone input Either MIC1 or MIC2 can be muxed to a programmable boost amplifier with selection by the MS bit (bit D8) in the General Purpose register, 20h. The boost amplifier gain (0 dB or 20 dB) is set by the 20dB bit (D6) in the Mic Volume register, 0Eh. Nominal input levels at the two gain settings are 1 Vrms and 0.1 Vrms respectively. The amplifier output is selectable (Record Select register, 1Ah) by either the right or left channels of the Record Select Mux for conversion on either or both channels of the stereo ADCs. The amplifier output can also be accessed at the stereo mixer MIX1 (muting and mixing adjustments via Mic Volume register, 0Eh) where it is mixed equally into both left and right channels of Stereo Mix 3D for access to the stereo outputs Line Out and Line Level Out. Access to the Mono analog output is selected by a mux controlled by the MIX bit (D9) in General Purpose register, 20h.
MONO_OUT	37	O	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. The optional TI 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 through the Mono Volume register, 06h.
PC_BEEP	12	I	Mono Input This line level (1 Vrms nominal) mono input is mixed equally into both channels of the Stereo Mix signal at MIX2 under the control of the PC_Beep Volume control register, 0Ah. The PC_BEEP level can be muted or adjusted from 0 dB to -45 dB in 3 dB steps. The Stereo Mix signal feeds both the Line Out and Line Level Out analog outputs and is also selectable at the Record Select Mux. During Initialization or Cold Reset, (reset pin held active low), PC_BEEP is switched directly to both channels of the Line Out stereo output, bypassing all volume controls. This allows signals such as PC power-on self-test tones to be heard through the audio system of the PC before the codec registers are configured.
PHONE	13	I	Mono Input This line level (1 Vrms nominal) mono input is selectable at the Record Select Mux for conversion by either channel of the stereo ADC. It can also be mixed equally into both channels of the Stereo Mix signal at MIX2 under the control of the Phone Volume register, 0Ch. The PHONE level can be muted or adjusted from +12 dB to -34.5 dB in 1.5-dB steps. The Stereo Mix signal feeds both the Line Out and Line Level Out analog stereo outputs and is also selectable at the Record Select Mux.
VIDEO_L	16	I	Left Stereo Channel Input This line level input (1 Vrms nominal) is selectable at the left channel of the stereo Record Select Mux for conversion by the left channel ADC. It can also be mixed into the left channel of the Stereo Mix 3D signal at MIX1 under the control of the Video Volume register, 14h. The VIDEO_L level can be muted (along with VIDEO_R) or adjusted from +12 dB to -34.5 dB in 1.5-dB steps. Stereo Mix 3D is combined into the Stereo Mix signal at MIX2 for access to the stereo outputs Line Out and Line Level Out.
VIDEO_R	17	I	Right Stereo Channel Input This line level input (1 Vrms nominal) is selectable at the right channel of the stereo Record Select Mux for conversion by the right channel ADC. It can also be mixed into the right channel of the Stereo Mix 3D signal at MIX1 under the control of the Video Volume register, 14h. The VIDEO_R level can be muted (along with VIDEO_L) or adjusted from +12 dB to -34.5 dB in 1.5-dB steps. Stereo Mix 3D is combined into the Stereo Mix signal at MIX2 for access to the stereo outputs Line Out and Line Level Out.
DIGITAL I/O AND CLOCKING
BIT_CLK	6	I/O	AC Link clock An OUTPUT when in Primary Codec mode. This pin provides a 12.288 MHz clock for the AC Link. 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.
EAPD	47	O	External Amplifier Power Down control signal This output is set by the EAPD bit (bit D15) in the Powerdown Control/ Status register, 26h. As with the other logic outputs, the output voltage is set by DV_DD. This pin is intended to be connected to the shutdown pin on an external power amplifier. For normal operation the default value of EAPD = 0 will enable the external amplifier allowing an input on PC_BEEP to be heard during Cold Reset.
ID0#	45	I	Codec Identity ID1# and ID0# determine the Codec Identity for multiple codec use. The Codec Identity configures the codec in either Primary or one of three Secondary Codec modes. These Identity pins are of inverted polarity relative to the Codec Identity bits ID1, ID0 (bits D15, D14) in the read-only Extended Audio ID register, 28h. If the ID0# pin (pin 45) is connected to ground then the ID0 bit (D14, reg 28h) will be set to “1”. Similarly, connection to DV_DD will set the ID0 bit to “0”. If left open (NC), ID0# is pulled high by an internal pull-up resistor.
ID1#	46	I	Codec Identity ID1# and ID0# determine the codec address for multiple codec use. The Codec Identity configures the codec in either Primary or one of three Secondary Codec modes. These Identity pins are of inverted polarity relative to the Codec Identity bits ID1, ID0 (bits D15, D14) in the read-only Extended Audio ID register, 28h. If the ID1# pin (pin 46) is connected to ground then the ID1 bit (D15, reg 28h) will be set to “1”. Similarly, connection to DV_DD will set the ID1 bit to “0”. If left open (NC), ID1# is pulled high by an internal pull-up resistor.
RESET#	11	I	Cold Reset This active low signal causes a hardware reset which returns the control registers and all internal circuits to their default conditions. RESET# MUST be used to initialize the LM4549B after Power On when the supplies have stabilized. Cold Reset also clears the codec from both ATE and Vendor test modes. In addition, while active, it switches the PC_BEEP mono input directly to both channels of the LINE_OUT stereo output.
SDATA_IN	8	O	Output from codec This is the output for AC Link Input Frames from the LM4549B codec to an AC '97 Digital Audio Controller. These frames can contain both codec status data and PCM audio data from the ADCs. The LM4549B clocks data from this output on the rising edge of BIT_CLK.
SDATA_OUT	5	I	Input to codec This is the input for AC Link Output Frames from an AC '97 Digital Audio Controller to the LM4549B codec. These frames can contain both control data and DAC PCM audio data. This input is sampled by the LM4549B on the falling edge of BIT_CLK.
SYNC	10	I	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 sampled on the falling 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.
XTL_IN	2	I	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 22, C1, C2) to suit the crystal (e.g. C1 = C2 = 33 pF for a crystal designed for a 20 pF load. Assumes 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 (V_IH, V_IL). This pin is only used when the codec is in Primary mode. It may be left open (NC) for any Secondary mode.
XTL_OUT	3	O	24.576-MHz crystal output 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).
POWER SUPPLIES AND REFERENCES
AV_DD	25	I	Analog supply
AV_SS	26	I	Analog ground
DV_DD1	1	I	Digital supply
DV_DD2	9	I	Digital supply
DV_SS1	4	I	Digital ground
DV_SS2	7	I	Digital ground
V_REF	27	O	Nominal 2.2-V internal reference Not intended to sink or source current. Use short traces to bypass (3.3-µF, 0.1-µF) this pin to maximize codec performance. See text.
V_{REF_OUT}	28	O	Nominal 2.2-V reference output Can source up to 5 mA of current and can be used to bias a microphone.
3D SOUND AND NO-CONNECTS (NC)
3DN	34	O	These pins are used to complete the TI 3D Sound stereo enhancement circuit. Connect a 0.022 µF capacitor between pins 3DP and 3DN. TI 3D Sound can be turned on and off via the 3D bit (D13) in the General Purpose register, 20h. TI 3D Sound uses a fixed-depth type stereo enhancement circuit hence the 3D Control register, 22h is read-only and is not programmable. If TI 3D Sound is not needed, these pins should be left open (NC).
3DP	33	O
NC	29	NC	These pins are not used and should be left open (NC). For second source applications these pins may be connected to a noise-free supply or ground (e.g. AV_DD or AV_SS), either directly or through a capacitor.
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