LM4546AVH NSC [National Semiconductor], LM4546AVH Datasheet - Page 12

• Manufacturer Part Number: LM4546AVH
• Description: AC 97 Rev 2 Multi-Channel Audio Codec with Sample Rate Conversion and National 3D Sound
• Manufacturer: NSC [National Semiconductor]

www.national.com
Typical Performance Characteristics
3DP, 3DN
V
RESET#
Name
Name
DV
DV
DV
DV
Name
REF_OUT
AV
AV
ID0#
ID1#
V
NC
REF
DD1
DD2
SS1
SS2
DD
SS
14–17
29–32
38–44
47, 48
33,34
Pin
Pin
Pin
11
45
46
25
26
27
28
1
9
4
7
I / O
I / O
I / O
NC
O
O
O
I
I
I
I
I
I
I
I
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 LM4546A 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.
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 have the
same polarity as 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
high by an internal pull-up resistor.
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 have the
same polarity as 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
high by an internal pull-up resistor.
Analog supply
Analog ground
Digital supply
Digital supply
Digital ground
Digital ground
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. This pin must be tied to AV
Nominal 2.2 V reference output
Can source up to 5 mA of current and can be used to bias a microphone.
These pins are used to complete the National 3D Sound stereo enhancement circuit. Connect a
0.022 µF capacitor between pins 3DP and 3DN. National 3D Sound can be turned on and off via
the 3D bit (D13) in the General Purpose register, 20h. National 3D Sound uses a fixed-depth type
stereo enhancement circuit hence the 3D Control register, 22h is read-only and is not
programmable. If National 3D Sound is not needed, these pins should be left open (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
200308 Version 5 Revision 1
DD
POWER SUPPLIES AND REFERENCES
3D SOUND AND NO-CONNECTS (NC)
or AV
SS
), either directly or through a capacitor.
Print Date/Time: 2009/07/15 15:26:52
12
Functional Description
Functional Description
Functional Description
DD
DD
will set the ID0 bit to “0”. If left open (NC), ID0# is pulled
will set the ID1 bit to “0”. If left open (NC), ID1# is pulled
DD
with a 10 kΩ pull-up resistor.