LM4540VH National Semiconductor, LM4540VH Datasheet

IC AUDIO CODEC '97 18BIT 48LQFP

LM4540VH

Manufacturer Part Number
LM4540VH
Description
IC AUDIO CODEC '97 18BIT 48LQFP
Manufacturer
National Semiconductor
Type
Audio Codec '97r
Datasheet

Specifications of LM4540VH

Data Interface
Serial
Resolution (bits)
18 b
Number Of Adcs / Dacs
2 / 2
Sigma Delta
Yes
Dynamic Range, Adcs / Dacs (db) Typ
90 / 89
Voltage - Supply, Analog
4.2 V ~ 5.5 V
Voltage - Supply, Digital
3 V ~ 5.5 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
48-LQFP
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Other names
*LM4540VH

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
LM4540VHX
Manufacturer:
Texas Instruments
Quantity:
10 000
© 1999 National Semiconductor Corporation
LM4540
AC ’97 Codec with National 3D Sound
General Description
The LM4540 is an audio codec for PC systems which per-
forms the analog-intensive function of the Analog Codec ’97
Rev 1.03 architecture. Using 18-Bit
ers, the LM4540 provides 90dB of dynamic range.
The LM4540 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 A/D’s and D/A’s
and an analog mixer with 2 stereo and 3 mono inputs, each
of which has separate gain, attenuation and mute control. In
addition, the LM4540 provides National’s 3D Sound stereo
enhancement technology.
The LM4540 features AC-Link, a synchronous, fixed rate se-
rial bus for connection to the digital AC ’97 Controller. The
separation of the analog and digital functions of the AC ’97
architecture allows for system design flexibility and in-
creased overall performance.
Block Diagram
FIGURE 1. LM4540 Block Diagram
A/D and D/A convert-
DS100906
Key Specifications
Features
n Audio Codec ’97 compliant
n Stereo 18-Bit
n National’s 3D Sound circuitry
n Power management support
n Digital Interface 3V and 5V compliant
Applications
n PC Audio Systems Requiring Only 2 Stereo Inputs (CD,
n Analog Mixer Dynamic Range
n D/A Dynamic Range
n A/D Dynamic Range
oversampling
Line) and 3 Mono Inputs (Mic, Phone, PC Beep)
A/D’s and D/A’s with 128X
February 1999
www.national.com
DS100906-1
95dB (typ)
89dB (typ)
90dB (typ)

Related parts for LM4540VH

LM4540VH Summary of contents

Page 1

... AC ’97 architecture allows for system design flexibility and in- creased overall performance. Block Diagram FIGURE 1. LM4540 Block Diagram © 1999 National Semiconductor Corporation DS100906 Key Specifications n Analog Mixer Dynamic Range n D/A Dynamic Range n A/D Dynamic Range Features n Audio Codec ’ ...

Page 2

... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage Storage Temperature Input Voltage ESD Susceptibility (Note 5) pins 27, 28 pin 3 ESD Susceptibility (Note 6) pin 3 Junction Temperature Soldering Information Electrical Characteristics The following specifications apply for AV for 0dB is 1Vrms unless otherwise specified ...

Page 3

Electrical Characteristics The following specifications apply for AV DD for 0dB is 1Vrms unless otherwise specified. Symbol Parameter Analog to Digital Converters Dynamic Range (Note 2) Frequency Response Digital to Analog Converters Resolution Dynamic Range (Note 2) THD Total Harmonic ...

Page 4

Electrical Characteristics The following specifications apply for AV for 0dB is 1Vrms unless otherwise specified. Symbol Parameter Digital Timing Specifications (Note 2) T SYNC active high pulse width SH T SYNC inactive to BIT_CLK start up SYNC2CLK T Setup to ...

Page 5

Timing Diagrams Clocks DS100906-10 Data Setup and Hold DS100906-11 Digital Rise and Fall DS100906-12 Cold Reset DS100906-13 Warm Reset DS100906-14 5 www.national.com ...

Page 6

Typical Application FIGURE 2. LM4540 Typical Application Circuit www.national.com 6 DS100906-3 ...

Page 7

... This input can be used to reject common mode signals on the CD_L or CD_R inputs. CD_GND 19 I CD_GND ground point not a DC ground point. This input must be AC-coupled to the CD input signal’s ground. Top View Order Number LM4540VH See NS Package Number VBH48A 7 DS100906-2 www.national.com ...

Page 8

Pin Description (Continued) Analog I/O (Continued) Name Pin Functional Description This line level input can be routed through the Input Mux and recorded by the right ADC. In addition, this analog input gets summed into the right ...

Page 9

Pin Description (Continued) Digital I/O and Clocking Name Pin 24.576 MHz crystal input. Use a fundamental-mode type crystal. When operating from a XTL_IN 2 I crystal 24.576 MHz crystal output. When operating from a crystal, ...

Page 10

Typical Performance Characteristics ADC Noise Floor DS100906-15 ADC Frequency Response DS100906-19 www.national.com DAC Noise Floor DS100906-16 DAC Frequency Response DS100906-20 10 Analog Loopthru Noise Floor DS100906-18 ...

Page 11

11 www.national.com ...

Page 12

Application Information AC Link Serial Interface Protocol AC Link Output Frame The audio output frame (output from AC ’97 Controller) con- tains control and PCM data targeted for the LM4540 control registers and stereo DAC. The Tag slot, slot 0, ...

Page 13

Application Information (Continued) Bit Description Comment Right 11 Playback 1 = Valid slot PCM Data SD_OUT Slot 1: Control Address Slot 1 is used both to write to the LM4540 registers as well as read back a register’s current value. ...

Page 14

Application Information FIGURE 7. Start of Audio Input Frame Bit Description Comment Codec Ready 15 0=Not Ready, 1=Ready Bit Slot 1 data 14 Status Address is valid valid Slot 2 data 13 Status Data is valid valid Slot 3 data ...

Page 15

Application Information (Continued) Mixer Input Volume Registers (Index 0Ch - 12h, 18h) These registers control the input volume controls including mute. Each volume control is 5 bit which provides from a range of +12dB gain to 34.5dB attenuation. For stereo ...

Page 16

... National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. 48-Lead , TQFP 1.4mm, JEDEC (M) Order Number LM4540VH NS Package Number VBH48A 2. A critical component is any component of a life support ...

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