Microphone Mixer Evaluation Module

Microphone Mixer Evaluation Module
Microphone Mixer Evaluation
Module
DATA MANUAL: SLOU009
Date: July 1997
IMPORTANT NOTICE
Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue
any product or service without notice, and advise customers to obtain the latest version of relevant information
to verify, before placing orders, that information being relied on is current and complete. All products are sold
subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those
pertaining to warranty, patent infringement, and limitation of liability.
TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent
TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily
performed, except those mandated by government requirements.
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF
DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL
APPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR
WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER
CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO
BE FULLY AT THE CUSTOMER’S RISK.
In order to minimize risks associated with the customer’s applications, adequate design and operating
safeguards must be provided by the customer to minimize inherent or procedural hazards.
TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent
that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other
intellectual property right of TI covering or relating to any combination, machine, or process in which such
semiconductor products or services might be or are used. TI’s publication of information regarding any third
party’s products or services does not constitute TI’s approval, warranty or endorsement thereof.
Copyright  1999, Texas Instruments Incorporated
TRADEMARKS
TI is a trademark of Texas Instruments Incorporated.
Other brands and names are the property of their respective owners.
3
Contents
1. Layout Definition ...................................................................................................... 6
2. Operation .................................................................................................................. 8
3. Input/Output Connections........................................................................................ 9
4. Layout...................................................................................................................... 11
5. Bill of Materials ....................................................................................................... 13
Figures
Figure 1. Mic Mixer EVM Component Placement .............................................................. 6
Figure 2. Mic Mixer EVM Schematic.................................................................................. 9
4
If You Need Assistance
If You need Assistance...
If You Want to...
Do This...
Request more information about Call the PIC✝ hotline:
Texas instruments Mixed Signal
(972) 644-5580
Products
or send a fax to the PIC:
(972) 480-7800
or write to:
Texas Instruments
Incorporated
Product Information
Center, MS
3123
P.O. Box 660246
Dallas, Texas 75266
Order Texas Instruments
documentation
Call the PIC✝ hotline:
(972) 644-5580
Ask questions about product
operation or report suspected
problems
Call the PIC✝ hotline:
(972) 644-5580
Report mistakes in this
Marketing
document or any other TI
Correction:
Mixed Signal Products
documentation
Send a fax to MSP
Documentation
(214) 480-3160
or send your comments to:
Texas Instruments
Incorporated
MSP Marketing
Documentation
Correction, MS 8710
P.O. Box 660199
Dallas, Texas 75266-0199
✝ Texas Instruments Product Information Center
5
1. Layout Definition
The Mic/Mixer EVM is designed to provide basic volume
control and a microphone interface to the P-n-P Audio Power
Amplifier Evaluation Platform. With the Mic/Mixer plugged in
to the P-n-P, the user can sing along with music from a
favorite CD (karaoke) or simply use the volume control to
adjust the listening level of the line inputs.
Figure 1. Mic Mixer EVM Component Placement
TLC2274
R21
C11
R15
SLOP107
MIC/MIXER
Rev. B 1997
R Volume
R2
L Volume
Vdd
R_OUT
R6
U2
J6
L_OUT
L_IN
R1
Mic Volume
C3
C10
R20
C9
R12
R10
R19
R18
C4 C2
R9
C6
R17
R4
R25
R5
R_IN
J3
C1
R3
R24
S1 R11
TLC2274
J1
R8
C5
JP1
R16
R14
U1
C7
J2
R22
C8 R23
C12
R13
R7
Operating the Mic Mixer Evaluation Module (SLOP107)
6
TLC2274
U1,2 - TLC2274CD
Quad op Amp, RRO, 2MHz
C1,5,9 - Capacitor, 1.0 µF Ceramic
C2,4,6,11 - Capacitor, 47 pF Ceramic
C3 - Capacitor, 10 µF Electrolytic
C7,8 - Capacitor, 2.2 µF Ceramic
C10,12 - Capacitor, 0.1 µF Ceramic
R1,2,11 - Pot, 50 k, Slide, Audio Taper
R3,5,8,12,14 - Resistor, 10 kΩ Carbon
R16,17,18,19 - Resistor, 10 kΩ Carbon
R20,21,25 - Resistor, 10 kΩ Carbon
R4,6,13,15 - Resistor, 20 kΩ Carbon
R22,23,24 - Resistor, 20 kΩ Carbon
R9 - Resistor, 47 kΩ Carbon
R7 - Resistor, 2.2 kΩ Carbon
R10 - Pot, 200 k, 3/4 turn
JP1,2 -0.1” header, 2-pin, 3-pin
J2 - 1/8” Stereo Jack
Operating the Mic Mixer Evaluation Module (SLOP107)
7
2. Operation
The basis of the Mic/mixer design is the TLC2274 quad CMOS
Rail to Rail op amp from TI. The bandwidth, distortion and
noise performance of the TLC2274 make it an ideal workhorse
in PC audio applications.
Power: 5.0 to 16 Vdc, 10 mA
Audio Inputs: L/R IN, AC Coupled, 1 Vrms Nominal, G = 0 to
2, individual L/R slide control with audio taper,
Audio Outputs:
L/R Out, DC Coupled (Vcc/2 offset), THD
< 0.004% Nominal 1 kHz.
NOTE:MIC INTERFACE:MIC IN, 1/8” STANDARD INPUT
JACK COMPATIBLE WITH MOST ELECTRET OR
DYNAMIC MICROPHONES, G = 0 TO 7.5 WITH R19
SET TO MIN, G = 0 TO 83 WITH R19 SET TO MAX.
INDIVIDUAL MIC LEVEL SLIDE CONTROL MIXES
MIC INPUT TO BOTH LINE OUTPUTS. MIC BIAS
OUTPUT SET TO VCC*0.66 SELECTABLE TO RING
OR TIP.
8
SLOU009
3. Input/Output Connections
Figure 2. Mic Mixer Schematic
T PA
Mic/Mixer EVM, SLOP107 Rev. B
VDD
PUMP UP THE VOLUME
C1
1.0 uF
R In
R3
10 k
R16
10 k
1
13
3
mid
R7
2.2 k
mid
U1a
C6 47 pF
R8
C5
1.0 uF 10 k
6
R15
20 k
U1b
R25
10 k
7
5
R24
20 k
mid
C9
1.0 uF
R6
20 k
R5
10 k
J3
6
R2
50 k
AT
mid
9
R11
50 k
AT
mid
VDD
U1d
R10
200 k
LT
13
mid
R22
20 k
14
12
mid
R23
20 k
C8
2.2 uF
U1c
C11
47 pF
8
10
R19
10 k
mid
R20
10 k
U2b
9
R21
10 k
U2c
8
7
5
R Out
mid
C2 47 pF
R14
10 k
JP2
J4
R13
20 k
C7
2.2 uF
Tip
L In
R12
10 k
3
mic bias
R9
47 k
Ring
J2
12
2
1
R18
10 k
U2d
14
V DD
JP1
Mic In
R17
10 k
U2a
2
R1
50 k
AT
C4
47 pF
J
C3 6
10 uF
R4
20 k
J1
GND
10
03/04/97
* use 0.1 bypass on U1 (C12), U2 (C10)
> red traces must be as short as possible!
J5
L Out
mid
Each audio input channel is AC coupled through a 1 uF
capacitor into a volume control potentiometer. The slide pot is
logarithmic (audio Taper) which compensates for the nonlinear
response of the ear resulting in a linear volume control. A
single stage amp with a gain of -2 is used to buffer the volume
control form the summing stage amplifier. A midrail (virtual
ground) voltage is generated with a voltage divider from the
supply voltage and buffered with a single amplifier. This
voltage is used to bias the AC signal to the center of the
operating voltage range to prevent positive or negative clipping
of the audio signals. The voltage is set to Vcc/2.
The microphone interface is compatible with common
SoundBlaster type electret mics and dynamic mics. Electret
mics require a bias voltage to operate. The bias circuit can be
Operating the Mic Mixer Evaluation Module (SLOP107)
9
configured to bias the ring or tip of the mic connector. Some
experimentation may be required to determine the proper
setting for each different mic. The bias voltage is generated
with a resistor divider from the main supply voltage and is
0.66*Vcc. The input stage is a single amp with a gain of 4.7
driving a volume control pot. An isolation resistor is required
due to the capacitive nature of the slide pots resulting in a
0.8*4.7 or 3.8 max gain. the main gain stage is after the level
control pot and can be adjusted for gains of 2 to 22. This
makes the maximum mic gain 4.7*0.8*22 = 83. 47 pF
bandwidth limiting caps are placed across the feedback
resistors on the gain stages of the mic interface. This is a
technique designed to prevent oscillation in high gain and
capacitive loading circuits of which this has both.
The output stage for each channel is a unity gain summing
amp that adds the signal from the line inputs to the signal from
the mic according to the ratio set by the level control pots.
Bandwidth limiting caps are again used to help stabilize the
outputs that could be driving unknown but possibly very
capacitive loads.
10
SLOU009
4. Layout
NOTE: Layouts are not to scale.
Operating the Mic Mixer Evaluation Module (SLOP107)
11
12
SLOU009
5. Bill of Materials
File: micmixer.xls
Date: 03/05/97
Ref Des
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
C11
C12
J1
J2
J3
J4
J5
J6
JP1
JP2
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
R11
R12
R13
R14
R15
R16
R17
R18
R19
R20
R21
R22
R23
R24
R25
U1
U2
PCB
Part No.
C3216Y5V1C105Z
PCC470CCT-ND
C3225Y5V1C106Z
PCC470CCT-ND
C3216Y5V1C105Z
PCC470CCT-ND
C3216Y5V1C225Z
C3216Y5V1C225Z
C3216Y5V1C105Z
PCC104BCT-ND
PCC470CCT-ND
PCC104BCT-ND
161-3504
448XC3503BAN
448XC3503BAN
3362P-200K
448XC3503BAN
TLC2274CD
TLC2274CD
SLOP107
Description
Capacitor, Ceramic, 1.0 uF, 16V, Y5V, 1206
Capacitor, Ceramic, 47 pF, 50V, NPO, 1206
Capacitor, Ceramic, 10 uF, 16V, Y5V, 1206
Capacitor, Ceramic, 47 pF, 50V, NPO, 1206
Capacitor, Ceramic, 1.0 uF, 16V, Y5V, 1206
Capacitor, Ceramic, 47 pF, 50V, NPO, 1206
Capacitor, Ceramic, 2.2 uF, 16V, Y5V, 1206
Capacitor, Ceramic, 2.2 uF, 16V, Y5V, 1206
Capacitor, Ceramic, 1.0 uF, 16V, Y5V, 1206
Capacitor, Ceramic, 0.1 uF, 50V, X7R, 1206
Capacitor, Ceramic, 47 pF, 50V, NPO, 1206
Capacitor, Ceramic, 0.1 uF, 50V, X7R, 1206
Header, 2-pin, 0.025"-sq, 100-mil centers
Phone Jack, Stereo, 1/8"
Header, 2-pin, 0.025"-sq, 100-mil centers
Header, 2-pin, 0.025"-sq, 100-mil centers
Header, 2-pin, 0.025"-sq, 100-mil centers
Header, 2-pin, 0.025"-sq, 100-mil centers
Header, 3-pin, 0.025"-sq, 100-mil centers
Header, 2-pin, 0.025"-sq, 100-mil centers
Potientiometer, 50K Ohm, Slide, Audio taper, 1.4"
Potientiometer, 50K Ohm, Slide, Audio taper, 1.4"
Resistor, CF, 10K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 20K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 10K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 20K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 2.2K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 10K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 47K Ohm, 1/8 W, 5 %, 1206
Potientiometer, 200K Ohm, 1-turn, 1/4"-sq
Potientiometer, 50K Ohm, Slide, Audio taper, 1.4"
Resistor, CF, 10K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 20K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 10K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 20K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 10K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 10K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 10K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 10K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 10K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 10K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 20K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 20K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 20K Ohm, 1/8 W, 5 %, 1206
Resistor, CF, 10K Ohm, 1/8 W, 5 %, 1206
IC,Quad Op Amp, RRO, 2 MHz, SO-14
IC,Quad Op Amp, RRO, 2 MHz, SO-14
Printed Circuit Board, 2-layer
Source
TDK
Digikey
TDK
Digikey
TDK
Digikey
TDK
TDK
TDK
Digikey
Digikey
Digikey
Mouser
Page
245
245
245
245
245
245
92
CTS
CTS
CTS
TI
TI
TI
Operating the Mic Mixer Evaluation Module (SLOP107)
13
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertising