STEVAL-CCA021V1 STMicroelectronics, STEVAL-CCA021V1 Datasheet - Page 20

• Manufacturer Part Number: STEVAL-CCA021V1
• Description: BOARD EVAL AUDIO FOR STM32F103
• Manufacturer: STMicroelectronics

Specifications of STEVAL-CCA021V1

• Amplifier Type: Class D
• Output Type: Mono jack connector, 2 terminal connectors, 2 RCA jacks
• Max Output Power X Channels @ Load: 2.2W x 1 or 2 @ 4 Ohm
• Operating Temperature: -40°C ~ 85°C
• Board Type: Fully Populated
• Utilized Ic / Part: STM32F103, TS4657(TS2012, TS4962, TS472)
• Description/function: Audio D/A
• Operating Supply Voltage: 3 V to 5.5 V
• Output Power: 2.8 W
• Product: Audio Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: TS4657
• Other names: 497-10338

Connectors and functionality of the TS4657 audio card
Figure 17. TS4657 stereo DAC output audio RCA connectors J1, J3
9.5
20/46
3
4
5
6
7
8
Microphone functionality
An onboard microphone is available on the TS4657 audio card. The microphone is
connected to the microphone preamplifier TS472, which operates in single-ended output
configuration. The preamplifier output is available on the I
connected also to the ADC input pin of the STM32 MCU on the controller board.
The microphone unit U5 is supplied from the TS472 preamplifier 2.0 V bias pin. R11, R12
(1 KΩ) resistors are polarizing resistors for biasing of the microphone. C19 and C20 are
input coupling capacitors that block the DC voltage at the amplifier input pins and their value
determines also the cut-off of the low input frequencies. C18 and C23 are low pass filter
capacitors which allow to cut-off the high frequencies (100 pF ~ 20 kHz). C28 is assembled
with 0Ω resistor in order to have DC coupling between the preamplifier and the STM32
microcontroller. For AC coupling the C28 value determines also the cut-off of the low output
frequencies. The preamplifier gain can be changed by different values of the R17 resistor
(see TS472 datasheet on www.st.com). In this configuration the gain is fixed to 40 dB. R3
represents the input impedance of the following stage and is also used to charge the output
capacitor C28. R3 is assembled in the default configuration but can be safely removed. R15
is not necessary in case the standby pin connection is correctly handled on the side of the
microcontroller. TS472 has a weak pull-down resistor already embedded. If there is no
connection on the standby pin to the microcontroller, the preamplifier is in the standby mode.
The amplifier is powered from +3.3 V coming from the controller board.
LRCLK
SDAT
BCLK
MCLK
FMT2
FMT1
interface
Digital
audio
Control interface
NCP
PCP
9
STDBY
V CCA V CCD
13
20
Digital
filters
19
LDO
2
GNDD
Doc ID 15867 Rev 1
1
GNDA
DAC
DAC
10
GNDA
LDO
V REGD
15
18
16
GNDA
14
17
GNDD
V REGA
21
E-PAD
L OUT
R OUT
U1
12
11
2
820 Ω
820 Ω
C10
2.2 nF
C14
S audio connector P1 and is
2.2 nF
R4
R5
GND
GND
GND
GND
RCA WBTOR 1
RCA WBTOR 1
J3
J1
UM0722
AM00486