ON Semiconductor BELASIGNA R262 BR262PMEVK, BelaSigna R262, BR262PMEVK User Manual
BR262PMEVK
BELASIGNA) R262
Prototyping Module
Evaluation Board
User'sManual
The BelaSigna R262 Prototyping Module
The BelaSigna R262 prototyping module is a miniature,
self-contained unit that can be integrated into a product or
prototype to evaluate the performance of BelaSigna R262
“in-form-factor”.
Key Features
The module is shown in Figure 1 and features:
A Miniature Size of only 22 mm 6mm
The 30-ball WLCSP Version of BelaSigna R262
(BR262W30A103E1G)
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EVAL BOARD USER’S MANUAL
Two MEMS Microphones Spaced 10 mm Apart
(Knowles Part Number SPU0410HR5H−PB)
Through-hole Test Points for External Connections
Configured to Boot Directly to the ROM Application
Using the Internal Clock
2
I
C and GPIO Signals Available on Test Points
An Onboard I
Application
2
C EEPROM for Optional Custom
Dual MEMS
Microphones
Figure 1. BelaSigna R262 Prototyping Module
Default Configuration
The prototyping module configures BelaSigna R262 to
run off its internal oscillator and to boot directly into the
ROM-based noise reduction algorithm. The module is
pre-configured to simultaneously output two different
algorithm turnings: a pure close-talk output on AO0, and an
output that is close-talk mixed 60% towards far-talk on
AO1. All that is required is to supply the module with 1.8 to
Through-hole Test
points
BelaSigna R262
3.3 VDC (requires approximately 20 mA), and to connect
the analog outputs to your in-form-factor design. Power is
connected to VBAT (+) and GND (−). The prototyping
module configures the ROM application as summarized in
Table 1 when power is applied.
A description of all test points and a complete schematic
and layout is available in Appendix A.
Semiconductor Components Industries, LLC, 2012
December, 2012 − Rev. 0
1 Publication Order Number:
EVBUM2166/D
BR262PMEVK
Table 1. BelaSigna R262 PROTOTYPING MODULE LSAD CONFIGURATION
Pin Name Preset Description
CLOCK_SEL (SPI_CLK/GPIO0) 7 Internal Clock
BOOT_SEL (SPI_CS/GPIO1) 4 Active Mode
CHAN_SEL (SPI_SERO/GPIO2) 3 Dual Output Noise Reduction
ALPHA_SEL (SPI_SERI/GPIO3) 4 Mixer set 60% between Start and End of Range
Talk Distance Selectable between Close-talk and Far-talk
(5 cm – 500 cm)
(Two Single-ended Analog Outputs)
Channel 0 as per BOOT_SEL “Start of Range” (Close-talk)
Channel 1 as per BOOT_SEL and ALPHA_SEL
Connecting the Prototyping Module
The analog output signals are available on AO0 (6),
AO1 (7), and GNDA (−). An optional momentary
push-button control can be connected between GP5 (5) and
GNDD (−) that can be used to swap the two processed
outputs between AO0 and AO1. The pinout for the module,
along with typical connections are illustrated in Figure 2.
The analog outputs of the device can be connected to your
system’s analog inputs as single-ended signals using AO0
and GNDA and/or AO1 and GNDA. If the module is
re-configured to output a mono, differential analog output
by changing the CHAN_SEL resistors R4 and R5, via I
2
commands, or by loading a custom application, you can
GND
1.8 to 3.3 VDC
connect AO0 and AO1 to your system as a differential
analog signal.
NOTE: The analog output impedance is 3 kW and is intended to drive
a high-impedance (line-level) input, not speakers nor
headphones directly. Refer to the BelaSigna R262 datasheet
for more information on output stage characteristics.
You can also use the prototyping module as a digital
microphone replacement outputting a stereo DMIC signal
on test point GP4 (4), provided you supply an appropriate
DMIC clock signal on the CLK (8) test point and
re-configure the module’s CLOCK_SEL resistive divider to
C
match the provided clock frequency. Refer to the
BelaSigna R262 datasheet for more information.
Analog Output 1
Analog Output 0
Analog GND
Swap Channels
Figure 2. BelaSigna R262 Prototyping Module Typical Connections
Operating the Prototyping Module
The default configuration of the prototyping module
provides the widest noise reduction adjustment range
(close-talk to far-talk) by selecting preset 4 on the
BOOT_SEL input, and is pre-configured to simultaneously
output two different algorithm tunings: a pure close-talk
output on AO0, and an output that is close-talk mixed 60%
towards far-talk on AO1. The processed outputs from these
two algorithm tunings are available as single-ended analog
outputs on AO0 – GNDA, and AO1 – GNDA. The
application will swap the output channels when GP5 is
momentarily pulled low. If a momentary push-button is
connected between GP5 and GNDD, pressing and releasing
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this button will swap the two processed outputs between
AO0 and AO1.
Close-Talk
Close-talk mode aggressively filters noise and manages
gain to pick up speech within 5 to 10 cm from the
microphone array, effectively attenuating both speech and
noise that is farther away. This mode is suitable for mobile
handsets and radios where the speech source is very close to
the microphones and the noise level can be quite high; up to
90 dB SPL. Noise reduction performance in this mode
ranges from 20 to 30 dB SNR improvement (SNR−I),
depending on the type of noise.
2
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