NXP Semiconductors MCU-SMHMI-HDUG, Руководство пользователя

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NXP Semiconductors
MCU-SMHMI-HDUG
Smart HMI Hardware Development User Guide
Amplifier gain is fixed and defined by R20/R23 value. Volume control has to occur in the
software domain. Audio stream (similar to PWM) is provided by the i.MX RT117H MQS
interface and is filtered before feeding the analog audio amplifier. Although the amplifier
is connected to MQS-RIGHT/MQS_LEFT (PWM) from i.MX RT117H, the incoming signal
must be differential (complementary digital data).
The figure below shows the circuit diagram of the audio amplifier.
VDD_5V
GND GND GND
GND GND
GND
GND GND
GND GNDGND
GND
MQS_RIGHT
MQS_LEFT
AUDIO_SD
C18
220PF
SPKN
C19
0.022UF
C17
220PF
C20
1.0UF R24
10K
DNP
C15
1000pF
FB2
120 OHM@100MHz
1 2
C262
0.1UF
SPKP
R23
82K
R25
10K
R19
10K
C21
1000pF
R22
10K
R20
82K
C14
0.022UF
R21
10K
DNP
C22
10uF
PAM8013
U4
OUT+
C3
P
V
D
D
B
2
OUT-
A3
V
D
D
B
1
IN-
C1
IN+
A1
SD
C2
G
N
D
A
2
P
G
N
D
B
3
FB3
120 OHM@100MHz
1 2
OUTP
OUT+
OUT-
OUTN
Figure 14. Class-D audio amplifier
The table below shows signal mapping between the audio amplifier PAM8013 and i.MX
RT117H MCU on the SLN-TLHMI-IOT board.
PAM8013 pin name Board signal i.MX RT117H pin name (number)
INP MQS_RIGHT GPIO_EMC_B1_40 (K1)
INN MQS_LEFT GPIO_EMC_B1_41 (L1)
SD AUDIO_SD GPIO_EMC_B2_19 (U2)
Table 17. PAM8013 – i.MX RT117H signal mapping
2.7 Sensors
The SLN-TLHMI-IOT board supports the following sensors:
• Two micro-electromechanical systems (MEMS) microphones
• One passive infrared (PIR) sensor
2.7.1 Microphones
The SLN-TLHMI-IOT board embeds two Knowles SPH0641LM4H-1 miniature, high-
performance, low-power, bottom-port silicon digital microphones (M200 and M201) with
single-bit PDM output. To allow data from the two microphones transmitting on the same
data line, the SELECT pin of M200 is connected to VDD_1V8 whereas the SELECT pin
of M201 is connected to GND. One of the microphones is sampled on the rising edge of
the MIC_CLK signal and the other microphone on the falling edge of signal, by the MCU.
To achieve better signal-to-noise ratio (SNR) of the audio input stream, the microphones
are powered by 1.8 V. An additional voltage-level translator NTB0102DP is required to
interface to the i.MX RT117H MCU with the appropriate levels.
The figure below shows the circuit diagrams of the two microphones.
MCU-SMHMI-HDUG All information provided in this document is subject to legal disclaimers. © NXP B.V. 2022. All rights reserved.
User guide Rev. 0 — 4 November 2022
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