Decoupling Capacitors and Resistor Roles

0:21

General
Project
+3V3
C23
C24
C25
C26
C27
C29
GND
NVCC_GPIO
NVCC_GPIO_3V3
R11
Here’s what each of those items is and does in your schematic:
  • 3V3: Power net portal indicating the 3.3 V rail. It ties any connected pins/components to the 3.3 V supply across the schematic.
  • C26: 0402 capacitor connected to NVCC_GPIO. Functions as a local decoupling/bulk cap to stabilize the NVCC_GPIO I/O supply against transients and switching noise.
  • C27: 0402 capacitor on NVCC_GPIO. Additional decoupling placed physically near other sinks of this rail to reduce impedance at higher frequencies.
  • R11: 0402 resistor between +3V3 and NVCC_GPIO. Likely a 0 Ω link (or small value) used as an isolate/jumper for measurement, filtering option, or to split planes for bring-up and fault isolation.
  • C24: 0402 capacitor on NVCC_GPIO. High-frequency bypass (typically 100 nF) close to NVCC_GPIO pins of the MCU to shunt fast transients to ground.
  • C29: 0603 capacitor on NVCC_GPIO. Likely a larger value (e.g., 1 µF–4.7 µF) to provide local bulk energy and reduce low-frequency droop on the I/O rail.
  • C23: 0603 or 0402 capacitor on NVCC_GPIO. Another decoupling/bulk element; together with C24/C25/C26/C27 it forms a distributed decoupling network covering a broader frequency range.
  • NVCC_GPIO_3V3: Power net portal labeling the NVCC_GPIO rail as a 3.3 V I/O supply domain for the MCU’s GPIO banks. This makes the I/O level 3.3 V and ties the various decouplers to that domain.
  • C25: 0402 capacitor on NVCC_GPIO. Another close-in high-frequency decoupler to minimize loop area and keep the rail quiet near sensitive pins.
In short: +3V3 is your main 3.3 V rail. NVCC_GPIO_3V3/NVCC_GPIO is the 3.3 V domain feeding the MCU’s I/O supply pins. R11 links +3V3 to NVCC_GPIO (optionally allowing isolation). C23, C24, C25, C26, C27, and C29 are the decoupling/bulk capacitors distributed around that rail to ensure stable, low-noise operation.
Clarify R11 value
Check capacitor values
Placement guidance
Rail separation decision
Noise/EMI concern
73 days

Ready.


U2
Manufacturer Part Number
MIMXRT1011CAE4A
is X1 adequate for my design?

@copilot is X1 adequate for my design?
2y
Based on your provided information, Designator X1 is a crystal oscillator (ABS07-32.768KHZ-T). Crystal Oscillators are used in electronics to generate precise, stabilised frequencies and are crucial components in various devices such as communications equipment, computers, and watches.
The X1 oscillator frequency (32.768 kHz) is commonly used for real-time clocks (RTC). Looking at the information provided about the i.MX RT1010 MCU, it seems that this MCU indeed has an RTC (Real Time Clock) feature, which suggests the usage of a 32.768 kHz crystal. The data sheet for the i.MX RT1010 Crossover Processors (IMXRT1010HDG) also confirms that a nominal frequency of $32.768 \mathrm{kHz} $ is recommended for the oscillator.
The selected crystal (ABS07-32.768KHZ-T) should be suitable per the MCU's datasheet. However, you need to ensure that the load capacitance of the crystal matches the capacitance seen by the oscillator circuit on your board. You can calculate this value based on the parasitic capacitance of the board layout and the input capacitance of the oscillator circuit on the i.MX RT1010. If the crystal's load capacitance and the board capacitance don't match, the oscillator may not start or it may run at a different frequency than expected.
It is recommended to cross-check your circuit's load capacitance and compare it to the specified load capacitance of the Crystal. This frequency should also align with the requirements of your application.
For best performance, ensure that the layout of the oscillator circuit minimizes noise and parasitic capacitance by following the recommendations in the MCU's hardware design guide.
In conclusion, based on the info provided, your crystal seems to be appropriate. However, verifying load capacitance, layout considerations, and the specifications of your entire design is essential for ensuring its full functionality.
2y
is R13 correct as a pull-up resistor?

@copilot is R13 correct as a pull-up resistor?
2y
Based on the information provided, resistor R13 connects to JTAG_TRSTB with a resistance value of 10kΩ. Given its usage in the JTAG interface, it can very well be a pull-up resistor. A pull-up resistor in this case could be providing a default state (usually logic high or '1') when the JTAG line is not actively being driven. However, to verify whether R13 is a pull-up resistor or not, I would also need to know the other pin (P1) connection. If the other pin of R13 is connected to a logic high voltage level or VCC, it would strengthen the argument of R13 being a pull-up resistor.
For confirmation, please provide more details or check the connections as discussed. Making an assumption without additional information could lead to an incorrect interpretation of the circuit.
2y
1
what is a good alternative part for MIMXRT1011

@copilot what is a good alternative part for MIMXRT1011
2y
A good alternative would be the ATSAME53J19A-AU microcontroller from Microchip. It is also an Arm Cortex-M7 based microcontroller, running at up to 300 MHz, with better power efficiency. It has 512KB of Flash memory and 192KB of SRAM, a bit more memory than the i.MX RT1010. The ATSAME53 also contains a nice set of peripherals including SPI, USART, I2C, USB, and SDIO, similar to the i.MX RT1010. It can be a drop-in replacement if you're not utilizing the full speed of i.MX RT1010.
Keep in mind that when choosing an alternative part, you need to consider the specifics of your application, and it's important to assess not only the hardware characteristics but also the available software support, including drivers, middleware, and Real-Time Operating Systems (RTOS) support. Also, footprint compatibility is important for hardware design considerations.
However, it's crucial to assess these options carefully as they have different specifications, so one should ensure they meet the requirements of your specific project. As always, please refer to the respective datasheet for a detailed comparison among these options.
2y
4
R13
Resistance
10k Ω
C7
Capacitance
22u F
JTAG_TDI
C5
Capacitance
4.7u F
+3V3
XTALO
RTC_XTALI
LORA_UART_TX
VDD_SNVS_CAP
C19
Capacitance
12p F
VDD_USB_CAP
R10
Resistance
30k Ω
R11
Resistance
0 Ω
C10
Capacitance
0.1u F
VDD_HIGH_CAP
NVCC_PLL
C14
Capacitance
4.7u F
NVCC_GPIO_3V3
JTAG_TRSTB
C22
Capacitance
0.22u F
RTC_XTALO
RTC_XTALO
JTAG_TMS
ON_OFF
JTAG_TCK
SPI_SCK
SPI_MOSI
JTAG_TDI
XTALI
C13
Capacitance
0.22u F
NVCC_PLL
XTALO
C12
Capacitance
0.22u F
C8
Capacitance
0.22u F
LORA_UART_RX
JTAG_TCK
VDD_HIGH_CAP
+3V3
C15
Capacitance
0.22u F
C6
Capacitance
0.22u F
LORA_RST
VDD_SNVS_CAP
+3V3
VDD_USB_CAP
C16
Capacitance
0.22u F
JTAG_TRSTB
JTAG_TDO
JTAG_TDO
JTAG_TMS
SPI_CS1
C11
Capacitance
4.7u F
C9
Capacitance
10u F
SPI_MISO
X1


  • Ground
    A common return path for electric current. Commonly known as ground.
  • Net Portal
    Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
  • Power Net Portal
    Wirelessly connects power nets on schematic. Identical to the net portal, but with a power symbol. Used to organize schematics and separate functional blocks. To wirelessly connect power net portals, give them the same designator. #portal #power
  • Generic Resistor
    A generic fixed resistor for rapid developing circuit topology. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard resistor values: 1.0Ω 10Ω 100Ω 1.0kΩ 10kΩ 100kΩ 1.0MΩ 1.1Ω 11Ω 110Ω 1.1kΩ 11kΩ 110kΩ 1.1MΩ 1.2Ω 12Ω 120Ω 1.2kΩ 12kΩ 120kΩ 1.2MΩ 1.3Ω 13Ω 130Ω 1.3kΩ 13kΩ 130kΩ 1.3MΩ 1.5Ω 15Ω 150Ω 1.5kΩ 15kΩ 150kΩ 1.5MΩ 1.6Ω 16Ω 160Ω 1.6kΩ 16kΩ 160kΩ 1.6MΩ 1.8Ω 18Ω 180Ω 1.8KΩ 18kΩ 180kΩ 1.8MΩ 2.0Ω 20Ω 200Ω 2.0kΩ 20kΩ 200kΩ 2.0MΩ 2.2Ω 22Ω 220Ω 2.2kΩ 22kΩ 220kΩ 2.2MΩ 2.4Ω 24Ω 240Ω 2.4kΩ 24kΩ 240kΩ 2.4MΩ 2.7Ω 27Ω 270Ω 2.7kΩ 27kΩ 270kΩ 2.7MΩ 3.0Ω 30Ω 300Ω 3.0KΩ 30KΩ 300KΩ 3.0MΩ 3.3Ω 33Ω 330Ω 3.3kΩ 33kΩ 330kΩ 3.3MΩ 3.6Ω 36Ω 360Ω 3.6kΩ 36kΩ 360kΩ 3.6MΩ 3.9Ω 39Ω 390Ω 3.9kΩ 39kΩ 390kΩ 3.9MΩ 4.3Ω 43Ω 430Ω 4.3kΩ 43KΩ 430KΩ 4.3MΩ 4.7Ω 47Ω 470Ω 4.7kΩ 47kΩ 470kΩ 4.7MΩ 5.1Ω 51Ω 510Ω 5.1kΩ 51kΩ 510kΩ 5.1MΩ 5.6Ω 56Ω 560Ω 5.6kΩ 56kΩ 560kΩ 5.6MΩ 6.2Ω 62Ω 620Ω 6.2kΩ 62KΩ 620KΩ 6.2MΩ 6.8Ω 68Ω 680Ω 6.8kΩ 68kΩ 680kΩ 6.8MΩ 7.5Ω 75Ω 750Ω 7.5kΩ 75kΩ 750kΩ 7.5MΩ 8.2Ω 82Ω 820Ω 8.2kΩ 82kΩ 820kΩ 8.2MΩ 9.1Ω 91Ω 910Ω 9.1kΩ 91kΩ 910kΩ 9.1MΩ #generics #CommonPartsLibrary
  • Generic Capacitor
    A generic fixed capacitor ideal for rapid circuit topology development. You can choose between polarized and non-polarized types, its symbol and the footprint will automatically adapt based on your selection. Supported options include standard SMD sizes for ceramic capacitors (e.g., 0402, 0603, 0805), SMD sizes for aluminum electrolytic capacitors, and through-hole footprints for polarized capacitors. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard capacitor values: 1.0pF 10pF 100pF 1000pF 0.01uF 0.1uF 1.0uF 10uF 100uF 1000uF 10,000uF 1.1pF 11pF 110pF 1100pF 1.2pF 12pF 120pF 1200pF 1.3pF 13pF 130pF 1300pF 1.5pF 15pF 150pF 1500pF 0.015uF 0.15uF 1.5uF 15uF 150uF 1500uF 1.6pF 16pF 160pF 1600pF 1.8pF 18pF 180pF 1800pF 2.0pF 20pF 200pF 2000pF 2.2pF 22pF 20pF 2200pF 0.022uF 0.22uF 2.2uF 22uF 220uF 2200uF 2.4pF 24pF 240pF 2400pF 2.7pF 27pF 270pF 2700pF 3.0pF 30pF 300pF 3000pF 3.3pF 33pF 330pF 3300pF 0.033uF 0.33uF 3.3uF 33uF 330uF 3300uF 3.6pF 36pF 360pF 3600pF 3.9pF 39pF 390pF 3900pF 4.3pF 43pF 430pF 4300pF 4.7pF 47pF 470pF 4700pF 0.047uF 0.47uF 4.7uF 47uF 470uF 4700uF 5.1pF 51pF 510pF 5100pF 5.6pF 56pF 560pF 5600pF 6.2pF 62pF 620pF 6200pF 6.8pF 68pF 680pF 6800pF 0.068uF 0.68uF 6.8uF 68uF 680uF 6800uF 7.5pF 75pF 750pF 7500pF 8.2pF 82pF 820pF 8200pF 9.1pF 91pF 910pF 9100pF #generics #CommonPartsLibrary
  • Generic Inductor
    A generic fixed inductor for rapid developing circuit topology. *You can now change the footprint and 3D model at the top level anytime you want. This is the power of #generics
  • Terminal
    Terminal
    An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.
  • RMCF0805JT47K0
    47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film #forLedBlink
  • 875105359001
    10uF Capacitor Aluminum Polymer 20% 16V SMD 5x5.3mm #forLedBlink #commonpartslibrary #capacitor #aluminumpolymer #radialcan
  • CTL1206FYW1T
    Yellow 595nm LED Indication - Discrete 1.7V 1206 (3216 Metric) #forLedBlink

Inspect

i.MX RT1010 LoRa Logger

i.MX RT1010 LoRa Logger
Description

Created
Last updated by nico
1 Contributor(s)
nico

Controls

Properties

Software
Bare metal
Connectivity
Lora, JTAG
Operating Voltage
5V
Antenna
Human Interface
Buttons, Display
Domain
Consumer Electronics

Availability & Pricing

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