No results for tactile switch 2 pin smd pushbutton.
Thought for a moment — Searching for VBUS solutions
Read PESD5V0S1BA,115 datasheet for reverse standoff voltage and clamp volta.
Read PESD5V0S1BA,115 datasheet for typical connection for 5V line to ground.
Found 3 results for small SMD momentary tactile pushbutton switch for BOOT and RESET buttons on an embedded PCB, normally open, top-actuated, compact consumer electronics.
Thought for 4 sec — Evaluating component selection
Read SMF5.0A datasheet for reverse standoff voltage and peak pulse .
Read SMF5.0A datasheet for pin polarity cathode anode and unidirect.
I need to write design notes that include component selections and the power budget, probably later. I should also add components. First, I want to get property config for a generic package, which might involve querying options for that package. Maybe I could skip including specifics like resistance or capacitance for now. I’ll try omitting the designator and see if it returns standard options that cover multiple choices.
Evaluating capacitor needs
I’m considering the capacitor requirements for my project. For C1, I’ll use a 1uF eFuse CIN. For C2, a 10uF eFuse COUT sounds good, and maybe I should stick with that. C3 will have a 1uF for LDO input.
USB-C powered low-power consumer environmental sensor node with integrated 2.4 GHz Wi-Fi (802.11 b/g/n) and Bluetooth Low Energy 5.x. The node measures ambient temperature and relative humidity using a digital sensor and is intended for fixed 5 V USB-C powered deployment.
Requirements
USB-C receptacle input, sink/device role, default 5 V operation only
Operates from USB-C sources advertising default current up to 3 A without USB PD negotiation
Include input protection strategy covering reverse current/blocking behavior, over-voltage protection, under-voltage lockout, and over-current limiting/protection considerations
Low-power Wi-Fi + BLE capable MCU/module
Digital temperature/relative humidity sensor on a low-power digital bus
3.3 V system rail for MCU and sensor
Consumer-oriented design with simple programming/debug access over USB
Sensor: Sensirion SHT40 digital temperature/relative humidity sensor on I2C
USB-C power entry: USB-C receptacle configured as a sink using dual 5.1 kΩ CC pull-down resistors
Input protection path: USB VBUS -> resettable fuse / current limiter stage -> surge/ESD protection -> reverse-blocking / ideal-diode style power-path controller stage with UVLO/OVLO control -> 3.3 V regulator
Main regulator: 3.3 V low-IQ LDO sized for ESP32-C3 Wi-Fi burst current with appropriate thermal margin
Programming/debug: Native USB D+/D- routed to ESP32-C3 USB pins with ESD protection
User interface: power/status LED optional; keep base design minimal and low-power
Preliminary Power Budget
Assumptions for sizing:
ESP32-C3 average active current: tens of mA, with Wi-Fi TX/RX bursts well above 300 mA
Design peak budget target on 3.3 V rail: >= 500 mA
SHT40 current is negligible relative to radio load
USB-C source may be capable of 0.5 A to 3 A; design input path should safely accept compliant 5 V sources across that range without drawing more than required by the load
Why 3.3 V LDO is acceptable:
5 V to 3.3 V drop is 1.7 V
At 300 mA average heavy activity, dissipation is about 0.51 W, which is manageable only with an adequately rated package and copper area
At burst conditions the average thermal load remains much lower than peak instantaneous current, but regulator transient response and output capacitance must support radio current pulses
Protection Intent
Reverse / backfeed protection: prevent system rail from driving current back into VBUS when unplugged or faulted
OVP / surge protection: clamp ESD/transients on VBUS and USB data lines; add front-end device with input over-voltage protection or controlled cutoff if supported by chosen part
UVLO: avoid brownout operation from drooping VBUS/cable conditions by selecting front-end device or regulator enable thresholding
OCP: fuse/current-limiter stage sized from the system power budget; protect against shorts while tolerating inrush and radio burst current
Key Nets Planned
VBUS_RAW
VBUS_PROTECTED
3V3
GND
USB_D+
USB_D-
USB_CC1
USB_CC2
I2C_SCL
I2C_SDA
EN
GPIO9_BOOT (or equivalent boot pin net)
Open Implementation Notes
Prefer module-based ESP32 design to simplify RF compliance and antenna matching
Keep ESP32 antenna region free of copper/components in layout
One pair of I2C pull-ups for the whole bus
Native USB avoids external USB-UART bridge and reduces standby current
Verify all selected protection parts against 5 V-only USB-C sink use case and consumer BOM availability