ESP32 Cellular eSIM
Worked for 19 mins 53 sec
Started the ESP32 cellular schematic, but I can’t continue because your account has no available ACUs right now.
Accomplished:
- Renamed project to ESP32 Cellular IoT and added a project description.
- Created a datasheet-backed TX62-W project component because it was not in the Flux library.
- Added core schematic parts: ESP32-S3-WROOM-1-N16R8, TX62-W, TXB0108 level shifter, USB-C connector, LTE/GNSS U.FL antenna connectors, boot/reset switches, and first-pass passives.
- Wired USB-C to ESP32 native USB, ESP32 boot/reset basics, TX62-W power/ground bulk caps, TX62-W 1.8 V I/O rail, level-shifted UART/control/status/flow-control signals, and LTE/GNSS antenna nets.
Open items:
- R5/R6 ESP32-S3 strapping pull-downs were added but not wired due to the ACU stop.
- ESP32 ground pins still need final ground wiring verification.
- Unused TX62-W/ESP32 pins need no-connect cleanup.
- Cellular 3.8 V and ESP32 3.3 V regulators still need to be selected and wired after a power budget.
- ERC currently has expected floating/legibility issues because the schematic is mid-build.
Suggested next steps:
- Refill/enable ACUs, then ask me to “continue the ESP32 cellular schematic.”
- Wire R5/R6 and finish ESP32/TX62-W no-connect cleanup.
- Add the power tree: USB-C input → 3.3 V ESP32 rail and high-current 3.8 V modem rail.
- Run ERC/design review and fix remaining schematic issues.
Continue schematic
Add power tree
Clean up pins
Check ERC/DRC
Refine this doc
Ask about this doc
LTE-M / NB-IoT Module Selection for ESP32 + Integrated eSIM
Recommendation
Use Telit Cinterion TX62-W with the official embedded eSIM/eUICC ordering option as the default module for an ESP32-based LTE-M / NB-IoT product.
This is the lowest-risk choice because the integrated eSIM option is explicitly documented, the module follows a conventional host-modem architecture suitable for ESP32 UART control, and carrier/certification visibility is better than most alternatives.
Ranked shortlist
Table
| Rank | Module family | Recommendation | Why |
|---|---|---|---|
| 1 | Telit Cinterion TX62-W | Default | LTE-M/NB-IoT, documented embedded eSIM option, GNSS, low-power modes, conventional AT-command modem integration, carrier approval visibility. |
| 2 | Sequans Monarch 2 GM02S | Strong alternative | LTE-M/NB-IoT with integrated SIM/eSIM/iSIM capability via secure enclave; technically attractive but provisioning/carrier flow should be confirmed early. |
| 3 | u-blox SARA-R500E | Conservative fallback | Clear embedded SIM story and strong u-blox ecosystem; may be older/narrower and region/connectivity-model dependent. |
| 4 | u-blox SARA-R52 | Good if external eUICC is acceptable | Modern LTE-M/NB-IoT platform with strong docs, but integrated eSIM/eUICC was not clearly confirmed in public materials. |
| 5 | Quectel BG95 | Avoid as default for integrated eSIM requirement | Capable, common LTE-M/NB-IoT module; official materials mention eSIM support, but integrated eUICC inside the module is ambiguous without FAE confirmation. |
Why TX62-W is the best default
- Explicit embedded eSIM option in Telit/Cinterion product materials.
- LTE Cat M1 and NB-IoT NB1/NB2 support.
- Suitable for ESP32 integration over UART with modem control pins.
- More conventional integration path than iSIM-centric platforms.
- Better fit for a beginner-friendly schematic and bring-up process.
- Lower risk than modules where “eSIM support” may only mean support for an external eUICC/MFF2 SIM.
Key design implications
For the ESP32 design, plan for:
- UART TX/RX between ESP32 and modem.
- Modem control pins: PWRKEY/ON, RESET, STATUS, RI/WAKE as available on the selected module.
- Dedicated cellular supply rail, typically around 3.8 V, sized for cellular TX current bursts.
- Large local bulk capacitance close to the modem supply pins.
- RF antenna connector or certified antenna with 50 ohm RF routing and keepout.
- USB test/debug access if supported by the module.
- Logic-level compatibility between ESP32 3.3 V GPIO and modem I/O domain.
Open confirmations before schematic freeze
Ask Telit/distributor for the exact TX62-W ordering code and written answers to:
- Which SKU includes embedded eSIM/eUICC?
- Is the embedded eUICC GSMA-certified?
- Which RSP standard is supported, such as SGP.22 or SGP.32?
- Is a bootstrap profile included?
- Which carriers/MVNOs support profile provisioning for this SKU?
- Does the eSIM SKU share the same regulatory/operator certifications as the non-eSIM SKU?
- Are MOQ and lead time acceptable?
- Are LTE-M and NB-IoT certified on the target networks, not just supported by the radio?
Important architecture note
If “integrated eSIM” is only desired to avoid a removable SIM socket, consider whether an external MFF2 eUICC is acceptable. It adds a small soldered part, but can reduce lifecycle risk by making the modem easier to second-source and the connectivity provider easier to control.
If integrated eSIM/eUICC remains a hard requirement, proceed with TX62-W embedded eSIM variant first and keep Sequans GM02S as the advanced alternative.
Recommendation
Ranked shortlist
Why TX62-W is the best default
Key design implications
Open confirmations before schematic freeze
Important architecture note
