component
CH318T
Public Made by Adomby adom
WCH(南京沁恒) Isolated USB ICs, TSSOP-20. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownCH318T
WCH(南京沁恒) · Isolated USB ICs · TSSOP-20
CH318T from WCH(南京沁恒), in a TSSOP-20. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | DMX | passive | Analog differential-pair signal, connected through the isolation capacitor or network transformer directly to the negative end of the differential extension line. |
| 2 | DPX | passive | Analog differential-pair signal, connected through the isolation capacitor or network transformer directly to the positive end of the differential extension line. |
| 3 | XO | output | Crystal oscillator inverting output; connects to the other terminal of the external crystal. |
| 4 | XI | input | Crystal oscillator input; connects to one terminal of the external crystal (an external clock input is also supported per the features list). |
| 5 | AVDDK | power_in | Analog core power pin; requires a 1uF decoupling capacitor to ground. |
| 6 | DMU | bidirectional | USB D- signal: upstream port D- in host (upstream) mode, or downstream port 1 D- in device (downstream) mode. |
| 7 | DPU | bidirectional | USB D+ signal: upstream port D+ in host (upstream) mode, or downstream port 1 D+ in device (downstream) mode. |
| 8 | DM2 | bidirectional | USB D- signal of downstream port 2 (device-mode chip only, per the function description). |
| 9 | DP2 | bidirectional | USB D+ signal of downstream port 2 (device-mode chip only, per the function description). |
| 10 | IO1 | bidirectional | Downstream general-purpose I/O sideband signal with tens-of-milliseconds mapping delay; input in host mode, output in device mode, mirroring the host-side IO1 level to the device side when high or low. |
| 11 | IO2 | bidirectional | Upstream general-purpose I/O sideband signal with tens-of-milliseconds mapping delay; output in host mode and input in device mode, with the device-side level mirrored to the host side. |
| 12 | IO3 | bidirectional | Upstream general-purpose I/O sideband signal with tens-of-milliseconds mapping delay; output in host mode and input in device mode, with the device-side level mirrored to the host side. |
| 13 | LED/MODE | bidirectional | Dual function: LED output for host/device chip connection status (active low, internal pull-up); during reset it selects mode, floating or pulled up through 5.1K to VDD33 for host mode, pulled down through 5.1K to GND for device mode. Rated 3.3V signal input with 5V tolerance. |
| 14 | DVDDK | power_in | Digital core power pin; requires a 0.1uF decoupling capacitor to ground. |
| 15 | GND | power_in | Common ground pin. |
| 16 | VDD33 | power_in | Analog supply input, externally supplied at 3.3V; requires a 1uF decoupling capacitor. |
| 17 | NC | unconnected | Reserved pin; must not be connected. |
| 18 | NC | unconnected | Reserved pin; must not be connected. |
| 19 | NC | unconnected | Reserved pin; must not be connected. |
| 20 | NC | unconnected | Reserved pin; must not be connected. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | WCH(南京沁恒) |
| Package | TSSOP-20 |
| Category | Signal Isolation Devices |
| Pins | 20 |
Electrical characteristics
Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).
| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Operating ambient temperature | TA | -40 | 85 | ℃ | 5 | ||
| Junction temperature range | TJ | -40 | 100 | ℃ | 5 | ||
| Storage ambient temperature | TS | -55 | 150 | ℃ | 5 | ||
| Operating supply voltage at VDD33 | VDD33 | -0.4 | 4 | V | 5 | ||
| HBM ESD withstand, USB signal pins | VESDUSB | 6 | K V | HBM human body model | 5 | ||
| HBM ESD withstand, other pins | VESDIO | 2 | K V | HBM human body model | 5 | ||
| External supply voltage at VDD33 | VDD33 | 3.2 | 3.3 | 3.4 | V | TA=25℃, VDD33=3.3V | 5 |
| Operating current, upstream high-speed, 2 downstream high-speed | ICC | 80 | mA | TA=25℃, VDD33=3.3V; upstream high-speed, 2 downstream high-speed ports | 5 | ||
| Operating current, upstream high-speed, 1 downstream high-speed | ICC | 68 | mA | TA=25℃, VDD33=3.3V; upstream high-speed, 1 downstream high-speed port | 5 | ||
| Operating current, upstream high-speed, 2 downstream full-speed | ICC | 55 | mA | TA=25℃, VDD33=3.3V; upstream high-speed, 2 downstream full-speed ports | 5 | ||
| Low-level input voltage | VIL | 0 | 0.8 | V | TA=25℃, VDD33=3.3V | 5 | |
| High-level input voltage | VIH | 2 | V | TA=25℃, VDD33=3.3V; printed upper limit is VDD33, no numeric value | 5 | ||
| Low-level output voltage | VOL | 0.4 | 0.6 | V | sink current 5mA, TA=25℃, VDD33=3.3V | 5 | |
| Pull-up equivalent resistance | RPU | 30 | 40 | 55 | kΩ | TA=25℃, VDD33=3.3V | 5 |
| Pull-down equivalent resistance | RPD | 30 | 40 | 55 | kΩ | TA=25℃, VDD33=3.3V | 5 |
| Power-supply low-voltage reset threshold | Vlvr | 2.4 | 2.9 | 3.2 | V | TA=25℃, VDD33=3.3V | 5 |
CAD (KiCad official)
- Symbol:
CH318T - Footprint:
Package_SO:TSSOP-20_4.4x6.5mm_P0.65mm - 3D model: TSSOP-20 (KiCad packages3D, STEP)
- 3D model files:
ch318t-etched.step/ch318t-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);ch318t.step/ch318t.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: WCH(南京沁恒) datasheet (9 pp, sha256
b2afb37bcc476658, retrieved 2026-10-18, tier: lcsc) - Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
- Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-haiku-5-5(text), consensusclaude-sonnet-5-5(agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish. - CAD: KiCad official libraries (CC-BY-SA 4.0).