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Contents

README

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CH450H

WCH Jiangsu Qin Heng · Digital Tube Drivers · SOP-20-300mil

CH450H from WCH Jiangsu Qin Heng, in a SOP-20-300mil. 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 DIG3 output Digit-3 cathode drive output for 7-segment display, active-low; doubles as keyboard column-scan output active-high; VOL ≤0.8 V at 80 mA sink, max continuous per-pin current 120 mA.
2 DIG4 output Digit-4 cathode drive output for 7-segment display, active-low; doubles as keyboard column-scan output active-high; VOL ≤0.8 V at 80 mA sink, VOH ≥4.5 V at 8 mA.
3 SCL input 2-wire serial clock input; internal pull-up 100-300 µA; data sampled on rising edge; VIL ≤0.8 V, VIH ≥2.0 V; clock rate 0-2 MHz.
4 SDA bidirectional 2-wire serial data input and open-drain output; internal pull-up 250-400 µA; MSB first; VIL ≤0.8 V, VIH ≥2.0 V; output valid within 30 ns of SCL falling edge.
5 GND power_in Common ground reference; continuous current rating not less than 100 mA; decouple with ≥0.1 µF ceramic and ≥100 µF electrolytic capacitor near VCC-GND pins.
6 DIG5 output Digit-5 cathode drive output for 7-segment display, active-low; doubles as keyboard column-scan output active-high; VOL ≤0.8 V at 80 mA sink.
7 DIG6 output Digit-6 cathode drive output for 7-segment display, active-low; doubles as keyboard column-scan output active-high; VOL ≤0.8 V at 80 mA sink.
8 DIG7 output Digit-7 cathode drive output for 7-segment display, active-low; doubles as keyboard column-scan output active-high; VOL ≤0.8 V at 80 mA sink.
9 RSTH output Power-on reset output, active-high; threshold voltage 2.3-2.9 V; reset pulse duration 6-50 ms; VOH ≥4.5 V at 4 mA, VOL ≤0.5 V at 4 mA.
10 SEG0 tri_state Segment-A drive, tri-state output active-high (min 15 mA source, VOH ≥4.5 V at 15 mA, VOL ≤0.5 V at 18 mA); keyboard row-scan input active-high with internal pull-down −50 µA; VILseg ≤0.5 V, VIHseg ≥1.8 V.
11 SEG1 tri_state Segment-B drive, tri-state output active-high (VOH ≥4.5 V at 15 mA, VOL ≤0.5 V at 18 mA); keyboard row-scan input active-high with internal pull-down −50 µA.
12 VCC power_in Positive supply voltage 3.0-5.5 V; continuous current not less than 100 mA; max 6.0 V absolute; decouple with ≥0.1 µF ceramic and ≥100 µF electrolytic near pin.
13 SEG2 tri_state Segment-C drive, tri-state output active-high (VOH ≥4.5 V at 15 mA, VOL ≤0.5 V at 18 mA); keyboard row-scan input active-high with internal pull-down −50 µA.
14 SEG3 tri_state Segment-D drive, tri-state output active-high (VOH ≥4.5 V at 15 mA, VOL ≤0.5 V at 18 mA); keyboard row-scan input active-high with internal pull-down −50 µA; can wake CH450 from sleep when active.
15 SEG4 tri_state Segment-E drive, tri-state output active-high (VOH ≥4.5 V at 15 mA, VOL ≤0.5 V at 18 mA); keyboard row-scan input active-high with internal pull-down −50 µA.
16 SEG5 tri_state Segment-F drive, tri-state output active-high (VOH ≥4.5 V at 15 mA, VOL ≤0.5 V at 18 mA); keyboard row-scan input active-high with internal pull-down −50 µA.
17 SEG6 tri_state Segment-G drive, tri-state output active-high (VOH ≥4.5 V at 15 mA, VOL ≤0.5 V at 18 mA); keyboard row-scan input active-high with internal pull-down −50 µA.
18 SEG7 tri_state Decimal-point segment drive, tri-state output active-high; keyboard row-scan input active-high with internal pull-down −50 µA; max continuous per-pin segment current 25 mA, total all-SEG current 130 mA.
19 INT# tri_state Keyboard interrupt output, active-low, open-drain with internal pull-up 500-5000 µA; asserted when valid keypress detected; deasserted automatically after MCU reads keycode via SDA.
20 DIG2 output Digit-2 cathode drive output for 7-segment display, active-low; doubles as keyboard column-scan output active-high; VOL ≤0.8 V at 80 mA sink, max continuous per-pin current 120 mA.

Key specifications

Parameter Value
Manufacturer WCH Jiangsu Qin Heng
Package SOP-20-300mil
Category LED Drivers
Pins 20

CAD (KiCad official)

  • Symbol: CH450H
  • Footprint: Package_SO:SOP-20_7.5x12.8mm_P1.27mm
  • 3D model: SOP-20-300mil, generated from the KiCad footprint (body from the F.Fab outline, terminals on the pads, 2.65 mm nominal SOIC height). Neither the vendor nor KiCad ships a 3D model for this package, so the dimensions are nominal, not the manufacturer's CAD (STEP)
  • 3D model files: ch450h-etched.step / ch450h-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); ch450h.step / ch450h.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: WCH Jiangsu Qin Heng datasheet (9 pp, sha256 eab0a68adccc158e, retrieved 2026-10-01, 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 0.2, primary claude-haiku-4-5-20251001 (text), consensus claude-sonnet-4-6 (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).

Datasheet PDF