HT1621B vs CS1621: 32×4 segment LCD driver alternative
CS1621 from I-CORE is a functional equivalent of the Holtek HT1621B: 32 × 4 RAM-mapped LCD driver with serial interface, 1/2 or 1/3 bias, buzzer output and WDT, 2.4–5.5 V.
Holtek's HT1621B is the default 32 × 4 segment LCD driver in meters, thermostats and appliance displays. I-CORE's CS1621 implements the same function and command set and is stocked in several packages.
Side-by-side comparison
| Parameter | HT1621B | CS1621CGO (I-CORE) |
|---|---|---|
| Display | 32 SEG × 4 COM (128 dots) | 32 SEG × 4 COM (128 dots) |
| Bias / duty | 1/2 or 1/3 bias; 1/2, 1/3, 1/4 duty | 1/2 or 1/3 bias; 1/2, 1/3, 1/4 duty |
| Clock | 256 kHz RC, or 32 kHz crystal / external | Internal 256 kHz RC, or external 32 kHz crystal / 256 kHz input |
| Interface | Serial (CS, WR, RD, DATA) | Serial (CS, WR, RD, DATA) |
| Extras | Buzzer output, time base / WDT | Buzzer output, time base / WDT, built-in bias resistor, VLCD pin |
| Supply voltage | 2.4–5.2 V | 2.4–5.5 V |
| Operating temperature | −40 to +85 °C | −40 to +85 °C |
| Packages we stock | — | SSOP-48, QFP-44, SSOP-24, SOP-24 |
Can CS1621 replace HT1621B?
Functionally yes: display RAM layout, bias/duty options, clock options and the serial command interface follow the HT1621 architecture. Pin assignments depend on the package, so compare the pin table for your package (for example SSOP-48 or LQFP/QFP-44) before reusing a layout.
Firmware
HT1621 drivers are the usual starting point. Confirm command codes (SYS EN, LCD ON, BIAS, TONE, WDT) in the CS1621 datasheet.
FAQ
- Does CS1621 work with HT1621 code?
- It uses the same RAM-mapped 32 × 4 architecture and serial command structure, so HT1621 drivers are the usual starting point. Verify command codes in the CS1621 datasheet.
- What supply range does CS1621 support?
- 2.4–5.5 V per the CS1621 datasheet (2024-12-B1).
Sources
- I-CORE CS1621 English datasheet, revision 2024-12-B1
- Holtek HT1621B listing on LCSC (C7532): 2.4–5.2 V, 256 kHz, 32 × 4, −40 to +85 °C
Figures are from the documents listed; always confirm against the latest datasheets before design-in. HT1621B is a part number of its respective owner and is shown for cross-reference only.