Silicon Labs CP2400-C-GDI

Overview

CP2400-C-GDI from Silicon Laboratories is a fixed-function 128-segment LCD driver with integrated GPIO expander (36 pins), real-time clock (SmaRTClock), 256-byte SRAM, and dual 16-bit timers. It operates from 1.8–3.6 V, supports 4-mux LCDs, features on-chip bias generation via internal charge pump, and delivers ultra-low power LCD mode current of 2.3 µA (typical) at 3.0 V. It is used in utility meters and thermostat displays requiring integrated timing and segment control.

For engineers reviewing the CP2400-C-GDI datasheet, CP2400-C-GDI pinout, CP2400-C-GDI application, or CP2400-C-GDI equivalent, key selection considerations include its SPI interface (4-wire, up to 2.5 Mbps), 48-pin QFN package (7×7 mm), 5 V-tolerant I/O, port match wake-up capability, and support for static/2-/3-/4-mux LCD configurations without external bias components.

Technical Context

The CP2400-C-GDI integrates three core subsystems: an LCD controller with programmable mux decoding and internal charge pump for bias voltage generation; a configurable GPIO expander with push-pull/open-drain outputs and two drive strength levels per pin; and a SmaRTClock RTC with crystal, self-oscillate, or external CMOS clock input modes and 36-hour alarm timer.

It uses a 20 MHz internal oscillator (±5 MHz min/max over temperature) as primary system clock source, supports synchronous SPI communication with external clock or internal clock operation, and implements five distinct power modes - Normal, RAM Preservation, Ultra Low Power LCD, Ultra Low Power SmaRTClock, and Shutdown - with shutdown current of 0.02 µA (typical at 3.0 V).

Key Specifications

Pinout & Package

Pb-free 48-pin QFN package (7×7 mm footprint, 0.5 mm pitch), thermally enhanced with exposed pad. Pin count and function mapping align with CP2400-GM/GQ variants; CP2400-C-GDI shares identical pinout and electrical behavior.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LCD driver with RTC and GPIO expansion applications.

Compared with CP2400-GQ and CP2402-GM, CP2400-C-GDI provides identical electrical performance and feature set in the smallest 48-pin QFN package, enabling highest-density layouts while maintaining full compatibility with CP2400 family firmware and register maps.

Availability

CP2400-C-GDI is available at Aetrix Electronics and suitable for utility meters, thermostat displays, and home security systems requiring stable component supply, long-term lifecycle support, and industrial-grade temperature operation.

Supply support for CP2400-C-GDI includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Silicon Laboratories is a fabless semiconductor company specializing in mixed-signal ICs for timing, wireless, MCU, and sensor applications.

The CP2400 family was designed to integrate LCD driving, real-time clock, GPIO expansion, and memory into a single chip for battery-powered industrial human-interface devices - reducing system cost and complexity.

FAQ

What interface does the CP2400-C-GDI support?

The CP2400-C-GDI supports only the 4-wire SPI interface (NSS, SCK, MOSI, MISO) with maximum data rates of 2.5 Mbps using an external clock or 1 Mbps using the internal clock. It does not support I²C or SMBus - those interfaces are exclusive to CP2401/CP2403 variants. This makes CP2400-C-GDI ideal for systems already using SPI peripherals and needing deterministic timing control.

Does CP2400-C-GDI require an external crystal for RTC operation?

No, CP2400-C-GDI does not require an external crystal for RTC operation. It supports three SmaRTClock modes: external 32.768 kHz crystal, external 32 kHz CMOS clock input on XTAL1/XTAL2, or self-oscillate mode with no external components. In self-oscillate mode, it achieves ~14 kHz frequency with AGC enabled and consumes only 2.0 µA - useful when absolute time accuracy is secondary to ultra-low power.

How many GPIO pins does CP2400-C-GDI provide in its 48-pin package?

The CP2400-C-GDI provides 36 GPIO pins in its 48-pin QFN package: P0.0–P0.7 (8), P1.0–P1.7 (8), P2.0–P2.7 (8), P3.0–P3.7 (8), and P4.0–P4.3 (4). All are software-configurable as push-pull or open-drain outputs with two drive strength levels, or as digital inputs with internal pullups - enabling flexible peripheral interfacing without external logic.

What LCD multiplexing schemes does CP2400-C-GDI support?

The CP2400-C-GDI supports static, 2-mux, 3-mux, and 4-mux LCD configurations. Its internal mux decode logic and charge pump automatically adapt bias voltage and timing to the selected scheme. In 4-mux mode, it drives up to 128 segments using 32 common lines (COM0–COM3) and 32 segment lines - making it suitable for high-information displays like multi-digit utility meters.

Is CP2400-C-GDI pin-compatible with other CP2400 variants?

Yes, CP2400-C-GDI is pin-compatible with CP2400-GM and CP2400-GQ in the 48-pin package configuration - sharing identical pin numbering, function mapping, and electrical characteristics. Differences are limited to packaging (QFN vs QFP) and ordering suffixes; firmware, layout, and schematic design can be reused across all CP2400-SPI variants without modification.