CP2120-GM

Overview

The CP2120-GM is a single-chip SPI to I2C bridge controller and GPIO port expander manufactured by Silicon Labs. It integrates an SPI interface supporting transfers up to 1.0 Mbit/s, an I2C master interface operating at configurable rates up to 400 kHz, and eight general-purpose input/output pins. The device includes 256 bytes of data buffers (255 RX/TX), an internal oscillator, and an on-chip voltage monitor. It operates within a supply voltage range of 3.0 V to 3.6 V with a typical current consumption of 3.8 mA to 4.1 mA. The component is housed in a Pb-free 20-pin QFN package measuring 4 mm x 4 mm.

Feature Summary

• Integrates a slave SPI interface for communication with a host controller and an I2C master interface for connecting to peripheral devices.
• Provides eight configurable general-purpose I/O pins that support push-pull or open-drain configurations.
• Includes an edge-triggered interrupt source pin and an active low interrupt indicator pin for event signaling.
• Features an internal oscillator eliminating the need for external clock components and an on-chip voltage monitor.

Applications

• SPI to I2C protocol bridging in embedded systems
• GPIO expansion for microcontrollers via I2C peripherals
• Edge-triggered interrupt handling in industrial control interfaces

Procurement Notes

Verify component authenticity through official Silicon Labs channels or authorized distributors. Confirm the specific GM suffix corresponds to the 20-pin QFN package variant. Ensure compliance with RoHS directives as indicated in manufacturer documentation. Validate revision numbers against the latest datasheet specifications before integration into production designs.

Selection Notes

Select this component when an SPI host requires access to I2C buses without firmware complexity. Consider the 400 kHz I2C speed limit and 1.0 Mbit/s SPI throughput for bandwidth requirements. Evaluate the 3.0 V to 3.6 V supply voltage constraints against system power rails. Note that the device is marked as not recommended for new designs; assess alternative successors if long-term availability is critical.

Part Context

The CP2120 belongs to Silicon Labs' family of highly integrated bridge controllers designed to simplify interface conversions. It serves as a hardware solution for migrating legacy I2C-based designs to SPI-controlled architectures. The device reduces PCB space and component count by integrating necessary oscillators and buffers on a single chip.

Replacement Considerations

Public documentation explicitly marks the CP2120 as 'Not Recommended for New Designs.' Verify current lifecycle status and potential obsolescence. Consult Silicon Labs for officially confirmed substitute part numbers suitable for new product implementations.