STMicroelectronics STCC2540IQTR

Overview

STCC2540 from STMicroelectronics is a USB charging controller IC integrating a BC1.2-compliant charger emulator, wide-bandwidth USB 2.0 data switch (1100 MHz), and low-R_ON (65 mΩ typ.) N-channel power switch in a single VFQFPN-16 package. It supports DCP/CDP/SDP modes, proprietary Apple/BlackBerry/Korean tablet charging, and delivers up to 2.8 A adjustable current limit with soft-start, overcurrent, thermal, reverse voltage/current, and undervoltage protection. Used in notebook USB ports for high-current charging during S3/S4/S5 states.

For engineers reviewing the STCC2540 datasheet, STCC2540 pinout, STCC2540 application, or STCC2540 equivalent, key selection criteria include BC1.2 mode flexibility, integrated data switch bandwidth, VBUS discharge timing (350 ms typ.), CHARGING flag behavior (20 mA threshold), and FAULT deglitching (7–12 ms delay).

Technical Context

The STCC2540 implements a state-machine-driven charger emulator supporting BC1.2 CDP/SDP/DCP, YD/T 1591-2009, and proprietary divider modes via three logic-controlled CTL pins. Emulation includes D+–D− shorting (DCP), 2.7 V/2.0 V divider outputs (Apple), and dynamic mode transitions - e.g., auto-switch from CDP to DCP auto-detect upon device detachment with 10 s timeout.

Its integrated 1100 MHz USB 2.0 data switch maintains signal integrity with ≤4 Ω R_ON, <47 dB crosstalk, and >17 dB isolation at 250 MHz, while the power switch features constant-current limiting (500 mA–2.8 A via ILIM resistor), 0.8 ms turn-on, and 0.3 ms turn-off delays under 1 µF/100 Ω load.

Key Specifications

Pinout & Package

Package: VFQFPN-16 (3 mm × 3 mm × 0.8 mm) with exposed thermal pad for PCB-level heat dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar USB charging controller applications.

Compared with TPS65987D and FUSB302B, the STCC2540 uniquely integrates BC1.2 emulation, USB 2.0 data switching, and 2.8 A power switching in one VFQFPN-16 package - eliminating external components required by both alternatives for Type-A USB charging applications.

Availability

STCC2540 is available at Aetrix Electronics and suitable for notebook USB ports, all-in-one PC hubs, and universal wall charging adapters requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for STCC2540 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, delivering automotive, industrial, and consumer ICs with emphasis on power efficiency, integration, and system-level reliability.

The STCC2540 belongs to ST's USB Power Delivery and Charging portfolio, designed specifically to simplify high-current USB charging implementation in space-constrained computing and peripheral platforms without sacrificing BC1.2 or regional standard compliance.

FAQ

What is the purpose of the ILIM pin and how is current limit set?

The ILIM pin accepts an external resistor to program the power switch's current limit from 500 mA to 2.8 A. Using R_ILIM = 17.2 kΩ sets 2.8 A (typ.), while 96 kΩ sets 500 mA (typ.). The relationship is linear and specified in Table 4 of the datasheet, with ±20% tolerance across temperature. No calibration or trimming is required.

How does the CHARGING output behave in CDP vs. DCP mode?

In CDP mode, CHARGING asserts only after successful CDP handshaking *and* output current exceeds 20 mA. In DCP mode, it asserts immediately upon current exceeding 20 mA. Both deassert after current falls below threshold for 5 seconds (tCHG_DGL_OFF), enabling host-controlled DC-DC shutdown to save battery power in S4/S5 states.

Can the STCC2540 support remote wakeup from S3 without VBUS discharge?

Yes - when CTL pins transition from 111 (CDP S0) to 011 (CDP S3) or 110 (SDP S0) to 010 (SDP S3), the device skips VBUS discharge and keeps the data switch active. This preserves USB resume signaling for low-speed devices. Full-speed/high-speed devices trigger automatic DCP auto mode instead, which does require discharge.

What protection features are implemented and how are faults reported?

The STCC2540 integrates overcurrent (constant-current limiting), thermal shutdown (140°C trip), reverse current/voltage blocking, and undervoltage lockout (4.1 V typical). All faults drive the open-drain FAULT pin low with 7–12 ms deglitching. The FAULT pin combines overcurrent, thermal, and reverse events - individual fault sources require external monitoring of current, temperature, and VOUT–VIN differential.