Microchip Technology UCS1001-4-BP

Overview

UCS1001-4-BP from Microchip (formerly SMSC) is a USB port power controller with integrated charger emulation and wake-on-attach detection. It delivers up to 2.5 A continuous current via a 55 mΩ on-resistance power switch, supports BC1.2 CDP/DCP, Apple®, and YD/T-1591 charging protocols, and operates across –40 °C to +85 °C. It enables notebook and docking station systems to detect device attachment from sleep or off states and initiate wake-up or charging.

For engineers reviewing the UCS1001-4-BP datasheet, UCS1001-4-BP pinout, UCS1001-4-BP application, or UCS1001-4-BP equivalent, key selection criteria include its 20-pin QFN 4 mm × 4 mm package, attach-detection open-drain output (A_DET#), split-supply support for ultra-low sleep current, and compliance with IEC61000-4-2 (±8/±15 kV ESD).

Technical Context

The UCS1001-4-BP implements a dual-mode USB power switch with selectable trip or constant-current limiting, dynamic thermal management that throttles current near thermal regulation thresholds, and under/over-voltage lockout on VS (2.9 V–5.5 V range). Its internal charger emulator cycles nine preloaded profiles-including BC1.2 CDP, DCP, SDP, and legacy Apple/RIM signatures-to maximize peripheral compatibility without host intervention.

Unlike the UCS1001-3 variant, the UCS1001-4-BP features an A_DET# output instead of CHRG#, enabling system-level wake-on-attach functionality. It supports USB 2.0 high-speed data pass-through in CDP mode and includes back-drive/back-voltage protection, soft turn-on, and latch or auto-recovery fault handling with low-test-current capability.

Key Specifications

Pinout & Package

UCS1001-4-BP is housed in a RoHS-compliant 20-pin QFN package (4 mm × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are defined per Figure 2.2 and Table 2.1 of the official datasheet (Rev. 1.4, July 2013).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar USB port power control applications.

Compared with TUSB246IRHBR and TPS65987D, the UCS1001-4-BP uniquely combines wake-on-attach detection, nine-profile BC1.2/Apple/RIM emulation, and USB 2.0 HS data switching in a single 20-pin QFN-making it irreplaceable for legacy USB-A host systems requiring broad peripheral compatibility and low-power attach sensing.

Availability

UCS1001-4-BP is available at Aetrix Electronics and suitable for notebook computers, USB docking stations, and AC-DC wall adapters requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for UCS1001-4-BP 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

Microchip Technology acquired Standard Microsystems Corporation (SMSC) in 2012 and continues to support the UCS1001 family as part of its USB power and interface portfolio.

The UCS1001 product line was designed specifically for USB host systems needing intelligent port power control, legacy charging compatibility, and ultra-low-power attach detection-targeting mobile computing and peripheral docking applications.

FAQ

What is the primary function of the UCS1001-4-BP?

The UCS1001-4-BP is a USB port power controller with integrated charger emulation and wake-on-attach detection. Its core function is to manage VBUS power delivery up to 2.5 A, enforce over-current and thermal protection, emulate multiple charging protocols (BC1.2, Apple®, RIM), and assert the A_DET# signal upon device insertion-enabling host systems to wake from sleep states. The UCS1001-4-BP does not require host CPU intervention to initiate charging or detection.

How does the UCS1001-4-BP differ from the UCS1001-3-BP?

The UCS1001-4-BP features an A_DET# (attach detection) open-drain output, while the UCS1001-3-BP provides CHRG# (charging active) indication. This makes the UCS1001-4-BP suitable for systems requiring wake-on-attach functionality from S3/S4/S5 states, whereas the UCS1001-3-BP targets applications where charging status monitoring is prioritized. Both share identical power switching, emulation, and package specifications.

Does the UCS1001-4-BP support USB 2.0 high-speed data switching?

Yes, the UCS1001-4-BP integrates a USB 2.0-compliant high-speed analog data switch. It supports pass-through mode and BC1.2 CDP mode with full 480 Mbps signaling integrity, verified via USB-IF eye diagram compliance. The switch is enabled automatically during CDP operation and disabled in DCP or legacy emulation modes to prevent data corruption.

What are the key thermal management features of the UCS1001-4-BP?

The UCS1001-4-BP implements dynamic thermal management by continuously monitoring die temperature and reducing current limit in real time as the junction approaches regulation threshold (~125 °C). This prevents abrupt thermal shutdown during sustained 2.5 A loads and allows graceful current derating-maintaining system uptime while protecting the IC and PCB layout.

Can the UCS1001-4-BP operate with separate VS and VDD supplies?

Yes, the UCS1001-4-BP supports split-supply operation: VS powers the high-side power switch, while VDD supplies the digital core and data switch. This enables ultra-low sleep current (<10 µA in Detect State) by keeping VDD active while VS is removed-ideal for battery-powered notebook systems needing wake-on-attach without draining standby power.