Microchip Technology AT43USB380E-AC

Overview

AT43USB380E-AC from Microchip Technology (formerly Atmel) is a USB 2.0 Full-Speed Host/Function Processor with integrated On-The-Go (OTG) interface, supporting Host Negotiation Protocol (HNP) and Session Request Protocol (SRP). It operates as a single-chip USB controller in host or peripheral mode, requires an external charge pump (e.g., AT43CD001) for OTG session negotiation and VBUS control, and delivers up to 16 GPIOs via multiplexed data bus pins. Used in portable embedded systems requiring dual-role USB connectivity.

For engineers reviewing the AT43USB380E-AC datasheet, AT43USB380E-AC pinout, AT43USB380E-AC application, or AT43USB380E-AC equivalent, key selection considerations include OTG interface signal mapping (ID, SESS_VLD, DISCHARGE), configurable 8/16/32-bit host processor interface width, firmware API compatibility with AT43USB370, and external charge pump integration requirements.

Technical Context

The AT43USB380E-AC implements a hardware-accelerated USB 2.0 Full-Speed (12 Mbps) transceiver with on-die OTG logic that manages role swapping via ID pin detection and session validity monitoring using SESS_VLD, SESS_END, SESS_HIGH, and SESS_LOW inputs. Its internal OTG block handles HNP/SRP state machines without host processor intervention.

It features a programmable host interface width (8/16/32-bit) controlled by BWIDTH[1:0], eliminating dedicated handshaking signals (PROG, SEL, READY, DONE, MORE, INTR_IN) used in AT43USB370; register access is direct via D[15:0]/D[31:16] and CS_N/OE_N/WE_N, with WAIT_N retained only for SYS_CLK synchronization.

Key Specifications

Pinout & Package

AT43USB380E-AC is housed in a 100-pin TQFP package (14 mm × 14 mm, 0.5 mm pitch) with exposed thermal pad. Power distribution includes 5× VDD (3.3 V), 10× VSS (GND), and 3× VDD18 (1.8 V supply output).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar USB OTG host/function processor applications.

Compared with AT43USB370 and ISP1301, the AT43USB380E-AC uniquely integrates OTG logic, configurable host bus, and direct register access in a single chip - reducing system-level complexity, eliminating external glue logic, and accelerating time-to-market for dual-role USB embedded products.

Availability

AT43USB380E-AC is available at Aetrix Electronics and suitable for portable medical devices, industrial handheld terminals, smartphone docking stations, and USB OTG camera modules requiring stable component supply across multi-year production cycles.

Supply support for AT43USB380E-AC 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 Atmel in 2016 and maintains full support for legacy Atmel USB products including the AT43USB380E-AC.

The AT43USB380E-AC belongs to Atmel's USB OTG Processor product line, designed specifically for cost-sensitive, space-constrained embedded systems requiring seamless USB host/peripheral role switching without external protocol processors.

FAQ

What is the primary function of the AT43USB380E-AC in a USB OTG system?

The AT43USB380E-AC serves as a single-chip USB 2.0 Full-Speed Host/Function Processor with integrated OTG interface logic. It enables dynamic role switching between host and peripheral modes using hardware-managed ID pin detection and session monitoring signals (SESS_VLD, SESS_END, etc.). The AT43USB380E-AC offloads HNP and SRP protocol handling from the main system processor, allowing real-time USB connectivity in portable embedded applications without requiring a full USB stack on the host MCU.

Does the AT43USB380E-AC require an external charge pump, and why?

Yes, the AT43USB380E-AC requires an external charge pump such as the AT43CD001 to implement USB OTG functionality. The AT43USB380E-AC itself does not generate VBUS voltage; instead, it controls the charge pump via DISCHARGE, PUMP_EN, EN, and LOW_CUR signals to source VBUS during host mode and discharge it during peripheral mode. This separation allows flexible power management and compliance with OTG electrical specifications for session negotiation and current limiting.

How does the host processor interface of the AT43USB380E-AC differ from that of the AT43USB370?

The AT43USB380E-AC replaces the fixed 32-bit host interface of the AT43USB370 with a configurable 8/16/32-bit parallel bus controlled by BWIDTH[1:0]. It eliminates six handshaking signals (PROG, SEL, READY, DONE, MORE, INTR_IN) used in AT43USB370, enabling direct register access via CS_N, OE_N, and WE_N. The AT43USB380E-AC also repurposes D[31:16] as up to 16 GPIOs in narrower bus modes - a capability absent in AT43USB370.

Can firmware developed for the AT43USB370 be reused with the AT43USB380E-AC?

Yes, firmware for the AT43USB370 is largely reusable with the AT43USB380E-AC. Both share identical high-level ANSI C APIs, low-level driver libraries, and debugging tools. The AT43USB380E-AC adds fewer than 10 OTG-specific APIs for session control and role negotiation. Existing AT43USB370 code runs unchanged in non-OTG configurations; only OTG-enabled features require minor integration of new API calls - significantly reducing migration effort.

What package type and pin count does the AT43USB380E-AC use?

The AT43USB380E-AC is packaged in a 100-pin Thin Quad Flat Package (TQFP) with 0.5 mm pitch and dimensions of 14 mm × 14 mm, including an exposed thermal pad. It features 5 VDD (3.3 V), 10 VSS (ground), and 3 VDD18 (1.8 V output) pins distributed across the perimeter to ensure stable power delivery and thermal performance in compact portable designs.