Microchip's USB251xB is a family of versatile, cost-effective, and power-efficient USB 2.0 hub controllers. Leveraging Microchip's innovative MultiTRAK™ technology that delivers industry-leading data throughput in mixed-speed USB environments, the USB251xB family is a USB port expansion solution for applications that demand ultra low power and a small footprint without compromising on performance.
Well-suited for consumer and mobile applications, all members of the USB251xB family are available in a space-saving package. The common 36-pin package shared among the 2/3/4 port hub controllers measures only 6x6 mm and provides an ultra small footprint for space-constrained designs while allowing scalable port expansion from two to four ports.
Over 30 programmable features including Microchip's unique PortMap, PortSwap, and PHYBoost are designed to aid system designers in simplifying PCB layout and optimizing bill-of-material cost. Every downstream port of the USB251xB hubs can be enabled to support USB Battery Charging 1.1 specification as a Charging Downstream Port (CDP). A CDP provides universal battery charging capability to a compliant mobile phone or portable electronic device using a standard USB port.
The USB251xB supports an extended operating temperature range of 0° to 85°C. The USB251xBi is designed to meet -40° to 85°C industrial temperature requirements. Note that the "M2" products are the preferred device for new designs. The M2 products offer the newest production flow with the advantage of increased efficiencies and capacity. No product revisions of the USB251xB family are near the end of the product cycle, and all remain in full production.
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Feature
Highlights
High performance, ultra low-power, small footprint hub controller IC with 2, 3, or 4 downstream ports (indicated by the “x” in the part number)
Fully compliant with the USB 2.0 specification
Enhanced OEM configuration options available through either a single serial I2C® EEPROM, or SMBus slave port
MultiTRAK - High-performance multiple transaction translator which provides one transaction translator per port
PortMap - Flexible port mapping and disable sequencing
PortSwap - Programmable USB differential-pair pin locations ease PCB design by aligning USB signal lines directly to connectors
PHYBoost - Programmable USB signal drive strength for recovering signal integrity using 4-level driving strength resolution
Features
USB251xB/xBi products are fully footprint compatible with USB251x/xi/xA/xAi products as direct drop-in replacements
Full power management with individual or ganged power control of each downstream port
Fully integrated USB termination and pull-up/pulldown resistors
Supports a single external 3.3 V supply source; internal regulators provide 1.2 V internal core voltage
Onboard 24 MHz crystal driver, ceramic resonator, or external 24/48 MHz clock input
Customizable vendor ID, product ID, and device ID
4 kilovolts of HBM JESD22-A114F ESD protection (powered and unpowered)
Supports self- or bus-powered operation
Support the USB Battery Charging specification Rev. 1.1 for Charging Downstream Ports (CDP)
36-pin QFN (6x6 mm) RoHS compliant package
USB251xBi products support the industrial temperature range of -40°C to +85°C
USB251xB products support the extended commercial temperature range of 0°C to +85°C
Target Applications
Mobile PC Docking Stations
LCD Monitors/TVs
PC Motherboards
Gaming Consoles
Multi-Function Printers
Cable/DSL Modems
Set-Top Boxes
DVD/CD-ROM/DVR
HDD Enclosures
Keyboards
KVM Switches
Server Front Panels
Point-of-Sale (POS) Systems
IP Telephony
Automobile/Home Audio Systems
Industrial
Catalogue
FPGA / CPLD
Memory
MOS 
MCU 
DSP
OCEP
Secondary 
Other 
