The TUSB2046B is a 3.3-V CMOS hub device that provides one upstream port and four downstream ports in compliance with the Universal Serial Bus (USB) specification as a full-speed hub. Because this device is implemented with a digital state machine instead of a microcontroller, no firmware programming is required. Fully-compliant USB transceivers are integrated into the ASIC for all upstream and downstream ports. The downstream ports support both full-speed and low-speed devices by automatically setting the slew rate according to the speed of the device attached to the ports. The configuration of the BUSPWR terminal selects either the bus-powered or the self-powered mode.
Configuring the GANGED input determines the power switching and overcurrent detection modes for the downstream ports. External power-management devices, such as the TPS2044, are required to control the 5-V source to the downstream ports according to the corresponding values of the PWRON terminal. Upon detecting any overcurrent conditions, the power-management device sets the corresponding OVRCUR terminal of the TUSB2046B to a logic low. If GANGED is high, all PWRON outputs switch together and if any OVRCUR is activated, all ports transition to the power-off state. If GANGED is low, the PWRON outputs and OVRCUR inputs operate on a per-port basis.
The TUSB2046B provides the flexibility of using a 6-MHz or a 48-MHz clock. The logic level of the TSTMODE terminal controls the selection of the clock source. When TSTMODE is low, the output of the internal APLL circuitry is selected to drive the internal core of the device. When TSTMODE is high, the TSTPLL/48MCLK input is selected as the input clock source and the APLL circuitry is powered down and bypassed. The internal oscillator cell is also powered down while TSTMODE is high.
Low EMI emission is achieved because the TUSB2046B is able to utilize a 6-MHz crystal input. Connect the crystal as shown in . An internal PLL then generates the 48-MHz clock used to sample data from the upstream port and to synchronize the 12 MHz used for the USB clock. If low-power suspend and resume are desired, a passive crystal or resonator must be used. However, a 6-MHz oscillator may be used by connecting the output to the XTAL1 terminal and leaving the XTAL2 terminal open. The oscillator TTL output must not exceed 3.6 V.
For 48-MHz operation, the clock cannot be generated with a crystal using the XTAL2 output because the internal oscillator cell supports only the fundamental frequency.
See Figure 7 and Figure 8 in the input clock configuration section for more detailed information regarding the input clock configuration.
The EXTMEM terminal enables or disables the optional EEPROM interface. When the EXTMEM terminal is high, the product ID (PID) displayed during enumeration is the general-purpose USB hub. For this default, terminal 5 is disabled and terminal 6 functions as the GANGED input terminal. If custom PID and vendor ID (VID) descriptors are desired, the EXTMEM terminal must be low (EXTMEM = 0). For this configuration, terminals 5 and 6 function as the EEPROM interface with terminals 5 and 6 functioning as EECLK and EEDATA, respectively. See for a description of the EEPROM memory map.
Other useful features of the TUSB2046B include a package with a 0.8-mm terminal pitch for easy PCB routing and assembly, push-pull outputs for the PWRON terminals eliminate the need for pullup resistors required by traditional open-collector I/Os, and OVRCUR terminals have noise filtering for increased immunity to voltage spikes.
(1) JEDEC descriptor S-PQFP-G for low profile quad flat pack (LQFP).
|Supply Voltage(s) (V)|
|Operating Temperature Range (C)|
|Approx. Price (US$)|
|Integrated MCU Architecture|
|Automotive||TUSB2046B-Q1||Q100 devices qualified for high-reliability automotive applications targeting zero defects|
|Part #||Name||Product Family||Comments|
|TPS2041B||Single-Channel Current-Limited Power Distribution Switch||USB Power and Charging Port Controllers - Fixed Current Limited Switch||
TPS2041used for ganged-port power management provides overcurrent protection for the downstream ports. |
See Literature slls413i
|TPS2044B||Quad Current-Limited Power Distribution Switches||USB Power and Charging Port Controllers - Fixed Current Limited Switch||
The overcurrent protection can be provided by a TPS2044 quad device or a TPS2024 single power switch. It is recommended to use TPS2041B instead of TPS2024 and TPS2044B instead of TPS2044. |
See Literature slls413i Recommend keeping the outputs individually connected to all ports instead of ganged together
|TPS2505||Integrated Dual USB Power Switch with Boost Converter and LDO||USB Power and Charging Port Controllers - Switch with Boost Converter||Power Switch for downstream ports|
|TPS2500||Integrated USB Power Switch with Boost Converter||USB Power and Charging Port Controllers - Switch with Boost Converter||Power Switch for downstream ports|
|TPD4E001||Low-Capacitance 4-Channel +/-15-kV ESD Protection Array for High-Speed Data Interfaces||ESD Protection Diodes - High Performance TVS Diodes||Provides IEC61000-4-2 ESD Protection to the USB Interface for 2 downstream ports|
|TPD4S009||4-Channel ESD Solution for High-Speed Differential Interface||ESD Protection Diodes - High Performance TVS Diodes||Provides IEC61000-4-2 ESD Protection to the USB Interface for 2 downstream ports|
|TPD3E001||Low-Capacitance 3-Channel +/-15KV ESD-Protection Array for High-Speed Data Interfaces||ESD Protection Diodes - High Performance TVS Diodes||Provides IEC61000-4-2 ESD Protection to the USB Interface for single port|
|TPD2S017||2-Channel Ultra Low Clamp Voltage ESD Solution with Series-Resistor Isolation||ESD Protection Diodes - High Performance TVS Diodes||Provides IEC61000-4-2 ESD Protection to the USB Interface for single port|