SLLSF36A August 2017 – September 2017 TUSB214-Q1
The TUSB214-Q1 is a USB High-Speed (HS) signal conditioner, designed to compensate for ISI signal loss in a transmission channel. TUSB214-Q1 has a patent-pending design which is agnostic to USB Low Speed (LS) and Full Speed (FS) signals and does not alter their signal characteristics, while HS signals are compensated. In addition, the design is compatible with USB On-The-Go (OTG) and Battery Charging (BC) specifications. The TUSB214-Q1 includes a USB BC Charging Downstream Port (CDP) controller.
Programmable signal gain through an external resistor permits fine tuning device performance to optimize signals helping to pass USB HS electrical compliance tests at the connector. Additional DC boost configurable by three level input DC_BOOST helps overcoming the cable losses.
The footprint of TUSB214-Q1 allows a board layout using this device such that it does not break the continuity of the DP/DM signal traces. This permits risk free system design of a complete USB channel with flexible use of one or multiple TUSB214-Q1 devices as needed for optimal signal integrity. This allows system designers to plan for this device and use it only if signal integrity analysis and/or lab measurements sow a need. If such a need is not warranted, the device can be left unpopulated without any board rework.
The EQ pin of the TUSB214-Q1 is used to configure the AC boost of the device. The four levels are set through different values of an external pulldown resistor at this pin.
The DC_BOOST pin of the TUSB214-Q1 is a tri-level pin, used to set the DC gain of the device according to Table 1.
|DC BOOST SETTING VIA PIN STRAP|
|DC_BOOST||DC Boost Setting (mV)|
The TUSB214-Q1 main function is a signal conditioner offering the AC/DC Boost features to the incoming DP/DM signals. For applications in which USB host or hub does not provide USB BC charging downstream port (CDP) functionality, the TUSB214-Q1 can perform this task.
TUSB214-Q1 automatically detects a LS connection and does not enable signal compensation. CD pin is asserted high.
TUSB214-Q1 automatically detects a FS connection and does not enable signal compensation. CD pin is asserted high.
TUSB214-Q1 automatically detects a HS connection and will enable signal compensation as determined by the configuration of the DC_BOOST pin and the external pulldown resistance on its EQ pin. CD pin is asserted high.
TUSB214-Q1 is disabled when its RSTN pin is asserted low. In shutdown mode the USB channel is still fully operational, but there is neither signal compensation nor any indication from the CD pin as to the status of the channel.
TUSB214-Q1 supports 100 kHz I2C for device configuration, status readback and test purposes. This controller is enabled after SCL and SDA pins are sampled high shortly after de-assertion of RSTN. In this mode, the register as described in Table 2 can be accessed by I2C read/write transaction to 7-bit slave address 0x2C. It is necessary to set CFG_ACTIVE bit and reset it to zero after making changes to the EQ and DC Boost level registers to restart the state machine.
All registers or fields in Table 2 which are not specifically mentioned are considered reserved. The default value of these reserved registers or fields must not be changed. It is suggested to perform a read-modify-write operation to maintain the default value of the reserved fields.
|0x01||6:4||ACB_LVL||RW||XXX (Sampled from EQ pin at reset)||
Sets the level of AC Boost
000 : Level 0 AC Boost programmed [MIN]
001 : Level 1 AC Boost programmed
011 : Level 2 AC Boost programmed
111 : Level 3 AC Boost programmed [MAX]
0 : Normal mode. State machine enabled.
1 : Configuration mode: State machine disabled.
After reset, if I2C mode is true (SCL and SDA are both pulled high) it is maintained until it is cleared by an I2C write, but, if I2C mode is not true, it is cleared automatically.
|0x0E||2:0||DCB_LVL||RW||XXX (Sampled from DC_BOOST pin at reset)||
Sets the level of DC Boost
011 : 40mV (DC_Boost = L)
101 : 60mV (DC_Boost = M, default)
111 : 80mV (DC_Boost = H)