SLUSCX8C March 2019 – March 2021 TPS92682-Q1
PRODUCTION DATA
The TPS92682-Q1 device is an automotive-grade two-channel controller with Serial Peripheral Interface (SPI) interface, ideally suited for exterior lighting applications. The device is optimized to achieve high-performance solutions and features all of the functions necessary to implement LED drivers based on step-up or step-down power converter topologies with a small form-factor at a lower cost.
The two channels of the TPS92682-Q1 device can be configured independently as CC (constant current) or CV (constant voltage) mode. The device implements fixed-frequency peak current mode control to achieve regulation and fast dynamic response. Each channel can be configured as boost, boost-to-battery, SEPIC, or other converter topologies.
In CC mode, the integrated low offset and rail-to-rail current sense amplifier provide the flexibility required to power a single string consisting of 1 to 20 series connected LEDs while maintaining 4% current accuracy over the operating temperature range. The LED current regulation threshold is set by the analog adjust input CHxIADJ register over 28:1 dimming range. The TPS92682-Q1 incorporates an internal 10-bit counter for the PWM dimming function for each channel. The PWM width and frequency are programmable through the SPI registers. Alternatively, the device can also be configured to implement direct PWM dimming based on the duty cycle of the external PWM signal connected to PWM1 or PWM2 pins for channel-1 or channel-2, respectively. The internal PWM signals control the GATEx and PDRVx outputs, which control the external N-channel switching FETs and P-channel dimming FETs connected in series with LED strings.
The TPS92682-Q1 can be configured in CV mode. In this mode, the device regulates the voltage connected to the FBx/OVx pins to an internal programmable reference voltage, set by the CHxIADJ register. In CV mode, the TPS92682-Q1 can be used as the first stage of a two-stage LED driver in an ECU (electronic control unit) of an exterior lighting application. The device can also be configured to operate in two-phase mode, where the switching frequencies of the two channels are phase-shifted by 180° and the channel-1 compensation loop, including COMP1 and the FB1/OV1, is shared between the two channels.
The TPS92682-Q1 incorporates an enhanced programmable fault feature. A selected number of faults, including ILIMIT (cycle-by-cycle current limit), OV (output Overvoltage), UV (output Undervoltage), and OC (LED Overcurrent), can be programmed to be latched faults, or automatically re-start the channel when the fault is cleared and after a programmed timer is expired. In addition, the TPS92682-Q1 includes open-pin faults for the FBx, ISNx, and RT pins. Other fault and diagnostic features include Thermal Shutdown (TSD), Thermal Warning (TW), LED Undercurrent (UC), and POR. Each channel includes an active-low fault pin ( FLT) that is pulled low when a fault occurs. For each fault, there is an associated fault read-bit in the register map that can be read through SPI communication interface. For a complete list of the fault and diagnostic features, refer to the Faults and Diagnostics section.
The TPS92682-Q1 includes a limp home (LH) function that is initiated when the LH pin is set high. In LH mode, the operation of the device is set by the LH registers. The LH registers are programmed upon initialization of the device. To exit the LH mode, the LH pin must be set low and the LH bit in the CFG1 register must be written to “0”.
The TPS92682-Q1 device has numerous enhanced programmable features that can be accessed through the 4-wire SPI bus. The SPI bus consists of four signals: SSN, SCK, MOSI, and MISO. The SSN, SCK, and MOSI pins are TTL inputs into the device.