Automotive Grade DC-DCs and Voltage Detectors

Torex Semiconductor Ltd. has launched its first AEC-Q100 qualified XD products (two dc-dc converters and one voltage detector) for automotive applications. Torex opened a new Technology Center in the Kansai area of Japan in May this year to develop products for the automotive market, with a particular focus on the development of high-performance analog power supply ICs for infotainment, telematics, automotive cameras, sensors, and body-related equipment. As announced last week as part of PowerPulse's electronica coverage, these three new products are the first to be released as a result of the development work done by the new team in Kansai and are outlined in more detail below.

The XD9260/61 series (AEC-Q100 Grade 2) is a high speed transient response 1.5A synchronous step‐down dc-dc converter. The extremely fast load transient performance is as a result of a new High Speed Circuit Architecture for Transient with Constant On Time (Hi‐SAT COT) control method, which, when compared to standard Constant On Time (COT) control, provides less fluctuation in oscillation frequency against load and input voltage.

The unique Hi‐SAT COT architecture enables ultra‐fast transient response, low ripple and high efficiency while using small external components that optimize PCB mounting area for space saving. Hi‐SAT COT is able to dynamically adjust the on‐time duration based on the input voltage, output voltage, and load current so that it can achieve relative constant frequency operation. Constant switching frequency minimizes the EMI interference at some sensitive bands of certain frequencies in the system.

The XD9260/61 is available in the small USP‐6C package and with the 3.0MHz switching frequency a 1.0μH inductor can be used for applications that require a small form factor. Additional features include: Low supply current of 15μA (fOSC=1.2MHz); Switching frequency of either 1.2MHz or 3.0MHz, user selectable; Operating temperature range of -40 to +105 degrees C; Ceramic capacitor 1005 size supported; Equipped with soft-start (0.3ms, typical) and under-voltage lockout function (UVLO).

The XD9242/43 series (AEC-Q100 Grade 3) is a synchronous pwm step‐down dc-dc converter with an integral 0.11Ω (typical) P-channel and a synchronous 0.12Ω (typical) N‐channel switching transistor built‐in. Output currents of up to 2A can be achieved using a simple circuit. The XD9242/43 operates with input voltages ranging between 2.7V and 6.0V, and its output voltage can be set between 0.9V and VIN by using two external resistors. With switching frequencies of 1.2MHz or 2.4MHz, small inductors can be used, making the series suited to applications where height and PCB area is limited.

The XD9242/43 series features various protection circuits, such as a thermal shutdown circuit that stops operation when the chip’s temperature reaches 150 degrees C and a UVLO (Under Voltage Lock Out) circuit that does the same when the input voltage decreases below 2.5V. Both of the above functions are implemented using hysteresis, and will allow the XC9242 to resume normal operation when the chip’s temperature drops below 130 degrees C and when the input voltage increases to 2.68V respectively.

The XD9242/42 is available in a SOP‐8FD package designed to maximize power dissipation. The SOP‐8FD integrates a large GND tab underneath the package which can be directly bonded to the PCB to improve the thermal performance. Other features include: Efficiency 95%, typical, (fOSC=1.2MHz, Vin=5.0V, Vout=3.3V); Operating voltage range is 2.7V to 6.0V; Internal reference voltage 0.8V ±2.0%; output voltage can be set as desired beginning from 0.9V using an resistor; Selection of either 1.2MHz (±15%) or 2.4MHz (±15%) as switching frequency; Equipped with soft-start (1ms typical), CL discharge function and under-voltage lockout function (UVLO); Operating temperature range of -40 to +85 degrees C.

The XD6130/XD6131 series (AEC-Q100 Grade 1) are voltage detectors with watchdog function. The watchdog timeout time and release delay time can be set as desired using a single external capacitor. These voltage detectors are used for microprocessor monitoring and when the power voltage reaches the detect voltage, or a Low to High pulse is not input to the watchdog pin within the watchdog timeout time, an L level signal is output from the RESETB pin.

Available in a small SOT26 package, the XD6130 includes Manual RESET function, whereas the XD6131 allows the user to turn off the Watch Dog Timer via the EN pin. With an operating temperature range of ‐40 to +125 degrees C and AEC‐Q100 Grade 1 rating, these IC are designed for automotive ECU applications. Additional features include: User selectable watchdog time out time and release delay time as desired using a single externally mounted capacitor; Detection voltage temperature characteristics: ±50ppm/ degree C; User selectable manual reset function (XD6130 Series) or watchdog ON/OFF function (XD6131 Series) according to application; Low supply current 8.1μA (detection) / 2.5μA (watchdog function OFF).