R1245x Series AEC-Q100 Compliant 1.2 A, 30 V Step Down DC/DC Converter for Automotive Applications No. EC-269-201022 OUTLINE The R1245x is a Step-down DC/DC converter with internal N-channel high side Tr. That is developed with CMOS process technology. The ON resistance of the built-in high-side transistor is 0.35 and the R1245x can provide the maximum 1.2 A output current. Each of the ICs consists of an oscillator, a PWM control circuit, a voltage reference unit, an error amplifier, a phase compensation circuit, a slope compensation circuit, a soft-start circuit, protection circuits, an internal voltage regulator, and a switch for bootstrap circuit. The ICs can make up a step-down DC/DC converter with an inductor, resistors, a diode, and capacitors. The R1245x is a current mode operating type DC/DC converter without an external current sense resistor, and realizes fast response and high efficiency. As an output capacitor, a ceramic type capacitor can be used with the R1245x. The options of the internal oscillator frequency are preset at 330 kHz for version A and B, 500 kHz for version C and D, 1000 kHz for version E and F, 2400 kHz for version G and H. As for protection, an Lx peak current limit circuit cycle by cycle, a thermal shutdown function and an under voltage lockout (UVLO) function are built in. Furthermore, there are two types for short protection, for A/C/E/G version, a latch protection function which makes the output latch off if the output voltage keeps lower than the set output voltage for a certain time after detecting current limit is built in, for B/D/F/H version, a fold-back protection function which changes the oscillator frequency slower after detecting short circuit or equivalent. As for the packages of the R1245x, HSOP-8E and DFN2020-8 are available. FEATURES Input Voltage Range (Maximum Rating) 4.5 V to 30 V (32 V) Operating Temperature 40C to 105C Internal N-channel MOSFET Driver Typ. RON = 0.35 Adjustable Output Voltage with External Resistor 0.8 V or more Feedback Voltage and Tolerance 0.8 V1.0% Peak Current Limit Typ. 2.0 A UVLO Function Released Voltage Typ. 4.0 V Operating Frequency 330 kHz (A/B version), 500 kHz (C/D version), 1000 kHz (E/F version), 2400 kHz (G/H version) Fold-back Protected Frequency 170 kHz (B/D version), 250 kHz (F version), 400 kHz (H version) Latch Protection Delay Time Typ. 4 ms for A/C/E/G version Built-in Thermal Shutdown Circuit Typ. 160C Ceramic Capacitors Recommended for Input and Output Stand-by Current Typ. 0 A Packages HSOP-8E, DFN2020-8 1 R1245x No. EC-269-201022 APPLICATIONS Power source for car accessories including car audio equipment, car navigation system, and ETC system. Power source for control units including EV inverter and charge control. SELECTION GUIDE In the R1245x, the package, type of short protection (Latch or Fold-back), and the oscillator frequency can be selected with the users request. Selection Guide Product Name Package Quantity per Reel Pb Free Halogen Free R1245S003 -E2- E HSOP-8E 1,000 pcs Yes Yes R1245L003-TR-AE DFN2020-8 3,000 pcs Yes Yes : Designation of the oscillator frequency and the protection function option. Symbol Oscillator Frequency Latch Protection Fold-back Protection A 330 kHz B 330 kHz C 500 kHz D 500 kHz E 1000 kHz F 1000 kHz G 2400 kHz H 2400 kHz : Designated Automotive Class Code Operating Temperature Guaranteed Specs Screening Range Temperature Range A 40C to 105C 25C High Temperature J 40C to 105C 40C to 105C High and low Temperature Automotive class code (A, J) varies depending on the package and function. Automotive Class Code Package Function A J A, B, G, H HSOP-8E C, D, E, F DFN2020-8 A, B, C, D, E, F, G, H 2