R1245S003C-E2-JE

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) ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ 4.5 V to 30 V (32 V) Operating Temperature ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ −40°C to 105°C Internal N-channel MOSFET Driver ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. RON = 0.35  Adjustable Output Voltage with External Resistor ꞏꞏꞏꞏꞏꞏ 0.8 V or more Feedback Voltage and Tolerance ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ 0.8 V1.0% Peak Current Limit ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. 2.0 A UVLO Function Released Voltage ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. 4.0 V Operating Frequency ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ 330 kHz (A/B version), 500 kHz (C/D version), 1000 kHz (E/F version), 2400 kHz (G/H version) Fold-back Protected Frequency ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ 170 kHz (B/D version), 250 kHz (F version), 400 kHz (H version) Latch Protection Delay Time ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. 4 ms for A/C/E/G version Built-in Thermal Shutdown Circuit ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. 160°C Ceramic Capacitors Recommended for Input and Output Stand-by Current ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Typ. 0 A Packages ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ 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 user’s 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 A B C D E F G H Oscillator Frequency 330 kHz 330 kHz 500 kHz 500 kHz 1000 kHz 1000 kHz 2400 kHz 2400 kHz Latch Protection  Fold-back Protection        #: Designated Automotive Class Code A Operating Temperature Range −40°C to 105°C Guaranteed Specs Temperature Range 25°C High Temperature J −40°C to 105°C −40°C to 105°C High and low Temperature Screening Automotive class code (A, J) varies depending on the package and function. Package HSOP-8E DFN2020-8  2 Function Automotive Class Code A J A, B, G, H   C, D, E, F  A, B, C, D, E, F, G, H  R1245x No. EC-269-201022 BLOCK DIAGRAM V IN Thermal Shutdown C E UVLO 5V Regulator Regulator BST Shutdown SETPULSE Oscillator *1 FB MAXDUTY S D Lx R Reference + + Soft Start Circuit (1 ms) 0.8 V Limit Latch Circuit (4 ms) *1 Current Slope Circuit GND Peak Current Limit Circuit R1245x Block Diagram *1 Version A B C D E F G H Oscillator Frequency 330 kHz 330 kHz 500 kHz 500 kHz 1000 kHz 1000 kHz 2400 kHz 2400 kHz Short Protection Type Latch Fold-back Latch Fold-back Latch Fold-back Latch Fold-back 3 R1245x No. EC-269-201022 PIN DESCRIPTIONS Top View 8 7 6 Bottom View 5 5 6 7 Top View 8 8 7 6 Bottom View 5 1 2 3 4 4 3 6 7 8 3 2 1 ∗2 ∗1 1 5 2 2 3 4 4 1 SOP-8E Pin Configuration DFN2020-8 Pin Configuration R1245S Pin Description Pin No. Symbol Description 1 Lx Lx Switching Pin 2 VIN Power Supply Pin 3 CE Chip Enable Pin (Active with ”H”) 4 TEST TEST pin (must be open for user side.) *1 5 GND Ground Pin 6 FB Feedback Pin 7 NC No connection 8 BST Bootstrap Pin *1 Connect the backside heat radiation tab to GND or same as GND level (recommendation). The tab is connected to the GND pin. R1245L Pin Description Pin No. Symbol 1 Lx 2 VIN 3 VIN 4 CE 5 GND∗2 6 FB 7 TEST 8 BST *2 Description Lx Switching Pin Power Supply Pin Power Supply Pin Chip Enable Pin (Active with ”H”) Ground Pin Feedback Pin Test Pin (must be open for user side) Bootstrap Pin Connect the backside heat radiation tab to GND or same as GND level (recommendation). The tab is connected to the GND pin. 4 R1245x No. EC-269-201022 INTERNAL EQUIVALENT CIRCUIT FOR EACH PIN Regulator VIN BST LX LX Regulator VIN CE FB Regulator TEST 5 R1245x No. EC-269-201022 ABSOLUTE MAXIMUM RATINGS Absolute Maximum Ratings Symbol VIN (GND = 0 V) Item Unit −0.3 to 32 V VLX − 0.3 to VLX + 6 V Input Voltage VBST BST Pin Voltage VLX Lx Pin Voltage −0.3 to VIN + 0.3 V VCE CE Pin Input Voltage −0.3 to VIN + 0.3 V VFB Feedback Pin Voltage −0.3 to 6 V PD Power Dissipation (HSOP-8E)*1 Power Dissipation (DFN2020-8)*1 Tj Tstg *1 Rating Ultra High Wattage Land Pattern 3600 Standard Land Pattern 1100 mW Junction Temperature −40 to 150 °C Storage Temperature Range −55 to 150 °C Refer to POWER DISSIPATION for detailed information. ABSOLUTE MAXIMUM RATINGS Electronic and mechanical stress momentarily exceeded absolute maximum ratings may cause the permanent damages and may degrade the lifetime and safety for both device and system using the device in the field. The functional operation at or over these absolute maximum ratings is not assured. RECOMMENDED OPERATING CONDITIONS Recommended Operating Conditions Symbol Item VIN Input Voltage Ta Operating Temperature Range Rating Unit 4.5 to 30 V −40 to 105 °C RECOMMENDED OPERATING CONDITIONS All of electronic equipment should be designed that the mounted semiconductor devices operate within the recommended operating conditions. The semiconductor devices cannot operate normally over the recommended operating conditions, even if when they are used over such conditions by momentary electronic noise or surge. And the semiconductor devices may receive serious damage when they continue to operate over the recommended operating conditions. 6 R1245x No. EC-269-201022 ELECTRICAL CHARACTERISTICS VIN = 12 V, unless otherwise noted. The specifications surrounded by are guaranteed by design engineering at –40°C ≤ Ta ≤ 105°C. R1245x003x-AE Electrical Characteristics (Ta = 25°C) Symbol Item Conditions IIN VIN Consumption Current VIN = 30 V, VFB = 1.0 V VUVLO1 UVLO Detect Voltage Falling 3.55 VUVLO2 UVLO Released Voltage Rising 3.75 VFB VFB Voltage Tolerance Ta = 25°C 0.792 0.800 0.808 –40°C ≤ Ta ≤ 105°C 0.781 Version A/B Version C/D fOSC Oscillator Frequency Version E/F Version G/H fFLB Maxduty tstart tDLY Fold-back Frequency Oscillator Maximum Duty Cycle Min. Ta = 25°C 300 –40°C ≤ Ta ≤ 105°C 280 Ta = 25°C 450 –40°C ≤ Ta ≤ 105°C 430 Ta = 25°C 900 –40°C ≤ Ta ≤ 105°C 870 Ta = 25°C 2200 Typ. Max. Unit 0.5 1.80 mA VUVLO2 VUVLO2 −0.2 −0.05 4.0 0.819 330 500 1000 2400 Version D VFB < 0.56 V 170 Version F VFB < 0.56 V 250 Version H VFB < 0.56 V 400 Version E/F 86 Version G/H 74 1100 kHz 2600 2650 170 91 550 1140 VFB < 0.56 V Version C/D V 360 590 Version B 91 V 380 –40°C ≤ Ta ≤ 105°C 2150 Version A/B 4.25 V kHz % Soft-start Time VFB = 0.72 V 1.0 ms Delay Time for Latch Protection Version A/G 4 ms 7 R1245x No. EC-269-201022 VIN = 12 V, unless otherwise noted. The specifications surrounded by are guaranteed by design engineering at –40°C ≤ Ta ≤ 105°C. R1245x003x-AE Electrical Characteristics Symbol Item (Ta = 25°C) Conditions Typ. Max. Unit Lx High Side Switch ON Resistance Lx High Side Switch Leakage Current Lx High Side Switch Limited Current VIN = 30 V, VCE = 0 V VCEL CE “L” Input Voltage VIN = 30 V VCEH CE “H” Input Voltage VIN = 30 V 1.6 IFB VFB Input Current VIN = 30 V, VFB = 1.0 V –0.3 0 0.3 μA ICEL CE “L” Input Current VIN = 30 V, VCE = 0 V –0.3 0 0.3 μA ICEH CE “H” Input Current VIN = 30 V, VCE = 30 V –0.3 0 0.3 μA Standby Current VIN = 30 V 0 5.0 μA RLXH ILXHOFF ILIMLXH Istandby VBST - VLX = 4.5 V  0.35 VBST - VLX = 4.5 V All of units are tested and specified under load conditions such as Tj ≈ Ta = 25°C. 8 Min. 0 1.2 5.0 2.0 μA A 0.3 V V R1245x No. EC-269-201022 VIN = 12 V, unless otherwise noted. R1245x003x-JE Electrical Characteristics (–40°C ≤ Ta ≤ 105°C) Symbol Item Conditions Typ. Max. Unit IIN VIN Consumption Current VIN = 30 V, VFB = 1.0 V 0.5 1.80 mA VUVLO1 UVLO Detect Voltage Falling 3.55 VUVLO2 −0.2 VUVLO2 −0.05 V VUVLO2 UVLO Released Voltage Rising 3.75 4.0 4.25 V VFB VFB Voltage Tolerance Ta = 25°C 0.792 0.800 0.808 –40°C ≤ Ta ≤ 105°C 0.781 0.819 Version A/B fOSC Oscillator Frequency Version G/H Min. Ta = 25°C 300 –40°C ≤ Ta ≤ 105°C 280 Ta = 25°C 2200 330 360 380 2400 –40°C ≤ Ta ≤ 105°C 2150 V 2600 kHz 2650 Version B VFB < 0.56 V 170 Version H VFB < 0.56 V 400 kHz fFLB Fold-back Frequency Maxduty Oscillator Maximum. Duty Cycle Version A/B 91 Version G/H 74 Soft-start Time VFB = 0.72 V 1.0 ms Version A/G 4 ms 0.35  tstart tDLY RLXH ILXHOFF ILIMLXH Delay Time for Latch Protection Lx High Side Switch ON Resistance Lx High Side Switch Leakage Current Lx High Side Switch Limited Current VBST − VLX = 4.5 V 0 VIN = 30 V, VCE = 0 V VBST - VLX = 4.5 V % 1.2 5.0 2.0 μA A 0.3 V VCEL CE “L” Input Voltage VIN = 30 V VCEH CE “H” Input Voltage VIN = 30 V 1.6 IFB VFB Input Current VIN = 30 V, VFB =1.0 V –0.3 0 0.3 μA ICEL CE “L” Input Current VIN = 30 V, VCE = 0 V –0.3 0 0.3 μA ICEH CE “H” Input Current VIN = 30 V, VCE = 30 V –0.3 0 0.3 μA Standby Current VIN = 30 V 0 5.0 μA Istandby V 9 R1245x No. EC-269-201022 OPERATING DESCRIPTIONS OPERATION OF THE BUCK CONVERTER AND THE OUTPUT CURRENT The DC/DC converter charges energy in the inductor when the switch turns on, and discharges the energy from the inductor when the switch turns off and controls with less energy loss, so that a lower output voltage than the input voltage is obtained. Refer to the following figures. ILmax IL ILmin i1 VIN Switch L Diode i2 topen VOUT COUT GND ton toff t=1/fosc Basic Circuit Current flowing through the Inductor Step 1: The switch turns on and current IL (= i1) flows, and energy is charged into COUT. At this moment, IL increases from ILmin (= 0) to reach ILmax in proportion to the on-time period (ton) of the switch. Step 2: When the switch turns off, the diode turns on in order to maintain IL at ILmax, and current IL (= i2) flows. Step 3: IL (= i2) decreases gradually and reaches IL = ILmin = 0 after a time period of topen, and the diode turns off. This case is called as discontinuous mode. If the output current becomes large, next switching cycle starts before IL becomes 0 and the diode turns off. In this case, IL value increases from ILmin (> 0), and this case is called continuous mode. In the case of PWM control system, the output voltage is maintained by controlling the on-time period (ton), with the oscillator frequency (fosc) being maintained constant. 10 R1245x No. EC-269-201022 TYPICAL APPLICATION CIRCUIT R1245x00xA/B Typical Application Circuit, 330 kHz, VOUT = 1.2 V, VIN = 24 V R1245x00xC/D Typical Application Circuit, 500 kHz, VOUT = 3.3 V, VIN = 24 V *TEST pin must be open. 11 R1245x No. EC-269-201022 R1245x00xE/F Typical Application Circuit, 1000 kHz, VOUT = 3.3 V VIN = 12 V R1245x00xG/H Typical Application Circuit, 2400 kHz, VOUT = 5. 0 V, VIN = 12 V *TEST pin must be open. 12 R1245x No. EC-269-201022 OUTPUT CURRENT AND SELECTION OF EXTERNAL COMPONENTS The calculation method of output current and the relation between the output current and external components are as follows: When the switch of Lx turns on: (Wherein, the peak to peak value of the ripple current is described as IRP, the ON resistance of the switch is described as RONH, and the diode forward voltage as VF, and the DC resistance of the inductor is described as RL, and on time of the switch is described as ton) VIN = VOUT + (RONH + RL)  IOUT + L  IRP / ton ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Equation 1 When the switch turns off (the diode turns on) as toff: L  IRP / toff = VF + VOUT + RL  IOUT ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Equation 2 Put Equation 2 to Equation 1 and solve for ON duty of the switch, ton / (toff + ton) = DON, DON = (VOUT + VF + RL  IOUT) / (VIN + VF - RONH  IOUT)ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Equation 3 Ripple Current is as follows: IRP = (VIN −VOUT −RONH  IOUT −RL  IOUT)  DON / fosc / L ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Equation 4 wherein, peak current that flows through L, and the peak current ILmax is as follows: ILmax = IOUT + IRP / 2 ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Equation 5 As for the valley current ILmin, ILmin = IOUT - IRP / 2 ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Equation 6 If ILmin < 0, the step-down DC/DC converter operation becomes current discontinuous mode. Therefore the current condition of the current discontinuous mode, the next formula is true. IOUT < IRP / 2 ꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏꞏ Equation 7 Consider ILmax and ILmin, conditions of input and output and select external components. 13 R1245x No. EC-269-201022 Ripple Current and Lx current limit The ripple current of the inductor may change according to the various reasons. In the R1245x, as an Lx current limit, Lx peak current limit is used. Therefore the upper limit of the inductor current is fixed. The peak current limit is not the average current of the inductor (output current). If the ripple current is large, peak current becomes also large. The characteristic is used for the fold-back current limit of version B/D/F/H. In other words, the peak current limit is maintained and the switching frequency is reduced, as a result, the average current of the inductor is reduced. To release this condition, at 170 kHz for version B/D, at 250 kHz for version F, at 400 kHz for version H must not be beyond the peak current limit. In the Figure 1, the sequence of the Lx current limit function is described. VOUT VOUT Limit Latch (R1245x00x A/C/E/G) open 4msec 4msec t short shutdown IOUT shutdown restart (CE=0→"H") VOUT VOUT FB