Efficiency up to 95%, no need for heatsinks High reflo w temperature SMD package Features Adjustable output voltage buck converter DC/DC Converter Wide input range (4.74V - 32V) Short circuit protection, thermal shutdown Switching Remote on/off control Very low shutdown current Regulator R-78AA-0.5 Positive to negative converter Description 0.5 Amp The R-78AAxx-0.5SMD series are adjustable output non-isolated buck converters that meet SMD the requirements for RoHS 10/10 as well as the reflow soldering temperatures associated with vapor phase soldering, making these high efficiency switching regulators ideally suited to modern pick-and-place mass production. The efficiency of up to 97% means that very little energy Single Output is wasted as heat. The additional features of remote on/off control, continuous short circuit protection and adjustable output voltages will find many uses in the battery-powered, industrial, medical and automotive markets. Selection Guide Part Input Output Vout Output Efficiency Number Voltage Range Voltage Adjust Range Current min Vin max. Vin (1) VDC VDC VDC A % % R-78AA1.5-0.5SMD 4.75 - 30 1.5 fixed 0.5 73 63 R-78AA1.8-0.5SMD 4.75 - 32 1.8 1.5 - 3.0 0.5 82 71 R-78AA2.5-0.5SMD 4.75 - 32 2.5 1.5 - 3.0 0.5 87 77 R-78AA3.3-0.5SMD 4.75 - 32 3.3 3.0 - 5.5 0.5 91 81 R-78AA5.0-0.5SMD 6.5 - 32 5.0 3.0 - 8.0 0.5 94 86 R-78AA6.5-0.5SMD 8.0 - 32 6.5 3.3 - 11.0 0.5 95 88 R-78AA9.0-0.5SMD 11 - 32 9.0 4.5 - 12.6 0.5 96 92 R-78AA12-0.5SMD 15 - 32 12 4.5 - 12.6 0.5 97 94 R-78AA15-0.5SMD 18 - 32 15 fixed 0.5 97 95 Notes: Note1: Input voltage ranges valid for nominal output voltages Vin must be higher than Vout including adjust range and dropout voltage EN60950-1 certified IEC60950-1 certified Model Numbering R-78AA -0.5 SMD- (2) nom. Output Voltage Packaging Output Current Package Notes: Note2: add suffix -R f or tape & reel packaging Ordering Examples: R-78AA5.0-0.5SMD-R = 5.0VDC Output Voltage, 0.5A, SMD, tape and reel packaging R-78AA2.5-0.5SMD = 2.5VDC Output Voltage, 0.5A, SMD, tube www.recom-power.com REV.: 5/2019 I-1R-78AA-0.5 DC/DC Converter Series Specifications (measured Ta= 25C, 10% minimum load, unless otherwise stated) BASIC CHARACTERISTICS Parameter Condition Min. Typ. Max. Absolute Maximum Input Voltage 34VDC 5mA 7mA Quiescent Current Vin= min. to max. 0.4W Internal Power Dissipation Output Voltage Adjustability see calculation (3) Minimum Load 0% 50ms Start-up time ON/OFF CTRL DC-DC ON Open or 2.8VDC<Vr<5VDC ON/OFF CTRL DC-DC OFF GND or 0VDC<Vr<0.8VDC Input Current of CTRL Pin DC-DC OFF 1.8A Standby Current 20A 30A 2.4VDC 2.6VDC 2.8VDC CTRL Thereshold Voltage 250mV CTRL Voltage Hysterese Internal Operating Frequency 280kHz 330kHz 380kHz 1.5VDC tp 6.5VDC 20mVp-p 30mVp-p Output Ripple and Noise 20MHz BW 9VDC to 15VDC 30mVp-p 40mVp-p with normal start-up time, no external components 470F Maximum Capacitive Load with <1 second start-up time + diode protection circuit 6800F Notes: Note3: Operation under no load will not harm the converter, but specifications may not be met. A minimum load of 6mA is recommended Output Voltage Adjustability Adjustment Resistor Values V0 R1 R2 R3 Vref(V) 1.8V 10k 21k 5.6k 1.23 R2(R1 + R3) x (Vref - Vo) + Vref x R1R3 Rdown = 2.5V 22k 21k 5.6k 1.23 R2Vo - Vref (R1 + R2) 3.3V 16.9k 10k 5.6k 1.23 5.0V 30.9k 10k 10k 1.23 6.5V 43k 10k 10k 1.23 R2R3 (Vref - Vo) + Vref R1 (R2 + R3) 9V 63.4k 10k 22.1k 1.23 Rup = 12V 88.7k 10k 22.1k 1.23 R2 (Vo - Vref) - Vref R1 +V +V in out R down R1 Controlled IC V adj R3 R2 R up GND GND Vref continued on next page www.recom-power.com REV.: 5/2019 I-2