500 mA DC-DC Step Down Converter P78AS-Series ● ● ● ● ● ● ● ● Non isolated 10 Pin SMD package Function compatible with 78Mxx linear regulator Efficiency up to 96 % Operating temperature range -40...+85 °C Continuous short circuit protected Thermal shut down Adjustable output voltage Model guide Type P78AS3R3 P78AS05 P78AS09 P78AS12 P78AS15 Input voltage Range Nominal [VDC] [VDC] [VDC] Output Adjust trim Current range [VDC] [mA] 4.5..28 6..28 11..28 14..28 17..28 12 12 24 24 24 3.3 5.0 9.0 12.0 15.0 1.8…5.5 2.5…8 3…11.5 4.5…13.5 4.5…15.5 Voltage Capacitive load max. [µF] 500 500 500 500 500 1000 1000 1000 1000 1000 Efficiency @ Vin min. @ Vin max. [%] [%] 90 94 95 95 96 75 81 87 90 92 Specifications Output Voltage accuracy Input voltage regulation Load regulation Dynamic load stability Temperature coefficient Ripple and noise (at 20 MHz BW) Short circuit protection (hiccup mode) Thermal shutdown Output current limit Input Short circuit input power Quiescent current ON control threshold OFF control threshold ON / OFF control current Shut down quiescent current ± 3 %, max. ± 0.5 %, max. ± 0.75 % @ load 10..100 % ± 75 mV @ load 10..100 % ± 0.02 % / °C 25 mVp-p, max. Continuous, automatic recovery 150 °C, typ. internal temp. 1.8 A, typ. 1.8 W, max. 15 mA, typ. > 1.5 V, max. 6 V <1V < 2 µA 30 µA, max. General Thermal shutdown Switching frequency Reliability calc. MTBF @ 25 °C MIL-HDBK-217F Environmental Operating ambient temperature Operating case temperature Storage temperature Derating Humidity Cooling Physical Dimensions Weight Case material Soldering temperature 160 °C, internal junction 330 kHz, typ. > 2 Mio. h -40 °C ... +85 °C 100 °C, max. -55 °C ... +125 °C see diagram Up to 95%, non-condensing Free air convection SMD10 15.24 x 8.5 x 7.25 mm 2.3 g Plastic UL94-V0 See soldering profile Page 1 of 5 Deutschland: Inselkammerstraße 10 D-82008 Unterhaching Tel.: 089 614 503-10 E-Mail: [email protected] Schweiz: Gründenstrasse 82 CH-8247 Flurlingen Tel.: 052 647 42 00 E-Mail: [email protected] 500 mA DC-DC Step Down Converter P78AS-Series Standard application circuit 5 1 P78AS +Vin +Vout Rtd 10 6 7,9 Open ONstate C1 10 µF 470 pF C3 100 µF C2 Rtu GND GND 1. 2. 3. Type P78AS3R3 P78AS05 P78AS09 P78AS12 P78AS15 C2 22 µF, 16 V 10 µF, 25 V C1,C2: Choose a ceramic type capacitors; C3 is require ,for best performance , use a 100 μF or more capacitance. C1,C2 are require and should be placed close to the pins of the converter, with shortest possible traces. Do not connect the converter parallel or a hot swap connection. Adjustment resistor values Type Adj. range Adj. Vout [V] 1.8 2.5 3.0 3.3 3.6 3.9 4.5 4.9 5.0 5.1 5.5 6.5 7.2 8.0 9.0 10.0 11.0 11.5 12.0 13.0 13.5 14.0 14.5 15.0 15.5 P78AS3R3 1.8…5.5 V Rtd [kΩ] Rtu [kΩ] 24.31 98.9 364 ∞ ∞ 129.1 59.1 24.3 15.25 14.05 12.8 8.65 P78AS05 2.5…8 V Rtd [kΩ] Rtu [kΩ] 25.28 47.5 67.3 95.8 140.9 411 2060 ∞ ∞ 208.5 58.5 15.57 7.8 3.15 P78AS09 3…11.5 V Rtd [kΩ] Rtu [kΩ] 3.1 5.79 8.47 11.8 19.14 25.77 27.3 29.22 37.8 70.8 115.3 243.1 ∞ ∞ 18.84 4.47 1.61 P78AS12 4.5…13.5 V Rtd [kΩ] Rtu [kΩ] 4.55 8.05 9.16 10.41 15 29.8 43.5 64.8 105 180.6 370 635 ∞ ∞ 40.6 15 P78AS15 4.5…15.5 V Rtd [kΩ] Rtu [kΩ] 2.69 5.55 6.17 6.98 10 18.5 26.2 36.7 52.9 76.3 111 134.1 167.7 277.8 385 586 1128 ∞ ∞ 88.2 Note: The above dates only are as reference, you could make corresponding adjustment with actual output when they are at practical application. Application circuit to reduce output ripple. It is recommented to add a LC filter to output. 5 1 10 C1 10 µF GND L 10…47µH P78AS +Vin 7,9 +Vout 6 470 pF C2 100µF C3 22 µF GND Page 2 of 5 Deutschland: Inselkammerstraße 10 D-82008 Unterhaching Tel.: 089 614 503-10 E-Mail: [email protected] Schweiz: Gründenstrasse 82 CH-8247 Flurlingen Tel.: 052 647 42 00 E-Mail: [email protected] 500 mA DC-DC Step Down Converter P78AS-Series ON / OFF control function The ON/OFF pin 10 provides several features for adjusting and sequencing the power supply. An user has the flexibility of using the ON/OFF pin 10 as: 1) A digital on/off control by pulling down the ON/OFF pin with an open-drain transistor. 1 +Vin ON/ OFF C1 7, 9 10 5 P78AS On/Off Contr. +Vout C2 6 C3 470 pF GND GND 2) Line UVLO. If desired to achieve a UVLO voltage, an resistor divider from Vin to ON/OFF to GND can be used to disable the converter until a higher input voltage is achieved. For example, it is not useful for a converter with 12 V output to start up with a 12 V input voltage, as theoutput cannot teach regulation. To enable the converter when the input voltage reaches 14 V, a 51 kΩ / 5.1 kΩ resistor divider from Vin to GND can be connected to the ON/OFF pin. Both the precision 1.25 V threshold and 150 mV hysteresis are multiplied by the resistor ratio, providing a proportional 12 % hysteresis for any startup threshold. So, the turn off threshold would be between 12.3 V to 15.7 V. 1 5 P78AS +Vin +Vout 51kΩ 10 C1 5.1kΩ 100 µF 6 7,9 470 pF GND GND 3) Power supply sequencing. By connecting a small capacitor from ON/OFF to GND, the 2 μA current source and 1.25 V threshold can provide a stable and predictable delay between startup of multiple power supplies. For example, a startup delay of roughly 64 ms is provided using C5 100 nF, or roughly 136 ms by using 220 nF. 1 5 P78AS +Vin 10 C1 +Vout 100 µF 6 7,9 C5 470 pF GND GND C5 220 nF, Power on delay 136 ms Channel 1 yellow: Voltage on pin 10, Channel 2 blue: + Vout Test circuit for output ripple & noise, start up time and load tansient response 25.4 +Vin P78AS 1 10 7, 9 C1 12.7 Unit:mm 1µ +Vout 10 µ Cer. Cer. 5 6 C2 470 pF 12.7 C3 Oscilloscope measure points GND GND Page 3 of 5 Deutschland: Inselkammerstraße 10 D-82008 Unterhaching Tel.: 089 614 503-10 E-Mail: [email protected] Schweiz: Gründenstrasse 82 CH-8247 Flurlingen Tel.: 052 647 42 00 E-Mail: [email protected] 500 mA DC-DC Step Down Converter P78AS-Series Page 3 of 5 Deutschland: Inselkammerstraße 10 D-82008 Unterhaching Tel.: 089 614 503-10 E-Mail: [email protected] Schweiz: Gründenstrasse 82 CH-8247 Flurlingen Tel.: 052 647 42 00 E-Mail: [email protected] 500 mA DC-DC Step Down Converter P78AS-Series Page 4 of 5 Deutschland: Inselkammerstraße 10 D-82008 Unterhaching Tel.: 089 614 503-10 E-Mail: [email protected] Schweiz: Gründenstrasse 82 CH-8247 Flurlingen Tel.: 052 647 42 00 E-Mail: [email protected] 500 mA DC-DC Step Down Converter P78AS-Series Dimensions Pin 1 5 6 7 9 10 Connections +V Input +V Output Trim input GND GND ON/OFF control PHI-CON is a trademark of HY-LINE Power Components. Only for professional use by professionals! Not for resale or distribution to the general public in any way! Read the instructions for use carefully before using! Life Support Policy: HY-LINE does not authorize the use of any of its products for use in life support devices or systems without the express written approval of an officer of the Company. Life support systems are devices which support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in significant injury to the user. Rev: 2.14 f Page 5 of 5 Deutschland: Inselkammerstraße 10 D-82008 Unterhaching Tel.: 089 614 503-10 E-Mail: [email protected] Schweiz: Gründenstrasse 82 CH-8247 Flurlingen Tel.: 052 647 42 00 E-Mail: [email protected]