High frequency low power 1A step down converter with adjustable output voltage between 1.5V to 12V. Figure 1. Demonstration board

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1 E5.09 DEMONSTRATION BOARD High frequency low power A step down converter with adjustable output voltage between.5v to V What you get. Demo board low power A step down converter E5.09 with adjustable output voltage, optimized for an output voltage range between.5v to V. What you need in addition. An external Power supply for input voltage VS between 4.5V and 40.0V 3 Connectors. Pin VS (TP) and GND (TP) are input supply pins. Pin TP3 (V OUT ) and GND (TP4) provide the output voltage 3. CON also provide the output voltage, only the connector is different 4. The Power Good status is shown by the LED DPGOOD. The high-voltage open-drain interface at PGOOD will pull to GND as long as the rising output voltage is typ. <9.5% of the nominal output voltage. If E5.09 device is turned off at pin ON, the PGOOD output is driven to independent of V. 5. Short pin and of JP to enable converter (default). Short pin and 3 of JP to set converter into sleep mode. 6. The output voltage can be changed with the trimmer in the range of typically.5v to V. 4 Start of operation Figure. Demonstration board. Connect a power supply to VS and GND and set pin- of JP. The adjustable output voltage is now provided between Vout and GND with maximum A load. See maximum output current vs. output voltage in datasheet. The input voltage must be minimum 0.5V higher than the output voltage. 3. The PowerGood state is shown by the LED DPGOOD. If the LED DPGOOD shines, the switching regulator works properly. /5

2 E5.09 DEMONSTRATION BOARD 5 Efficiency Diagram Efficiency vs set to 5V E Efficiency [%] η [%] 9V η [%] 3,8V η [%] 8V , 0, 0,3 0,4 0,5 0,6 0,7 0,8 0,9, I_OUT [A] Figure. Efficiency diagram 6 Schematic TP VS TP GND C 47uF/50V JP CLOSED C uf C3 uf ON 3 4 PG 5 EP ON PG OCP LXT R 4k IC _QFN L 33uH (LPS ) D SS4 C6 330pF C4 00uF/35V R 0. C5 0uF TP3 CON Pin Pin PSS54_G TP4 GND 3 JP ON R3 4k7 PG 3 R4 k7 TR 0k H H H3 H4 DPGOOD green Figure 3. Board schematic /5

3 E5.09 DEMONSTRATION BOARD 7 Bill of Material Unit Pos.-No. Value Order-No. Supplier Remark Manufacturer R 4k, % P4.0KCCT-ND Digi-Key 0805, /8W Panasonic R 0., 5% 73L3R0JCT-ND Digi-Key 0805, /8W CTS R3 4k7, % P4.7KCCT-ND Digi-Key 0805, /8W Panasonic R4 k7, % P.7KCCT-ND Digi-Key 0805, /8W Panasonic TR 0k, 0% TS53YLK00 Schukat SMD-Cermet Trimmer 0K Vishay C 47µF, 50V, 0% PCE384CT-ND Digi-Key EEEFKV470P Panasonic C4 00µF, 35V, 0% PCE3836CT-ND Digi-Key EEE-FKV0XP Panasonic C C3 µf, 50V, 0% ND Digi-Key GRM3MR7H05KA88L Murata C5 0µF, 35V, 0% ND Digi-Key GRM3ER7YA06KAL Murata C6 330pF, 50V, 0% ND Digi-Key GCM885CH33JA6D Murata IC E5.09 E5.09 Elmos Low Power step down converter,.5v to 40V, A Elmos D DPGOOD 33µH,.5A, 0% TOPLED green LED SS4-E3/6TGICT-ND ND Digi-Key Digi-Key Diode Schottky A 40V SMA 0805 ma TOPLED green clr LED Vishay OSRAM L ) 33µH,.5A, 0% JP SMD jumper closed JP pin strip 3 pin LPS ML_ Coilcraft mohm, Isat=.8A Coilcraft - : turn on switching regulator (default), -3 : shut off switching regulator ) for further details concerning Coilcraft inductors visit 3/5

4 E5.09 DEMONSTRATION BOARD 8 Layout Hints Figure 4. Top view Figure 5. Bottom view The Layout version. provides an example for double layer PCB layouts. It forms small current loops regarding input current and output current, related to the common GND point centred between C, C4 and D. Please note that there is a special routing for the feedback connection from R to the resistive divider TR and R4 at (pin and ). With this routing inductive coupling effects are avoided (due to the changing field generated in L) in the loop formed by the feedback connection - a simple routing right of the Inductor L may lead to distortions in the feedback loop. The AC ripple voltage of the coil is coupled with a small capacitor C6 to the pin to obtain a small offset triangle voltage (around 0mVpp) at this pin. This lead to a stable operating frequency. A ground shield is intentionally routed between the switching node LXT and the capacitor C6 respectively TR and R4 to reduce capacitive coupling from LXT to the pin. The shielded power inductor LPS8045 (Coilcraft) is a good compromise between size, costs and load capacity. The 33µH inductance is needed for guarantee A output current up to V output voltage. In case of 5V output voltage and A output current a 8µH inductance is sufficient, e.g. LPS635, see figures Maximum Output Current vs. Ouput Voltage in chapter 9.. in the datasheet. For lower application currents adjust overcurrent protection at OCP by R to meet the new inductor saturation current. 4/5

5 E5.09 DEMONSTRATION BOARD Usage Restrictions Elmos Semiconductor AG provide the E5.09 Demonstration Board simply and solely for IC evaluation purposes in laboratory. The Kit or any part of the Kit must not be used for other purposes or within non laboratory environments. Especially the use or the integration in production systems, appliances or other installations is prohibited. The pcb s are delivered to customer are for the temporary purpose of testing, evaluation and development of the Elmos IC s only. Elmos will not assume any liability for additional applications of the pcb. Disclaimer Elmos Semiconductor AG shall not be liable for any damages arising out of defects resulting from () delivered hardware or software, () non observance of instructions contained in this document, or (3) misuse, abuse, use under abnormal conditions or alteration by anyone other than Elmos Semiconductor AG. To the extend permitted by law Elmos Semiconductor AG hereby expressively disclaims and user expressively waives any and all warranties of merchantability and of fitness for a particular purpose, statutory warranty of non-infringement and any other warranty or product liability that may arise by reason of usage of trade, custom or course of dealing. Elmos Semiconductor AG Headquarters Heinrich-Hertz-Str. 447 Dortmund Germany Phone + 49 (0) Fax + 49 (0) sales@elmos.com Note Elmos Semiconductor AG (below Elmos) reserves the right to make changes to the product contained in this publication without notice. Elmos assumes no responsibility for the use of any circuits described herein, conveys no licence under any patent or other right, and makes no representation that the circuits are free of patent infringement. While the information in this publication has been checked, no responsibility, however, is assumed for inaccuracies. Elmos does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of a life-support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications. Copyright 03 Elmos - Reproduction, in part or whole, without the prior written consent of Elmos, is prohibited. 5/5