SP6136 (7A MAX.) Evaluation Board Manual Easy Evaluation for the SP6136ER1 12V Input, 0 to 7A Output Synchronous Buck Converter Precision 0.80V 1% High Accuracy Reference Small form factor Feature Rich: Single supply operation, Over- current protection with auto-restart, Power Good Output, Enable input, Fast transient response, Short Circuit Shutdown Protection, Programmable soft start TSSOP Package & SMT components for small, low profile Power Supply SP6136EB SCHEMATIC 1 VIN VCC VCC 1 6 Ci 1 C1 22uF 12V 0.1uF DBST 16V SD101AWS 1210 8 7 6 5 1 GND MT 8 CVCC Si4354DY CBST CIN & COUT CERAMIC 1210 X5R 4.7uF 4 18.5mOhm 0.1uF 10V 1 GL GH 12 1 2 3 GH 2 Note: PGND 11 SWN U1 SWN 3 All resistors & capacitors size GND SP6136 AGND 10 ISP 1 17 0603 unless other wise specified DIEPAD 9 CSP CS RS3 ISN 2 4 8 7 6 5 VFB 0.1uF 10K1% 6.8nF MB R5 R3 Inter-Technical SC7232-2R2 SS GL Si4886DY 2.2uH, 10.4 mOhm NP 4 13.5mOhm 10.0k,1% CSS 1 VOUT 47nF 1 2 3 EN UVIN 7 1 1 RS1 Co J1 3.30V SS 2 ISP 100uF 5 3 3 6.3V 0-7A PTC36SAAN 5.11k,1% RS2 1210 ISN PWRGD 1 GND2 C2 R4 CP1 5.11k,1% 4 0.01uF 9 NP 12pF R1 CZ2 RZ2 CZ3 RZ3 68.1k,1% CF1 22pF 560pF 30.9K,1% 270pF 1K 1% R2 21.5k,1% VFB Rev 5/01/06 SP6136 Evaluation Manual Copyright 2006 Sipex Corporation 1 5 16 COMP VCC 6 15 EN UVIN 7 14 PWRGD VIN 8 13 SS BST 1 USING THE EVALUATION BOARD 1) Powering Up the SP6136EB Circuit the R1 and R2 combination to meet the Connect the SP6136ER1 Evaluation Board exact output voltage setting by restricting with an external +12V power supply. R1 resistance range such that 50K R1 Connect with short leads and large 100K for overall system loop stability. diameter wire directly to the VIN and GND posts. Connect a Load between the Note that since the SP6136ER1 Evaluation VOUT and GND2 posts, again using Board design was optimized for 12V down short leads with large diameter wire to conversion to 3.30V, changes of output minimize inductance and voltage drops. voltage and/or input voltage may alter performance from the data given in the 2) Measuring Output Load Power Supply Data section. Characteristics Its best to GND reference scope and digital POWER SUPPLY DATA meters using the Star GND post in the center of the board. VOUT ripple can best The SP6136ER1 is designed with an be seen touching probe tip to the pad for accurate 1.5% reference over line, load and COUT and scope ground collar touching temperature. Figure 1 data shows a typical Star GND post avoid a ground lead on the SP6136ER1 Evaluation Board efficiency probe which will increase noise pickup. plot, with efficiencies to 92% and output currents to 7A. Load Regulation in Figure 2 3) Using the Evaluation Board with shows only 0.12% change in output voltage Different Output Voltages from no load to 7A. Figures 3 and 4 show While the SP6136ER1 Evaluation Board the fast transient response. Start-up has been tested and delivered with the corresponding to different load conditions is output set to 3.30V, by simply changing one shown in Figures 5, 6 and 7, where the resistor, R2, the SP6136ER1 can be set to input current rises smoothly as the soft-start other output voltages. The relationship in ramp increases. In Figure 8 the hiccup the following formula is based on a voltage mode gets activated in response to an divider from the output to the feedback pin output dead short circuit condition and will VFB, which is set to an internal reference soft-start until the over-load is removed. voltage of 0.80V. Figure 9 and 10 show output voltage ripple Standard 1% metal film resistors of surface less than 11mV over complete load range. mount size 0603 are recommended. While data on individual power supply Vout = 0.80V ( R1 / R2 + 1 ) => boards may vary, the capability of the R2 = R1 / ( Vout / 0.80V ) 1 SP6136ER1 of achieving high accuracy over a range of load conditions shown here Where R1 = 68.1K and for Vout = 0.80V is quite impressive and desirable for setting, simply remove R2 from the board. accurate power supply design. Furthermore, one could select the value of Rev 5/01/06 SP6136 Evaluation Manual Copyright 2006 Sipex Corporation Page 2 of 9