Evaluation board user guide enpirion power solutions EN6338QI 3A PowerSoC Step-Down DC-DC Switching Converter with Integrated Inductor EVALUATION BOARD OVERVIEW 2 3 1 9 10 8 5 6 4 7 Figure 1: Evaluation Board (EVB) Features (Top View) NOTE A: The EN6338I Evaluation Board is shown in Figure 1 with the important features numbered. NOTE B: The following instructions will directly correlate with the numbers shown in Figure 1. Page 1 Evaluation Board User Guide Intel Enpirion Power Solutions: EN6338QI synchronize the internal switching frequency to the EVALUATION BOARD INSTRUCTIONS external signal. Do not leave this pin floating. 1) Input Supply (VIN) - Connect 2.7V to 6.6V supply on 7) Power OK (POK) - This is the open drain Power OK VIN (X1). Pay attention to input polarity and do not turn flag. When VOUT is over 90% of regulation, POK will be on until everything is connected correctly. pulled high to VIN through the R1 resistor (R1 is on the backside of the board). 2) Ground (GND) - Connect the input and output ground to GND (X2, X4). Table 1: External Compensation Recommendations 3) Output Voltage (VOUT) - Connect the load to VOUT C OUT (X3). If the instructions were followed up to this point, V V R C R IN OUT B A A (0805) the device may be powered on. 4) Enable (ENA) The ENA is used to enable or disable 0.75V OPEN 27pF the device. Connecting a jumper on ENA (JP2) towards 0.9V 1M 27pF the OFF side will disable the device. Similarly, connecting a jumper on the ENA (JP2) towards the ON side will 1.0V 604k 22pF enable the device. An external signal may be applied to the ENA (TP10) to enable or disable the device (ON > 1.2V 332k 22pF 1.5V, OFF < 1.2V) . 2.7V 6.6V 200k 2 x 22F 1.5V 200k 18pF 5) Output Voltage Settings (J1) - The output voltage may be adjusted quickly by placing a jumper one of the 1.8V 143k 18pF selections on J1. The voltages are pre-set by the resistors R11, R10, R9, R8 (on back of board) which 2.5V 84.5k 15pF corresponds to 3.3V, 2.5V, 1.8V and 1.0V respectively. 3.3V 59k 15pF No jumper will set the voltage to the reference voltage of 0.75V. The compensation C (C = C10) may be A A adjusted according to Table 1 for best results. The output voltage may also be adjusted to any voltage as 8) Soft Start Capacitor (C ) The soft start capacitor is SS indicated by the equation for R shown in Figure 2. B 15nF by default and can be between 10nF to 100nF. The output rise time is controlled by (C = C8). The voltage SS EN6338QI rise time calculation is shown: V OUT VOUT Rise Time t ms = C nF x 0.08 RISE ss C OUT C = 15nF t 1.2ms SS RISE R (47F 400F) A C A PGND 200k (15pF 68pF) C = 100nF t 8ms SS RISE V = 0.75V FB 9) Bulk Capacitors The EN6338QI may support up to VFB 400F on the output, but the compensation should be 0.75V x R adjusted accordingly. Using Table 1 as the reference for A R = B V - C , if C is increased, then the C (C = C10)should also OUT 0.75V A OUT A A be increased. The relationship is linearly shown below: AGND C +100F C +10pF OUT A Figure 2: VOUT Resistor Divider & Compensation The recommended maximum output capacitance Capacitor (C ) is 400F and phase-lead capacitance (C ) OUT MAX A MAX is 68pF. 6) Light Load Mode/Clock Sync (SYNC) At static Logic HIGH (PVIN), device will allow automatic engagement of 10) Output Ripple Measurement (SMA1) A SMA cable light load mode. At static logic LOW (GND), the device is may be connected to SMA1 to measure the AC coupled forced into PWM only. A clocked input to this pin will output ripple. Page 2