USERS MANUAL ISL85410EVAL1Z, ISL854102EVAL1Z, ISL85418EVAL1Z AN1905 Rev.4.00 Evaluation Boards User Guide Oct 18, 2016 Description Key Features The ISL85410EVAL1Z, ISL854102EVAL1Z, and Wide input voltage range 3V to 40V ISL85418EVAL1Z boards are intended for use for point-of-load Synchronous operation for high efficiency applications sourcing from 3V to 40V. The boards are used to No compensation required evaluate the performance of the ISL85410, ISL854102, and Integrated high-side and low-side NMOS devices ISL85418 wide V low quiescent current high-efficiency IN Selectable PFM or forced PWM mode at light loads synchronous buck regulators with 1A (ISL85410), 1.2A Internal fixed (500kHz) or adjustable switching frequency (ISL854102) and 800mA (ISL85418EVAL1Z) output current. 300kHz to 2MHz The ISL85410, ISL854102, and ISL85418 are offered in a Continuous output current up to 1A (ISL85410), 1.2A 4mmx3mm 12 Ld DFN package with 1mm maximum height. (ISL854102), and 800mA (ISL85418) 2 The converter occupies 1.516cm area. Internal or external soft-start Minimal external components required Specifications Power-good and enable functions available These boards have been configured and optimized for the following operating conditions: Related Literature V = 24V For a full list of related documents please visit our website IN - ISL85410, ISL85418, ISL854102, product pages V = 3.3V OUT I = 1A (ISL85410), 1.2A (ISL854102), and 800mA MAX (ISL85418) Ordering Information f = 500kHz SW PART NUMBER DESCRIPTION Peak efficiency: >84% at 50% load ISL85410EVAL1Z Evaluation board (1A output current) Output ripple: <3mV at 1.2A ISL85418EVAL1Z Evaluation board (800mA output current) Dynamic response: 4.5% ISL854102EVAL1Z Evaluation board (1.2A output current) (0A to 1.2A and 1.2A to 0A steps, PWM, di/dt = 1A/s) Board temperature: +25C FIGURE 1. BLOCK DIAGRAM AN1905 Rev.4.00 Page 1 of 11 Oct 18, 2016Evaluation Boards User Guide ISL85410EVAL1Z, ISL854102EVAL1Z, ISL85418EVAL1Z Frequency Control Recommended Equipment The ISL85410, ISL854102, and ISL85418 have an FS pin that The following materials are recommended to perform testing: controls the frequency of operation. Programmable frequency 0V to 50V power supply with at least 2A source current allows for optimization between efficiency and external capability component size. It also allows low frequency operation for low V when minimum on-time would limit the operation Electronic loads capable of sinking current up to 2A OUTs otherwise. Default switching frequency is 500kHz when FS is tied Digital Multimeters (DMMs) to V (R = 0). By removing R , the switching frequency could CC 10 10 100MHz quad-trace oscilloscope be changed from 300kHz (R = 340k) to 2MHz (R = 32.4k). 12 12 Signal generator Please refer to datasheets ISL85410, ISL854102, and ISL85418 for calculating the value of R . Do not leave this pin floating. 10 Quick Setup Guide Disabling/Enabling Function 1. Ensure that the circuit is correctly connected to the supply and The ISL85410, ISL85418 evaluation boards contain an S1 switch loads prior to applying any power. that enables or disables the part, thus allowing low quiescent 2. Connect the bias supply to VIN, the plus terminal to VIN (P4), details this function. current state. Table 2 and the negative return to GND (P5). TABLE 2. SWITCH SETTINGS 3. Verify that the position is ON for S1. S1 ON/OFF CONTROL 4. Turn on the power supply. ON Enable V OUT 5. Verify the output voltage is 3.3V for V OUT. OFF Disable V OUT Evaluating the Other Output Voltage The ISL85410EVAL1Z, ISL854102EVAL1Z and ISL85418EVAL1Z SYNC Control board outputs are preset to 3.3V however, output voltages can The ISL85410, ISL85418 evaluation boards have a SYNC pin that be adjusted from 0.6V to 15V. The output voltage programming allows external synchronization frequency to be applied. Default resistor, R , will depend on the desired output voltage of the 2 board configuration has R = 200k to V , which defaults to regulator and the value of the feedback resistor R , as shown in 6 CC 1 PWM operation mode and also to the preselected switching Equation 1. frequency set by R (see datasheets and previous section 12 0.6 ------------------------------ R = R (EQ. 1) 2 1 Frequency Control for details). If this pin is tied to GND the IC V 0.6 OUT will operate in PFM mode. The S2 switch allows forced PFM or PWM modes. If the output voltage desired is 0.6V, then R is shorted. Please 1 note that if V is less than 1.8V, the switching frequency and OUT Soft-Start/COMP Control compensation must be changed for 300kHz operation due to R selects between internal (R = 0) and external soft-start. minimum on-time limitation. Please refer to datasheets 15 15 ISL85410, ISL854102, and ISL85418 for further information. R selects between internal (R = 0) and external 11 11 compensation. For applications where repetitive restarts of the Table 1 shows the component selection that should be used for IC are required, it is recommended to add a 350k resistor in the respective V . OUT parallel to CSS in order to allow its fast discharge. Please refer to , ISL854102, and the pin description table of the ISL85410 ISL85418 datasheets. TABLE 1. EXTERNAL COMPONENT SELECTION V L C +C R R C R R C OUT 1 5 6 1 2 4 12 3 7 (V) (H) (F) (k ) (k ) (pF) (k ) (k ) (pF) 12 22 2x22 90.9 4.75 22 115 150 470 5 22 47+22 90.9 12.4 27 DNP 100 470 (Note 1) 3.3 22 47+22 90.9 20 27 DNP 100 470 (Note 1) 2.5 22 47+22 90.9 28.7 27 DNP 100 470 (Note 1) 1.8 12 47+22 90.9 45.5 27 DNP 70 470 (Note 1) NOTE: 1. Connect FS to V . CC AN1905 Rev.4.00 Page 2 of 11 Oct 18, 2016