USERS MANUAL ISL91127IRN-EVZ, ISL91127IRA-EVZ UG080 Rev 2.00 Evaluation Board User Guide October 28, 2016 Description Key Board Features The ISL91127IR is a high-current buck-boost switching regulator Small, compact design for systems using new battery chemistries. It uses Intersils Jumper selectable EN (enabled/disabled) proprietary buck-boost algorithm to maintain voltage regulation, Jumper selectable MODE (auto-PFM/forced-PWM) while providing excellent efficiency and very low output voltage ripple when the input voltage is close to the output voltage. The Connectors, test points and jumpers for easy probing ISL91127IRN-EVZ and ISL91127IRA-EVZ platforms allow quick evaluation of the high performance features of the ISL91127IR References buck-boost regulator series. ISL91127IR datasheet Specifications Ordering Information The boards are designed to operate at the following operating conditions: PART NUMBER DESCRIPTION Input voltage rating from 1.8V to 5.5V ISL91127IRN-EVZ Evaluation Board for ISL91127IRNZ Resistor programmable output voltage on the ISL91127IRA-EVZ Evaluation Board for ISL91127IRAZ ISL91127IRA-EVZ Fixed 3.3V output voltage on the ISL91127IRN-EVZ Up to 2A output current (PVIN = 2.5V, V = 3.3V) OUT 2.5MHz switching frequency Operating temperature range: -40C to +85C ISL91127IRAZ VIN PVIN LX1 GND VIN LX2 VOUT VOUT MODE GND FB EN SGND PGND FIGURE 1. ISL91127IRA-EVZ BLOCK DIAGRAM UG080 Rev 2.00 Page 1 of 7 October 28, 2016ISL91127IRN-EVZ, ISL91127IRA-EVZ 10. To determine efficiency, measure input and output voltages Functional Description at J1 and J2 headers. The bench power supply can be The ISL91127IRN-EVZ and ISL91127IRA-EVZ provide simple connected to the PVIN and GND headers on J2. The electronic and GND headers on J1. platforms to demonstrate the features of the ISL91127IR load can be connected to the V OUT buck-boost regulator. The ISL91127IRN-EVZ is for the fixed 3.3V Measure the input and output currents. Calculate efficiency output IC ISL91127IRNZ. The ISL91127IRA-EVZ is for the based on these measurements. adjustable output IC ISL91127IRAZ. The evaluation boards have TABLE 1. OUTPUT VOLTAGE PROGRAMMING FOR ISL91127IRA-EVZ been functionally optimized for best performance of the ISL91127IR IC series. The input power and load connections are DESIRED OUTPUT VOLTAGE R RESISTOR VALUE 2 (V) (k ) provided through multi-pin connectors for high current operation. 2.0 124 The ISL91127IRA-EVZ and ISL91127IRN-EVZ evaluation boards are shown in Figures 4 and 5. The boards enable function is 2.5 88.7 controlled by the on-board jumper header J3. Similarly, the Mode 3.0 68.1 function is controlled by the on-board jumper header J4. 3.3 60.4 The schematic of the ISL91127IRA-EVZ evaluation board is shown in Figure 6 and the schematic of the ISL91127IRN-EVZ is 3.4 57.6 shown in Figure 7. The PCB layout images for all layers are shown 4.0 46.4 in Figures 8 and 9. The bill of materials of ISL91127IRA-EVZ is shown in Table 2 and the bill of materials of ISL91127IRN-EVZ is 4.5 40.2 shown in Table 3. 5.0 35.7 5.1 34.8 Operating Range The V range of the boards is 1.8V to 5.5V. The V range for IN OUT the ISL91127IRA-EVZ is 2V to 5V. The I range of the boards is OUT 0A to 2A. The operating ambient temperature range is -40C to LX1 +85C. 2V/DIV Quick Start Guide LX2 2V/DIV For the ISL91127IRA-EVZ board, the default output voltage is set V at 3.3V. If other output voltages are desired, resistor R can be OUT 2 2V/DIV set to a desired voltage as shown in Table 1 (use a resistor with 1% accuracy). EN Refer to the following Quick Setup Guide to configure and I = 200mA 2V/DIV OUT power-up the board for proper operation. During the power-on process, the expected waveforms are shown in Figures 2 and 3. 400s/DIV FIGURE 2. ISL91127IR START-UP WITH V = 2V AND V = 3.3V IN OUT Quick Setup Guide 1. Install jumper on J3, shorting EN to V . IN 2. Install jumper on J4, shorting MODE to V . IN 3. Connect power supply to J2, with voltage setting between LX1 1.8V and 5.5V. 2V/DIV 4. Connect electronic load to J1. LX2 5. Place scope probes on the V test point and other test OUT 2V/DIV points of interest. V 6. Turn on the power supply. OUT 2V/DIV 7. Monitor the output voltage start-up sequence on the scope. The waveforms will look similar to that shown in Figures 2 and 3. EN 2V/DIV I = 200mA 8. Turn on the electronic load. OUT 9. Measure the output voltage with the voltmeter. The voltage 400s/DIV should regulate within datasheet specification limits. FIGURE 3. ISL91127IR START-UP WITH V = 4V AND V = 3.3V IN OUT UG080 Rev 2.00 Page 2 of 7 October 28, 2016