USERS MANUAL ISL9120IRx-EVZ UG042 Rev 0.00 Evaluation Board July 17, 2015 Description Key Features The ISL9120IR is a highly integrated buck-boost switching Small, compact design regulator for systems using new battery chemistries. It uses Jumper selectable EN (enabled/disabled) Intersils proprietary buck-boost algorithm to maintain voltage Jumper selectable BYP (buck-boost/forced bypass) regulation, while providing excellent efficiency and very low output voltage ripple when the input voltage is close to the Connectors, test points and jumpers for easy probing output voltage. The ISL9120IRx-EVZ platforms allow quick evaluation of the high performance features of the ISL9120IR References buck-boost regulator series. ISL9120IR Datasheet Specifications Ordering Information The boards are designed to operate under the following conditions: PART NUMBER DESCRIPTION Input voltage range of 1.8V to 5.5V ISL9120IRN-EVZ Evaluation board for ISL9120IRNZ, fixed 3.3V Resistor programmable output voltage on the ISL9120IRA-EVZ output Fixed 3.3V output voltage on the ISL9120IRN-EVZ ISL9120IRA-EVZ Evaluation board for ISL9120IRAZ, adjustable output Up to 800mA output current (V = 2.5V, V = 3.3V) IN OUT Operating temperature range: -40C to +85C ISL9120IRAZ VIN VIN LX1 GND LX2 VOUT VOUT BYP FB GND EN FIGURE 1. ISL9120IRA-EVZ BLOCK DIAGRAM UG042 Rev 0.00 Page 1 of 7 July 17, 2015 SGND PGNDISL9120IRx-EVZ TABLE 1. OUTPUT VOLTAGE PROGRAMMING FOR ISL9120IRA-EVZ Functional Description DESIRED OUTPUT VOLTAGE R RESISTOR VALUE 2 The ISL9120IRx-EVZ evaluation boards provide simple platforms (V) (k ) to demonstrate the features of the ISL9120IR buck-boost 2.0 124 regulator. The ISL9120IRN-EVZ is for the fixed 3.3V output IC ISL9120IRNZ. The ISL9120IRA-EVZ is for the adjustable output 2.5 88.7 IC ISL9120IRAZ. The evaluation boards have been functionally 3.0 68.1 optimized for best performance of the ISL9120IR IC series. The 3.3 60.4 input power and load connections are provided through multipin 3.4 57.6 connectors for high current operations. 4.0 46.4 The ISL9120IRA-EVZ evaluation board schematic is shown in 4.5 40.2 Figure 5, on page 3. The boards enable function is controlled by the on-board jumper header J3. Similarly, the forced bypass 5.0 35.7 function is controlled by the on-board jumper header J4. The schematic for the ISL9120IRN-EVZ is shown in Figure 7, on page 5. The PCB layout images for all layers are shown in Figures 8 and 9 on page 6. The bill of materials for the EN (2V/DIV) ISL9120IRA-EVZ is shown in Table 2 on page 4. The bill of materials for the ISL9120IRN-EVZ is shown in Table 3 on page 5. Operating Range V (1V/DIV) OUT The V range of the boards is 1.8V to 5.5V. The V range for the IN OUT ISL9120IRA-EVZ is 2V to 5V. The I range of the boards is 0 to 1A. OUT The operating ambient temperature range is -40C to +85C. Quick Start Guide For the ISL9120IRA-EVZ board, the default output voltage is set I (500mA/DIV) L at 3.3V. Should other output voltages be desired, resistor R can 2 be changed to set a desired voltage as shown in Table 1 (use a 400s/DIV resistor with 1% accuracy). FIGURE 2. SOFT-START (V = 3V, V = 3.3V, NO LOAD) IN OUT Refer to the following Quick Setup Guide to configure and power up the board for proper operation. During the power-on process, the expected waveforms are shown in Figures 2 and 3. EN (2V/DIV) Quick Setup Guide 1. Install jumper on J3, shorting EN to VIN. 2. Install jumper on J4, shorting BYP to GND. 3. Connect power supply to J1, with a voltage setting between V (1V/DIV) OUT 1.8V and 5.5V. 4. Connect electronic load to J2. 5. Place scope probes on the V test point and other test OUT points of interest. 6. Turn on the power supply. 7. Monitor the output voltage start-up sequence on the scope. The I (500mA/DIV) L waveforms will look similar to that shown in Figures 2 and 3. 400s/DIV 8. Turn on the electronic load. FIGURE 3. SOFT-START (V = 4V, V = 3.3V, NO LOAD) 9. Measure the output voltage with the voltmeter. The voltage IN OUT should regulate within datasheet spec limits. Recommended PCB Layout Correct PCB layout is critical for proper operation of the ISL9120IR. The input and output capacitors should be positioned as closely to the IC as possible. The ground connections of the input and output capacitors should be kept as short as possible and should be on the component layer to avoid problems that are caused by high switching currents flowing through PCB vias. UG042 Rev 0.00 Page 2 of 7 July 17, 2015