Application Note 1912 Author: Sameer Dash ISL91110IIN-EVZ, ISL91110II2A-EVZ, ISL91110IIA-EVZ Evaluation Boards Description Key Board Features The ISL91110 is a high-current buck-boost switching regulator for systems using new battery chemistries. It uses Intersil’s proprietary buck-boost algorithm to maintain voltage regulation, while providing excellent efficiency and very low output voltage ripple when the input voltage is close to the output voltage. The ISL91110IIN-EVZ, ISL91110II2A-EVZ and ISL91110IIA-EVZ platforms allow quick evaluation of the high performance features of the ISL91110 buck-boost regulator series. • Small, compact design • Jumper selectable EN (enabled/disabled) • Jumper selectable MODE (auto-PFM/forced-PWM) • Connectors, test points, and jumpers for easy probing References • ISL91110 Data Sheet. Specifications Ordering Information The boards are designed to operate at the following operating conditions: • Input voltage rating from 1.8V to 5.5V PART NUMBER • Resistor programmable output voltage on the ISL91110IIA-EVZ • Fixed 3.3V output voltage on the ISL91110IIN-EVZ • Fixed 3.5V output voltage on the ISL91110II2A-EVZ • Up to 2A output current (PVIN = 2.5V, VOUT = 3.3V) DESCRIPTION ISL91110IIN-EVZ Evaluation Board for ISL91110IINZ ISL91110II2A-EVZ Evaluation Board for ISL91110II2AZ ISL91110IIA-EVZ Evaluation Board for ISL91110IIAZ • 2.5MHz switching frequency • Operating temperature range: -40°C to +85°C ISL91110IIAZ VIN GND PVIN LX1 VIN LX2 VOUT VOUT MODE FB GND PGND SGND EN FIGURE 1. ISL91110IIA-EVZ BLOCK DIAGRAM March 12, 2014 AN1912.1 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas LLC 2014. All Rights Reserved Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners. Application Note 1912 Functional description The ISL91110IIN-EVZ, ISL91110II2A-EVZ and ISL91110IIA-EVZ provides simple platforms to demonstrate the feature of the ISL91110 buck-boost regulator. The ISL91110IIN-EVZ is for the fixed 3.3V output IC ISL91110IINZ. The ISL91110II2A-EVZ is for the fixed 3.5V output IC ISL91110II2AZ and the ISL91110IIA-EVZ is for the adjustable output IC ISL91110IIAZ. The Evaluation boards have been functionally optimized for best performance of the ISL91110 IC series. The input power and load connections are provided through multi-pin connectors for high current operations. The ISL91110IIA-EVZ evaluation board is shown in Figures 4 and 5. The board’s enable function is controlled by the on-board jumper header J3. Similarly the Mode function is controlled by the on-board jumper header J4. be connected to the VOUT and GND headers on J2. Measure the input and output currents. Calculate efficiency based on these measurements. 11. To test external sync, remove the jumper at J4, then apply an external clock between 2.75MHz and 3.25MHz on the MODE input (the center pin of header J4). TABLE 1. OUTPUT VOLTAGE PROGRAMMING For ISL91110IIA-EVZ DESIRED OUTPUT VOLTAGE (V) R2 RESISTOR VALUE (kΩ) 2.0 665 2.5 470 3.0 365 3.3 324 3.4 309 4.0 249 4.5 215 5.0 191 The schematic of the ISL91110IIA-EVZ evaluation board is shown in Figure 6. The schematic for the ISL91110IIN-EVZ and ISL91110II2A-EVZ is shown in Figure 7. The PCB layout images for all layers are shown in Figures 8 and 11. The bill of materials of the ISL91110IIA-EVZ is shown in Table 2. The bill of materials of the ISL91110IIN-EVZ and ISL91110II2A-EVZ is shown in Table 3. Operating Range The VIN range of the boards is 1.8V to 5.5V. The VOUT range for the ISL91110IIA-EVZ is 2V to 5V. The IOUT range of the boards is 0 to 2A. The operating ambient temperature range is -40°C to +85°C. Quick Start Guide For the ISL91110IIA-EVZ board, the default output voltage is set at 3.3V. Should other output voltages are desired, resistor R2 can be changed to set to a desired voltage as shown in Table 1 (use a resistor with 1% accuracy). 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. LX1 2V/DIV LX2 2V/DIV VOUT 2V/DIV EN 2V/DIV IOUT = 200mA 400µs/DIV Quick Setup Guide 1. Install jumper on J3, shorting EN to VIN. FIGURE 2. ISL91110 START-UP WITH VIN = 2V and VOUT = 3.3V 2. Install jumper on J4, shorting MODE to VIN. 3. Connect power supply to J1, with voltage setting between 1.8V and 5.5V. 4. Connect electronic load to J2. 5. Place scope probes on the VOUT test point, and other test points of interest. LX1 2V/DIV LX2 2V/DIV 6. Turn on the power supply. 7. Monitor the output voltage start-up sequence on the scope. The waveforms will look similar to that shown in Figures 2 and 3. VOUT 2V/DIV 8. Turn on the electronic load. EN 2V/DIV 9. Measure the output voltage with the voltmeter. The voltage should regulate within datasheet spec limits. 10. To determine efficiency, measure input and output voltages at the Kelvin sense test points (S+ and S-), which are part of J1 and J2 headers. The bench power supply can be connected to the PVIN and GND headers on J1. The electronic load can 2 IOUT = 200mA 400µs/DIV FIGURE 3. ISL91110 START-UP WITH VIN = 4V and VOUT = 3.3V AN1912.1 March 12, 2014 Application Note 1912 ISL91110IIA-EVZ Evaluation Board FIGURE 4. ISL91110IIA-EVZ TOP VIEW FIGURE 5. ISL91110IIA-EVZ BOTTOM VIEW 3 AN1912.1 March 12, 2014 Application Note 1912 ISL91110IIA-EVZ Evaluation Board Schematic FIGURE 6. ISL91110IIA-EVZ EVALUATION BOARD SCHEMATIC TABLE 2. ISL91110IIA-EVZ EVALUATION BOARD BILL OF MATERIALS ITEM# QTY DESIGNATORS PART TYPE FOOTPRINT 1 1 U1 ISL91110IIAZ W4x5.20; WLCSP Intersil ISL91110 Buck-Boost Regulator with Adjustable Output Voltage INTERSIL 2 1 L1 1µH 3.2mmx2.5mmx1.2mm Power Inductor Toko DFE322512C series, 4.6A (typ), 34mΩ (typ) TOKO 3 1 C1 330µF 7343 Capacitor, Tantalum ANY 4 2 C2, C3 10µF/16V/X5R 0603 Capacitor, Generic ANY 5 2 C4, C5 22µF/10V/X5R 0603 Capacitor, Generic ANY 6 1 C6 56pF 0402 Capacitor, 56pF 50V 5% NP0 0402 ANY 7 1 C7 0.1µF 0402 Capacitor, Generic ANY 8 1 R1 1.02MΩ, 1% 0402 Resistor, Generic ANY 9 1 R2 324kΩ, 1% 0402 Resistor, Generic ANY 10 2 R3, R4 1MΩ, 5% 0603 Resistor, Generic ANY 11 2 J1, J2 HDR-6 HDR-6 Vert. Pin Header, 6-Pin, 0.1” Spacing, Generic ANY 12 2 J3, J4 HDR-3 HDR-3 Vert. Pin Header, 3-Pin, 0.1” Spacing, Generic ANY 13 3 TP1, TP2, TP3 SCOPE PROBE SCOPE PROBE 4 DESCRIPTION VENDORS Test Point, Scope Probe 131-5031-00 TEKTRONIX AN1912.1 March 12, 2014 Application Note 1912 ISL91110IIN-EVZ, ISL91110II2A-EVZ Evaluation Board Schematic FIGURE 7. ISL91110IIN-EVZ, ISL91110II2A-EVZ EVALUATION BOARD SCHEMATIC TABLE 3. ISL91110IIN-EVZ, ISL91110II2A-EVZ EVALUATION BOARD BILL OF MATERIALS ITEM# QTY DESIGNATORS PART TYPE FOOTPRINT DESCRIPTION VENDORS 1 1 U1 ISL91110IINZ, ISL91110II2AZ W4x5.20; WLCSP Intersil ISL91110 Buck-Boost Regulator INTERSIL 2 1 L1 1µH 3 1 C1 330µF 7343 Capacitor, Tantalum ANY 4 2 C2, C3 10µF/16V/X5R 0603 Capacitor, Generic ANY 5 2 C4, C5 22µF/10V/X5R 0603 Capacitor, Generic ANY 6 1 C6 DNP 0402 7 1 C7 0.1µF 0402 Capacitor, Generic ANY 8 1 R1 0Ω 0402 Resistor, Generic ANY 9 1 R2 DNP 0402 10 2 R3, R4 1MΩ, 5% 0603 Resistor, Generic ANY 11 2 J1, J2 HDR-6 HDR-6 Vert. Pin Header, 6-Pin, 0.1” Spacing, Generic ANY 12 2 J3, J4 HDR-3 HDR-3 Vert. Pin Header, 3-Pin, 0.1” Spacing, Generic ANY 13 3 TP1, TP2, TP3 SCOPE PROBE SCOPE PROBE Test Point, Scope Probe 131-5031-00 TEKTRONIX 5 3.2mmx2.5mmx1.2mm Power Inductor Toko DFE322512C series, 4.6A (typ), 34mΩ (typ) TOKO ANY ANY AN1912.1 March 12, 2014 Application Note 1912 PCB Layout FIGURE 8. TOP LAYER FIGURE 9. INNER LAYER 1 6 AN1912.1 March 12, 2014 Application Note 1912 PCB Layout (Continued) FIGURE 10. INNER LAYER 2 FIGURE 11. BOTTOM LAYER Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that the Application Note or Technical Brief is current before proceeding. For information regarding Intersil Corporation and its products, see www.intersil.com 7 AN1912.1 March 12, 2014