USERS MANUAL ISL8203MEVAL2Z AN1941 Rev 1.00 Evaluation Board August 29, 2014 The ISL8203M is a complete, dual step-down power module Key Features with integrated PWM controller, synchronous switching V range 2.85V to 6V MOSFETs, inductors, and passives. The ISL8203M is rated for IN dual 3A output current or 6A current sharing operation with an V adjustable 0.8V to 5V OUT input range of 2.85V to 6V. The two channels are 180 Peak current limiting and hiccup mode short circuit out-of-phase for input RMS current and EMI reduction. protection The simplicity of the ISL8203M is its off the shelf, unassisted Over-temperature protection implementation. It is easy to apply this complete step-down Internal digital soft-start power module to any low voltage low power application. External synchronization up to 4MHz The ISL8203MEVAL2Z evaluation board is designed to Flexibility to operate in dual output mode or parallel single demonstrate the performance of the ISL8203M. The board is output mode with simple resistor changes. by default set up to demonstrate two 3A outputs independently, and can also be easily set up for current Mechanical switch for enable and power-good LED indicator sharing 6A by changing placeholder resistors. Connectors, test points, and jumpers for easy probing Related Resources Recommended Equipment ISL8203M datasheet 0V to 6V power supply with at least 5A source current capability Ordering Information Electronic load capable of sinking current up to 6A PART NUMBER DESCRIPTION Digital multimeters (DMMs) ISL8203MEVAL2Z ISL8203M Dual 3A/Single 6A 100MHz quad-trace oscilloscope Power Module Evaluation Board LOAD2 (0A TO 3A) - + (2.85V TO 6V) LOAD1 (0A TO 3A) FIGURE 1. ISL8203MEVAL2Z BOARD PHOTO AN1941 Rev 1.00 Page 1 of 14 August 29, 2014ISL8203MEVAL2Z 8. Measure the output voltage at test points VOUT1 or VOUT2 Functional Description and GND test point. The ISL8203Ms two 3A outputs may be used independently or Programming the Output Voltage combined to deliver a single 6A output. Each of the two channels employs the current mode pulse width modulation scheme for The ISL8203MEVAL2Z evaluation board has several preset fast transient response and pulse-by-pulse current limiting. The output voltages, 1.0V, 1.2V, 1.5V, 2.5V, and 3.3V, which can be two channels each operate at a fixed 1MHz switching frequency, selected in J1 and J2 jumper. To program for other output and are 180 out-of-phase, which reduces the input and output voltages in the range from 0.8V to 5V, the user can use a noise. The ISL8203M offers internal digital soft-start, external feedback resistor divider based on Equation 1. synchronization, overcurrent protection, and over-temperature protection. For further information, please refer to the ISL8203M R FB TOP (EQ. 1) V =1 + -------------------------------------------------- 0.8V OUT datasheet. R FB BOTTOM The top feedback resistor R is typically 100k . In the Quick Start FB-TOP ISL8203MEVAL2Z evaluation board, the top feedback resistor is Dual Output Mode R (for channel 1) and R (for channel 2). 12 11 1. Make sure the placeholder resistors are set for dual output Setting Parallel Single Output Mode mode according to Table 1 (The ISL8203MEVAL2Z evaluation The ISL8203MEVAL2Z evaluation board is by default set up in board is by default set up in dual output mode). dual output mode with two independent outputs, but it can also 2. Set the ENABLE switches S1 and S2 to OFF positions. be easily modified to parallel single output circuit by changing 3. Select the output voltage for channel 1 by making a selection several placeholder resistors. Table 1 shows the placeholder sets on jumper J1. Similarly, select the output voltage for to program the default dual output mode and the parallel single channel 2 by making a selection on jumper J2. output mode. 4. Connect the positive of a power supply to VIN1 and VIN2 TABLE 1. PLACEHOLDER SETS TO PROGRAM DUAL OUTPUT MODE connectors, and the negative of the power supply to one or AND PARALLEL SINGLE OUTPUT MODE both of the GND connectors. Make sure the power supply is DUAL OUTPUT PARALLEL SINGLE OUTPUT not enabled when making connections. PLACEHOLDER MODE MODE 5. Turn the power supply on. R Open 0 6. Turn ENABLE switch S1 to ON position to enable channel 1 13 and switch S2 to on position to enable channel 2. Each R 0 Open 24 ENABLE switch can control channel 1 and channel 2 R 0 Open 25 independently. R Open 0 7. The power-good LED should glow in green if both channel 1 28 and channel 2 are operating properly. If either one channel is R , R Open 0 (SMD, size 2010) or copper 18 19 disabled or not operating properly, the LED will glow in red. strips 8. Measure the channel 1 (or channel 2) output voltage at test points VOUT1 (or VOUT2) test point and adjacent GND test External Synchronization point. The frequency of operation can be synchronized up to 4MHz by Parallel Single Output Mode an external signal applied to the SYNC pin. The switching frequency per channel is half of the external signals frequency 1. Set the placeholder resistors for parallel single output mode applied to the SYNC pin. The maximum external signal frequency according to Table 1. is limited by the SW minimum on time (140ns MAX) 2. Set the ENABLE switches S1 and S2 to OFF positions. requirement, which can be calculated as shown in Equation 2. 3. Select the output voltage using either one of the jumpers J1 V 1 1 OUT ---- ------------------ ------------------------ f ==f and J2, but do not use both J1 and J2 at the same time. (EQ. 2) SW MAX 2 SYNC MAX V 140ns IN 4. Connect the positive of a power supply to VIN1 and VIN2 connectors, and the negative of the power supply to one or where: both of the GND connectors. Make sure the power supply is f is the maximum external signal frequency not enabled when making connections. SYNC-MAX 5. Turn the power supply on. f is the maximum switching frequency per channel SW-MAX 6. Turn both ENABLE switches S1 and S2 to on positions, in any order. Both ENABLE switches need to be in the on position in order to enable the output. 7. The power-good LED should glow in green if the output is operating properly. If module is disabled or not operating properly, the LED will glow in red. AN1941 Rev 1.00 Page 2 of 14 August 29, 2014