DEMO MANUAL DC1558A LTC3589 8-Output Regulator with 2 Sequencing and I C DESCRIPTION Demonstration Circuit 1558A is a multioutput power sup- The LTC3589 has two status registers, PGSTAT and IRQ- 2 ply with a pushbutton controller and I C, featuring the STAT, that can be used to determine the current state of LTC 3589EUJ. The LTC3589 has three synchronous buck the device. regulators, a buck-boost regulator, an always-on LDO, and 2 The two status registers can be read via I C and indicate three LDO regulators. The input range of the LTC3589 is which regulators are in regulation and if an undervoltage ideal for single cell Li-Ion/Polymer battery applications. (UV) or overtemperature (OT) event occurred. The com- The switching regulator settings such as enables, feed- mand registers which are used to control the switching back voltages, operating modes and other functions can regulators and program the special functions can also be 2 2 be controlled via I C. All of the regulators, except the read back via I C to assure the correct data was received. always-on LDO1, can also be enabled via external enable Refer to the LTC3589 data sheet for more details on the pins. After the first regulator is enabled, the remaining electrical and timing specifications. enable pins use a precision threshold to allow hardwired Design files for this circuit board are available at power-up sequences. All the regulators, except LDO1, can 2 DEMO MANUAL DC1558A QUICK START PROCEDURE DC1558A VIN range is 2.7V to 5.5V, ideal for single cell product page located at www.linear.com/product/ Li-Ion/Polymer battery applications. DC1558A utilizes LTC3589. The GUI installer will place a shortcut in 2 the DC590B, USB to I C interface board, to control the the start menu at location: Linear Technology Corp/ LTC3589 and to read back the contents of the command demoboards/LTC3589 GUI. Click on the shortcut to start and status registers. the GUI. The GUI reads back the current voltages of the regulators. LDO1 should read 1.2V, and VIN should read The DC1558 is easy to set up to evaluate the performance 5V, all others should be 0V. of the LTC3589. Refer to Figure 1 and Figure 2 for proper measurement equipment set-up and follow the evaluation 3. Press the PB1 button on the DC1558A for more than procedure below using the DC590B board. 0.5s, and all of the power supplies should come up and the displayed GUI page should match Figure 3. The NOTE. When measuring the input or output voltage ripple, sequencing for these supplies was set by LTC using care must be taken to avoid a long ground lead on the resistor divider networks from the supply outputs to oscilloscope probe. Measure the input or output voltage control the ENx lines. Note: All displayed voltages are ripple by touching the probe tip directly across the VIN or 30mV. VOUT and GND terminals. See Figure 2 for proper scope probe technique. 4. Each of the supplies can be loaded to test the regula- tors, but be aware that LDO2 to LDO4 can be powered 1. Ensure that JP1 to JP3, and SW1 are in their default from VIN (see JP1 and JP2), on the DC1558A and the positions, as shown in Figure 1. Set PS1 to 5V and turn dissipation can be significant. If significant current is on. The RST0 LED should light until LDO1 comes on, desired from these regulators, care in input voltage and the PGOOD LED should come on and stay on. selection will be required. NOTE. The DVCC voltage level may be selected on the 5. Press and hold the PB1 button for more than 5 seconds, DC590B. This is done by setting the VCCIO jumper, and all of the regulators, except LDO1, will shut down. JP6, on the DC590B board to one of the following The GUI will show the voltages for all regulators, other settings: 3.3V, 5V, removed for 2.7V or set to external than always on LDO1, as 0V. LDO1 should read 1.2V if an external supply is desired to be used. Please set and V should read 5V. IN DVCC to 5V. Please refer to the documentation for the DC590B board for more information. 6. Refer to the USING THE LTC3589 SOFTWARE section for more information on how to control the device using 2. Start the Linear Technology QuikEval program. Down- the LTC3589 control window. load and install the latest version of the QuikEval program from the following weblink: