DEMO MANUAL DC1808B-A/DC1808B-B LTC3589EUJ-1/LTC3589EUJ-2 8-Output Regulator with 2 Sequencing and I C Description Demonstration circuit 1808B-A/1808B-B is a multioutput The LTC3589EUJ-x has two status registers, PGSTAT and 2 power supply with a pushbutton controller and I C, featur- IRQSTAT, that can be used to determine the current state ing the LTC 3589EUJ-1 (-A) or LTC3589EUJ-2 (-B). The of the device. LTC3589EUJ-x has three synchronous buck regulators, 2 The two status registers, which can be read via I C, in- a buck-boost regulator, an always-on LDO and three LDO dicate which regulators are in regulation and if a UV or regulators. The input voltage range of the LTC3589EUJ-x OT event occurred. The command registers, which are is ideal for single-cell Li-Ion/Polymer battery applications. used to control the switching regulators and program the The switching regulator settings, such as enables, feed- 2 special functions, can also be read back via I C to assure back voltages, operating modes and other functions, can the correct data was received. 2 be controlled via I C. All of the regulators, except the Refer to the LTC3589EUJ data sheet for more details on always-on LDO1, can also be enabled via external enable the electrical and timing specifications and for an explan- pins. After the first regulator is enabled, the remaining ation of the different device options (LTC3589-1 and enable pins use a precision threshold to allow hardwired LTC3589-2). Also see Table 1 in this demo manual. power-up sequences. All the regulators, except LDO1, can 2 also be enabled via the I C. Design files for this circuit board are available at DEMO MANUAL DC1808B-A/DC1808B-B Quick s Dp 1. Ensure that JP1 to JP3, and SW1 are in their default LTC3589, LTC3589-1, AND LTC3589-2 FUNCTIONAL positions, as shown in Figure 1. Set PS1 to 5V and turn COMPARISON on. The RST0 LED should light until LDO1 comes on, Table 1 summarizes the functional differences between the and the PGOOD LED should come on and stay on LTC3589, LTC3589-1, and LTC3589-2. NOTE: The DV voltage level may be selected on the CC Table 1. LTC3589, LTC3589-1 and LTC3589-2 Functional Differences DC590B. This is done by setting the V jumper, JP6, CCIO LTC3589 LTC3589-1 LTC3589-2 on the DC590B board to one of the following settings: Power-On Inhibit 1 Second <2ms <2ms 3.3V, 5V, removed for 2.7V, or set to external if an external Enable Delay supply is used. Please set DV to 5V. CC Buck2 Current Output 1A 1.2A 1.2A Buck3 Current Output 1A 1.2A 1.2A 2. Start the Linear Technology QuikEval program. This program should automatically detect the presence of the PGOOD Fault Timeout Enabled by Disabled by Disabled by Default. Default. Default. LTC3589EUJ-x demo board (DC1808B-A/1808B-B) and 2 2 2 I C Disable. I C Enable. I C Enable. activate the appropriate GUI, as seen in Figure 3. The PWR ON to WAKE 50ms 2ms 2ms GUI reads back the current voltages of the regulators. Delay LDO1 should read 1.2V, and V should read 5V all IN LDO3 V 1.8V 2.8V 2.8V OUT others should be 0V. LDO4 V 1.8V, 2.5V, 1.2V*, 1.8V, 1.2V*, 1.8V, OUT 2.8V*, 3.3V 2.5V, 3.2V 2.5V, 3.2V *Indicates Default V OUT 3. Press the PB1 button on the DC1808B-A/1808B-B for 2 2 Default LDO4 Enable LDO34 EN Pin I C I C more than 0.5s all of the power supplies should come Wait to Enable Until Yes, by Default. Yes, by Default. No, by Default. up and the displayed GUI page should match Figure 3. 2 2 2 Output < 300mV I C Select. I C Select. I C Select. The sequencing for these supplies was set by Linear Insert 2k Discharge Yes, if Start-Up Yes, if Start-Up Always Technology, using resistor divider networks from the Resistor When Is Wait to Enable Is Wait to Enable supply outputs to control the ENx lines. Disabled Until Output < Until Output < 300mV 300mV 4. Each of the supplies can be loaded to test the regulators, but be aware that LDO2~4 on the DC1558A are powered from V , and the dissipation can be significant. If IN significant current is desired from these regulators, care with input voltage selection will be required. 5. Press and hold the PB1 button for more than 5s, and all of the regulators, except LDO1, will shut down. The GUI will show the voltages for all regulators, other than always-on LDO1, as 0V. 6. Refer to the Using the LTC3589EUJ Software section for more information on how to control the device using the LTC3589EUJ control window. 7. Refer to the LTC3589EUJ data sheet for more details on how the LTC3589EUJ operates. 8. When done, close the LTC3589EUJ GUI and turn off all loads and power supplies. dc1808babbf 2 ure roce tart