DEMO MANUAL DC1830B-C/DC1830B-D LTC4000-1 Battery Charger Controller and PowerPath Manager with Maximum Power Point Control DESCRIPTION Demonstration circuit 1830B is a battery charger control- This circuit was designed to demonstrate the high levels ler and PowerPath manager with maximum power point of performance and small solution size attainable using control (MPPC) featuring the LTC 4000-1. MPPC extracts this part to control a switch mode power converter to near maximum power from high impedance sources form a battery charger, intelligent PowerPath manager and such as solar panels, wind turbines or fuel cells. MPPC power supply system. It produces a regulated 5.0A/14.6V is achieved by means of an input voltage regulation con- battery charger output as well as a system output of up to trol loop. This board should be connected to a front-end 5.5A: suitable for a wide variety of portable applications DC/DC power supply for a complete charger solution. including instruments, industrial equipment, power tools and computers. The DC1830B is customizable to handle a wide variety of applications with output voltages from 3V to 30V and The DC1830B-C provides a solution complete with both output currents up to 6.5A with the PFETs supplied, and up battery charger control and PowerPath management. It to 60V and/or 13A with higher voltage rating and/or added includes a second PFET (Q2) between VOUT-SYS and PFETs. The reference design provided with DC1830B is BAT to provide instant-on functionality which keeps targeted at 4-cell LiFePO (14.6V/5A) applications. VOUT-SYS within a narrow range regardless of battery 4 voltage, and disconnects the battery when it is fully charged The DC1830B loop compensation values were proven with and power is available from the front-end DC/DC converter. the LTC3845A buck power converter shown and are typi- Thermal regulation circuitry is also provided to limit the cal for other applications. The output of this demo board temperature of both PFETs. was specifically tailored for a Tenergy 10A-hour battery, P/N 30207. Other voltages can be set by changing ROFB2 The DC1830B-D provides a simple battery-charger-con- and RBFB2. The desired nominal voltage can be accurately troller-only solution without the PowerPath manager. It trimmed by using trim resistors ROFBX and RBFBX. For deletes the second PFET and thermal regulation circuitry. example, for 14.4V battery float voltage, change ROFB2 In this case, the battery is always online and VOUT-SYS and RBFB2 to 86.6k, and add 7.5M at ROFBX and RBFBX tracks the BAT voltage. for greater setpoint accuracy. Other parameters can be ad- Design files for this circuit board are available at justed to suit specific applications with guidance provided DEMO MANUAL DC1830B-C/DC1830B-D PERMORMANCE SUMMARY Specifications are at T = 25C A SYMBOL PARAMETER CONDITIONS/COMMENTS MIN TYP MAX UNITS V Input Supply Range This Is the Input Voltage of the Front-End DC/DC Supply 20 60 V IN V Input Regulation Voltage This Is the Input Voltage Lower Limit Set by the LTC4000-1 35.1 V IN-MP V Battery Float Voltage 14.4 14.6 14.8 V FLOAT Output Regulation Line and Load (20V to 60V, 0A to 4.5A) 0 % I Battery Charge Current 5.0 A BAT Battery Charge Current Trickle 0.6 A t Charge Termination Time V = V 2.9 Hours T BAT FLOAT V System Output Voltage 12.3 14.6 15.5 V OUT-SYS I System Output Current Range 0 5.5 A OUT-SYS QUICK START PROCEDURE Demonstration circuit 1830 is offered for use in com- 2. With power off, connect the supply to the input terminals bination with a front-end DC/DC converter, and will need VIN and GND. to be customized to suit the intended application. It has NOTE: been supplied with components for a design as outlined a. Input voltages lower than 20V can keep the converter in the Performance Summary, and tested in conjunction from turning on due to the undervoltage lockout with the LTC3845A buck converter that it was tailored feature of the LTC4000-1. to. A separate demonstration board is available for the LTC4000-1/LTC3789 buck-boost combination, the b. Input voltages lower than the MPPC regulation point DC1721B. The LTC4000-1 data sheet should be used for (35.1V) will reduce the associated DC/DC converters guidance in determining circuit values for the application output to a minimum. at hand. You may follow the Design Example on page 26 of c. If efficiency measurements are desired, refer to Fig- the data sheet. Table 1 provides a summary of parameter ure 1 for the test setup. adjustments. 3. Set CHARGE jumper to ENABLE. NOTE: The PFETs supplied on this board are rated at 30V. 4. Turn on the power at the input. Once the circuit has been customized to suit the application at hand, it is easy to set up to evaluate the performance of NOTE: Make sure that the input voltage never exceeds the LTC4000-1 when combined with a suitable switching 60V. power converter, such as the LTC3845A. Voltages and 5. Check for the proper BAT output voltage of 14.6V. Turn currents cited in this procedure are for the design as de- off the power at the input. livered if the design has been customized, substitute the appropriate values. Refer to Figure 1 for proper measure- 6. Now that the proper output voltage is established, con- ment equipment setup and follow the procedure below: nect a variable load capable of sinking 6A at 16V to the output terminals BAT and GND. Set the current for 0A. WARNING: BATTERIES ARE POTENTIALLY DANGEROUS HIGH ENERGY SOURCES. IMPROPER CONNECTION, 7. Turn on the power at the input. OVERCHARGE, OR RAPID DISCHARGE COULD RESULT NOTE: If there is no output, temporarily disconnect the IN EXPLOSION AND/OR FIRE. load to make sure that the load is not set too high. 1. Set an input power supply that is capable of 60V and 3A, to 36V. Then turn off the supply. dc1830b-c/b-df 2