Evaluation circuit EVAL-LTC7878-AZ features the LTC®7878: a 70V parallelable buck-boost controller with inductor DCR current sensing. The LTC7878 is a four-switch buck-boost switching regulator designed to operate above, below, or equal to the output voltage safely and easily. The constant-frequency, peak-current mode architecture allows phase-lockable switching frequency up to 600kHz. A programmable input or output current loop regulates the average input or output current loop, making it suitable for battery charging applications. Additionally, with a wide 5V to 70V input and output range and seamless, low-noise transition between operating regions, the LTC7878 is ideal for industrial and telecom systems.
The EVAL-LTC7878-AZ operates from a 18V to 65V input voltage range and generates an output of 24V and at least a 20A load. The board features two LTC7878’s in parallel to achieve very high power. The parallel operation is set to a switching frequency of 100kHz, which results in an efficient circuit. Both phases are set 180° offset to interleave the switching while still providing great current sharing.
The LTC7878 has a precision voltage reference that can generate an output voltage with a 1% tolerance over the full operating conditions. The converter achieves over 98% efficiency with a 20A load at full operating VIN.
This board can be easily modified to regulate output voltages from 1V to 70V. Its multiphase/multi-ICs parallel operation feature allows for simple alterations for higher power.
The EVAL-LTC7878-AZ provides a high-performance, cost-effective solution for generating a 24V output. The LTC7878 data sheet gives a complete description of this part, its operation, and applications information. The data sheet must be read in conjunction with this user guide for EVAL-LTC7878-AZ.
Design files for this circuit board are available at www.analog.com.
