The evaluation circuit EVAL-LTC7899-AZ features the LTC®7899: a 140V Low IQ, synchronous, negative input to positive output controller with programmable 5V to 10V gate drive. Split gate drivers allow for easily adjustable turn-on and turn-off of FETs. User adjustable adaptive and set dead time control modes are available for optimal gate timing. Additionally, the IC features low IQ, up to 2.5MHz programmable/synchronizable switching frequency, spread spectrum, in a small 28-lead (4mm x 5mm) QFN package. These features allow for a wide variety of applications including industrial, military, and telecommunications systems.
The EVAL-LTC7899-AZ operates from a -32V to -54V input voltage range and generates a positive 48V output, up to 8.8A load current. The EVAL-LTC7899-AZ is set to a 150kHz switching frequency, which results in up to 97.3% peak efficiency.
The LTC7899 supports a wide input and output voltage range (|VIN- |+VOUT) up to 135V. The evaluation circuit has been designed with 120V FETs, various FETs of similar footprint can be substituted to fit a wide array of applications.
The EVAL-LTC7899-AZ provides a high-performance, cost-effective solution for generating a positive 48V output from a negative input. The LTC7899 data sheet gives a complete description of this part, its operation, and application information. The data sheet must be read in conjunction with this user guide for EVAL-LTC7899-AZ.
Design files for this circuit board are available at www.analog.com.
