DC1757A: 12V @ 12A, 5 ~ 36V in, Buck/Boost

Summary

Demonstration circuit 1757A is a high efficiency synchronous buck-boost DC/DC converter with a 6V to 36V input voltage range. It can supply a 12A maximum load current with a 12V output. The demo board features the LTC®3789EGN controller. The constant frequency current mode architecture allows a phase-lockable frequency of up to 600 kHz, while an optional output current feedback loop provides support for applications such as battery charging.

With a wide input range, wide output range and seamless transfers between operation modes, the LTC3789 is ideal for automotive, telecom, distributed DC power systems and battery-powered applications.

The light load operation mode of the converter is determined with the MODE/PLLIN pin. Use JP2 jumper to select pulse-skipping mode or forced continuous mode (CCM) operation. The switching frequency is pre-set at about 200 kHz. The converter can also be externally synchronized to an external clock through the MODE/PLLIN pin (PLLIN terminal on the board). To shut down the converter, force the RUN pin below 1.2V (JP1: OFF).

The power good output (PGOOD terminal) is low when the output voltage is outside of the ±10% regulation window.

Specifications

Manufacturer	Analog Devices Inc.
Category	AC/DC and DC/DC Conversion
Sub-Category	DC/DC SMPS - Single Output
Eval Board Part Number	DC1757A-ND
Eval Board Supplier	Analog Devices Inc.
Eval Board	Board not Stocked
Topology	Step Up/Down
Outputs and Type	1 Non-Isolated
Voltage Out: Factory Set	12 V
Current Out	12 A
Voltage In	5 ~ 36 V
Efficiency @ Conditions	>96%, 12V in, 12V @ 2.2 ~ 12 A >94%, 6V in, 12V @ 1.4 ~ 12 A >94%, 24V in, 12V @ 3.3 ~ 12 A >92%, 36V in, 12V @ 4.4 ~ 12 A
Voltage Out Range	0.8 ~ 38 V
Features	Current Limit (Adj. or Fixed) LDO Regulator(s), On-Chip Light Load Mode Power Good Output Short Circuit Protection Shutdown, Enable, Standby Soft Start Synchronizable Under Voltage Protection, Brown-Out
Switching Frequency	200 kHz
Standby Current [Typical]	40 µA
Quiescent Current [Typical]	3 mA
Component Count + Extras	68 + 16
Internal Switch	No
Design Author	Linear Technology
Application / Target Market	Automotive Power: Auxiliary Power Supply Power: Industrial Power
Standby Current [Maximum]	60 µA
Quiescent Current [Maximum]	- Not Given
Main I.C. Base Part	LTC3789
Date Created By Author	2011-07
Date Added To Library	2015-07