Maxim Integrated Debuts Two 60V DC-DC Inverting ConvertersApril 12, 2021 by Gary Elinoff
The synchronous devices feature integrated level-shifters, and are said to offer a 6% energy efficiency advantage over competitive devices
The MAX17577 and MAX17578 are highly integrated step-down converters that can save up to 72% of board space by greatly reducing the number of required external components. The 6% efficiency advantage means that the devices also dissipate 35% less power, generating less harmful waste heat.
Image courtesy of Maxim
The MAX17577 and MAX17578 operate over an unusually wide input range of from 4.5 to 60 volts, with outputs adjustable from -0.9 volts to -36 volts. Maximum output current is 1 amp, and the devices offer a peak efficiency of 90.6%
CCM or DCM
Both units feature peak current-mode control architecture, and their main difference lies in their mode of operation. The MAX17577 operates in continuous conduction mode (CCM) at all loads for a constant frequency operation. The MAX17578 operates in discontinuous conduction mode (DCM), which yields better efficiency at light loads.
Low minimum ON-time allows higher switching frequencies and small solution sizes, and the units can switch at frequencies ranging from 400 kHz to 2.2 MHz.
Simplified application circuit for the MAX17577 and MAX17578. Image courtesy of combined datasheet
As per John Woodward, business management director, Industrial Power Product Line at Maxim Integrated, “By integrating level shifters, the MAX17577 and MAX17578 reduces design size and component count dramatically for baseband solutions and IoT devices.” He goes on to state that. “These efficient negative voltage regulators reduce system temperature rise and support the industry’s widest input voltage range to provide robust protection against unpredictable voltage transients.”
- System IO pins, such as Enable, Reset and UVLO can be driven by signals referenced to the system’s ground. This eliminates the necessity for external-level shifter circuits.
- Overload protection works in hiccup-mode
- The units’ two internally integrated MOSFETS feature typical on-resistances of 330 mΩ and 163 mΩ, high-side and low-side, respectively
- Both devices feature a 6.2 µA shutdown current
- Continuous power derating of 24.4 mW/°C at temperatures above +70°C
- Minimum on-time and off-time are typically 60ns and 150ns, respectively
- Industrial automation
- Building automation
- Communication systems
- Point of load power
- Gate drive circuitry
- Motion control
- High voltage, single board systems
- The devices operate over an ambient operating temperature range of -40 to +120°C
- Both units are available in 12-pin, 3 x 3 mm TDFN packages
- RoHS compatibility is available
Getting to Market Faster
Maxim offers evaluation kits for both inverting converters. Both switch at 600 kHz. The kits are programmable and fully exercise the devices’ capabilities. Additionally, the EV kits themselves provide a layout example useful to OEMs seeking to best utilize the units
For the MAX17577, the MAX17577EVKIT# the evaluation kit operates from a 16 to 48-volt input, and produces a -12 volt output at load currents up to 0.8A. It features the MAX17577 operating in continuous conduction mode (CCM) at all loads.
The MAX17578EVKIT# evaluation kit, for the MAX17578 tests over an input range of 16 to 55 volts and presents a -5 volt output at loads up to 1 amp. Here, the MAX17578 is showcased in discontinuous conduction mode (DCM).