New Industry Products

Control Vout of Any DC-DC Regulator with a Serial PMBus Interface

January 22, 2018 by Paul Shepard

Analog Devices announces the Power by Linear™ LTC7106, a PMBus I²C controlled precision bidirectional current DAC designed to adjust the output voltage of virtually any dc-dc regulator. Through its PMBus compatible interface, the LTC7106 receives a 7-bit serial code and converts it to a bidirectional (source, sink) output current.

When the current is fed into the feedback network of a regulator, its output voltage can be programmed dynamically for load power/performance optimization or margining in response to serial VID commands. Available in a 2mm x 3mm DFN-10 package, the LTC7106 enables small and simple solution for a wide range of discrete and modular dc-dc voltage regulators.

Its internal power-on reset circuitry keeps the DAC output current at zero until a valid write takes place. Other features include a range bit for easy interfacing to almost any impedance resistor divider, and an open-drain output for controlling the Run or Enable pin of the regulator.

To prevent abrupt changes in the DAC output current and subsequently the output voltage of the regulator, an internal digital programmable slew rate can be programmed from 500ns/step to 3.5ms/step.

The LTC7106 operates over an input voltage range of 2.5V to 5.5V and is supported by the easy to use LTpowerPlay® development tool with graphical user interface (GUI).

Additional features include ±1% output current accuracy over temperature, a wide range bidirectional DAC output current from ±16µA to ±256µA, wide DAC operational voltage range from 0.4V to 2V, and a precision enable threshold to support external undervoltage lockout. Extended and industrial temperature versions are available from -40 to 125 degrees C.

Summary of Features:

  • Vout Control of Any Regulator
  • ±1% Output Current Accuracy (-40°C to 125°C)
  • PMBus/I²C Compliant Serial Interface
  • Input Voltage Range: 2.5V to 5.5V
  • 7-Bit Programmable DAC Output Current for Vout Control
  • Wide Range of IDAC Output Current: ±16µA to ±256µA
  • Programmable Slew Rate: 500ns ~ 3.5ms per Bit
  • High Impedance at IDAC Output When Disabled or at DAC Code Zero
  • Wide DAC Operation Output Voltage (0.4V to 2.0V)
  • Precision Enable Threshold to Support External UVLO
  • Available in 10-Lead 3mm × 2mm DFN Package

The LTC7106 is available for immediate delivery. Pricing starts at $1.25 each in lots of 1,000 pieces.