Data Sheet

DATA SHEET | SENTIMATE
4.4.2. External DC input path
When power source comes from external DC supply the acceptable voltage range can accommodate the most used
typical DC values like 5V, 12V and 24V; the input can be from 5 to 40Vdc.
In this extended voltage input with fixed 3,3V output one of the most important thing is the efficiency and then a switch-
ing buck configuration has been designed.
For this power section SENTIMATE integrate the ADI LT8606 that is a 42V, 350mA Synchronous Step-Down Regulator
with 2.5μA Quiescent Current, with the following features.
• Wide Input Voltage Range: 3.0V to 42V
• Ultralow Quiescent Current Burst Mode® Operation:
o <3μA IQ Regulating 12VIN to 3.3VOUT
o Output Ripple <10mVP-P
• High Efficiency 2MHz Synchronous Operation:
o >92% Efficiency at 0.35A, 12VIN to 5VOUT
• 350mA Maximum Continuous Output
• Fast Minimum Switch-On Time: 35ns
• Adjustable and Synchronizable: 200kHz to 2.2MHz
• Spread Spectrum Frequency Modulation for Low EMI
• Allows Use of Small Inductors
• Low Dropout
• Peak Current Mode Operation
• Accurate 1V Enable Pin Threshold
• Internal Compensation
• Output Soft-Start and Tracking
• Small Thermally Enhanced 10-Lead MSOP Package or 8-Pin 2mm × 2mm DFN Package
Implementation of the LT3106 on SENTIMATE board
The input connector accept voltage from 5V to 40V DC, here in after the circuit implemented in SENTIMATE board.
4.4.1. Power Path
The two power stages described above produce both a 3,3V stabilized voltage and then only one of them are selected
as main voltage source for the entire SENTIMATE board. This selection process is done by the LTC4415 dual 4A ideal
diode from ADI.
The LTC4415 contains two monolithic PowerPath ideal diodes, each capable of supplying up to 4A with typical forward
conduction resistance of 50mΩ. The diode voltage drops are regulated to 15mV during forward conduction at low cur-
rents, extending the power supply operating range and ensuring no oscillations during supply switchover. Less than 1μA
of reverse current flows from OUT to IN making this device well suited for power supply ORing applications.