Triple-Output Buck Controllers
Oscillator Timing Resistor Connection. Connect a 15.6kI to 93.75kI resistor from RT to SGND to
program the switching frequency from 200kHz to 1.2MHz.
Analog Ground. Connect SGND and PGND_ together at one point near the input bypass capacitor
Controller 2 Power Ground. Connect the input filter capacitor’s negative terminal, the source of the
synchronous MOSFET, and the output filter capacitor’s return to PGND2.
Controller 2 Low-Side Gate-Driver Output. DL2 is the gate-driver output for the synchronous MOSFET.
Controller 2 Low-Side Gate-Driver Supply. Connect externally to REG through a 1I to 4.7I resistor.
Connect a minimum of 0.22FF ceramic capacitor from DREG2 to PGND2.
Controller 2 High-Side MOSFET Source Connection/Synchronous MOSFET Drain Connection.
Connect the inductor and the negative side of the boost capacitor to LX2.
Controller 2 High-Side Gate-Driver Output. DH2 drives the gate of the high-side MOSFET.
Controller 2 High-Side Gate-Driver Supply. Connect a 0.1FF ceramic capacitor from BST2 to LX2.
Controller 2 Enable/Tracking Input. See Figure 2. When tracking (MAX15048), connect the same
resistive voltage-divider used for FB2 from output 1 to EN2 to SGND for coincident tracking. Connect
EN2 to analog ground for ratiometric tracking. When sequencing (MAX15049), EN2 must be above
0.6V for PWM controller 2 to start.
Controller 2 Feedback Regulation Point. Connect to the center tap of a resistive voltage-divider from
the converter output to SGND to set the output voltage. The FB2 voltage regulates to 0.6V (typ).
Controller 2 Transconductance Error-Amplifier Output. Connect COMP2 to the compensation
feedback network of output 2.
(5mm × 5mm)