Data Sheet

ADPL76030

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Rev.0

21 of 40

Figure 39. Peak-Buck in Buck-Boost Region (VIN ~> VOUT)

(3) Peak-Boost in Buck-Boost Region (V

IN)<~VOUT

When VIN is slightly lower than VOUT, the ADPL76030 uses peak-boost current-mode control in buck-boost region

(Figure 40). Switch A is always turned on for the beginning of the cycle and switch B is always turned on for the

remainder of the cycle. At the beginning of every cycle, switches A and C are turned on and the inductor current

ramps up. When the inductor current hits the peak boost current threshold commanded by VC voltage at boost

current comparator A4 during (A + C) phase, switch C is turned off and switch D is turned on for the rest of the cycle.

Figure 40. Peak-Boost in Buck-Boost Region (VIN<<VOUT)

(4) Peak-Boost in Boost Region (V

IN << VOUT)

When VIN is much lower than VOUT, the ADPL76030 uses peak-boost current-mode control in boost region (Figure 41).

Switch A is always on and switch B is always off. At the beginning of every cycle, switch C is turned on and the inductor

current ramps up. When the inductor current hits the peak boost current threshold commanded by VC voltage at

boost current comparator A4 during (A+C) phase, switch C is turned off and switch D is turned on for the rest of the

cycle. Switches C and D alternate, behaving like a typical synchronous boost regulator.

A

B

C

D

IL

A+D

A+C

B+D

A+D

A+C

B+D

A

B

C

D

IL

A+D

A+C

B+D

A+D

A+C

B+D