MAX8792 Maxim Integrated Products, MAX8792 Datasheet - Page 13

• Manufacturer Part Number: MAX8792
• Description: Single Quick-PWM Step-Down Controller
• Manufacturer: Maxim Integrated Products

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The Quick-PWM control architecture is a pseudo-fixed-
frequency, constant on-time, current-mode regulator
with voltage feed-forward (Figure 2). This architecture
Figure 2. MAX8792 Functional Block Diagram
TON
FB
EN
PGOOD
Free-Running Constant-On-Time PWM
EA - 0.2V
Controller with Input Feed-Forward
EA + 0.3V
______________________________________________________________________________________
TRIG
ONE-SHOT
AMPLIFIER
t
ON
ERROR
MAX8792
Q
COMPUTE
ON-TIME
PROTECTION
AND FAULT
PGOOD
Controller with Dynamic REFIN
IN
FB
INTEGRATOR
Single Quick-PWM Step-Down
(CCV)
BLANK
EA
relies on the output filter capacitor’s ESR to act as a cur-
rent-sense resistor, so the output ripple voltage provides
the PWM ramp signal. The control algorithm is simple:
the high-side switch on-time is determined solely by a
one-shot whose pulse width is inversely proportional to
Q
S
R
START/STOP
ONE-SHOT
SOFT-
t
OFF(MIN)
Q
VALLEY CURRENT LIMIT
TRIG
S
R
ZERO CROSSING
Q
BLANK
DECODE
TRANSITION DETECTION
QUAD-
LEVEL
REF
2V
DYNAMIC OUTPUT
DH
LX
DL
REFIN
BST
GND
SKIP
REF
V
ILIM
V
DD
CC
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