Datasheet

Data Sheet ADP1851
Rev. 0 | Page 3 of 24
SIMPLIFIED BLOCK DIAGRAM
Figure 2. Simplified Block Diagram
BST
PGND
+
–
+
–
+
–
+
–
FB
PH
OV_TH
UV_TH
PGOOD
CURRENT SENSE
AMPLIFIER
DH
DL
ILIM
SW
V
REF
= 0.6V
+
+
–
ERROR
AMPLIFIER
FB
COMP
SS/TRK
PWM
COMPARATOR
SLOPE COMPENSATION
AND RAMP GENERATOR
CURRENT-LIMIT
CONTROL
RAMP
50µA
OV
CS GAIN
DRIVER LOGIC
CONTROL AND
STATE
MACHINE
OVER_LIM
PULSE SKIP
OVER_LIM
LDO
LOGIC
EN
VIN
UVLO
OSCILLATOR
FREQ
SYNC
REF
VCCO
OV
UV
0.6V
THERMAL
SHUTDOWN
AGND
(EPAD)
FAULT
OV
LOGIC
OVER_LIM
OV
EN
EN_SW
PH
LOGIC
UV
3kΩ
0.9V
DCM
*0 (ZERO) GAIN IS FOR VOLTAGE MODE WITH RAMP FROM 0.7V TO 2.2V.
ZERO
CROSS
DETECT
12.5kΩ
A
V
= 0*, 3, 6, 12
VCCO
EN_SW
1MΩ
–
+
VCCO
VCCO
VCCO
VCCO
0.63V
6.5µA
10595-002