a8450 Allegro MicroSystems, Inc., a8450 Datasheet - Page 5

• Manufacturer Part Number: a8450
• Description: Automotive Multioutput Voltage Regulator
• Manufacturer: Allegro MicroSystems, Inc.

A8450KLB-DS, Rev. 2
Figure 1a. NPOR fault due to undervoltage lockout on the V33 or FB pins
Figure 1b. Power-off using V
Figure 1c. Power-on using ENBAT, followed by power-off using ENB
Slope of V
Slope of V
V33 can sustain regulation with normal load by bulk capacitor (COUT) on V
REG
VREG Monitor
V
(which controls
OUTV5A/V5D
ENBAT signals power-on
V
V
V
V
OUTVADJ
V
V
OUTVADJ
OUTV33
OUTVADJ
V
V
OUTV33
V
OUTV33
OUTV33
V
V
ENBAT
ENBAT
V
V
V
V
V
NPOR
NPOR
NPOR
V
REG
ENB
ENB
REG
V
REG
CP
BB
Charge pump ramping
Charge pump OK flag set
and V
POR event initiates
BB
V
V
UVLOV33
OUTV5A/V5D
OUTVADJ
exceeded; VADJ enabled
from A to B determined by I
, V
A B
OUTV33
V
BB
Timing Diagrams
> 6 V
, and V
V
HYSV33
Automotive Multioutput Voltage Regulator
t
SS
OUTVADJ
+7 V
LOAD
V
) from A to B determined by I
REG
V
UVLOV33
t
POR
and output capacitor (C3, C4).
t
= 1.8 V
POR
V
V
ENB signals power-off
UVLOVREG
UVLOV33
V
t
POR
UVLO(33)
REG
.
LOAD
and COUT.
V
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
A
HYSVADJ
t
POR
t
B
V
POR
UVLOVADJ
A8450
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