A8499
High Voltage Step-Down
Regulator
Package LJ, 8-pin SOIC
with exposed thermal pad
The A8499 is a step down regulator that will handle a
wide input operating voltage range.
The A8499 is supplied in a low-profile 8-lead SOIC
with exposed pad (package
LJ).
Approximate Scale 1:1
FEATURES
8 to 50 V input range
Integrated DMOS switch
Adjustable fixed off-time
Highly efficient
Adjustable 1.2 to 24 V output
APPLICATIONS
Printer power supplies
Consumer equipment power supplies
TYPICAL APPLICATION
+42 V
Efficiency vs. Output Current
CBOOT
0.01 μF
C3
100 μF
50 V
C3
0.22 μF
ENB
LX
A8499
TSET
RTSET
L1
47 μH
VOUT
3.3 V / 1.2 A
Efficiency %
BOOT
VIN
VBIAS
R1
17.8 kΩ
ESR
COUT
220 μF
10 V
121 kΩ
GND
FB
D1
90.0
88.0
86.0
84.0
82.0
80.0
78.0
76.0
74.0
72.0
70.0
0
200
400
600
800
1000
V
OUT
(V)
3.3
5
1200
1400
R2
10.2 kΩ
I
OUT
(mA)
Circuit for 42 V step down to 3.3 V at 1.2 A. Efficiency data from circuit shown in left panel.Data is for reference only.
A8499-DS
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
