A8499-DS
High Voltage Step-Down
Regulator
A8499
„ 8 to 50 V input range
„ Integrated DMOS switch
„ Adjustable fixed off-time
„ Highly efficient
„ Adjustable 1.2 to 24 V output
Package LJ, 8-pin SOIC
with exposed thermal pad
FEATURES
„ Printer power supplies
„ Consumer equipment power supplies
APPLICATIONS
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).
VIN
LX
BOOT
ENB
TSET
GND
VBIAS
FB
+42 V
220 µF
10 V
ESR
VOUT
COUT
3.3 V / 1.2 A
17.8 kΩ
R1
L1
D1
R2
10.2 kΩ
0.22 µF
0.01 µF
CBOOT
C3 C3
RTSET
121 kΩ
47 µH
100 µF
50 V
A8499
Efficiency vs. Output Current
70.0
72.0
74.0
76.0
78.0
80.0
82.0
84.0
86.0
88.0
90.0
0 200 400 600 800 1000 1200 1400
I
OUT
(mA)
E
f
f
i
ci
e
n
cy
%
3.3
5
V
OUT
(V)
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.
TYPICAL APPLICATION
Approximate Scale 1:1