LX1734
TM
®
1.0MHz Inverting DC/DC Converter
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, the following specifications apply over the operating ambient temperature 0°C
≤
T
A
≤
85°C and the following
test conditions: V
IN
= 5V
Parameter
Minimum Operating Voltage
V
IN
Under Voltage Lockout
Reference Voltage
Reference Voltage Line Regulation
NFB Pin Bias Current
Quiescent Current
Quiescent Current
Switching Frequency
Maximum Duty Cycle
Switch V
CESAT
Switch Leakage Current
Switch Circuit Current Limit
High
Low
Shutdown Input Voltage
Bias
Current
WWW .
Microsemi
.C
OM
Symbol
V
IN
UVLO
V
NFB
I
NFB
I
Q
I
SHDN
Test Conditions
Min
LX1734
Typ
Max
Units
V
V
V
mV
µA
mA
µA
MHz
%
mV
µA
mA
V
V
µA
µA
V
IN
rising, regulator remains off
4.5V
<
V
IN
<
5.5V, T
AMB
> 25°C
(Regulator Not Switching, V
NFB
= -2V)
V
SD
< 0.28V
I
OUT
= 5mA to 250mA
I
SW
= 600mA
V
SW
= 10V
Duty Cycle < 50%
Device Active
Device Disabled
V
= 0.28V
SD
V
SDH
V
SDL
I
SD
4.25
3.2
4.25
-1.205 -1.235 -1.255
18
-4
-8
9
12
300
0.8
1.4
82
650
800
0.02
1
700
2
0.8
-5
0.4
1.0
30
50
V
SD
= 5V
BLOCK DIAGRAM
V
IN
UVLO
BIAS
SD
SW
+
-
-
Q1
Q2
40pF
100k
+
Σ
R
SET
Q
S
CLR
Q
Q3
+
Ramp
Generator
1.1MHz
Oscillator
0.1Ω
-
E
LECTRICALS
E
LECTRICALS
NFB
R1 (External) R2 (External)
V
OUT
GND
C
PL
Figure 2
– Simplified Block Diagram
Copyright
©
2002
Rev. 3.0a, 2005-03-14
Microsemi
Microsemi Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 3
MICROSEMI [ MICROSEMI CORPORATION ]
