LX1734
TM
®
1.0MHz Inverting DC/DC Converter
KEY FEATURES
Fixed Frequency 1.0MHz
Operation
Very Low Noise: 1mV
P-P
Output
Ripple Possible With Cuk
Topology
Stable Operation With Ceramic or
Tantalum Capacitors
-5V at 250mA from 5V Input
Uses Small Surface Mount L/C
Components
Wide Input Range: 4.2V to 8V
Low VCESAT Switch: 600mV at
600mA
6-Lead 3x3mm JEDEC MLPM
Package
Functionally Compatible with
LT1611 or LT1931
APPLICATIONS/BENEFITS
Disk Drive MR Head Bias
Digital Camera CCD Bias
LCD Bias
GaAs FET Bias
Local -5V or -12V Supplies
DESCRIPTION
The LX1734 is an inverting
DC/DC current-mode controller. With
a 750mA integrated switch, the
LX1734 can generate large output
currents in a small footprint. The
LX1734 minimizes external com-
ponent size and cost by implementing
a high switching frequency of
1.0MHz, while generating -5V at
250mA.
When configured in the dual
inductor inverting topology very low
output voltage ripple approaching
1mV
P-P
can be achieved when used in
conjunction with ceramic output
capacitors. The dual inductor can be
implemented as a coupled or separate
cores.
Fixed frequency operation ensures a
clean output free from low frequency
noise typically present with charge pump
solutions. The low impedance output
remains within 1% of nominal during
large load steps. The 18V switch allows
high voltage outputs to be generated.
The LX1734 is available in the space
saving 6-lead 3x3 Jedec MO-229
package, which has the same footprint
and lead spacing as the SOT-23A. A
complete inverter function utilizes less
than 0.3
2
inches of PCB space.
WWW .
Microsemi
.C
OM
IMPORTANT:
For the most current data, consult
MICROSEMI’s
website:
http://www.microsemi.com
PRODUCT HIGHLIGHT
L1A
22µH
V
IN
= 5V
V
IN
C1
10µF
SW
C2
1µF
L1B
22µH
R1
29.4k
LX1734
NFB
SD
GND
V
OUT
= -5V
@ 150mA
R2
10k
C4
1000pF
C3
22µF
Note: L1A and L1B are shown as coupled. Individual inductors can also be used.
C1, C2, C3 are ceramic capacitors
LX1734
LX1734
Figure 1
PACKAGE ORDER INFO
Plastic MLPL
LM
6-Pin
T (°C)
A
RoHS Compliant / Pb-free
Transition DC: 0452
0 to 85
LX1734CLM
Note: Available in Tape & Reel. Append the letters “TR” to the
part number. (i.e. LX1734CLM-TR)
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 1
MICROSEMI [ MICROSEMI CORPORATION ]
