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www.fairchildsemi.com
REV. 1.2.6 6/13/02
Features
Guaranteed start up in PWM at 0.9V input
Synchronous rectification requires no external diode
True load disconnect from battery input in shutdown
Up to 75mA at 3.3V and 40mA at 5V from 1V input
Up to 375mA at 3.3V and 300mA at 5V from 3V input
Peak efficiency > 90%
1μA battery input current in shutdown (with V
Internal Oscillator frequency: 300kHz to ±15%
ILC6383: Fixed 3.3V or 5V output
ILC6383-ADJ: Adjustable output to 6V maximum
Low battery detector with 100ms transient rejection delay
Powergood output flag when V
OUT
= 0V)
OUT
is in regulation
Applications
Cellular Phones, Pagers
Palmtops, PDAs and portable electronics
High efficiency 1V step up converters
Description
The ILC6383 series of step-up DC-DC converters operate
from 1-cell to 3-cell input. They are direct replacement for
ILC6382, in applications where SYNC pin is not used. The
PFM or PWM operating mode is user selectable through
SEL pin connected to ground or left open, respectively. The
choice should be dependent upon the current to be delivered
to the load: PFM is recommended for input voltage higher
than 1.5V and loads below 100mA, while PWM is recom-
mended for more than 50mA load current and in noise sensi-
tive applications. In shutdown mode, the device allows true
load disconnect from battery input. Designed for wireless
communications applications, the oscillator frequency is set
at 300kHz with no harmonics at sub 20kHz audio band or at
455kHz IF band.
Internal synchronous rectification and externally selectable
PFM/PWM mode of operation allows the selection of the
best efficiency at light or full load. The ILC6383 is capable
of delivering 75mA at 3.3V output from a single cell input.
The ILC6383-XX offers 3.3V or 5V fixed output voltage
while the ILC6383-ADJ allows adjustable output voltage to
6V maximum. Output voltage accuracy is ±3.5% over full
operating temperature range.
Additional features include power good output (POK) and an
internal low battery detector with 100ms transient rejection
delay. The device will reject low battery input transients
under 100ms in duration. The ILC6383 series is available in
a space saving eight lead micro SOP (MSOP-8) package.
ILC6383
1-Cell to 3-Cell Boost DC-DC Converter with True
Load Disconnect, 3.3V, 5V or Adjustable Output
47
μ
F
ON
OFF
V
IN
1 to 3-cell
R5
R6
15
μ
H
L
C
OUT
47
μ
F
R1
R2
ILC6383-ADJ
MSOP-8
L
X
V
IN
LBI/SD
SEL
GND
LBO
V
FB
V
OUT
V
OUT
V
OUT
= 1.25 (1+R1/R2)
1
2
3
4
8
7
6
5
CIN
+
+
47
μ
F
ILC6383-XX
1
3
2
4
8
6
7
5
L
X
V
IN
LBI/SD
SEL
GND
LBO
POK
V
OUT
ON
OFF
V
IN
1 to 3-cell
R5
R6
15
μ
H
MSOP-8
L
V
OUT
47
μ
F
C
OUT
Low Battery
Detector Output
Power Good Output
C
IN
+
+
PWM
PFM
PWM
PFM
Figure 1. ILC6383CIR-XX
Figure 2. ILC6383CIR-ADJ
Typical Applications