www.fairchildsemi.com
ILC6363
Step-Up DC-DC Converter for One-Cell Lithium-Ion
Batteries
Features
• ILC6363CIR-50: Fixed 5.0V output; custom voltages are
available upon request
• ILC6363CIR-ADJ: Adjustable output to 6V maximum
• Capable of 500mA output current
• Peak efficiency: > 90% at V
OUT
= 3.6V, I
OUT
= 300mA,
V
IN
= 3.6V
• No external diode is required (synchronous rectification)
• Battery input current of 300µA at no load
• True load disconnect from battery input in shutdown
(1µA)
• Oscillator frequency: 300kHz ±15%
• Low battery detector with 100ms transient rejection delay
• Power good output flag when V
OUT
is in regulation
• MSOP-8 package
voltage exceeds the output voltage by more than 800mV, the
output will begin to track the input linearly.
The ILC6363 is a direct replacement for ILC6360, in appli-
cations 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 better efficiency at light load,while
PWM is recommended for more than 50mA load current.
In shutdown mode, the device allows true load disconnect
from battery input.
Configured as a 300kHz, fixed frequency PWM/PFM boost
converter, the ILC6363 can perform a limited buck operation
in PFM mode, when the input voltage is up to 0.8V higher
than the output voltage.
The ILC6363 is unconditionally stable with no external
compensation; the sizes of the input and output capacitors
influence input and output ripple voltages, respectively.
Since the ILC6363 has an internal synchronous rectifier, the
standard fixed voltage version requires minimal external
components: an inductor, an input capacitor, and an output
capacitor. If a tantalum output capacitor is used, then an
additional 10µF ceramic output capacitor will help reduce
output ripple voltage.
Other features include a low battery input detector with a
built-in100ms transient rejection delay and a power good
indicator useful as a system power on reset.
Applications
• Cellular phones
• Palmtops, PDAs and portable electronics
• Equipment using single Lithium-Ion batteries
Description
The ILC6363 step-up/step-down DC-DC converter is a
switch mode converter, capable of supplying up to 500mA
output current, at a fixed or user selectable output voltage.
The range of input, and output voltage options makes the
ILC6363 ideal for Lithium-ion (Li-ion), or any other battery
application, where the input voltage range spans above and
below the regulated output voltage. When ILC6363’s input
Typical Circuit
C
IN
100µF
+
V
IN
2.7V to 4.2V
ON
OFF
R6
4
SEL
POK
5
ILC6363CIR-XX
L
1
15µH
2
R5
3
LBI/SD
LBO
6
Low Battery
Detector Output
Power Good Output
(Fixed V
OUT
only)
V
IN
GND
7
L
X
V
OUT
8
C
OUT
10µF 100µF
+
+
V
OUT
Optimized to Maximize Battery Life
ILC6363 Efficiency (%)
80
3.6
70
Time
3.0
MSOP-8
PWM
PFM
Figure 1.
REV. 1.3.5 5/21/02
Battery Voltage (V)
90
4.2
ILC6363
PRODUCT SPECIFICATION
Pin Assignments
L
X
1
V
IN
2
LB/SD 3
SEL 4
MSOP
(TOP VIEW)
8 V
OUT
7 GND
6
LBO
L
X
1
V
IN
LB/SD
2
3
8 V
OUT
7 GND
6
5
MSOP
(TOP VIEW)
LBO
V
FB
5 POK
SEL 4
ILC6363CIR-XX
ILC6363CIR-ADJ
Pin Definitions
Pin Number
1
2
3
Pin Name
L
X
V
IN
LBI/SD
Pin Function Description
Inductor input
. Inductor L connected between this pin and the battery
Input Voltage
. Connect directly to battery
Low battery detect input and shutdown
. Low battery detect threshold
is set with this pin using a potential divider. If this pin is pulled to logic low
then the device will shutdown.
Select Input
. A low logic level signal applied to this pin selects PFM
operation mode. If the pin is left open or high logic level is applied, PWM
mode is selected.
Power Good Output
. This open drain output pin will go high when
output voltage is within regulation, 0.92•V
OUT(NOM)
< V
threshold
<
0.98•V
OUT(NOM)
Feedback Input
. This pin sets the adjustable output voltage via an
external resistor divider network. The formula for choosing the resistors
is shown in the “Applications Information” section.
Low Battery Output
. This open drain output will go low if the battery
voltage is below the low battery threshold set at pin 3.
Ground of the IC
. Connect this pin to the battery and system ground
Regulated output voltage
.
4
SEL
POK
(ILC6363CIR-XX
5
V
FB
(ILC6363CIR-ADJ)
6
7
8
LBO
GND
V
OUT
Absolute Maximum Ratings
Parameter
Voltage on V
OUT
pin
Voltage on LBI, Sync, LBO, POK, V
FB
, L
X
and V
IN
pins
Peak switch current on L
X
pin
Current on LBO pin
Continuous total power dissipation at 85°C
Short circuit current
Operating ambient temperature
Maximum junction temperature
Storage temperature
Lead temperature (soldering 10 sec.)
Package thermal resistance
2
θ
JA
IL
X
I
SINK(LBO)
P
D
I
SC
T
A
T
J(MAX)
T
stg
Symbol
V
OUT
Ratings
-0.3 to 7
-0.3 to 7
1
5
315
Internally protected
(1 sec. duration)
-40 to 85
150
-40 to 125
300
206
Units
V
V
A
mA
mW
A
°C
°C
°C
°C
°C/W
REV. 1.3.5 5/21/02
PRODUCT SPECIFICATION
ILC6363
Electrical Characteristics ILC6363CIR-50 in PFM Mode
Parameter
Output Voltage
Maximum Output
Current
Load Regulation
No Load Battery
Input Current
Efficiency
Symbol
V
OUT(nom)
I
OUT
∆
V
OUT
V
OUT
I
IN (no load)
η
I
OUT
= 0mA
I
OUT
= 20mA
Conditions
2.7V < V
IN
< 4.2V
V
OUT
≥
0.96V
OUT(nom)
,
V
IN
= 2.7V
1mA < I
OUT
< 50mA
Min.
4.875
4.825
(SEL in LOW State)
Unless otherwise specified, all limits are at V
IN
= V
LBI
= 3.6V, I
OUT
= 1mA and T
A
= 25°C, test circuit Figure 1.
BOLDFACE
type indicate limits over the specified operating temperature range. (Note 2)
Typ.
5.0
250
1
300
85
Max.
5.125
5.175
Units
V
mA
%
µA
%
(SEL Open)
Unless otherwise specified, all limits are at V
IN
= V
LBI
= 3.6V, I
OUT
= 100mA and T
A
= 25°C, test circuit Figure 1.
BOLDFACE
type indicate limits over the full operating temperature range. (Note 2)
Parameter
Output Voltage
Maximum Output
Current
Load Regulation
Efficiency
Symbol
V
OUT(nom)
I
OUT
∆
V
OUT
V
OUT
η
Conditions
2.7V < V
IN
< 4.2V
V
OUT
≥
0.92V
OUT(nom)
50mA < I
OUT
< 200mA
50mA < I
OUT
< 300mA
I
OUT
= 300mA
Min.
4.850
4.800
Typ.
5.0
500
3
4
92
Max.
5.150
5.200
Units
V
mA
%
%
Electrical Characteristics ILC6363CIR-50 in PWM Mode
REV. 1.3.5 5/21/02
3
ILC6363
PRODUCT SPECIFICATION
General Electrical Characteristics
T
A
= 25°C, V
IN
= V
LBI
= 3.6V, I
OUT
= 50mA, unless otherwise specified.
BOLDFACE
indicate limits over the specified operating temperature range. (Note 2).
Parameter
LBO output voltage low
LBO output leakage current
Shutdown input voltage low
Shutdown input voltage high
SEL input voltage high
SEL input voltage low
POK output voltage low
POK output voltage high
POK output leakage Current
POK threshold
POK hysteresis
Feedback voltage
(ILC6363CIR-ADJ only)
Output voltage adjustment
range (ILC6363CIR-ADJ only)
Minimum startup voltage
Input voltage range
Symbol
V
LBO(low)
I
LBO(hi)
V
SD(low)
V
SD(hi)
V
SEL(hi)
V
SEL(low)
V
POK(low)
V
POK(hi)
I
L(POK)
V
TH(POK
V
HYST
V
FB
V
OUT(ADJ) min
V
OUT(ADJ) max
V
IN(start)
V
IN
Conditions
I
SINK
= 2mA, open drain
output, V
LBI
= 1V
V
LBO
= 5V
Min.
Typ.
Max.
0.4
Units
V
µA
V
V
V
V
V
V
µA
V
mV
V
V
1
1
1.5
2
0.4
6
0.4
I
SINK
= 2mA, open drain
output
6V at pin 5
0.92xV
OUT
0.95xV
OUT
50
1.225
1.212
V
IN
= 0.9V, I
OUT
= 50mA
V
IN
= 3V, I
OUT
= 50mA
I
OUT
= 10mA, PWM
mode
V
OUT
= V
OUT(nominal)
± 4%
I
OUT
= 10mA
V
LBI/SD
< 0.4V,
V
OUT
= 0V
(short circuit)
N-Channel MOSFET
P-Channel MOSFET
255
1.175
1.150
Pins LB/SD,SEL and
VFB, (Note 3)
(Note 4)
100
120
0.9
1
1
1.250
2.5
6
0.9
0.4
6
2
0.98xV
OUT
1.275
1.288
1
V
OUT(nomi-
nal)
+ 0.8V
10
V
V
Battery input current in load
disconnect mode
Switch on resistance
Oscillator frequency
LBI input threshold
Input leakage current
LBI hold time
I
IN(SD)
µA
R
ds(on)
f
osc
V
REF
I
LEAK
t
HOLD(LBI)
400
750
300
1.250
345
1.325
1.350
200
mΩ
kHz
V
nA
mS
Notes:
1. Absolute maximum ratings indicate limits which, when exceeded, may result in damage to the component. Electrical
specifications do not apply when operating the device outside its rated operating conditions.
2. Specified min/max limits are production tested or guaranteed through correlation based on statistical control methods.
Measurements are taken at constant junction temperature as close to ambient temperature as possible using low duty cycle
pulse testing.
3. Guaranteed by design
4. In order to get a valid low-battery-output (LBO) signal, the input voltage must be lower than the low-battery-input (LBI)
threshold for a duration greater than the low battery hold time (Hold(LBI)). This feature eliminates false triggering due to
voltage transients at the battery terminal.
4
REV. 1.3.5 5/21/02
PRODUCT SPECIFICATION
ILC6363
Application Information
The ILC6363 performs boost DC-DC conversion by control-
ling the switch element as shown in the simplified circuit in
Figure 3 below.
PWM Mode Operation
The ILC6363 uses a PWM or Pulse Width Modulation
technique. The switches are constantly driven at typically
300kHz. The control circuitry varies the power being
delivered to the load by varying the on-time, or duty cycle,
of the switch SW1 (see Figure 5). Since more on-time
translates to higher current build-up in the inductor, the
maximum duty cycle of the switch determines the maximum
load current that the device can support. The minimum value
of the duty cycle determines the minimum load current that
can maintain the output voltage within specified values.
There are two key advantages of the PWM type controllers.
First, because the controller automatically varies the duty
cycle of the switch's on-time in response to changing load
conditions, the PWM controller will always have an opti-
mized waveform for a steady-state load. This translates to
very good efficiency at high currents and minimal ripple on
the output. Ripple is due to the output cap constantly accept-
ing and storing the charge received from the inductor, and
delivering charge as required by the load. The “pumping”
action of the switch produces a sawtooth-shaped voltage as
seen by the output.
The other key advantage of the PWM type controllers over
pulse frequency modulated (PFM) types is that the radiated
noise due to the switching transients will always occur at
(fixed) switching frequency. Many applications do not care
much about switching noise, but certain types of applica-
tions, especially communication equipment, need to mini-
mize the high frequency interference within their system as
much as possible. Use of the PWM converter in those cases
is desirable.
Figure 3. Basic Boost Circuit
When the switch is closed, current is built up through the
inductor. When the switch opens, this current is forced
through the diode to the output. As this on and off switching
continues, the output capacitor voltage builds up due to the
charge it is storing from the inductor current. In this way, the
output voltage is boosted relative to the input.
In general, the switching characteristic is determined by the
output voltage desired and the current required by the load.
The energy transfer is determined by the power stored in the
coil during each switching cycle.
P
L
= ƒ(t
ON
, V
IN
)
Synchronous Rectification
The ILC6363 also uses a technique called “synchronous
rectification” which removes the need for the external diode
used in other circuits. The diode is replaced with a second
switch or in the case of the ILC6363, an FET as shown in
Figure 4 below.
V
IN
SW2
-
+
POK
GND
SHUTDOWN
CONTROL
PFM Mode Operation
ILC6363
V
OUT
L
X
SW1
PWM/PFM
CONTROLLER
For light loads the ILC6363 can be switched to PFM. This
technique conserves power by only switching the output if
the current drain requires it. As shown in the Figure 5, the
waveform actually skips pulses depending on the power
needed by the output. This technique is also called “pulse
skipping” because of this characteristic.
In the ILC6363, the switchover from PWM to PFM mode is
determined by the user to improve efficiency and conserve
power.
The Dual PWM/PFM mode architecture was designed spe-
cifically for applications such as wireless communications,
which need the spectral predictability of a PWM-type
DC-DC converter, yet also need the highest efficiencies
possible, especially in Standby mode.
V
REF
+
-
DELAY
LBO
SEL
LB/SD
Figure 4. Simplified ILC6383 block diagram
The two switches now open and close in opposition to each
other, directing the flow of current to either charge the induc-
tor or to feed the load. The ILC6363 monitors the voltage on
the output capacitor to determine how much and how often
to drive the switches.
REV. 1.3.5 5/21/02
5
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