ILC6363 Datasheet, PDF (7/14 Pages) Fairchild Semiconductor – Step-Up DC-DC Converter for One-Cell Lithium-Ion Batteries

PRODUCT SPECIFICATION
ILC6363
When the ILC6363 is shut down, the synchronous rectifier
disconnects the output from the input. This ensures that there
is only leakage (I_IN < 1µA typical) from the input to the out-
put so that the battery is not drained when the ILC6363 is
shut down.
ON/OFF
2 ^VIN
ILC6363
R5
3
LBI/SD
R6
7 GND
Figure 8. Shut Down Control
Power Good Output (POK)
The POK output of the ILC6363 indicates when V_OUT is
within the regulation tolerance of the set output voltage.
POK output is an open drain device output capable of sink-
ing 2mA. It will remain pulled low until the output voltage
has risen to typically 95% of the specified V_OUT. Note that a
pull-up resistor must be connected from the POK output
(pin 5 of ILC6363CIR-XX) to either ILC6363’s output or to
some other system voltage source.
Adjustable Output Voltage Selection
The ILC6363-ADJ allows the output voltage to be set using
a potential divider. The formula for setting the adjustable
output voltage is;
V_OUT = V_FB x (1+R1/R2), R1+R2 ≤ 100kΩ
Where V_FB is the threshold set which is 1.25V nominal.
CIN
100µF L
VIN
1 to 3-cell
ON
OFF
15mH
R5
R6
ILC6363-ADJ
1
LX
2 VIN
VOUT ⁸
GND 7
3 _{LBI/SD LBO} 6
4 _SEL
VFB ⁵
PWM
PFM
MSOP-8
VOUT
+ ^100µF
COUT
R1
R2
VOUT = 1.25 (1+R1/R2)
Figure 9. Adjustable Voltage Configuration
Negative Voltage Output
It is possible to generate a negative output voltage as a
secondary supply using the ILC6363. This negative voltage
may be useful in some applications where a negative bias
voltage at low current is required.
1A Schottky Diodes
-V
0.01µF
0.01µF
L
ILC6363
1 LX
VIN
2 VIN
Figure 10. Negative Output Voltage
External Component Selection
Inductors
The ILC6363 is designed to work with a 15µH inductor in
most applications. There are several vendors who supply
standard surface mount inductors to this value. Suggested
suppliers are shown in table 1. Higher values of inductance
will improve efficiency, but will reduce peak inductor current
and consequently ripple and noise, but will also limit output
current.
Vendor
Coilcraft
muRata
Sumida
TDK
Part Number
D03316P-153
D01608C-153
LQH4N150K
LQH3C150K
CDR74B-150MC
CD43-150
CD54-150
NLC453232T-150K
Contact
[phone]
[phone]
[phone]
[phone]
Capacitors
Input Capacitor
The input capacitor is necessary to minimize the peak
current drawn from the battery. Typically a 100µF tantalum
capacitor is recommended. Low equivalent series resistance
(ESR) capacitors will help to minimize battery voltage
ripple.
Output Capacitor
Low ESR capacitors should be used at the output of the
ILC6363 to minimize output ripple. The high switching
speeds and fast changes in the output capacitor current, mean
that the equivalent series impedance of the capacitor can
contribute greatly to the output ripple. In order to minimize
these effects choose an output capacitor with less than 10nH
of equivalent series inductance (ESL) and less than 100mΩ
of equivalent series resistance (ESR). Typically these
characteristics are met with ceramic capacitors, but may also
be met with certain types of tantalum capacitors. Suitable
vendors are shown in the following table.
REV. 1.3.5 5/21/02
7