Impala Linear Corporation
ILC6360
Step-Up/Step Down DC-DC Converter for
1-Cell Lithium-Ion Batteries
General Description
The ILC6360 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
ILC6360 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 ILC6360’s input
voltage exceeds the output voltage by more than 800mV,
the output will begin to track the input linearly.
Configured as a 300kHz, fixed frequency PWM boost con-
verter, the ILC6360 performs the buck operation by seam-
lessly switching to PFM, when the output voltage rises near
the positive range of regulation. However, since the transition
point between PWM and PFM mode is dependent upon both
line, and load regulation, under certain conditions, regulation
will remain in PWM mode even in the buck mode of operation.
The ILC6360 is unconditionally stable with no external com-
pensation; the sizes of the input and output capacitors influ-
ence the ripple on the input, and output voltages. Since the
ILC6360 has an internal synchronous rectifier, the standard
fixed voltage version requires minimal external components:
an inductor, an input capacitor, and an output capacitor. An
additional 10µF ceramic output capacitor will help reduce
output ripple voltage.
Other features include an external sync input for synchro-
nizing the PWM frequency, low battery input detector with
100ms transient rejection delay built-in, and, a power good
indicator useful as a system power on reset.
Features
• ILC6360CIR-36: Fixed 3.6V output; custom
voltages possible
• ILC6360CIR-ADJ: Adjustable output to 6V maximum
• Capable of 500mA output current
• Peak efficiency: > 90% at V
OUT
= .6V,I
OUT
= 300mA,
V
IN =
3.6V
• No external diode is required (synchronous rectification)
• Battery input current of 250mA at no load
• True load disconnect from battery input in shutdown (1mA)
• OSC freq: 300kHz ±15%
• External freq synchronization from 150kHz to 500kHz
• Low battery detector with 100ms transient rejection delay
• Power good output flag when V
OUT
is in regulation
• MSOP-8 package
Applications
• Cellular phones
• Palmtops, PDAs and portable electronics
• Equipment using single Lithium-Ion batteries
Patent Pending
Optimized to Maximize Battery Life
ILC6360 Efficiency (%)
ILC6360 Efficiency @ I
OUT
= 300mA
IN
100µF
C
ILC6360CIR-ADJ
L
1
15µH
2
R5
3
LBI/SD
SYNC
LBO
V
FB
6
5
R6
4
Low Battery
Detector Output
Power Good Output
C
OUT
10µF
100µF
Battery Voltage (V)
90
4.2
+
V
IN
2.7V to 4.2V
L
X
V
IN
V
OUT
GND
8
+
7
+
V
OUT
3.6V/500mA
80
Typical Li-ion Battery Discharge Curve
3.6
ON
OFF
70
Time
3.0
Ext Sync
(Connect to GND if unused)
MSOP-8
Typical Performance Characteristics for 1-cell Li-ion
Typical Step-up/Step-down Application Circuit
(Note: R5 and R6 are required only if LBI feature is used)
Impala Linear Corporation
ILC6360 1.1
(408) 574-3939
www.impalalinear.com
Jan 1999
1
IMPALA [ Impala Linear Corporation ]
