1
DEMO MANUAL DC193
NO DESIGN SWITCHER
OUTPUT CURRENT (A)
0.01
100
95
90
85
80
75
70
0.10
1.00
DC193 • TPC01
EFFICIENCY (%)
V
IN
= 3.3V
V
OUT
= 2.5V
PARAMETER
CONDITION
VALUE
Input Voltage Range
Operating Input Voltage
2.5V to 6V
Maximum Input Voltage
7V
Output Voltage
Set by Jumper, J1, in J1A Position
2.5V ±0.06V
Set by Jumper, J1, in J1B Position
3.3V ±0.10V
Set by Jumper, J1, in J1C Position and add Optional Adjust Resistor, R6
2.5V to 5V
Typical Supply Current
I
OUT
= 0mA, V
IN
= 3.5V
165µA
LTC1626 Single-Cell Li-Ion,
High Efficiency, Step-Down
DC/DC Converter
DESCRIPTIO
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
Burst Mode is a trademark of Linear Technology Corporation.
PERFOR
M
A
N
CE SU
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ARY
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The DC193 demonstration circuit is a step-down (buck)
regulator using the LTC
®
1626 operating from a single-cell
Li-Ion battery pack. The output voltage is easily set to 2.5V
or 3.3V with a simple jumper selection. Other output
voltages can be programmed with an optional resistor.
The demo board highlights the capabilities of the LTC1626,
which is able to smoothly shift from a high efficiency
switch-mode DC/DC regulator to a low-dropout linear
regulator (i.e., 100% duty cycle) when the Li-Ion battery
voltage drops to near the output voltage. When the battery
voltage rises again, the LTC1626 smoothly shifts back to
a high efficiency DC/DC converter. At low load currents,
the LTC1626 automatically switches to Burst Mode
TM
operation to reduce switching losses and maintain high
operating efficiencies. Further, the LTC1626 draws a mere
0.5µA when in shutdown mode. A built-in 0.32
Ω
P-channel
switch allows up to 0.6A of output current and provides up
to 95% efficiency. Exclusive use of small surface mount
components results in a highly efficient application in a
very small board space.
Gerber files for this circuit board are available. Call the
LTC factory.
Efficiency vs Load Current
TYPICAL PERFOR A CE CHARACTERISTICS A D BOARD PHOTO
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