Linear Technology DC193 Demo Manual

DESCRIPTIO
The DC193 demonstration circuit is a step-down (buck)
regulator using the LTC
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,
PERFORMANCE
PARAMETER
Input Voltage Range
Output Voltage
Typical Supply Current
TYPICAL PERFOR A CE CHARACTERISTICS A D BOARD PHOTO
Efficiency vs Load Current
100
95
90
85
80
75
70
0.01
Arrow.com.
Downloaded from
U
®
1626 operating from a single-cell
SUMM ARY
CONDITION
Operating Input Voltage
Maximum Input Voltage
Set by Jumper, J1, in J1A Position
Set by Jumper, J1, in J1B Position
Set by Jumper, J1, in J1C Position and add Optional Adjust Resistor, R6
I = 0mA, V = 3.5V
OUT IN
W U
V = 3.3V
IN
V = 2.5V
OUT
0.10
OUTPUT CURRENT (A)
DC193 • TPC01
LTC1626 Single-Cell Li-Ion,
High Efficiency, Step-Down
the LTC1626 automatically switches to Burst Mode
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 0.32Ω 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.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Burst Mode is a trademark of Linear Technology Corporation.
1.00
DEMO MANUAL DC193
NO DESIGN SWITCHER
DC/DC Converter
U
TM
VALUE
2.5V to 6V
7V
2.5V ±0.06V
3.3V ±0.10V
2.5V to 5V
165µA
1