LTC3406/LTC3406B DC500 Description
Demonstration circuit DC500 is a constant-frequency step-down
converter, using the LTC3406, or LTC3406B, monolithic synchronous
buck regulators. The DC500 has an input voltage range of 2.7V to 5.5V,
and is capable of delivering up to 600 mA of output current at minimum
input voltage of 3V. In Burst Mode operation, which is the mode of low
load current operation offered by the LTC3406, the DC500 supply current
is typically only 25 uA at no load, and less than 1 uA in shutdown. In
noise sensitive applications, the LTC3406B is available, which runs in
pulse-skipping mode at low load currents. The DC500 is a very efficient
circuit: up to 96%. These features, plus the LTC3406/LTC3406B coming
in a tiny 5-pin ThinSOT package and having an operating frequency of 1.5
MHz (allowing the exclusive use of low profile surface mount
components), make the DC500 demo board an ideal circuit for use in
battery-powered, hand-held applications.
Design files for this circuit are
available. Call the LTC Factory.
LTC3406/LTC3406B DC500 Quick Start Guide
The DC500 demonstration board is easy to set up to evaluate the performance of
the LTC3406/LTC3406B. One word of caution: when the board is right-side up
(the title is legible at the top of the board), the output voltage turret is on the left
side of the board, and the input voltage turret is on the right side of the board.
Set up the circuit appropriately.
Please follow the procedure outlined below for proper operation.
1. Connect the input power supply to the Vin and GND terminals on the
right-side of the board. Do not hot-plug Vin or increase Vin over the
rated maximum supply voltage of 5.5V, or the part may be damaged.
Move the shunt at JP1 to the “ON” position. Refer to figure 1 for
proper measurement equipment setup.
2. Connect the load between the Vout and GND terminals on the left-side
of the board. Refer to figure 1 for proper measurement equipment
setup.
3. To shut down the circuit, connect the RUN pin to ground by inserting
the JP1 jumper into the upper position. Note the pull down resistor on
the schematic and demo circuit assembly. Do not leave this pin
floating.
