QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 870A-A
HIGH EFFICIENCY MONOLITHIC SYNCHRONOUS BUCK REGULATOR
1
LTC3410
DESCRIPTION
Demonstration circuit 870A-A is a high efficiency,
high frequency buck converter, incorporating the
LTC3410 monolithic synchronous regulator. The
DC870 has an input voltage range of 2.25V to 5.5V,
and is capable of delivering up to 300mA of output
current. It has an output voltage range from 0.8V to
5V, and an operating frequency of 2.25MHz (allowing
the exclusive use of low profile surface mount com-
ponents). In Burst Mode operation, which is the
mode of low load current operation offered by the
LTC3410, the DC supply current is typically only 26uA
at no load, and less than 1uA in shutdown The
DC870 is a very efficient circuit: up to 96%. These
features, plus the LTC3410 coming in a tiny, low-
profile 6-pin SC70 package, make the DC870 demo
board an ideal circuit for use in battery-powered,
hand-held applications.
Design files for this circuit board are available. Call
the LTC factory.
LTC and Burst Mode are trademarks of Linear Technology Corporation
Table 1.
Performance Summary (T
A
= 25°C)
PARAMETER CONDITION VALUE
Minimum Input Voltage 2.25V
Maximum Input Voltage 5.5V
Output Voltage V
OUT
V
IN
= 2.25V to 5.5V, I
OUT
= 0A to 0.3A
1.8V ±4%
Typical Output Ripple V
OUT
V
IN
= 5V, I
OUT
= 0.3A (20 MHz BW) 20mV
P–P
Line ±1%
Output Regulation
Load ±1%
Nominal Switching Frequency 2.25 MHz
QUICK START PROCEDURE
The DC870A-A is easy to set up to evaluate the per-
formance of the LTC3410. For proper measurement
equipment configuration, set up the circuit according
to the diagram in Figure 1. Before proceeding to test,
insert shunt on jumper JP1 into the off position, con-
necting the RUN pin to ground (GND), which shuts
down the circuit.
NOTE:
When measuring the input or output voltage
ripple, care must be taken to avoid a long ground lead
on the oscilloscope probe. Measure the input or out-
put voltage ripple by touching the probe tip directly
across the Vin or Vout and GND terminals. See
Figure 2 for proper scope probe technique.
1.
Connect the input power supply and the load to 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. Refer to figure 1 for proper
measurement equipment setup.
