Datasheet

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT
1053E through 1053H
SYNCHRONOUS BOOST DC/DC CONVERTER
2
Table 2. Demonstration Circuit Board Information
Board
Number
LTC Part Number
Part
Marking
Frequency
Inductor
Mode
Action
1053A-A LTC3526EDC LCHW 1MHz 4.7µH Burst Discontinued, use 1053A-E
1053A-B LTC3526BEDC LCNN 1MHz 4.7µH No Burst Discontinued, use 1053A-F
1053A-C LTC3526EDC-2 LCNM 2MHz 2.2µH Burst Discontinued, use 1053A-G
1053A-D LTC3526BEDC-2 LCNP 2MHz 2.2µH No Burst Discontinued, use 1053A-H
1053A-E LTC3526LEDC LCSS 1MHz 4.7µH Burst
1053A-F LTC3526LBEDC LCST 1MHz 4.7µH No Burst
1053A-G LTC3526LEDC-2 LFFC 2MHz 2.2µH Burst
1053A-H LTC3526LBEDC-2 LFFD 2MHz 2.2µH No Burst
QUICK START PROCEDURE
There is one demonstration circuit board for
all four LTC3526L versions. The boards are
identified by the handwritten information on
the top of the pc board.
The boost converter can be evaluated using
the setup shown in Figure 1. Select one of the
three output voltages using jumpers JP1
through JP3. (With no jumpers installed, the
output voltage is 5V.) Set jumper JP4 in the
ON position and connect voltmeters and am-
meters as shown on the test setup. Connect a
power supply to the V
IN
and GND terminals
and a suitable load resistor between VOUT
and GND.
With a light load (1k resistor) at the output,
begin increasing the input power supply volt-
age. At approximately 750mV the output will
rise to the selected regulated voltage. In-
crease the input voltage to approximately
1.5V and increase the load current. Move out-
put voltage jumpers and verify output voltage.
Note the excellent load regulation when going
from a light load current to a heavier load, but
it is important to monitor the input voltage di-
rectly at the input terminals of the circuit
board. At very low input voltages, voltage
drops in the power supply wire; connections
and Ammeter will result in the input voltage at
the input terminals dropping below the mini-
mum voltage required for operation.
The input voltage can exceed the output volt-
age and still maintain regulation, although the
load current is less and efficiency is lower. It
should be noted that under some load current
conditions, the output voltage ripple could in-
crease as Vin approaches Vout. The increase
will occur in a narrow range when Vin is be-
tween 100 and 300mV below Vout. The ripple
voltage in this range can be from 30mV to
100mV pp. Increasing output capacitance will
reduce this ripple.
Due to the high inductor current slew rate in 5V
output applications, the 2MHz LTC3526L-2 may
not enter burst mode for input voltages less than
1.4V. For 5V applications requiring burst mode,
the 1MHz LTC3526L is recommended. Refer to
the Typical Performance Characteristics curves
for the burst mode thresholds for different input
and output voltages.