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XCM517

Series

■NOTE ON USE (Continued)

16. Please note the inductance value of the coil. The IC may enter unstable operation if the combination of ambient

temperature, setting voltage, oscillation frequency, and L value are not adequate.

In the operation range close to the maximum duty cycle, The IC may happen to enter unstable output voltage operation even

if using the L values listed below.

●

The Range of L Value

L Value

3.0MHz

1.0μH～2.2μH

3.3μH～6.8μH

1.2MHz

4.7μH～6.8μH

*When a coil less value of 4.7 μ H is used at

reach the current limit ILMI. In this case, it may

happen that the IC can not provide 600mA output

current.

<External Components>

17. It may happen to enter unstable operation when the IC operation mode goes into continuous operation mode under the

condition of small input-output voltage difference. Care must be taken with the actual design unit.

<External Components>

●Instructions of pattern layouts

2. Please mount each external component as close to the IC as possible.

3. Wire external components as close to the IC as possible and use thick, short connecting traces to reduce the circuit

impedance.

4. Make sure that the PCB GND traces are as thick as possible, as variations in ground potential caused by high ground

currents at the time of switching may result in instability of the IC.

5. This series’ internal driver transistors bring on heat because of the output current and ON resistance of driver transistors.