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■NOTE ON USE(Continued)

4)

The DC/DC converter of this IC uses a current-limiting circuit to monitor the coil peak current. If the potential dropout voltage

is large or the load current is large, the peak current will increase, which makes it easier for current limitation to be applied

which in turn could cause the operation to become unstable. When the peak current becomes large, adjust the coil inductance

and sufficiently check the operation.

The following formula is used to show the peak current.

L: Coil Inductance [H]

5)

If there is a large dropout voltage, a circuit delay could create the ramp-up of coil current with staircase waveform exceeding

the current limit.

6)

Even in the PWM control, the intermittent operation occurs and the ripple voltage becomes higher, when the minimum On

Time is faster than 85ns (TYP.) as well as the dropout voltage is large.

7） The ripple voltage could be increased when switching from discontinuous conduction mode to continuous conduction mode

and at switching to 100% Duty cycle. Please evaluate IC well on customer’s PCB.

8) PWM/PFM auto series may cause superimposed ripple voltage by continuous pulses if it uses in high temperature and no

load. It is necessa

It can make an effect as same as RFB2 is lower than 7.5 kΩ, Please refer to the < Output voltage setting > in the TYPCAL

APPLICATION CIRCUIT..

9) If the voltage at the EN/SS Pin does not start from 0V but it is at the midpoint potential when the power is switched on, the

soft start function may not work properly and it may cause the larger inrush current and bigger ripple voltages.

10) Torex places an importance on improving our products and their reliability. We request that users incorporate fail-safe designs

and post-aging protection treatment when using Torex products in their systems.

11) Instructions of pattern layouts

The operation may become unstable due to noise and/or phase lag from the output current when the wire impedance is

(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 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) Please note that internal driver transistors bring on heat because of the load current and ON resistance

of High side driver transistor, Low side driver transistor. Please make sure that the heat is dissipated properly,

especially at higher temperatures.