XC9515AA01ZL TOREX [Torex Semiconductor], XC9515AA01ZL Datasheet - Page 13

• Manufacturer Part Number: XC9515AA01ZL
• Description: 2 channel Synchronous Step-Down DC/DC Converter with Manual Reset
• Manufacturer: TOREX [Torex Semiconductor]

■NOTES ON USE (Continued)
7.
8.
9.
11. When the load current is light in PWM control, very narrow pulses will be outputted, and there is the possibility that some
12. When the difference between V
13. If the power input pin voltage is assumed to decrease rapidly (ex. from 6.0V to 0V) at the release of the operation
14. Please connect a pull-up resistor with 100 to 200kΩ to the output pin of the voltage detector block (V
15. The delay time of the voltage detector block in heavy load may extend because of the noise of the DC/DC block.
16. Use of the IC at voltages below the minimum operating voltage may lead the output voltage drop before achieving over
17. When P_VDD1 and P_VDD2 power supply pins and EN1 and EN2 enable pins are in undefined states, the latch
18. UVLO function works even if when V
●Instruction on Pattern Layout
10. With the DC/DC converter block of the IC, the peak current of the coil is controlled by the current limit circuit. Since the
1.
2.
3.
4. Make sure that the V
peak current increases when dropout voltage or load current is high, current limit starts operating, and this can lead to
instability. When peak current becomes high, please adjust the coil inductance value and fully check the circuit operation.
In addition, please calculate the peak current according to the following formula:
Driving current below the minimum operating voltage may lead malfunction to the UVLO circuit because of the noise.
Depending on the PC board condition, the latch function may be released from limit current detection state and the latch
time may extend or fail to reach the latch operation. Please locate the input capacitance as close to the IC as possible.
Spike noise and ripple voltage arise in a switching regulator as with a DC/DC converter. These are greatly influenced by
external component selection, such as the coil inductance, capacitance values, and board layout of external components.
Once the design has been completed, verification with actual components should be done.
cycles may be skipped completely.
there is the possibility that some cycles may be skipped completely.
although delay capacitance (Cd) pin is connected, please connect an Shottky barrier diode between the power input
(P_V
Precipitous and large voltage fluctuation at the power input pin may cause malfunction of the IC.
current limit.
protection circuit may not be reset so that the IC operation does not start correctly. Power supply and enable pins
（EN1,EN2） should be grounded before starting the IC operation.
【Undefined state conditions for each pin】
P_V
V
nanoseconds.
EN1
In order to stabilize V
as possible to the P_V
Please mount each external component as close to the IC as possible.
Wire external components as close to the IC as possible and use thick, short connecting traces to reduce the circuit
impedance.
at the time of switching may result in instability of the DC/DC converter.
DD1
=V
DD1
Peak current: Ipk = (V
L: Coil Inductance Value, f
=P_V
NE2
) pin and the delay capacitance (Cd) pin.
= 0.4V ~ 1.2V
DD
2=0.1V ~ 1.2V
SS
IN
DD1
's voltage level, we recommend that a by-pass capacitor (C
traces are as thick as possible, as variations in the V
IN
・P_V
- V
IN
OSC
OUT
and V
: Oscillation Frequency
DD2
) x OnDuty / (2 x L x fosc) + I
IN
input voltage falls below the UVLO voltage in very short time period like a few ten
OUT
pins and P_V
is small, and the load current is heavy, very wide pulses will be outputted and
SS1
・P_V
SS2
OUT
pins.
SS
potential caused by high V
IN1
and C
IN2
) be connected as close
DOUT
).
XC9515
SS
13/21
Series
currents