ncv8535 ON Semiconductor, ncv8535 Datasheet - Page 18

• Manufacturer Part Number: ncv8535
• Description: Ultra High Accuracy, Low Iq, 500 Ma Low Dropout Regulator With Enable
• Manufacturer: ON Semiconductor

Reverse Bias Protection
goes to zero, but the output voltage is kept high either by a
large output capacitor or another source in the application
which feeds the output pin.
the output pin to input pin through the PN junction with
limited current capability and with the potential to destroy
the IC.
withstand up to 7.0 V on the output pin with virtually no
current flowing from output pin to input pin, and only
negligible amount of current (tens of mA) flowing from the
output pin to ground for infinite duration.
Input Capacitor
recommended to improve the transient response of the
regulator and/or if the regulator is located more than a few
inches from the power source. It will also reduce the circuit's
sensitivity to the input line impedance at high frequencies.
The capacitor should be mounted with the shortest possible
track length directly across the regular's input terminals.
Output Capacitor
as long as it fulfills its 1.0 mF requirement. There are no
constraints on the minimum ESR and it will remain stable up
to an ESR of 5.0 W. Larger capacitor values will improve the
noise rejection and load transient response.
Noise Reduction Pin
capacitor (C
(see Figure 1). In applications where very low noise is not
required, the noise reduction pin can be left unconnected.
68 pF capacitor connected in parallel with R1 (see Figure 2)
is recommended to further reduce output noise and improve
stability.
Reverse bias is a condition caused when the input voltage
Normally in a bipolar LDO all the current will flow from
Due to an improved architecture, the NCV8535 can
An input capacitor of at least 1.0 mF, any type, is
The NCV8535 remains stable with any type of capacitor
Output noise can be greatly reduced by connecting a 10 nF
For the adjustable version, in addition to the 10 nF C
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APPLICATIONS INFORMATION
http://onsemi.com
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NCV8535
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18
Adjustable Operation
as shown in Figure 2 with a range of 1.25 to 10 V. The
appropriate resistor divider can be found by solving the
equation below. The recommended current through the
resistor divider is from 10 mA to 100 mA. This can be
accomplished by selecting resistors in the kW range. As
result, the I
can be ignored.
Example:
For V
Dropout Voltage
output voltage.
No-Load Regulation Considerations
temperature is higher than 85°C leakage current flowing
from input to output through pass transistor may cause
increase of output voltage out of specification range up to
input voltage level. To avoid this situation minimum load
current of 100 mA or higher is recommended if ambient
temperature exceeds 85°C.
Thermal Considerations
integrated circuit in the event that the maximum junction
temperature is exceeded. This feature provides protection
from a catastrophic device failure due to accidental
overheating. This protection feature is not intended to be used
as a substitute to heat sinking. The maximum power that can
be dissipated, can be calculated with the equation below:
The output voltage can be set by using a resistor divider
The voltage dropout is measured at 97% of the nominal
If there is no load at output of the regulator and ambient
Internal thermal limiting circuitry is provided to protect the
out
= 2.9 V, can use R
V out + 1.25 * 1 ) R1
adj
*R2 becomes negligible in the equation and
1.25 * 1 ) 36 kW
P D +
T J(max) * T A
27 kW
1
= 36 kW and R
R qJA
R2
+ 2.91 V
) I adj * R2
2
= 27 kW.
(eq. 1)
(eq. 2)
(eq. 3)