NCV8186 Datasheet, PDF (9/10 Pages) ON Semiconductor – Fast Transient Response Low Voltage 1 A LDO

NCV8186
The power dissipated by the LDO for given application
conditions can be calculated by the next equation:
P_D + V_IN @ I_GND ) ^ǒV_IN * V_OUT^Ǔ @ I_OUT [W] (eq. 2)
Where I_GND is the LDO’s ground current, dependent on the
output load current.
Connecting the exposed pad and N/C pin to a large ground
planes helps to dissipate the heat from the chip.
The relation of θ_JA and P_D(MAX) to PCB copper area and
Cu layer thickness could be seen on the Figure 23.
Reverse Current
The PMOS pass transistor has an inherent body diode
which will be forward biased in the case when V_OUT > V_IN.
Due to this fact in cases, where the extended reverse current
condition can be anticipated the device may require
additional external protection.
Power Supply Rejection Ratio
The LDO features very high power supply rejection ratio.
The PSRR at higher frequencies (in the range above
100 kHz) can be tuned by the selection of C_OUT capacitor
and proper PCB layout. A simple LC filter could be added
to the LDO’s IN pin for further PSRR improvement.
Enable Turn−On Time
The enable turn−on time is defined as the time from EN
assertion to the point in which V_OUT will reach 98% of its
nominal value. This time is dependent on various
application conditions such as V_OUT−NOM, C_OUT and T_A.
PCB Layout Recommendations
To obtain good transient performance and good regulation
characteristics place C_IN and C_OUT capacitors as close as
possible to the device pins and make the PCB traces wide.
In order to minimize the solution size, use 0402 or 0201
capacitors size with appropriate effective capacitance.
Larger copper area connected to the pins will also improve
the device thermal resistance. The actual power dissipation
can be calculated from the equation above (Power
Dissipation section). Exposed pad and N/C pin should be
tied to the ground plane for good power dissipation.
ORDERING INFORMATION TABLE
Part Number
Voltage
Option
NCV8186BMN175TAG
1.75 V
Marking
GA
Option
Without active discharge
Package
DFN8
(Pb−Free)
Shipping
3000 / Tape & Reel
www.onsemi.com
9