SP6213 Datasheet, PDF (4/10 Pages) Sipex Corporation – Micropower, SC-70, 100mA CMOS LDO Regulator

PIN NUMBER
3
4
5
1
2
PIN DESCRIPTION
PIN NAME
GND
V_OUT
V_IN
EN
NC
DESCRIPTION (FUNCTION)
Ground Connection
Regulator Output
Supply Input
Enable / Shutdown (Logic high=enable; logic low = shutdown)
No Connection
General Overview
Enable/Shutdown Operation
The SP6213 is turned off by pulling the EN pin low
and turned on by pulling it high. If this enable/
shutdown feature is not required, EN should be
tied to V_IN to keep the regulator output on at all
times.
Input Capacitor
A small capacitor of about 1µF is required from
V_IN to GND if e.g. a battery is used as the input.
Any good quality ceramic or tantalum capacitor
may be used at the input.
Output Capacitor
An output capacitor is required between V_OUT and
GND to prevent oscillation. The minimum size of
the output capacitor is a 0.47 µF ceramic. The
given datasheet values relate to an IC with a
ceramic output capacitor of 1µF. Larger values
make the IC more stable which means an improve-
ment of the regulator’s transient response. For a
lower output current, the output capacitance can be
chosen smaller in order to have the same output
stability.
No Load Stability
The SP6213 will remain stable and in regulation
with no external load (other than the internal
voltage driver) unlike many other voltage regula-
tors. This is especially important in CMOS RAM
keep-alive applications.
Thermal Considerations
The SP6213 is designed to provide 100 mA of
continuous current in a very tiny package. Maxi-
mum power dissipation can be calculated based on
THEORY OF OPERATION
the output current and the voltage drop across the
part. To determine the maximum power dissipa-
tion of the package, use the junction-to-ambient
thermal resistance of the device and the following
basic equation:
P_D = (T_J(max) - T_A) / Θ_JA
T_J(max) is the maximum junction temperature of the
die and is 125°C. T_A is the ambient operating. Θ_JA
is the junction-to-ambient thermal resistance for
the regulator and is layout dependent.The actual
power dissipation of the regulator circuit can be
determined using one simple equation:
P_D = (V_IN - V_OUT)*I_OUT + V_IN*I_GND
Substituting P_D(max) for P_D and solving for the
operating conditions that are critical to the applica-
tion will give the maximum operating conditions
for the regulator circuit. For example, if we are
operating the SP6213 at 3.0V output at room
temperature, with a minimum footprint layout, we
can determine the maximum input voltage for a set
output current.
P_D(max) =[(125°C -25°C) / (330°C/W)] = 303 mW.
To prevent the device from entering thermal shut-
down, maximum power dissipation can not be
exceeded. Using the output voltage of 3.0V and an
output current of 100 mA, the maximum input
voltage can be determined. Ground pin current can
be taken from the electrical spec’s- table (0.135
mA at 100 mA). The maximum input voltage is
determined as follows:
303mW = (V_IN – 3.0V)*100mA + V_IN*0.135mA
After calculations, we find that the maximum
input voltage of a 3.0V application at 100mA of
output current in an SC-70-5 package is 6.02V.
Rev. 9/22/03
SP6213 Micropower, SC-70, 100mA CMOS LDO Regulator
4
© Copyright 2003 Sipex Corporation