LP2985IM5-2.7 National Semiconductor, LP2985IM5-2.7 Datasheet - Page 12

• Manufacturer Part Number: LP2985IM5-2.7
• Description: IC,VOLT REGULATOR,FIXED,+2.7V,BIPOLAR,TSOP,5PIN,PLASTIC
• Manufacturer: National Semiconductor

Specifications of LP2985IM5-2.7

• Rohs Compliant: NO

www.national.com
Typical Performance Characteristics
V
Turn-On Time
Turn-On Time
Application Hints
EXTERNAL CAPACITORS
Like any low-dropout regulator, the LP2985 requires external
capacitors for regulator stability. These capacitors must be
correctly selected for good performance.
Input Capacitor
An input capacitor whose capacitance is
between the LP2985 input and ground (the amount of ca-
pacitance may be increased without limit).
This capacitor must be located a distance of not more than 1
cm from the input pin and returned to a clean analog ground.
Any good quality ceramic, tantalum, or film capacitor may be
used at the input.
Important: Tantalum capacitors can suffer catastrophic fail-
ure
low-impedance source of power (like a battery or very large
capacitor). If a Tantalum capacitor is used at the input, it
must be guaranteed by the manufacturer to have a surge
current rating sufficient for the application.
There are no requirements for ESR on the input capacitor,
but tolerance and temperature coefficient must be consid-
ered when selecting the capacitor to ensure the capacitance
will be
Output Capacitor:
The LP2985 is designed specifically to work with ceramic
output capacitors, utilizing circuitry which allows the regula-
OUT
(NOM) +1, T
due
1 µF over the entire operating temperature range.
to
surge
A
= 25˚C, ON/OFF pin is tied to V
current
when
connected
DS100140-39
DS100140-41
1 µF is required
IN
. (Continued)
to
a
Unless otherwise specified: C
Turn-On Time
Turn-On Time
12
tor to be stable across the entire range of output current with
an output capacitor whose ESR is as low as 5 m . It may
also be possible to use Tantalum or film capacitors at the
output, but these are not as attractive for reasons of size and
cost (see next section Capacitor Characteristics).
The output capacitor must meet the requirement for mini-
mum amount of capacitance and also have an ESR (equiva-
lent series resistance) value which is within the stable range.
Curves are provided which show the stable ESR range as a
function of load current (see ESR graph below).
IN
= 1µF, C
OUT
DS100140-40
DS100140-42
= 4.7µF, V
DS100140-7
IN
=