ST2L05-3300 STMicroelectronics, ST2L05-3300 Datasheet - Page 15

• Manufacturer Part Number: ST2L05-3300
• Description: DUAL VOLTAGE REGULATOR
• Manufacturer: STMicroelectronics

Specifications of ST2L05-3300

• Vo1: fixed
• Vo2: adjustable from 1.25 to VI - VDROP
• Guaranteed Current Of Output 1: 1 A
• Guaranteed Current Of Output 2: 1 A
• Operating Temperature Range: 0 °C to 125 °C
• Very Low Quiescent Current: 7 mA max overtemperature

6
6.1
6.2
6.3
6.4
Application hints
External capacitors
Like any low-dropout regulator, the ST2L05-3300 requires external capacitors for stability. It
is recommended to solder both capacitors as close as possible to the relative pins (1, 4 and
5).
Input capacitor
An input capacitor with a value of at least 2.2 µF is required. The amount of input
capacitance can be increased without limit if a good quality tantalum or aluminium capacitor
is used. SMD X7R or Y5V ceramic multilayer capacitors may not ensure stability in any
condition due to the variability of their frequency and temperature characteristics. The use of
this capacitor type is strictly related to the use of the output capacitors. For additional
details, please read the
at a distance of not more than 0.5" from the input pin of the device and returned to a clean
analog ground.
Output capacitor
The ST2L05-3300 is designed specifically to work with ceramic and tantalum capacitors.
Special care must be taken when a ceramic multilayer capacitor is used. Due to their
characteristics, this type of capacitor can sometimes have an ESR value lower than the
minimum required by the ST2L05-3300, and their relatively large capacitance can vary
greatly depending on the ambient temperature. The test results for the stability of the
ST2L05-3300 using multilayer ceramic capacitors show that a minimum value of 2.2 µF is
needed for both regulators. This value can be increased without limit if the input capacitor
value is greater than or equal to 4.7 µF, and up to 10 µF if the input capacitor is less than 4.7
µF. Surface-mountable solid tantalum capacitors offer a good combination of small physical
size, capacitance value and ESR in the range needed for the ST2L05-3300. Test results
show good stability for both outputs with values of at least 1 µF. The value can be increased
without limit for even better performance in areas such as transient response and noise.
Important:
The output capacitor must maintain an ESR in the stable region over the full operating
temperature to assure stability. Moreover, capacitor tolerance and variations due to
temperature must be considered to assure that the minimum amount of capacitance is
provided at all times. For this reason, when a ceramic multilayer capacitor is used, the better
choice for temperature coefficient is the X7R type, which holds the capacitance within ±
15%. The output capacitor should be located not more than 0.5" from the output pins of the
device and returned to a clean analog ground.
Adjustable regulator
The ST2L05-3300 has a 1.25 V reference voltage between the output and the adjust pins
(pins 4 and 2, respectively). When resistor R
constant current flows through R
voltage. Minimum load current is 2 mA max in all temperature conditions.
Output capacitor
1
and down to R
section below. The input capacitor must be located
1
is placed between these two terminals, a
2
to set the overall (V
O2
to GND) output
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