iru1205 International Rectifier Corp., iru1205 Datasheet - Page 3

• Manufacturer Part Number: iru1205
• Description: 300ma Ultra Low Dropout Positive Adjustable And Fixed Regulators -
• Manufacturer: International Rectifier Corp.

Note 1: Low duty cycle pulse testing with Kelvin con-
nections is required in order to maintain accurate data.
Note 2: Dropout voltage is defined as the minimum dif-
ferential voltage between V
tain regulation at V
voltage drops 1% below its nominal value.
PIN DESCRIPTIONS
PIN #
Rev. 2.3
07/16/02
1
2
3
4
4
5
Table 1- Nominal output voltage vs. part number.
(Adjustable Only)
PIN SYMBOL
(Fixed Only)
IRU1205
IRU1205-18
IRU1205-25
IRU1205-28
IRU1205-30
IRU1205-33
IRU1205-36
SOT-23
V
Gnd
C
Adj
V
En
5-PIN
OUT
BYP
IN
OUT
. It is measured when the output
IN
and V
The input pin of the regulator. Typically a large storage capacitor is connected from
this pin to ground to insure that the input voltage does not sag below the minimum
drop out voltage during the load transient response. This pin must always be higher
than V
the device to regulate properly.
Ground pin. This pin must be connected to the lowest potential in the system and all
other pins must be at higher potential with respect to this pin.
Enable pin. A low signal or left open on this pin shuts down the output. This pin must
be tied HI or to V
A resistor divider from this pin to the V
minimize the error due to the error amplifier, select the values of the resistor dividers
to be less than 10K .
A 470 to 1000pF bypass capacitor connected to this pin reduces the output noise.
The output of the regulator. A minimum of 2.2 F with max ESR of 1 capacitor must
be connected from this pin to ground to insure stability.
PIN DESCRIPTION
Voltage
Output
1.25V
1.8V
2.5V
2.8V
3.0V
3.3V
3.6V
OUT
OUT
required to main-
by at least the amount of the dropout voltage and some margin in order for
IN
for normal operation.
www.irf.com
IRU1205-18 / IRU1205-25 / IRU1205-28
IRU1205-30 / IRU1205-33 / IRU1205-36
Note 3: Ground current is the regulator quiescent cur-
rent plus the pass transistor current. The total current
from the supply is the sum of the load current plus the
ground pin current.
Note 4: The specification applies for the junction tem-
perature of 0 to +125 C.
The output voltage of the adjustable device can be set
using:
Where:
R1 = Resistor connected from output to the Adj pin
R2 = Resistor connected from Adj pin to Gnd
Vo = 1.25
OUT
pin and ground sets the output voltage. To
(
1+
R1
R2
)
IRU1205
3