iru1247-25 International Rectifier Corp., iru1247-25 Datasheet - Page 3

• Manufacturer Part Number: iru1247-25
• Description: Fixed Adjustable Dual Voltage Regulator
• Manufacturer: International Rectifier Corp.

Note 1: Low duty cycle pulse testing with Kelvin connections is required in order to maintain accurate data.
Note 2: Dropout voltage is defined as the minimum differential voltage between Vin and Vout required to maintain
regulation at Vout. It is measured when the output voltage drops 1% below its nominal value.
Note 3: Minimum load current is defined as the minimum current required at the output in order for the output
voltage to maintain regulation.
Note 4: Temperature stability is the change in output from nominal over the operating temperature range.
Note 5: Guaranteed by design, but not tested in production.
PIN DESCRIPTIONS
IRU1246
PIN # PIN SYMBOL
IRU1247-18, IRU1247-25
PIN # PIN SYMBOL
Rev. 1.6
07/13/01
1
2
3
4
5
1
2
3
4
5
Vout1
Vout2
Vout2
Vout1
Vadj
Gnd
Gnd
Vin
Vin
NC
The power 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 dropout
voltage during the load transient response. This pin must always be higher than both Vout
pins by the amount of the dropout voltage in order for the device regulate properly.
A resistor divider from this pin to Vout2 (pin4) and ground sets the output voltage.
This pin is connected to ground. It is also the TAB of the Ultra Thin-Pak package.
The output #2 (adjustable) of the regulator. A minimum of 4.7µF capacitor must be con-
nected from this pin to ground to insure stability.
The output #1 (3.3V) of the regulator. A minimum of 4.7µF capacitor must be connected
from this pin to ground to insure stability.
The power 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 dropout
voltage during the load transient response. This pin must always be higher than both Vout
pins by the amount of the dropout voltage in order for the device to regulate properly.
No connection.
This pin is connected to ground. It is also the TAB of the Ultra Thin-Pak package.
The output #1 (1.8V for 1247-18 and 2.5V for 1247-25) of the regulator. A minimum of
4.7µF capacitor must be connected from this pin to ground to insure stability.
The output #2 (3.3V) of the regulator. A minimum of 4.7µF capacitor must be connected
from this pin to ground to insure stability.
PIN DESCRIPTION
PIN DESCRIPTION
IRU1246 / IRU1247-18 / IRU1247-25
3