APU1205
APU1205-18 / APU1205-25 / APU1205-28
APU1205-30 / APU1205-33 / APU1205-36
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
IN
and V
OUT
required to main-
tain regulation at V
OUT
. It is measured when the output
voltage drops 1% below its nominal value.
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 +1258C.
PIN DESCRIPTIONS
PIN #
1
PIN SYMBOL
V
IN
PIN DESCRIPTION
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
OUT
by at least the amount of the dropout voltage and some margin in order for
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
IN
for normal operation.
A resistor divider from this pin to the V
OUT
pin and ground sets the output voltage. To
minimize the error due to the error amplifier, select the values of the resistor dividers
to be less than 10KV.
A 470 to 1000pF bypass capacitor connected to this pin reduces the output noise.
2
Gnd
3
En
4
Adj
(Adjustable Only)
4
C
BYP
(Fixed Only)
V
OUT
5
The output of the regulator. A minimum of 2.2mF with max ESR of 1V capacitor must
be connected from this pin to ground to insure stability.
Output
Voltage
1.25V
1.8V
2.5V
2.8V
3.0V
3.3V
3.6V
The output voltage of the adjustable device can be set
using:
Vo = 1.253 1+
5-PIN
SOT-23
APU1205
APU1205-18
APU1205-25
APU1205-28
APU1205-30
APU1205-33
APU1205-36
(
R1
R2
)
Where:
R1 = Resistor connected from output to the Adj pin
R2 = Resistor connected from Adj pin to Gnd
Table 1- Nominal output voltage vs. part number.
3/4
A-POWER [ ADVANCED POWER ELECTRONICS CORP. ]
