XC62E
Series
■Typical Application Circuit
GStandard
Circuit
PNP Tr
R
BE
R
B
EXT
C
IN
（Tantalum）
V
IN
V
OUT
C
L
（Tantalum）
V
IN
R
Ｌ
Peripherals :
CE
Vss
PNP Tr : 2SA1213
R
BE
R
B
C
IN
C
L
: 20kΩ∼47kΩ
: Please refer to Note 2 on the following page.
: 10µF(Tantalum)
: 47µF(Tantalum) 10µF minimum
3
■Operational Explanation
GFunctional
Description
Output voltage (V
OUT
) can be fixed by revising the external transistor's base current. This can be done by comparing the detected voltage level
and the set voltage power supply level.
With the XC62EP (CE negative voltage), if a voltage above the CE pin's "H" level is applied, the IC will enter stand-by mode where the base and
differential amplifier's currents are regulated.
■Directions for use
GSuggestions
for External Components
1. PNP Transistor
The selection of a transistor should take into account output current, input voltage and power dissipation for each specific application. It is
recommended that a transistor that has a low output saturated voltage (V
CE
) and high h
FE
characteristics be used.
2. R
B
Resistor
Although the IC unit is protected by a base current remitter circuit, it is recommended that a resistor (R
B
) be connected between the
transistor's base and the IC's EXT pin to protect the transistor.
Required output current can be calculated using the following equation although characteristic variations and conditions of use should be
carefully checked before use. The following equation also indicates the conditions needed to obtain I
OUT
(max.) at V
IN
(min.). However, the
larger the input current, the larger the output current (I
OUT
) that can be obtained.
V
IN
(min)-1.2(V)
R
B
0.7(V)
R
BE
I
OUT
(max)
h
FE
3. R
BE
Resistor, C
L
Capacitor
To prevent oscillation due to output load variation, use of a phase compensation capacitor C
L
is recommended. Please use a Tantalum
capacitor of at least 10µF. Please also use an R
BE
resistor of less than 47kΩ.
An R
BE
resistor of between 20kΩ and 47kΩ is recommended for less power consumption.
4. Input Impedance
In order to control oscillation brought about as a result of impedance at the power supply line, connect a capacitor of 10µF or more (Tantalum)
between the external transistor's emitter and the ground pin.
GSpecial
Note
1. Protection Circuit
The built-in protect circuit is to protect the IC only. Therefore to prevent output shorts and overshoot current through the transistor, use of a
resistor R
B
or an overshoot current protection circuit is recommended.
Care should also be taken with the transistor's power dissipation.
353
TOREX [ TOREX SEMICONDUCTOR ]
