sg2004-xs-tr sg-micro, sg2004-xs-tr Datasheet - Page 9

• Manufacturer Part Number: sg2004-xs-tr
• Description: 400ma, Low Power, Low Noise, Low Dropout, Linear Regulators
• Manufacturer: sg-micro

TYPICAL OPERATING CHARACTERISTICS
V
Application Notes
When LDO is used in handheld products, Attention must be paid to voltage spike which would damage SG2003 and
SG2004. In such applications, voltage spike will be generated at changer interface and V
changer adapters and USB equipments are hot-inserted. Besides this, handheld products will be tested on the
production line on the condition of no battery. Test Engineer will apply power from the connector pin which connects
with positive pole of the battery. When external power supply is turned on suddenly, the voltage spike will be
generated at the battery connector. The voltage spike will be very high, it always exceeds the absolute maximum
input voltage (6.0V) of LDO. In order to get robust design. Design Engineer needs to clear up this voltage spike. Zener
diode is a cheap and effective solution to eliminate such voltage spike. For example, BZM55B5V6 is a 5.6V small
package Zener diode which can be used to remove voltage spike in cell phone design. The schematic is shown in
below:
IN
= V
OUT(NOMINAL)
6
4
2
0
2
1
0
Input
Vcc
BZM55B5V6
+1V, C
IN
= 1µF, C
Time(10μs/div)
Start Up
OUT
1uF
Control
= 1µF, C
V
V
C
I
IN
OUT
IN
LOAD
= 5V
= C
= 2.5V
= 1mA
C
OUT
1
BP
= 1μF
= 0.01µF, T
IN
EN
A
SG2003/SG2004
= +25℃, unless otherwise noted.
9
GND
BP/FP
0.01uF
V
OUT
C
2
BUS
4.7uF
pin of USB interface when
SG2003/A
SG2004/A
V
OUT