sg2012-3.3xkc3r-tr sg-micro, sg2012-3.3xkc3r-tr Datasheet - Page 7

• Manufacturer Part Number: sg2012-3.3xkc3r-tr
• Description: 400ma , Low Power, Low Dropout, Linear Regulators
• Manufacturer: sg-micro

Application Notes
When LDO is used in handheld products, Attention must be paid to voltage spike which would damage SG2012. In
such applications, voltage spike will be generated at changer interface and V
pin of USB interface when changer
BUS
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:
Vcc
IN
V
V
Input
SG2012
OUT
OUT
1uF
C
C
4.7uF
1
2
BZM55B5V6
GND
7
SG2012