Diodes API9221 - Manual (Page 10)

API9221
CAR/WALL or USB SUPPLY INPUT LITHIUM BATTERY
CHARGER with OVP USB BYPASS and 10mA LDO
API9221
Document number: DS32204 Rev. 2 - 2
10 of 15
www.diodes.com
November 2011
© Diodes Incorporated
NEW PROD
UC
T
Functional Characteristics (cont.)
Power Supply Filtering and Stability
At each of the inputs VDC and VUSB, a local decoupling
capacitor is required to be connected to GND. A
minimum value of 1µF is recommended, ceramic type
X7R. (The USB standard sets an upper bound of
capacitance somewhat larger than this.)
At the linear regulator output VDC_LDO, a local
decoupling capacitor is required, connected to GND. A
value of 1µF is recommended, ceramic type X7R.
At the battery connection BAT, a local decoupling
capacitor is required, connected to GND. A value of 1µF
is recommended, ceramic type X7R.
Timing Diagram
EN
PPR
VUSB
VDC
VDC_LDO
USB_BYP
VBAT
IUSB
IVDC
CHG
0V
4.94V
I
USB_BYP
I
USB_BYP
+I
CHRG
I
LDO
I
LDO
+I
CHRG
ENABLED
PO
5.4V OVP
VUSB
PO
6.9V OVP
VDC
OVP
VDC
- HOVP
VDC
OVP
VUSB
- HOVP
VUSB
PO = Power-ON
I
CHRG
= Battery Charging Current