HY2120
2-Cell Lithium-ion/Lithium Polymer Battery Packs Protection ICs
a charger is removed and some load is connected, OC outputs “L”, however, load current can flow
through the parasitic diode of the external charge control Nch MOSFET. After that, when the VDD
pin voltage becomes lower than the overcharge detector threshold, OC becomes “H”.
Internal fixed output delay times for overcharge detection. If either or both of the voltage of Cell1 or
Cell2 keeps its level more than the overcharge detector threshold, and output delay time passes,
overcharge voltage is detected. Even when the voltage of Cell1 or Cell2 level becomes equal or
higher level than overcharge detection voltage (VCUn) if these voltages would be back to a level
lower than the overcharge detector threshold within a time period of the output delay time, the
overcharge is not detected.
11.3.Overdischarge Status
11.3.1. Products with Power-down Function
Batteries under normal operation mode, voltage of cell 1 that connected to VDD and VC pin or voltage
of cell 2 that connected to VC and VSS pin drops lower than overdischarge detection voltage (VDLn
)
and the mode continues longer than overdischarge detection delay time (TOD) during discharging,
HY2120 series will turn the OD pin output voltage from high level to low level and turn the discharging
control MOSFET off (OD pin) so as to stop discharging. This condition is called the “Overdischarge
Status”.
.
When MOSFET is off, CS pin voltage is pulled up by IC internal resistor to VDD, reducing IC power
consumption value to that of in the sleep mode (<0.1uA). This condition is called the “Sleep Mode”.
The overdischarge status will be leased by two following cases. OD pin output voltage turns from low
level to high level, conducting discharge control MOSFET.
(1) If CS pin voltage lowers than charge overcurrent detection voltage (VCIP) when charger is
connected, voltage of cell 1 and cell 2 goes higher than overdischarge detection voltage (VDLn), the
overdischarge status is released and back to normal operation mode.
(2) If CS pin voltage is higher than charge overcurrent detection voltage (VCIP) when charger is
connected, voltage of cell 1 and cell 2 goes higher than overdischarge release voltage (VDRn), the
overdischarge status is released and back to normal operation mode.
11.3.2. Products with Auto Overdischarge Recovery Function
Batteries under normal operation mode, voltage of cell 1 that connected to VDD and VC pin or
voltage of cell 2 that connected to VC and VSS pin drops lower than overdischarge detection voltage
(VDLn) and the mode continues longer than overdischarge detection delay time (TOD) during
discharging, HY2120 series will turn the OD pin output voltage from high level to low level and turn the
discharging control MOSFET off (OD pin) so as to stop discharging. This condition is called the
“Overdischarge Status”.
The overdischarge status will be released by three cases:
(1) When CS pin voltage is equal to or lower than the charge overcurrent detection voltage (VCIP) by
© 2009-2015 HYCON Technology Corp
www.hycontek.com
DS-HY2120-V15_EN
page13
HYCON [ HYCON Technology Corporation ]
