ZHCSGD8A May 2017 – May 2018
PRODUCTION DATA.
The device employs Narrow VDC architecture (NVDC) with BATFET separating system from battery. The minimum system voltage is set by REG0x0D/0C(). Even with a deeply depleted battery, the system is regulated above the minimum system voltage with BATFET.
When the battery is below minimum system voltage setting, the BATFET operates in linear mode (LDO mode), and the system is regulated above the minimum system voltage setting. As the battery voltage rises above the minimum system voltage, BATFET is fully on when charging or in supplement mode and the voltage difference between the system and battery is the VDS of BATFET. System voltage is regulated 160 mV above battery voltage when BATFET is off (no charging or no supplement current).
When BATFET is removed, the system node VSYS is shorted to SRP. Before the converter starts operation, LDO mode needs to be disabled. The following sequence is required to configure charger without BATFET.
In order to prevent any accidental SW mistakes, the host sets low input current limit (a few hundred milliamps) when device is out of HIZ.