ZHCSGD8A May 2017 – May 2018
PRODUCTION DATA.
As an industry standard, a high-accuracy current sense amplifier (CSA) is used to monitor the input current during forward charging, or output current during OTG (IADPT) and the charge/discharge current (IBAT). IADPT voltage is 20× or 40× the differential voltage across ACP and ACN. IBAT voltage is 8x/16× (during charging), or 8×/16× (during discharging) of the differential across SRP and SRN. After input voltage or battery voltage is above UVLO, IADPT output becomes valid. To lower the voltage on current monitoring, a resistor divider from CSA output to GND can be used and accuracy over temperature can still be achieved.
A maximum 100-pF capacitor is recommended to connect on the output for decoupling high-frequency noise. An additional RC filter is optional, if additional filtering is desired. Note that adding filtering also adds additional response delay. The CSA output voltage is clamped at 3.3 V.