Teclast X21, Руководство по обслуживанию

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frequency of typically 1 MHz. At light load currents, the part enters the power save mode operation; the
switching frequency is reduced and the quiescent current is typically only 15 µA; therefore it achieves the
highest efficiency over the entire load current range. The TPS6220x needs only three small external
components. Together with the tiny SOT23 package, a minimum system solution size can be achieved. An
advanced fast response voltage mode control scheme achieves superior line and load regulation with small
ceramic input and output capacitors.
Pin function is shown as the following figure
：
Pin Contiguous signal name Function description
1 VIN Voltage input
2 GND Grounding
3 EN IC enable pin
4 FB Output feedback
5 SW External device pin, voltage output
3.5.9 Function introduction to ISL6294
The ISL6294 is a cost-effective, fully integrated high input voltage single-cell Li-ion battery charger. The
charger uses a CC/CV charge profile required by Li-ion batteries. The charger accepts an input voltage up to
28V but is disabled when the input voltage exceeds the OVP threshold, typically 6.8V, to prevent excessive
power dissipation. The 28V rating eliminates the over-voltage protection circuit required in a low input voltage
charger.
The charge current and the end-of-charge (EOC) current are programmable with external resistors. When
the battery voltage is lower than typically 2.55V, the charger preconditions the battery with typically 20% of the
programmed charge current. When the charge current reduces to the programmable EOC current level during
the CV charge phase, an EOC indication is provided by the CHG pin, which is an open-drain output. An
internal thermal foldback function protects the charger from any thermal failure.
Two indication pins (PPR and CHG) allow simple interface to a microprocessor or LEDs. When no
adapter is attached or when disabled, the charger draws less than 1µA leakage current from the battery.
Pin function is shown as the following figure
：
Pin Contiguous signal name Function description
1 IN Power input
2 /PPR Charge voltage limit end
3 /CHG Charge state indication
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