IP5407

V1.31

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Copyright © 2019, Injoinic Corp.

Key / Lights / NTC

IP5407's keys, lighting lamp drive, and NTC temperature detection are realized by time-multiplexing. Refer

to the schematic diagram in Figure 5

IP5407 can recognize long and short button operation

 The key duration is longer than 50ms, but less than 2s, which is a short press action. A short press will

turn on the power indicator and boost output.

 If the key is pressed for longer than 2s, it is a long-press action. A long-press will turn the lighting LED

on or off.

 There will be no response when the key action is less than 50ms.

IP5407 integrates NTC function to detect battery temperature. When IP5407 is

working, NTC

PIN outputs a current of 20uA. At the same time, it detects the voltage of the NTC PIN to

determine the current battery temperature.

82K RNTC=100K

B=3950

VL=1.32V/1.52V

NTC

COMP

HT

LT

V=20uA*(R1//RNTC)

VH=0.38V/0.56V

key

flashliggt

KEY

Figure 5 Schematic diagram of key, lights, NTC

In the charging state: When NTC PIN detects a voltage of 1.32V, it means that the battery is 0 degrees , and stops

charging the battery;

When NTC PIN detects a voltage of 0.56V, it means that the battery is at 45 degrees, and stops charging the

battery;

In the discharge state:When NTC PIN detects a voltage of 1.52V, it means that the battery is -15 degrees low, and

stops charging to discharge to the outside;

When NTC PIN detects a voltage of 0.38V, it means that the battery is 60 degrees, and stops discharging to

the outside;

If the project does not require NTC, you need to connect the KEY pin to a 51K resistor to GND. Otherwise, it

may cause abnormal charging and discharging. When the IP5407 detects a key press, it will maintain the NTC

detection result before the key is pressed, and the NTC detection returns to normal after the key is released.