ML7396AB datasheet(67/140 Pages) LAPIS

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FEDL7396A/B/E-07

ML7396A/B/E

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●Temperature Measurement Function

ML7396 family has temeperature measurement function. This temperature information can be from A_MON pin (#24) as

analog output or digital information using [TEMP_MON:B0 0x79] register. Analog or digital can be switched by

[RSSI/TEMP_OUT:B1 0x03] register.

Notes:

1) Please do not set TEMP_OUT ([RSSI/TEMP_OUT:B1 0x03(4)]) and TEMP_ADC_OUT ([RSSI/TEMP_OUT:B1

0x03(5)]) at the same time. Correct value reading may not be guaranteed.

2) When TEMP_ADC_OUT is set, packet data is not able to receive normally.

[Analog output]

ML7396 family has current source circuits and its current flow through 75kΩ to A_MON pin (#24). From voltage information,

temperature information can be obtained.

Current from currwnt source circuits are 10μA at 25˚C. Following formula can be used to calculate temperature from the

current.

Itemp = (273+ Temp) / (273+25) * 10 (μA)

Therefore, if 75kΩ resister is connected, temprature can be calculated usng following formula.

Vamon = (273+ Temp) / (275+25) * 10E-6 * 75000

If temprature is -40˚C to +85˚C, Vamon will be 0.59V to 0.9V.

Therefore temperature can be calculated from voltage using following formula.

Temp = Vamon * 397.3 - 273

[Digital output]

Digital temperature information is using 6bits ADC to convert from the above analog information. Internally, 4samples

information are added and indicates as 8bits information in [TEMP_MON:B0 0x79] register. Ignorimg low 2 bits, upper 6bits

are used for average temperature information.

Temperature information is updated every 17.8μs. (if 2MHz is selected in [ADC_CLK_SET:B0 0x08] register, it is updated

every 16 μs)

ML7396AB датащи(PDF) 67 Page - LAPIS Semiconductor Co., Ltd.