BU9817FV Datasheet, PDF (8/15 Pages) Rohm – 4-channel temperature sensor IC for PCs with I2C BUS interface

Multimedia ICs
BU9817FV
!Circuit operation
Explanation of operating mode
Operating mode
Configuration
register settings
Normal mode
00000∗∗0b
Interval High mode
00110∗∗0b
Interval Low mode
00100∗∗0b
Shutdown mode
00000∗∗1b
ADC operation
conversion interval
1.221ms
1 second intervals
4 second intervals
Stopped
Open drain
operation timing
10th clock after
A / D conversion
10th clock after
A / D conversion
10th clock after
A / D conversion
Hold status
Register status
Current
consumption (typ.)
Normal operation
0.75mA
Normal operation
Normal operation
Note: average
less than 3µA
Note: average
less than 2µA
Hold data
Less than 1µA
Reset mode
00∗∗1∗∗∗b
Stopped
Reset fixed at high
Data reset
Less than 1µA
The asterisk can be either 0 or 1.
∗ Conversion time is for fCLK = 32.768kHz.
∗ These mode setting bits (bit 0 and bits 3 to 5) are common for each channel, the last setting of bits (bit0 and bits3 to 5) is
effective for all channels. Furthermore, bits 1 and 2 are independent and can be set for each channel.
∗ Note: These parameters are reference values derived through calculations and are not guaranteed characteristic values.
Explanation of ADC / open drain operation
(Normal mode)
Tad = 1.221ms, 40 clock
10 clock
ADC operation 4ch 1ch 2ch 3ch 4ch 1ch 2ch 3ch 4ch 1ch
OD1
OD2
OD3
OD4
(Interval mode)
ADC operation
OD1
OD2
OD3
OD4
Tin = 1s, 4s
Tc = 1.831ms, 60 clock
10 clock 10 clock
1ch 2ch 3ch 4ch 1ch
10 clock
1ch 2ch 3ch