ACT4910QW
Rev 1.0, 15-Sept-2017
ADC_ONE_SHOT = 0
ADC_CH_SCAN = 1
EN_ADCBUF = 1
CH0
CH1
CH2
6 to 1
MUX
8 Bit
Result
ADC
Start the automatic polling by changing EN_ADC to 1.
When in automatic polling mode, the ADC continuously
changes the MUX inputs to read all input channels. The
ADC continually overwrites the data in the output
register. After all channels have been converted, the
ADC_DATA_READY bit is set to 1. Note that nIRQ is not
asserted low in Automatic Polling mode. Ensure that
ADC data is valid and ready by reading the
ADC_DATA_READY before reading ADC data. After the
ADC_DATA_READY bit is set to 1, the user defines the
channel to be read with the ADC_CH_CONV [2:0] bits
in register 0x08h. Change ADC_CH_CONV to read
additional channels.
CH5
Clock
SEL[2:0]
Figure 7: ADC Block Diagram
Automatic Polling Conversion
Configure the IC for automatic polling conversion mode
by setting the following I2C bits in register 0x08h
Table 8: ADC Channels
Channel
Channel Description ADC_CH_CONV[2:0] ADC_CH_READ[2:0]
Value
CH0
CH1
CH2
CH3
CH4
CH5
Input Current
Input Voltage
000
001
010
011
100
101
000
001
010
011
100
101
IIN = (DOUT-128)*1.221/RILIM (A)
VIN = (DOUT-128)*0.392 (V)
VSTR = (DOUT-128)*0.392 (V)
VOUT = (DOUT-128)*0.392 (V)
Temp = 6.125*DOUT-1053.75 (deg C)
Storage Cap Voltage
Output Voltage
Die Temperature
GND
CMI, but can be changed at any time after startup.
Disable channel’s supervisory function by
programming the undervoltage register value to 0x00h
and the overvoltage register to 0xFFh.
Autonomous ADC Supervisory Function
a
The ACT4910 can be configured to automatically
measure any or all of the five system level parameters
and then then automatically notify the system if one of
the parameters falls out of its specified range. This
check is performed automatically, without any external
circuit components. The ACT4910 implements this
using internal digital undervoltage and overvoltage
comparators for all five ADC channels. Table 9 shows
each ADC channel’s undervoltage and overvoltage
registers. When in automatic polling mode, if an ADC
conversion result is below the undervoltage threshold or
above the overvoltage threshold, the IC asserts nIRQ
low. The uP can then read the status register 0x04h to
determine which parameter is out of range. nIRQ can
be masked by setting the ADC_OUTRNG_IRQ_MASK
bit. The default thresholds are determined by each ICs
Table 9: ADC Thresholds Registers
Undervoltage
Overvoltage
Threshold Register Threshold Register
Input Current
Input Voltage
0x0Ch
0x0Dh
0x14h
0x15h
0x16h
0x17h
0x18h
Storage Cap Voltage 0x0Eh
Output Voltage
0x0Fh
0x10h
Die Temperature
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