OPT3006
ZHCSFL9 –OCTOBER 2016
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Table 10. Configuration Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
Conversion time field (read or write).
The conversion time field determines the length of the light to digital conversion process. The
choices are 100 ms and 800 ms. A longer integration time allows for a lower noise
measurement.
The conversion time also relates to the effective resolution of the data conversion process. The
800-ms conversion time allows for the fully specified lux resolution. The 100-ms conversion
time with full-scale ranges above 0101b for E[3:0] in the result and configuration registers also
allows for the fully specified lux resolution. The 100-ms conversion time with full-scale ranges
below and including 0101b for E[3:0] can reduce the effective result resolution by up to three
bits, as a function of the selected full-scale range. Range 0101b reduces by one bit. Ranges
0100b, 0011b, 0010b, and 0001b reduces by two bits. Range 0000b reduces by three bits.
The result register format and associated LSB weight does not change as a function of the
conversion time.
11
CT
R/W
1b
0 = 100 ms
1 = 800 ms
Mode of conversion operation field (read or write).
The mode of conversion operation field controls whether the device is operating in continuous
conversion, single-shot, or low-power shutdown mode. The default is 00b (shutdown mode),
such that upon power-up, the device only consumes operational level power after appropriately
programming the device.
When single-shot mode is selected by writing 01b to this field, the field continues to read 01b
while the device is actively converting. When the single-shot conversion is complete, the mode
of conversion operation field is automatically set to 00b and the device is shut down.
When the device enters shutdown mode, either by completing a single-shot conversion or by a
manual write to the configuration register, there is no change to the state of the reporting flags
(conversion ready, flag high, flag low) or the INT pin. These signals are retained for
subsequent read operations while the device is in shutdown mode.
00 = Shutdown (default)
10:9
M[1:0]
R/W
00b
01 = Single-shot
10, 11 = Continuous conversions
Overflow flag field (read-only).
The overflow flag field indicates when an overflow condition occurs in the data conversion
process, typically because the light illuminating the device exceeds the programmed full-scale
range of the device. Under this condition OVF is set to 1, otherwise OVF remains at 0. The
field is reevaluated on every measurement.
If the full-scale range is manually set (RN[3:0] field < 1100b), the overflow flag field can be set
while the result register reports a value less than full-scale. This result occurs if the input light
has a temporary high spike level that temporarily overloads the integrating ADC converter
circuitry but returns to a level within range before the conversion is complete. Thus, the
overflow flag reports a possible error in the conversion process. This behavior is common to
integrating-style converters.
8
OVF
R
0b
If the full-scale range is automatically set (RN[3:0] field = 1100b), the only condition that sets
the overflow flag field is if the input light is beyond the full-scale level of the entire device.
When there is an overflow condition and the full-scale range is not at maximum, the OPT3006
aborts its current conversion, sets the full-scale range to a higher level, and starts a new
conversion. The flag is set at the end of the process. This process repeats until there is either
no overflow condition or until the full-scale range is set to its maximum range.
Conversion ready field (read-only).
The conversion ready field indicates when a conversion completes. The field is set to 1 at the
end of a conversion and is cleared (set to 0) when the configuration register is subsequently
read or written with any value except one containing the shutdown mode (mode of operation
field, M[1:0] = 00b). Writing a shutdown mode does not affect the state of this field; see the
Interrupt Reporting Mechanism Modes section for more details.
7
6
5
CRF
FH
R
R
R
0b
0b
0b
Flag high field (read-only).
The flag high field (FH) identifies that the result of a conversion is larger than a specified level
of interest. FH is set to 1 when the result is larger than the level in the high-limit register
(register address 03h) for a consecutive number of measurements defined by the fault count
field (FC[1:0]). See the Interrupt Reporting Mechanism Modes section for more details on
clearing and other behaviors of this field.
Flag low field (read-only).
The flag low field (FL) identifies that the result of a conversion is smaller than a specified level
of interest. FL is set to 1 when the result is smaller than the level in the low-limit register
(register address 02h) for a consecutive number of measurements defined by the fault count
field (FC[1:0]). See the Interrupt Reporting Mechanism Modes section for more details on
clearing and other behaviors of this field.
FL
22
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