TCS3404 TAOS [TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS], TCS3404 Datasheet - Page 19

• Manufacturer Part Number: TCS3404
• Description: DIGITAL COLOR SENSORS
• Manufacturer: TAOS [TEXAS ADVANCED OPTOELECTRONIC SOLUTIONS]

Gain Register (07h)
The LUMENOLOGY r Company
Reset Value:
PRESCALER
PRESCALER
The Gain register provides a common gain control adjustment for all four parallel ADC output channels. Two
gain bits [5:4] in the Gain Register allow the relative gain to be adjusted from 1
advantage of the gain adjust is to extend the dynamic range of the light input up to a factor of 64
or digital saturation occurs. If analog saturation has occurred, lowering the gain sensitivity will likely prevent
analog saturation especially when the integration time is relatively short. For longer integration times, the 16-bit
output could be in digital saturation (64K). If lowering the gain to 1
occurring, the use of PRESCALER can be useful.
The PRESCALER is 3 bits [2:0] in the gain register that divides down the output count (i.e. shifts the LSB of the
count value to the right). The PRESCALER adjustment range is divide by 1 to 64 in multiples of 2.
The most sensitive gain setting of the device would be when GAIN is set to 11b (64
to 000b (divide by 1). The least sensitive part setting would be GAIN 00 (1
64). If the part continues to be in digital saturation at the least sensitive setting, the integration time can be
lowered (see Timing Register section).
FIELD
GAIN
GAIN
Resv
Resv
07h
Resv
7
0
BITS
7:6
5:4
5:4
2:0
2:0
3
Resv
Reserved. Write as 0.
Analog Gain Control. This field switches the common analog gain of the four ADC channels. Four gain
modes are provided:
Reserved. Write as 0.
Prescaler. This field controls a 6-bit digital prescaler and divider. The prescaler reduces the sensitivity
of each ADC integrator as shown in the table below:
0
6
FIELD VALUE
FIELD VALUE
000
001
010
011
100
101
110
111
00
01
10
11
5
0
r
GAIN
Table 9. Gain Register
1
4
16
64
Divide by 1.
Divide by 2.
Divide by 4.
Divide by 8.
Divide by 16.
Divide by 32.
Divide by 64.
Not used.
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×
×
×
×
4
0
Resv
3
0
DESCRIPTION
PRESCALER MODE
×
2
0
does not prevent digital saturation from
r
GAIN
×
PRESCALER
DIGITAL COLOR SENSORS
) and PRESCALER 110 (divide by
×
1
0
to 64
×
), and PRESCALER is set
×
TCS3404, TCS3414
in 4
Copyright E 2011, TAOS Inc.
0
0
×
TAOS137A − APRIL 2011
increments. The
×
before analog
GAIN
19