S1F76680 Epson Electronics America, Inc., S1F76680 Datasheet - Page 13

• Manufacturer Part Number: S1F76680
• Description: Led Driver
• Manufacturer: Epson Electronics America, Inc.

7.3.2 Setting of automatic luminance control
[1] Connection of a sensor
[2] Selection of brightness evaluation sampling cycle
S1F76680 Technical Manual (Rev.1.22)
shown below.
VPD to evaluate brightness on the scale of 1 to 16.
supply, etc, are required to avoid noise influence as much as possible.
PDOUT pin as shown below as a measure.
The S1F76680 sensor evaluates brightness in the brightness evaluation sampling cycle (TSAMPL).
The following values can be selected for the sampling cycle by setting SAMPL pin.
When using default sampling cycle (655msec), set SAMPL pin to “OPEN.”
* This pin is pulled up to V
For enabling automatic luminance control, a luminance sensor and resistor have to be connected externally.
Connect the sensor between V
When current flowing to the sensor is assumed IPD, VPD=IPD×RPD is established. S1F76680 uses this
The voltage at PDOUT and PD pins is 0V in the standby state.
Measures, such as shorter wiring between the sensor and sense resistor and S1F76680, stable V
It is recommended that CPD, a capacitor in the range from 0.1 to 1µF, be connected between VPD and
IPD
Sensor
Sensor
SAMPL pin setting
H (pulled up)
VPD
L
Brightness
evaluation
DD1
SS2
=V
CPD
and PD pin, and sense resistor RPD between PDOUT and PD pin as
DD2
7. OPERATIONAL AND FUNCTIONAL DESCRIPTION
level in the IC.
LED current
setting table
RPD
EPSON
V
PDOUT
PD
SS2
Sampling cycle (TSAMPL)
Brightness evaluation
Sampling cycle TSAMPL
S1F76680
LED driver
1310msec
655msec
SS2
level
9