ISL29038
Typical Performance Curves
100
100
ALS RESPONSE (BLUE)
RANGE: 2k Lux
90
80
90
80
250mA
70
60
50
70
CIE 1924 PHOTOPIC CURVE
125mA
60
50
62.5mA
40
30
40
30
31.25mA
20
20
10
0
10
0
300
400
500
600
700
800
900
1000
1100
0
20
40
60
80
WAVELENGTH (nm)
18% GREY CARD PROXIMITY DISTANCE (mm)
FIGURE 6. PROXIMITY SENSITIVITY (Note 12)
FIGURE 7. ALS SENSITIVITY (Note 13)
100
90
15
80
70
60
50
40
30
20
10
0
10
5
50%
10%
0
-90
-60
-30
0
30
60
90
0
8k
16k
24k
32k
40k
AMBIENT LIGHT LEVEL (LUX)
ANGLE (°)
FIGURE 8. PROXIMITY AMBIENT LIGHT REJECTION (Note 14)
NOTES:
12. Figure 6 shows ISL29038 Proximity distance sweeps with different IRDR LED current settings using an 18% Grey card reflector.
FIGURE 9. ALS ANGULAR SENSITIVITY (Note 15)
13. Figure 7 shows ISL29038 Ambient Light Sensor Spectral response when compared to a theoretical CIE 1924 Photopic curve. The ‘Blue’ line shows
the ISL29038 response and the ‘Red’ line depicts the CIE 1924 Photopic curve.
14. Figure 8 shows the ISL29038 Proximity Ambient Light Rejection using a Norwood Solar Emulator. At 40k lux ambient light level, the Proximity
Washout Count (Reg 0x0D[7:1]) is 127 indicating a saturation in Proximity Signal processing path. The Proximity Washout bit 0x0D[0] is active at
approximately 90% of the maximum level. At 10% initial PROX count (due to optical leakage from IR LED to the ISL29038), the PROX data error is
under 2%. At 50% initial PROX count (severe optical leakage), the PROX data error is about 7%.
15. Figure 9 shows the Ambient Light Sensor Angular Sensitivity of the ISL29038 using a white LED light source.
FN7851.0
October 12, 2012
7
XICOR [ XICOR INC. ]
