sx150x_89b-datasheet
ADVANCED COMMUNICATIONS & SENSING
Rev 4 – 26
th
April 2011 31 www.semtech.com
SX1508B/SX1509B
World’s Lowest Voltage Level Shifting GPIO
with LED Driver and Keypad Engine
7:3
OFF Time of IO[X]:
0 : Infinite (Single shot mode, TOff directly controlled by RegData, Cf §4.8.3)
1 - 15 : TOffX = 64 * RegOffX[7:3] * (255/ClkX)
16 - 31 : TOffX = 512 * RegOffX[7:3] * (255/ClkX)
0xXX
RegOffX
0x00
2:0
OFF Intensity of IO[X]
- Linear mode : IOffX = 4 x RegOff[2:0]
- Logarithmic mode (fading capable IOs only) : IOffX = f(4 x RegOffX[2:0]) , Cf §4.8.5
7:5 Unused
0xXX
RegTRiseX
0x00
4:0
Fade In setting of IO[X]
0 : OFF
1 - 15 : TRiseX = (RegIOnX-(4xRegOffX[2:0])) * RegTRiseX * (255/ClkX)
16 - 31 : TRiseX = 16 * (RegIOnX-(4xRegOffX[2:0])) * RegTRiseX * (255/ClkX)
7:5 Unused
0xXX
RegTFallX
0x00
4:0
Fade Out setting of IO[X]
0 : OFF
1 - 15 : TFallX = (RegIOnX-(4xRegOffX[2:0])) * RegTFallX * (255/ClkX)
16 - 31 : TFallX = 16 * (RegIOnX-(4xRegOffX[2:0])) * RegTFallX * (255/ClkX)
0x69 RegHighInputB 0x00 7:0
Enables high input mode for each [input-configured] IO
0 : OFF. VIH max = 3.6V and VCCx min = 1.2V
1 : ON. VIH max = 5.5V and VCCx min = 1.65V
0x6A RegHighInputA 0x00 7:0
Enables high input mode for each [input-configured] IO
0 : OFF. VIH max = 3.6V and VCCx min = 1.2V
1 : ON. VIH max = 5.5V and VCCx min = 1.65V
0x7D RegReset 0x00 7:0
Software reset register
Writing consecutively 0x12 and 0x34 will reset the device (same as POR).
Always reads 0.
Table 11 – SX1509B Configuration Registers Description










