SX1509QBIULTRT Semtech, SX1509QBIULTRT Datasheet - Page 17

• Manufacturer Part Number: SX1509QBIULTRT
• Description: 16-chan GPIO W/ LED Driver & Keypad Engine (I2C)
• Manufacturer: Semtech

ADVANCED COMMUNICATIONS & SENSING
The minimum pulse width tLevelShiftMin which can be level shifted properly depends on VCCx and VDDM:
Input/Core/Output delays vs VCCx/VDDM are given in figures below.
4.6.4
Each IO’s polarity can be individually inverted by setting corresponding bit in RegPolarity register. Please note
that polarity inversion can also be combined with level shifting feature.
4.7
At start-up, the transition detection logic is reset, and NINT is released to a high-impedance state. The interrupt
mask register is set to 0xFF, disabling the interrupt output for transitions on all I/O ports. The transition flags are
cleared to indicate no data changes.
An interrupt NINT can be generated on any programmed combination of I/Os rising and/or falling edges through
the RegInterruptMask and RegSense registers.
If needed, the I/Os which triggered the interrupt can then be identified by reading RegInterruptSource register.
Rev 3 – 9
Interrupt (NINT)
Polarity Inverter
th
140.000
120.000
100.000
28
26
24
22
20
18
16
14
Sept. 2010
80.000
60.000
40.000
20.000
0.000
1
1.000
IO Output Delay vs. Supply Voltage ( LowDriveEn=0, 20pF Load)
1.5
SX1508QB Digital Core Delay vs. Supply Voltage
1.500
2
Figure 14 – Level Shifter Max Frequency Calculation Data
tLevelShiftMin = Input Delay + Core Delay + Output Delay
2.000
Typical
Typical
VDDM (V)
VCCx (V)
2.5
Worst Case
2.500
Worst Case
10.000
9.000
8.000
7.000
6.000
5.000
4.000
3.000
2.000
1.000
0.000
1.000
3.000
3
1.500
3.500
IO Input Delay vs. Supply Voltage
3.5
2.000
Typical
17
VCCx (V)
2.500
Worst Case
140.000
120.000
100.000
28
26
24
22
20
18
16
14
80.000
60.000
40.000
20.000
0.000
SX1507QB/SX1508QB/SX1509QB
1
1.000
World’s Lowest Voltage Level Shifting GPIO
3.000
IO Output Delay vs. Supply Voltage (LowDriveEn=1, 20pF Load)
SX1509QB Digital Core Delay vs. Supply Voltage
1.5
1.500
3.500
with LED Driver and Keypad Engine
2
2.000
Typical
Typical
VDDM (V)
VCCx (V)
2.5
Worst Case
2.500
Worst Case
3.000
3
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3.500
3.5