Table 10-1 Example Digital Switch Specification| PARAMETER | SPECIFICATION | MIN | MAX |
|---|
| VBAT | 7 V ≤ VBAT ≤ 16 V | 7 V | 16 V |
| VDIODE (voltage drop across the reverse-blocking diode) | 0 V ≤ VDIODE ≤ 1 V | 0 V | 1 V |
| RESD | 50 Ω ± 8% | 46 Ω | 54 Ω |
| RSW | 220 Ω Max when closed ± 8% | 0 Ω | 237.6 Ω |
| RDIRT | 5000 Ω Min | 5000 Ω | ∞ |
| Wetting current requirement | 10mA Typical | |
An example of digital switch connected to ground shown in Figure 10-1, with Table 10-1 summarizing its detailed requirements. The goal of this design is to utilize the TIC10024-Q1’s integrated comparator to detect and differentiate between the 2 switch states:
- State 1: SW open
- State 2: SW closed
To mimic real automotive systems, the battery is assumed to be fluctuating between 7 V and 16 V. Taking into account the voltage drop across the reverse-blocking diode, the V
S supply voltage to the TIC10024-Q1 device can fluctuate between 6 V and 16 V. R
DIRT is introduced to model the small leakage flowing across the switch in open state. When the switch changes position and the switch state changes from one to another, the TIC10024-Q1 is required to correctly detect the state transition and issue an interrupt to alert the microcontroller. The switch information needs to be stored in the status registers for the microcontroller to retrieve.