ZHCSO90A november 2022 – april 2023 TPS36-Q1
PRODUCTION DATA
The TPS36-Q1 offers one or two SET pins based on the pinout option selected. SET pins offer flexibility to the user to program the tWO timer on the fly to meet various application requirements. Typical use cases where SET pin can be used are
The tWO timer value for the device is combination of tWC timer selection based on the CWD pin or fixed timer value along with SET pin logic level. The tWC timer value is decided based on the Watchdog Close Time selector in the Section 5 section. The SET pin logic level is decoded during the device power up. The SET pin value can be changed any time during the operation. SETx pin change which leads to change of watchdog timer value or enable disable state, terminates the ongoing watchdog frame immediately. SETx pins can be updated when WDO or RESET output is asserted as well. The updated tWO timer value will be applied after output is deasserted and the tSD timer is over or terminated.
For a pinout which offers only SET0 pin to the user, the tWO ratio value is decided based on the Watchdog Open Time Ratio selector field in the orderable part number. Refer Section 5 for available options. Table 8-4 showcases an example of the tWO values for different SET0 logic levels when using Watchdog Close Time setting as option D = 10 msec.
Watchdog Open Time Ratio Selection | tWO | |
---|---|---|
SET0 = 0 | SET0 = 1 | |
A | 10 msec | 30 msec |
B | 30 msec | 70 msec |
C | 70 msec | 150 msec |
D | 150 msec | 310 msec |
E | 310 msec | 630 msec |
F | 630 msec | 1270 msec |
Pinout which offer both SET0 & SET1 pins to the user, the tWO ratio value is decided based on the Watchdog Open Time Ratio selector field in the orderable part number. Refer Section 5 for available options. Two SETx pins offer 3 different time scaling options. The SET[1:0] = 0b'01 combination disables the watchdog operation. Table 8-5 showcases an example of the tWO values for different SET[1:0] logic levels when using Watchdog Close Time setting as option G = 100 msec. The package pin out selected does not offer WD-EN pin.
Watchdog Open Time Ratio selection | tWO | |||
---|---|---|---|---|
SET[1:0] = 0b'00 | SET[1:0] = 0b'01 | SET[1:0] = 0b'10 | SET[1:0] = 0b'11 | |
A | 100 msec | Watchdog disable | 300 msec | 1500 msec |
B | 300 msec | Watchdog disable | 700 msec | 3100 msec |
C | 700 msec | Watchdog disable | 1500 msec | 6300 msec |
D | 1500 msec | Watchdog disable | 3100 msec | 12700 msec |
E | 3100 msec | Watchdog disable | 6300 msec | 25500 msec |
F | 6300 msec | Watchdog disable | 12700 msec | 51100 msec |
Selected pinout option can offer WD-EN pin along with SET[1:0] pins (Pin Configuration C, D). With this pinout, the WD-EN pin controls watchdog enable and disable operation. The SET[1:0] = 0b'01 combination operates as SET[1:0] = 0b'00.
Ensure the tWO value with SETx ratio does not exceed 640 sec. If a selection of close window timer and ratio results in tWO > 640 sec, the timer value will be restricted to 640 sec.
Figure 8-9 to Figure 8-11 show the timing behavior with respect to SETx status changes.