Reset Controller Specifications

Table 1. Reset, WDT, Oscillator Start-up Timer, Power-up Timer, Brown-out Detector Specifications
Sym. Description Min. Typ. Max. Units Conditions
tRST RESET pin pulse-width low to ensure reset(1) 2.5 — — μs  
RRST_UP RESET pin pull-up resistor — 35 — kΩ  
TWDT Watchdog Timer time-out period — 500 — ms 1:512 Prescaler
TSUT Power-up timer period — 64 — ms SUT = 0x07
TOST Oscillator start-up timer period(2) — 1024 — cycles  
VBOD Brown-out Detect voltage(3) —

1.90

2.45

2.7

2.85

 —

V

V

V

V

BODLEVEL0

BODLEVEL1

BODLEVEL2

BODLEVEL3
VBOD_HYS Brown-out Detect hysteresis — 44 — mV  
tBOD_ST Brown-out Detect start-up time — 1.9 — μs  
tBOD_128HZ BOD response time Sampling Mode @128 Hz — 7.81 — ms SAMPFREQ=0
tBOD_32HZ BOD response time Sampling Mode @32 Hz — 31.25 — ms SAMPFREQ=1
tBOD_RST Brown-out reset response time — 3 — μs  
Notes:
  1. 1.These values are based on simulation and not covered by production test limits.
  2. 2.By design, the Oscillator Start-up Timer (TOST) counts the first 1024 cycles, independent of frequency.
  3. 3.To ensure these voltage tolerances, VDD and GND must be capacitively decoupled as close to the device as possible. 0.1 μF and 0.01 μF values in parallel are recommended.
Table 2. Voltage Level Monitor Threshold Characteristics
Symbol Description Min. Typ. Max. Units Conditions
VDET Voltage detection threshold — 5 — % of BOD Threshold VLMLVL = 0x01
— 15 — % of BOD Threshold VLMLVL = 0x02
— 25 — % of BOD Threshold VLMLVL = 0x03
Parent topic: AC Characteristics