Rainbow Electronics DS1672 - Manual (Page 5)

DS1672
5 of 12
POWER-UP/POWER-DOWN CHARACTERISTICS
(T
A
= -40 °C to +85°C)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
V
CC
Detect to RST (V
CC
Falling)
t
RPD
10 µs
V
CC
Detect to RST (V
CC
Rising)
t
RPU
250 ms 11
V
CC
Fall Time; V
PF(MAX)
to V
PF(MIN)
t
F
300 ms
V
CC
Rise Time; V
PF(MIN)
to V
PF(MAX)
t
R
0 ms
Note 11: If the EOSC bit in the control register is set to logic 1, t
RPU
is equal to 250ms plus the startup time of the crystal oscillator.
Warning: Under no circumstances are negative undershoots, of any amplitude, allowed when device is in write
protection.
Figure 1. Timing Diagram
SCL
START
SDA
STOP
t BUF
REPEATED
START
t HD:STA
t
LOW
t HD:STA
t HD:DAT
t SU:DAT
t
HIGH
t SU:STA
t F
t SU:STO
Figure 2. Power-Up/Power-Down Timing
OUTPUTS
V
CC
V
PF(max)
INPUTS
HIGH-Z
RST
DON'T CARE
VALID
RECOGNIZED RECOGNIZED
VALID
t
RPD
V
PF(min)
t
F
t
PD
t
R
t
RPU