Power-up/power-down characteristics, Figure 1. power-up/power-down timing – Rainbow Electronics DS1338 User Manual
Page 4
DS1338 I
2
C RTC with 56-Byte NV RAM
4 of 15
POWER-UP/POWER-DOWN CHARACTERISTICS
(T
A
= -40°C to +85°C) (Note 1, Figure 1)
PARAMETER SYMBOL
MIN
TYP
MAX
UNITS
Recovery at Power-Up (Note 15)
t
REC
2
ms
V
CC
Fall Time; V
PF(MAX)
to V
PF(MIN)
t
VCCF
300
ms
V
CC
Rise Time; V
PF(MIN)
to V
PF(MAX)
t
VCCR
0
ms
Note 1:
Limits at -40°C are guaranteed by design and not production tested.
Note 2:
All voltages are referenced to ground.
Note 3:
SCL only.
Note 4:
SDA and SQW/OUT.
Note 5:
I
CCA
—SCL clocking at max frequency = 400kHz.
Note 6:
Specified with the I
2
C bus inactive.
Note 7:
Measured with a 32.768kHz crystal attached to X1 and X2.
Note 8:
After this period, the first clock pulse is generated.
Note 9:
A device must internally provide a hold time of at least 300ns for the SDA signal (referred to the V
IHMIN
of the SCL signal) to bridge
the undefined region of the falling edge of SCL.
Note 10:
The maximum t
HD:DAT
need only be met if the device does not stretch the LOW period (t
LOW
) of the SCL signal.
Note 11:
A fast-mode device can be used in a standard-mode system, but the requirement t
SU:DAT
≥ to 250ns must then be met. This is
automatically the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW
period of the SCL signal, it must output the next data bit to the SDA line t
R MAX
+ t
SU:DAT
= 1000 + 250 = 1250ns before the SCL line
is released.
Note 12:
C
B
—total capacitance of one bus line in pF.
Note 13:
Guaranteed by design. Not production tested.
Note 14:
The parameter t
OSF
is the time period the oscillator must be stopped for the OSF flag to be set over the voltage range of
0.0V ≤ V
CC
≤ V
CC MAX
and 1.3V ≤ V
BAT
≤ 3.7V.
Note 15:
This delay applies only if the oscillator is enabled and running. If the oscillator is disabled or stopped, no power-up delay occurs.
Figure 1. Power-Up/Power-Down Timing
OUTPUTS
V
CC
V
PF(max)
V
PF(min)
INPUTS
HIGH-Z
DON'T CARE
VALID
RECOGNIZED
RECOGNIZED
VALID
t
VCCF
t
VCCR
t
REC