Rainbow Electronics DS1339 - Manual (Page 18)

DS1339
18 of 18
POWER-UP DOWN CHARACTERISTICS (T
A
= -40°C to +85°C) (Note 12)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Recovery at Power-up t
REC
2 ms 13
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
Warning: Under no circumstances are negative undershoots, of any amplitude, allowed when the device
is in backup-battery mode.
NOTES:
1) SCL only.
2) SDA, and SQW/
INT
.
3) I
CCA
: SCL at f
SC
max, V
IL
= 0.0V, V
IH
= V
CC
, trickle charge disabled.
4) Specified with 2-wire bus inactive, V
IL
= 0.0V, V
IH
= V
CC
, trickle charge disabled.
5) After this period, the first clock pulse is generated.
6) 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) in order to bridge the undefined region of the falling edge of SCL.
7) The maximum t
HD:DAT
has only to be met if the device does not stretch the LOW period (t
LOW
) of the
SCL signal.
8) C
B
: Total capacitance of one bus line in pF.
9) A fast-mode device can be used in a standard-mode system, but the requirement t
SU:DAT
³ 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
RMAX
+ t
SU:DAT
= 1000 + 250 = 1250ns before the SCL line is released.
10) Using recommended crystal on X1 and X2.
11) The parameter t
OSF
is the period of time the oscillator must be stopped in order for the OSF flag to be
set over the voltage range of 0V ≤ V
CC
≤ V
CCMAX
and 1.3V ≤ V
BACKUP
≤ 3.7V.
12) Limits at -40°C are guaranteed by design and are not production tested.
13) This delay applies only if the oscillator is running. If the oscillator is disabled or stopped, no power-
up delay occurs.