DS1340_06 Datasheet, PDF (4/14 Pages) Maxim Integrated Products – I2C RTC with Trickle Charger

I²C RTC with Trickle Charger
POWER-UP/POWER-DOWN CHARACTERISTICS
(T_A = -40°C to +85°C) (Figure 2)
PARAMETER
Recovery at Power-Up
V_CC Fall Time; V_PF(MAX) to
V_PF(MIN)
SYMBOL
t_REC (Note 17)
t_VCCF
CONDITIONS
V_CC Rise Time; V_PF(MIN) to
V_PF(MAX)
t_VCCR
MIN TYP MAX UNITS
2
ms
300
µs
0
µs
WARNING: Under no circumstances are negative undershoots, of any amplitude, allowed when device is in battery-backup mode.
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
Note 8:
Note 9:
Note 10:
Note 11:
Note 12:
Note 13:
Note 14:
Note 15:
Note 16:
Note 17:
Limits at -40°C are guaranteed by design and not production tested.
After this period, the first clock pulse is generated.
A device must internally provide a hold time of at least 300ns for the SDA signal (referred to as the V_IH(MIN) of the SCL
signal) to bridge the undefined region of the falling edge of SCL.
The maximum t_HD:DAT only has to be met if the device does not stretch the low period (t_LOW) of the SCL signal.
A fast-mode device can be used in a standard-mode system, but the requirement t_SU:DAT ≥ to 250ns must 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.
C_B—total capacitance of one bus line in pF.
The parameter t_OSF is the period of time the oscillator must be stopped for the OSF flag to be set over the 0V ≤ V_CC ≤
V_CCMAX and 1.3V ≤ V_BAT ≤ 3.7V range.
All voltages are referenced to ground.
Measured at V_CC = typ, V_BACKUP = 0V, register 08h = A5h.
The use of the 250Ω trickle-charge resistor is not allowed at V_CC > 3.63V and should not be enabled.
Measured at V_CC = typ, V_BACKUP = 0V, register 08h = A6h.
Measured at V_CC = typ, V_BACKUP = 0V, register 08h = A7h.
I_CCA—SCL clocking at max frequency = 400kHz.
Specified with I²C bus inactive.
Measured with a 32.768kHz crystal attached to the X1 and X2 pins.
Limits at +25°C are guaranteed by design and not production tested.
This delay applies only if the oscillator is enabled and running. If the oscillator is disabled or stopped, no power-up delay
occurs.
SDA
t_BUF
t_LOW
t_R
t_F
t_HD:STA
SCL
STOP
START
t_HD:STA
Figure 1. Data Transfer on I²C Serial Bus
t_HD:DAT
t_HIGH
t_SU:DAT
t_SU:STA
REPEATED
START
4 _____________________________________________________________________
t_SP
t_SU:STO