DS3234
Extremely Accurate SPI Bus RTC
with Integrated Crystal and SRAM
Maxim Integrated | 5
www.maximintegrated.com
Pushbutton Reset Timing
t
RST
PB
DB
RST
Power-Switch Timing
V
CC
V
PF(MAX)
RST
V
PF(MIN)
t
VCCF
t
VCCR
t
REC
V
PF
V
PF
Note 2:
Limits at -40°C are guaranteed by design and not production tested.
Note 3:
All voltages are referenced to ground.
Note 4:
Measured at V
IH
= 0.8 x V
CC
or V
IL
= 0.2 x V
CC
, 10ns rise/fall time, DOUT = no load.
Note 5:
Current is the averaged input current, which includes the temperature conversion current. CRATE1 = CRATE0 = 0.
Note 6:
The
RST
pin has an internal 50k
Ω
(nominal) pullup resistor to V
CC
.
Note 7:
Measured at V
OH
= 0.8 x V
CC
or V
OL
= 0.2 x V
CC
. Measured from the 50% point of SCLK to the V
OH
minimum of DOUT.
Note 8:
With 50pF load.
Note 9:
The parameter t
OSF
is the period of time the oscillator must be stopped for the OSF flag to be set over the voltage range of
0V
≤
V
CC
≤
V
CC(MAX)
and 2.3V
≤
V
BAT
≤
V
BAT(MAX)
.
Note 10:
This delay only applies if the oscillator is enabled and running. If the
EOSC
bit is 1, t
REC
is bypassed and
RST
immediately
goes high.
Note 11:
Guaranteed by design and not production tested.
WARNING: Negative undershoots below -0.3V while the part is in battery-backed mode may
cause loss of data.
