User Manual

DS3234
Extremely Accurate SPI Bus RTC with
Integrated Crystal and SRAM
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ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 2.0V to 5.5V, V
CC
= active supply (see Table 1), T
A
= -40°C to +85°C, unless otherwise noted.) (Typical values are at V
CC
=
3.3V, V
BAT
= 3.0V, and T
A
= +25°C, unless otherwise noted. TCXO operation guaranteed from 2.3V to 5.5V on V
CC
and 2.3V to 3.8V on
V
BAT
.) (Notes 2, 3)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Logic 0 Output, 32kHz V
OL
I
OL
= 1mA 0.4 V
Logic 1 Output, DOUT V
OH
I
OH
= -1.0mA 0.85 x V
CC
V
Logic 0 Output, DOUT, INT/SQW V
OL
I
OL
= 3mA 0.4 V
Logic 0 Output, RST V
OL
I
OL
= 1.0mA 0.4 V
Output Leakage Current 32kHz,
INT/SQW, DOUT
I
LO
Output high impedance -1 0 +1 µA
Input Leakage DIN, CS, SCLK I
LI
-1 +1 µA
RST Pin I/O Leakage I
OL
RST high impedance (Note 6) -200 +10 µA
TCXO (V
CC
= 2.3V to 5.5V, V
BAT
= 2.3V to 3.8V, T
A
= -40°C to +85°C, unless otherwise noted.) (Notes 2 and 3)
Output Frequency f
OUT
V
CC
= 3.3V or V
BAT
= 3.3V
32.768 kHz
0°C to +40°C -2 +2
Frequency Stability vs.
Temperature
Δf/f
OUT
V
CC
= 3.3V or
V
BAT
= 3.3V
-40°C to 0°C and
+40°C to +85°C
-3.5 +3.5
ppm
Frequency Stability vs. Voltage Δf/V 1 ppm/V
-40°C 0.7
+25°C 0.1
+70°C 0.4
Trim Register Frequency
Sensitivity per LSB
Δf/LSB Specified at:
+85°C 0.8
ppm
Temperature Accuracy Temp -3 +3 °C
First year ±1.0
Crystal Aging Δf/f
OUT
After reflow,
not production tested
0–10 years ±5.0
ppm
ELECTRICAL CHARACTERISTICS
(V
CC
= 0V, V
BAT
= 2.0V to 3.8V, T
A
= -40°C to +85°C, unless otherwise noted.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
V
BAT
= 3.4V 1.5 2.3
Timekeeping Battery Current
(Note 5)
I
BATT
EOSC = 0, BBSQW = 0,
CRATE1 = CRATE0 = 0
V
BAT
= 3.8V 1.5 2.5
µA
Temperature Conversion Current I
BATTC
EOSC = 0, BBSQW = 0 400 µA
Data-Retention Current I
BATTDR
EOSC = 1 100 nA