Datasheet

LTC2439-1
5
24391fa
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
f
EOSC
External Oscillator Frequency Range ● 2.56 2000 kHz
t
HEO
External Oscillator High Period ● 0.25 390 µs
t
LEO
External Oscillator Low Period ● 0.25 390 µs
t
CONV
Conversion Time F
O
= 0V ● 143.8 146.7 149.6 ms
External Oscillator (Note 10)
● 20510/f
EOSC
(in kHz) ms
f
ISCK
Internal SCK Frequency Internal Oscillator (Note 9) 17.5 kHz
External Oscillator (Notes 9, 10) f
EOSC
/8 kHz
D
ISCK
Internal SCK Duty Cycle (Note 9) ● 45 55 %
f
ESCK
External SCK Frequency Range (Note 8) ● 2000 kHz
t
LESCK
External SCK Low Period (Note 8) ● 250 ns
t
HESCK
External SCK High Period (Note 8) ● 250 ns
t
DOUT_ISCK
Internal SCK 19-Bit Data Output Time Internal Oscillator (Notes 9, 11) ● 1.06 1.09 1.11 ms
External Oscillator (Notes 9, 10)
● 152/f
EOSC
(in kHz) ms
t
DOUT_ESCK
External SCK 19-Bit Data Output Time (Note 7) ● 19/f
ESCK
(in kHz) ms
t
1
CS ↓ to SDO Low ● 0 200 ns
t2 CS ↑ to SDO High Z ● 0 200 ns
t3 CS ↓ to SCK ↓ (Note 9) ● 0 200 ns
t4 CS ↓ to SCK ↑ (Note 8) ● 50 ns
t
KQMAX
SCK ↓ to SDO Valid ● 220 ns
t
KQMIN
SDO Hold After SCK ↓ (Note 5) ● 15 ns
t
5
SCK Set-Up Before CS ↓ ● 50 ns
t
6
SCK Hold After CS ↓ ● 50 ns
t
7
SDI Setup Before SCK↑ (Note 5) ● 100 ns
t
8
SDI Hold After SCK↑ (Note 5) ● 100 ns
The ● denotes specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 3)
TI I G CHARACTERISTICS
UW
Note 1: Absolute Maximum Ratings are those values beyond which the
life of the device may be impaired.
Note 2: All voltage values are with respect to GND.
Note 3: V
CC
= 2.7V to 5.5V unless otherwise specified.
V
REF
= REF
+
– REF
–
, V
REFCM
= (REF
+
+ REF
–
)/2; V
IN
= IN
+
– IN
–
,
V
INCM
= (IN
+
+ IN
–
)/2, IN
+
and IN
–
are defined as the selected positive
and negative input respectively.
Note 4: F
O
pin tied to GND or to V
CC
or to external conversion clock
source with f
EOSC
= 153600Hz unless otherwise specified.
Note 5: Guaranteed by design, not subject to test.
Note 6: Integral nonlinearity is defined as the deviation of a code from
a precise analog input voltage. Maximum specifications are limited by
the LSB step size (V
REF
/2
16
) and the single shot measurement. Typical
specifications are measured from the center of the quantization band.
Note 7: F
O
= GND (internal oscillator) or f
EOSC
= 139800Hz ±2%
(external oscillator).
Note 8: The converter is in external SCK mode of operation such that
the SCK pin is used as digital input. The frequency of the clock signal
driving SCK during the data output is f
ESCK
and is expressed in kHz.
Note 9: The converter is in internal SCK mode of operation such that
the SCK pin is used as digital output. In this mode of operation the
SCK pin has a total equivalent load capacitance C
LOAD
= 20pF.
Note 10: The external oscillator is connected to the F
O
pin. The external
oscillator frequency, f
EOSC
, is expressed in kHz.
Note 11: The converter uses the internal oscillator.
F
O
= 0V or F
O
= V
CC
.
Note 12: 1µV RMS noise is independent of V
REF
. Since the noise
performance is limited by the quantization, lowering V
REF
improves the
effective resolution.
Note 13: Guaranteed by design and test correlation.
Note 14: The low sleep mode current is valid only when CS is high.
Note 15: These parameters are guaranteed by design over the full
supply and temperature range. Automated testing procedures are
limited by the LSB Step Size (V
REF
/2
16
).