LTC2433-1IMS#TRPBF Linear Technology, LTC2433-1IMS#TRPBF Datasheet - Page 20

• Manufacturer Part Number: LTC2433-1IMS#TRPBF
• Description: IC ADC DIFF 16BIT 3WIRE 10-MSOP
• Manufacturer: Linear Technology

Specifications of LTC2433-1IMS#TRPBF

• Number Of Bits: 16
• Sampling Rate (per Second): 6.8
• Data Interface: MICROWIRE™, Serial, SPI™
• Number Of Converters: 2
• Power Dissipation (max): 1mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

LTC2433-1
APPLICATIO S I FOR ATIO
period. Thus, for settling errors of less than 1LSB, the
driving source impedance should be chosen such that
14.3 s/11 = 1.3 s. When an external oscillator of fre-
quency f
for a settling error of less than 1LSB,
Input Current
If complete settling occurs on the input, conversion re-
sults will be unaffected by the dynamic input current. An
incomplete settling of the input signal sampling process
may result in gain and offset errors, but it will not degrade
the INL performance of the converter. Figure 12 shows the
mathematical expressions for the average bias currents
flowing through the IN
sampling charge transfers when integrated over a sub-
stantial time period (longer than 64 internal clock cycles).
The effect of this input dynamic current can be analyzed
using the test circuit of Figure 13. The C
includes the LTC2433-1 pin capacitance (5pF typical) plus
the capacitance of the test fixture used to obtain the results
shown in Figures 14 and 15. A careful implementation can
bring the total input capacitance (C
thus achieving better performance than the one predicted
20
EOSC
SWITCHING FREQUENCY
f
f
SW
SW
V
V
I
V
V
I
REF
REF
I
I
REF
REF
IN
IN
IN
IN
= 69900Hz INTERNAL OSCILLATOR (F
= 0.5 • f
+
+
–
–
+
+
–
–
is used, the sampling period is 2/f
V
V
EOSC
CC
CC
U
V
V
EXTERNAL OSCILLATOR
I
I
I
I
LEAK
LEAK
LEAK
LEAK
CC
CC
+
I
I
I
I
LEAK
LEAK
LEAK
LEAK
and IN
U
R
R
R
R
SW
SW
SW
SW
20k
20k
20k
20k
–
(TYP)
(TYP)
(TYP)
(TYP)
pins as a result of the
IN
W
O
Figure 12. LTC2433-1 Equivalent Analog Input Circuit
+ C
= LOW)
PAR
24331 F12
0.18/f
) closer to 5pF
PAR
U
EOSC
capacitor
EOSC
C
6pF
(TYP)
EQ
and,
.
I IN
I IN
I REF
I REF
R
R
where
V
V
V
V
REF
REFCM
IN
INCM
EQ
EQ
Figure 14. +FS Error vs R
IN
AVG
AVG
: :
11 9
REF
1 67 10
V
V
AVG
AVG
INCM
INCM
.
.
IN
M
REF
IN
V
+ 0.5V
– 0.5V
IN
Figure 13. An RC Network at IN
V
1 5
2
IN
REF
.
INTERNAL OSCILLATOR
1 5
IN
12
3
2
1
0
.
2
V
IN
IN
0 5
INCM
1
0 5
V
REF
.
V
/
REF
V
REF
REF
IN
IN
F
T
.
INCM
V
f
O
EOSC
A
CC
REF
+
–
= GND
= 25 C
R
0 5
+
–
= 5V
= 2.5V
= 5V
R
R
R
0 5
EQ
.
= 5V
= GND
SOURCE
SOURCE
V
EQ
.
10
V
EXTERNAL OSCILLATOR
REFCM
INCM
C
V
V
R
IN
REFCM
INCM
R
C
EQ
= 0.001 F
IN
EQ
C
C
IN
IN
SOURCE
= 100pF
R
100
SOURCE
= 0.01 F
V
= 0pF
REFCM
V
C
C
REFCM
IN
IN
( )
at IN
1k
50
Hz
V
REF
C
C
+
V
PAR
PAR
/
20pF
20pF
REF
or IN
+
60
10k
V
IN
2
and IN
V
Hz Notch F
R
IN
2
24331 F14
EQ
R
–
IN
IN
EQ
LTC2433-1
(Small C
100k
+
–
–
24331 F13
O
IN
24331fa
LOW
)