User Manual

MAX1144/MAX1145
14-Bit ADCs, 150ksps, 3.3V Single Supply
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(AV
DD
= DV
DD
= 3.3V ±5%, f
SCLK
= 3.6MHz, external clock (50% duty cycle), 24 clocks/conversion (150ksps), bipolar input, V
REF
=
2.048V, C
REF
= 4.7µF, C
CREF
= 1µF, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Unipolar 7.5 10.5
MAX1144
Bipolar 5.9 8.4
Unipolar 100 1000
Input Impedance
MAX1145
Bipolar 3.4 5.3
kΩ
Input Capacitance 32 pF
CONVERSION RATE
Internal Clock Frequency 3 MHz
Aperture Delay t
AD
10 ns
Aperture Jitter t
AJ
50 ps
MODE 1 (24 EXTERNAL CLOCK CYCLES PER CONVERSION)
Unipolar 0.1 3.0
External Clock Frequency f
SCLK
Bipolar 0.1 3.6
MHz
Unipolar 4.17 125
Sample Rate
f
S
=
f
SCLK
/ 24
Bipolar 4.17 150
ksps
Unipolar 8 240
Conversion Time (Note 4)
t
CONV+ACQ
= 24 / f
SCLK
Bipolar 6.7 240
µs
MODE 2 (INTERNAL CLOCK)
External Clock Frequency
(Data Transfer Only)
4 MHz
Conversion Time (SSTRB low pulse width) 5.3 7 µs
Unipolar 1.67
Acquisition Time (Note 5)
Bipolar 1.39
µs
MODE 3 (32 EXTERNAL CLOCK CYCLES PER CONVERSION)
External Clock Frequency f
SCLK
Unipolar or bipolar 0.1 3.6 MHz
Sample Rate
f
S
=
f
SCLK
/ 32
Unipolar or bipolar 3.125 112 ksps
Conversion Time (Note 4)
t
CONV+ACQ
= 32 / f
SCLK
Unipolar or bipolar 8.89 320 µs
EXTERNAL REFERENCE
Input Range (Notes 6, 7) 1.9 2.048 2.2 V
V
REF
= 2.048V, f
SCLK
= 3.6MHz 110
V
REF
= 2.048V, f
SCLK
= 0 100Input Current
In power-down, f
SCLK
= 0 0.1
µA
DIGITAL INPUTS
Input High Voltage V
IH
2.4 V
Input Low Voltage V
IL
0.8 V
Input Leakage I
IN
V
IN
= 0 or DV
DD
-1 +1 µA