Datasheet
MAX1303
4-Channel, ±V
REF
Multirange Inputs,
Serial 16-Bit ADC
18 ______________________________________________________________________________________
001
010
011
100
101
110
111
0
-V
REF
/2
-V
REF
+V
REF
+V
REF
/2
+V
REF
/4
-V
REF
/4
EACH INPUT IS FAULT TOLERANT TO ±6V.
(CH_) - AGND1 (V)
INPUT RANGE SELECTION BITS, R[2:0]
FSR = V
REF
/2
FSR = V
REF
/2
FSR = V
REF
/2
FSR = V
REF
FSR = V
REF
FSR = V
REF
FSR = 2 x V
REF
+
3
/
4
V
REF
-
3
/
4
V
REF
Figure 6. Single-Ended Input Voltage Ranges
001
010
011
100
101
110
111
-V
REF
-2 x V
REF
+2 x V
REF
+V
REF
+V
REF
/2
-V
REF
/2
EACH INPUT IS FAULT TOLERANT TO ±6V.
(CH_+) - (CH_-) (V)
INPUT RANGE SELECTION BITS, R[2:0]
0
FSR = V
REF
FSR = 2 x V
REF
FSR = 4 x V
REF
-
3
/
2
V
REF
+
3
/
2
V
REF
Figure 7. Differential Input Voltage Ranges
Analog Input Bandwidth
The MAX1303 input-tracking circuitry has a 1.5MHz
small-signal bandwidth. The 1.5MHz input bandwidth
makes it possible to digitize high-speed transient events.
Harmonic distortion increases when digitizing signal fre-
quencies above 15kHz as shown in the -SFDR, THD vs.
Analog Input Frequency plot in the
Typical Operating
Characteristics
.
Analog Input Range and Fault Tolerance
Figure 6 illustrates the software-selectable single-
ended analog input voltage range that produces a valid
digital output. Each analog input channel can be inde-
pendently programmed to one of seven single-ended
input ranges by setting the R[2:0] control bits with
DIF/SGL = 0.
Figure 7 illustrates the software-selectable differential
analog input voltage range that produces a valid digital
output. Each analog input differential pair can be inde-
pendently programmed to one of three differential input
ranges by setting the R[2:0] control bits with DIF/SGL = 1.
Regardless of the specified input voltage range and
whether the channel is selected, each analog input is
±6V fault tolerant. The analog input fault protection is
active whether the device is unpowered or powered.
Any voltage beyond FSR, but within the ±6V fault-toler-
ant range, applied to an analog input results in a full-
scale output voltage for that channel.
Clamping diodes with breakdown thresholds in excess
of 6V protect the MAX1303 analog inputs during ESD
and other transient events (Figure 5). The clamping
diodes do not conduct during normal device operation,
nor do they limit the current during such transients.
When operating in an environment with the potential for
high-energy voltage and/or current transients, protect
the MAX1303 externally.