MAX1280EVC16 Maxim Integrated Products, MAX1280EVC16 Datasheet - Page 4

• Manufacturer Part Number: MAX1280EVC16
• Description: EVAL KIT FOR MAX1280
• Manufacturer: Maxim Integrated Products

Specifications of MAX1280EVC16

• Number Of Adc's: 1
• Number Of Bits: 12
• Sampling Rate (per Second): 400k
• Data Interface: Serial
• Inputs Per Adc: 8 Single Ended
• Input Range: ±VREF/2
• Power (typ) @ Conditions: 13.75mW @ 400kSPS
• Voltage Supply Source: Single Supply
• Operating Temperature: 0°C ~ 70°C
• Utilized Ic / Part: MAX1280
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Power-supply current can be monitored by measuring
the voltage across resistor R9 (for VDD1) or R10
(VDD2). These resistors are 10Ω ±1%, so every 0.001V
across R9 represents 100µA of supply current.
Problem: No output measurement. System seems to
report zero voltage or fails to make a measurement.
1) Check VDD1 and VDD2 supply voltages.
2) Check the 2.5V reference voltage using a DVM.
MAX1280 Evaluation Kit/Evaluation System
Figure 1. MAX1280 EV Kit Schematic
4
_______________________________________________________________________________________
O
CH4
CH5
CH6
CH7
CHO
CH1
CH2
CH3
JU1
1
2
Measuring Supply Current
SHDN
300Ω
300Ω
300Ω
300Ω
300Ω
300Ω
300Ω
300Ω
R5
R6
R7
R8
R1
R2
R3
R4
3
Troubleshooting
2
JU2
1
C5
0.01µF
C6
0.01µF
C7
0.01µF
C8
0.01µF
C1
0.01µF
C2
0.01µF
C3
0.01µF
C4
0.01µF
VDD1
10
5
6
7
1
2
3
4
9
8
CH2
SHDN
CHO
CH1
CH3
CH4
CH5
CH6
CH7
COM
MAX1280
U1
REFADJ
SSTRB
DOUT
3) Verify with an oscilloscope that the conversion-start
4) Verify that SHDN is being driven high.
Problem: Measurements are erratic, unstable; poor
accuracy.
1) Check the reference voltage using a DVM.
2) Use an oscilloscope to check for noise. When prob-
V
SCLK
V
GND
DD2
DD1
DIN
REF
CS
signal is being strobed.
ing for noise, keep the oscilloscope ground return
lead as short as possible, preferably less than 1/2in
(10mm).
20
19
18
16
15
14
13
12
17
11
C10
0.01µF
C9
4.7µF
10V
C11
0.1µF
C13
0.1µF
J1-38
J1-37
TP1-5
J1-31
TP1-4
J1-36
TP1-3
J1-29
TP1-2
J1-35
TP1-6
VDD1
C12
10µF
10V
C14
10µF
10V
REF
REFADJ
10Ω
10Ω
R10
1%
1%
R9
J1-7
TP1-1
TP1-7
J1-8
J1-1
J1-2
J1-3
J1-4
GND
VDD2
VDD1