Rainbow Electronics MAX1039 - Manual (Page 10)

MAX1036–MAX1039
Analog Input Bandwidth
The MAX1036–MAX1039 feature input tracking circuitry
with a 2MHz small signal-bandwidth. The 2MHz input
bandwidth makes it possible to digitize high-speed
transient events and measure periodic signals with
bandwidths exceeding the ADC’s sampling rate by
using undersampling techniques. To avoid high fre-
quency signals being aliased into the frequency band
of interest, anti-alias filtering is recommended.
Analog Input Range and Protection
Internal protection diodes clamp the analog input to
V
DD and GND. These diodes allow the analog inputs to
swing from (GND - 0.3V) to (V DD + 0.3V) without caus-
ing damage to the device. For accurate conversions,
the inputs must not go more than 50mV below GND or
above V
DD . If the analog input exceeds V DD by more
than 50mV, the input current should be limited to 2mA.
2.7V to 5.5V, Low-Power, 4-/12-Channel
2-Wire Serial 8-Bit ADCs
10 ______________________________________________________________________________________
ANALOG
INPUT
MUX
AIN1
AIN11/REF
AIN2
AIN3
AIN4
AIN5
AIN6
AIN7
AIN8
AIN9
AIN10
AIN0
SCL
SDA
INPUT SHIFT REGISTER
SETUP REGISTER
CONFIGURATION REGISTER
CONTROL
LOGIC
REFERENCE
4.096V (MAX1038)
2.048V (MAX1039)
INTERNAL
OSCILLATOR
OUTPUT SHIFT
REGISTER AND
12-BYTE RAM
REF
T/H
8-BIT
ADC
V DD
GND
MAX1038
MAX1039
Figure 3. MAX1038/MAX1039 Simplified Functional Diagram
TRACK HOLD
C T/H
TRACK HOLD
DIFFERENTIAL SINGLE ENDED
AIN0
AIN1
AIN2
AIN3/REF
GND
ANALOG INPUT MUX
CAPACITIVE
DAC
REF
MAX1036
MAX1037
Figure 4. Equivalent Input Circuit