Rainbow Electronics MAX1033 - Manual (Page 13)

Detailed Description
The MAX1032/MAX1033 multirange, low-power, 14-bit
successive-approximation ADCs operate from a single
+5V supply and have a separate digital supply allowing
digital interface with 2.7V to 5.25V systems. These 14-bit
ADCs have internal track-and-hold (T/H) circuitry that
supports single-ended and fully differential inputs. For
single-ended conversions, the valid analog input voltage
range spans from -12V below ground to +12V above
ground. The maximum allowable differential input volt-
age spans from -24V to +24V. Data can be converted in
a variety of software-programmable channel and data-
acquisition configurations. Microprocessor (µP) control is
made easy through an SPI-/QSPI-/MICROWIRE-compati-
ble serial interface.
The MAX1032 has eight single-ended analog input
channels or four differential channels (see the Block
Diagram at the end of the data sheet). The MAX1033 has
four single-ended analog input channels or two differen-
tial channels. Each analog input channel is independently
software programmable for seven single-ended input
ranges (0 to +6V, -6V to 0, 0 to +12V, -12V to 0, ±3V,
±6V, and ±12V) and three differential input ranges (±6V,
±12V, and ±24V). Additionally, all analog input channels
are fault tolerant to ±16.5V. A fault condition on an idle
channel does not affect the conversion result of other
channels.
MAX1032/MAX1033
8-/4-Channel, ±12V Multirange Inputs,
Serial 14-Bit ADCs
______________________________________________________________________________________ 13
Pin Description (continued)
PIN
MAX1032 MAX1033
NAME FUNCTION
21 18 AGND3
Analog Signal Ground 3. AGND3 is the ADC negative reference potential. Connect AGND3 to
AGND1. DGND, DGNDO, AGND3, AGND2, and AGND1 must be connected together.
22 19 AV DD2
Analog Supply Voltage 2. Connect AV DD2 to a +4.75V to +5.25V power-supply voltage.
Bypass AV DD2 to AGND2 with a 0.1µF capacitor.
23 20 AGND2
Analog Ground 2. This ground carries approximately five times more current than AGND1.
DGND, DGNDO, AGND3, AGND2, and AGND1 must be connected together.
24 1 AGND1 Anal og Gr ound 1. D GN D , D GN DO, AGN D 3, AGN D 2, and AGND 1 must b e connected together .
4–20mA
PLC
ACCELERATION
PRESSURE
TEMPERATURE
WHEATESTONE
WHEATESTONE
1 µF
0.1 µF AGND2 DGNDO AGND3 DGND
AV DD2 DV DD AV DD1
0.1 µF 0.1 µF 0.1 µF
5.0V 5.0V 5.0V
MAX1032
CHO
CH1
CH2
CH3
CH4
CH5
CH6
CH7
REF
AGND1
REFCAP
0.1 µF
3.3V
MC68HCXX
µC
DV DDO
SCLK
CS
DIN
SSTRB
DOUT
V DD
SCK
I/O
MOSI
I/O
MISO
V SS
Figure 1. Typical Application Circuit