MAX11040 Maxim Integrated Products, MAX11040 Datasheet - Page 14

• Manufacturer Part Number: MAX11040
• Description: Sigma-Delta ADC
• Manufacturer: Maxim Integrated Products

www.DataSheet4U.com
The MAX11040 operates with either a +2.5V internal
bandgap reference or an external reference source
between +2.3V and +2.7V applied at REFIO. Bypass
REFIO and each REF_ to AGND with a 1µF capacitor.
The reference voltage sets the positive and negative
full-scale voltage according to the following formula:
The reference voltage at REFIO (external or internal) is
individually buffered to generate the reference voltages
at REF0 to REF3 (see Figure 6.) These independent
buffers minimize the potential for crosstalk between
each of the internal ADCs.
The MAX11040 interface is fully compatible with
SPI/DSP standard serial interfaces (compatible with SPI
modes CPOL = 0, CPHA = 0 and CPOL = 1, and CPHA
= 1). The serial interface provides access to four on-
chip registers: Sampling Instant Control register (32
bits), Data Rate Control register (16 bits), Configuration
register (8 bits), and Data register (96 bits). All serial-
interface commands begin with a command byte,
which addresses a specific register, followed by data
bytes with a data length that depends on the specific
24-Bit, 4-Channel, Simultaneous-Sampling,
Cascadable, Sigma-Delta ADC
Figure 5. Low-Frequency Analog Input Overvoltage Detection and Recovery
14
______________________________________________________________________________________
±FS = ±0.88 V
FAULT
OVRFLW
LATENCY
REFIO
LATENCY
Serial Interface
Reference
DIGITAL OUTPUT
DATA AT DOUT
|AIN+ - AIN-|
register addressed and the number of devices cascad-
ed (see Figures 7, 8, and the Registers section).
The serial interface consists of eight signals: CS,
SCLK, DIN, DOUT, CASCIN, CASCOUT, DRDYIN,
and DRDYOUT. CASCIN, CASCOUT, DRDYIN, and
DRDYOUT are used for daisy chaining multiple devices
together. See the Multiple Device Connection section
for details on how to connect CASCIN, CASCOUT,
Figure 6. REFIO Input
RECOVERY TIME
REFIO
REF0
REF1
REF2
REF3
LATENCY
LATENCY
FAULT DETECTION
(V
FULL SCALE
THRESHOLD
(|0.88V
PFT
OR |V
REF
NFT
|)
|)
REFERENCE
+2.5V