MAX11616EVSYS+ Maxim Integrated Products, MAX11616EVSYS+ Datasheet - Page 18

• Manufacturer Part Number: MAX11616EVSYS+
• Description: EVALUATION SYSTEM FOR MAX11616
• Manufacturer: Maxim Integrated Products

Specifications of MAX11616EVSYS+

• Number Of Adc's: 1
• Number Of Bits: 8, 10, 12
• Sampling Rate (per Second): 94.4k
• Data Interface: I²C, Serial
• Inputs Per Adc: 12 Single Ended or 6 Differential
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: MAX11616
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

When idle, the MAX11612–MAX11617 continuously wait
for a START condition followed by their slave address
(see the Slave Address section). Upon reading a valid
address byte, the MAX11612–MAX11617 power up.
The internal reference requires 10ms to wake up, so
when using the internal reference it should be powered
up 10ms prior to conversion or powered continuously.
Wake-up is invisible when using an external reference
or V
Automatic shutdown results in dramatic power savings,
particularly at slow conversion rates and with internal
clock. For example, at a conversion rate of 10ksps, the
average supply current for the MAX11613 is 60µA (typ)
and drops to 6µA (typ) at 1ksps. At 0.1ksps the average
supply current is just 1µA, or a minuscule 3µW of power
consumption. See Average Supply Current vs. Conversion
Rate in the Typical Operating Characteristics section).
SEL[2:0] of the setup byte (Table 1) control the reference
and the AIN_/REF configuration (Table 6). When AIN_/REF
is configured to be a reference input or reference output
(SEL1 = 1), differential conversions on AIN_/REF appear
as if AIN_/REF is connected to GND (see note 2 of Table
4). Single-ended conversion in scan mode AIN_/REF is
ignored by the internal limiter, which sets the highest avail-
able channel at AIN2 or AIN10.
The internal reference is 4.096V for the MAX11612/
MAX11614/MAX11616 and 2.048V for the MAX11613/
MAX11615/MAX11617. SEL1 of the setup byte controls
whether AIN_/REF is used for an analog input or a refer-
ence (Table 6). When AIN_/REF is configured to be an
internal reference output (SEL[2:1] = 11), decouple
AIN_/REF to GND with a 0.1µF capacitor and a 2kΩ
series resistor (see the Typical Operating Circuit ). Once
Low-Power, 4-/8-/12-Channel, I
12-Bit ADCs in Ultra-Small Packages
Table 6. Reference Voltage, AIN_/REF, and REF Format
X = Don’t care.
18
SEL2
DD
______________________________________________________________________________________
0
0
1
1
1
1
as the reference.
SEL1
0
1
0
0
1
1
SEL0
X
X
0
1
0
1
Reference Voltage
Internal Reference
External reference
Internal reference
Internal reference
Internal reference
Internal reference
REFERENCE
VOLTAGE
V
DD
Reference output
Reference output
Reference input
(MAX11612/
Analog input
Analog input
Analog input
MAX11617)
MAX11613/
MAX11616/
AIN_/REF
powered up, the reference always remains on until recon-
figured. The internal reference requires 10ms to wake up
and is accessed using SEL0 (Table 6). When in shutdown,
the internal reference output is in a high-impedance state.
The reference should not be used to supply current for
external circuitry. The internal reference does not require an
external bypass capacitor and works best when left uncon-
nected (SEL1 = 0).
The external reference can range from 1V to V
maximum conversion accuracy, the reference must be
able to deliver up to 40µA and have an output imped-
ance of 500kΩ or less. If the reference has a higher out-
put impedance or is noisy, bypass it to GND as close to
AIN_/REF as possible with a 0.1µF capacitor.
Figure 12. Unipolar Transfer Function
11 . . . 111
11 . . . 110
11 . . . 101
00 . . . 011
00 . . . 010
00 . . . 001
00 . . . 000
OUTPUT CODE
0
2
C,
1
Reference output
Reference output
Reference input
2
Not connected
Not connected
Not connected
INPUT VOLTAGE (LSB)
(MAX11614/
MAX11615)
3
REF
FULL-SCALE
TRANSITION
External Reference
FS - 3/2 LSB
MAX11612–
MAX11617
REFERENCE
INTERNAL
1 LSB =
Always off
Always off
Always off
Always on
Always off
Always on
FS = V
ZS = GND
STATE
FS
REF
4096
V
REF
DD
. For