MAX11646EUA+ Maxim Integrated Products, MAX11646EUA+ Datasheet - Page 18

• Manufacturer Part Number: MAX11646EUA+
• Description: IC ADC 10BIT I2C 94.4KSPS 8UMAX
• Manufacturer: Maxim Integrated Products

Specifications of MAX11646EUA+

• Number Of Bits: 10
• Sampling Rate (per Second): 94.4k
• Data Interface: I²C, Serial
• Number Of Converters: 1
• Power Dissipation (max): 362mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
• Number Of Adc Inputs: 2
• Conversion Rate: 1 Ksps to 94.4 Ksps
• Resolution: 10 bit
• Input Type: Single-Ended
• Interface Type: I2C
• Snr: 60 dB
• Voltage Reference: Internal 4.096 V
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4.5 V
• Maximum Power Dissipation: 362 mW
• Maximum Operating Temperature: + 85 C
• Input Voltage: 4.5 V to 5.5 V
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The configuration and setup registers (Tables 1 and 2)
default to a single-ended, unipolar, single-channel conver-
sion on AIN0 using the internal clock with V
ence. The memory contents are unknown after power-up.
Automatic shutdown occurs between conversions when
the MAX11646/MAX11647 are idle. All analog circuits
participate in automatic shutdown except the internal
reference due to its prohibitively long wake-up time.
When operating in external clock mode, a STOP, not-
acknowledge, or repeated START condition must be
issued to place the devices in idle mode and benefit
from automatic shutdown. A STOP condition is not nec-
essary in internal clock mode to benefit from automatic
shutdown because power-down occurs once all con-
version results are written to memory (Figure 10). When
using an external reference or V
analog circuitry is inactive in shutdown and supply cur-
rent is less than 0.5µA (typ). The digital conversion
results obtained in internal clock mode are maintained
in memory during shutdown and are available for
access through the serial interface at any time prior to a
STOP or a repeated START condition.
When idle, the MAX11646/MAX11647 continuously wait
for a START condition followed by their slave address
(see the Slave Address section). Upon reading a valid
address byte the MAX11646/MAX11647 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
Low-Power, 1-/2-Channel, I
in Ultra-Tiny 1.9mm x 2.2mm Package
Table 6. Reference Voltage and REF Format
X = Don’t care.
* Preferred configuration for internal reference.
18
SEL2
DD
______________________________________________________________________________________
0
0
1
1
1
1
as the reference.
SEL1
Applications Information
0
1
0
0
1
1
SEL0
X
X
0
1
0
1
Automatic Shutdown
DD
Power-On Reset
as a reference, all
REFERENCE VOLTAGE
DD
External reference
Internal reference
Internal reference
Internal reference
Internal reference
as the refer-
V
DD
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 MAX11647 is 60µA (typ)
and drops to 6µA (typ) at 1ksps. At 0.1ksps the aver-
age supply current is just 1µA, or a minuscule 3µW of
power consumption (see Average Supply Current vs.
Conversion Rate (External Clock) in the Typical Operating
Characteristics ).
SEL[2:0] of the setup byte (Table 1) control the reference
and the REF configuration (Table 6).
The internal reference is 4.096V for the MAX11646 and
2.048V for the MAX11647. When REF is configured to be
an internal reference output (SEL[2:1] = 11), decouple
REF to GND with a 0.1µF capacitor and a 2kΩ series
resistor (see the Typical Operating Circuit ). Once powered
up, the reference always remains on until reconfigured.
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 exter-
nal circuitry. The internal reference does not require an
external bypass capacitor and works best when left
unconnected (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 500Ω or less. If the reference has a higher out-
put impedance or is noisy, bypass it to GND as close
as possible to REF with a 0.1µF capacitor.
Reference output
Reference output
Reference input
Not connected*
Not connected*
2
Not connected
C, 10-Bit ADCs
REF
INTERNAL REFERENCE STATE
Reference Voltage
Always off
Always off
Always off
Always on
Always off
Always on
External Reference
Internal Reference
DD
. For