MAX11615EEE+ Maxim Integrated Products, MAX11615EEE+ Datasheet - Page 10

• Manufacturer Part Number: MAX11615EEE+
• Description: IC ADC SERIAL 12BIT 8CH 16-QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX11615EEE+

• Number Of Bits: 12
• Sampling Rate (per Second): 94.4k
• Data Interface: I²C, Serial
• Number Of Converters: 1
• Power Dissipation (max): 666.7mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SSOP (0.150", 3.90mm Width)
• Resolution: 12 bit
• Interface Type: I2C
• Snr: 70 dB
• Voltage Reference: 2.048 V
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 2.7 V
• Maximum Power Dissipation: 666.7 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Input Voltage: 3.3 V
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

During the acquisition interval, the T/H switches are in
the track position and C
signal. At the end of the acquisition interval, the T/H
switches move to the hold position retaining the charge
on C
During the conversion interval, the switched capacitive
DAC adjusts to restore the comparator input voltage to
0V within the limits of a 12-bit resolution. This action
requires 12 conversion clock cycles and is equivalent
to transferring a charge of 11pF
C
digital representation of the analog input signal.
Sufficiently low source impedance is required to ensure
an accurate sample. A source impedance of up to 1.5kΩ
does not significantly degrade sampling accuracy. To
minimize sampling errors with higher source impedances,
connect a 100pF capacitor from the analog input to GND.
This input capacitor forms an RC filter with the source
impedance limiting the analog-input bandwidth. For larg-
er source impedances, use a buffer amplifier to maintain
analog-input signal integrity and bandwidth.
When operating in internal clock mode, the T/H circuitry
enters its tracking mode on the eighth rising clock edge
of the address byte, see the Slave Address section. The
T/H circuitry enters hold mode on the falling clock edge of
the acknowledge bit of the address byte (the ninth clock
pulse). A conversion or a series of conversions is then
internally clocked and the MAX11612–MAX11617 holds
SCL low. With external clock mode, the T/H circuitry
enters track mode after a valid address on the rising
Low-Power, 4-/8-/12-Channel, I
12-Bit ADCs in Ultra-Small Packages
Figure 4. Equivalent Input Circuit
10
T/H
T/H
______________________________________________________________________________________
to the binary weighted capacitive DAC, forming a
as a stable sample of the input signal.
AIN3/REF
AIN0
AIN1
AIN2
GND
T/H
ANALOG INPUT MUX
charges to the analog input

(V
IN+
- V
IN-
) from
C
C
T/H
T/H
edge of the clock during the read (R/W = 1) bit. Hold
mode is then entered on the rising edge of the second
clock pulse during the shifting out of the first byte of the
result. The conversion is performed during the next 12
clock cycles.
The time required for the T/H circuitry to acquire an
input signal is a function of the input sample capaci-
tance. If the analog-input source impedance is high,
the acquisition time constant lengthens and more time
must be allowed between conversions. The acquisition
time (t
to be acquired. It is calculated by:
where R
R
clock mode and t
The MAX11612–MAX11617 feature input-tracking circuit-
ry with a 5MHz small-signal bandwidth. The 5MHz input
bandwidth makes it possible to digitize high-speed tran-
sient events and measure periodic signals with band-
widths exceeding the ADC’s sampling rate by using
under sampling techniques. To avoid high-frequency
signals being aliased into the frequency band of interest,
anti-alias filtering is recommended.
Internal protection diodes clamp the analog input to
V
DD
IN
= 2.5kΩ, and C
and GND. These diodes allow the analog inputs to
ACQ
SOURCE
V
Analog Input Range and Protection
DD
) is the minimum time needed for the signal
t
ACQ
/2
2
C,
REF
REF
≥ 9
ACQ
is the analog-input source impedance,
IN

CAPACITIVE
DAC
CAPACITIVE
DAC
= 22pF. t
= 2/f
(R
SOURCE
Analog Input Bandwidth
SCL
for external clock mode.
ACQ
MAX11612
MAX11613
+ R
is 1.5/f
IN
)

SCL
C
IN
for internal