Datasheet

MAX11203/MAX11213 16-Bit, Single-Channel, Ultra-Low-Power,
Delta- Sigma ADCs with Programmable Gain
and GPIO
www.maximintegrated.com
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Detailed Description
The MAX11203/MAX11213 are ultra-low-power (< 300FA
active), high-resolution, low-speed, serial-output ADCs.
These ADCs provide the highest resolution per unit power
in the industry, and are optimized for applications that
require very high dynamic range with low power such
as sensors on a 4mA to 20mA industrial control loop.
Optional input buffers provide isolation of the signal inputs
from the switched capacitor sampling network, allow-
ing the devices to be used with very high impedance
sources without compromising available dynamic range.
The devices provide a high-accuracy internal oscillator,
which requires no external components. When used with
the specified data rates, the internal digital filter provides
more than 144dB rejection of 50Hz or 60Hz line noise. The
devices are highly configurable using the SPI interface
and include four GPIOs for external mux control.
Analog Inputs
The devices accept two analog inputs (AINP, AINN) in
buffered or unbuffered mode. The input buffer isolates
the inputs from the capacitive load presented by the
modulator, allowing for high source-impedance analog
transducers. The value of the SIGBUF bit in the CTRL1
register determines whether the input buffer is enabled
or disabled. See Table 12.
Input Voltage Range
The modulator input range is programmable for bipolar
(-V
REF
to +V
REF
) or unipolar (0 to V
REF
) ranges. The
U/B bit in the CTRL1 register configures the MAX11203/
MAX11213 for unipolar or bipolar transfer functions. See
Table 12.
System Clock
The devices incorporate a highly stable internal oscillator
that provides the system clock. The system clock runs
the internal state machine and is trimmed to 2.4576MHz
or 2.048MHz. The internal oscillator clock is divided
down to run the digital and analog timing. The LINEF bit
in the CTRL1 register determines the internal oscillator
frequency. See Tables 10 and 12. Set LINEF = 0 to select
the 2.4576MHz oscillator and LINEF = 1 to select the
Table 1. Continuous Conversion with SCYCLE Bit = 0
Table 2. Single-Cycle Conversion with SCYCLE Bit = 1
*LINEF = 0 sets the clock frequency to 2.4576MHz and the input sampling frequency to 245.76kHz. LINEF bit = 1 sets the clock
frequency to 2.048MHz and the input sampling frequency to 204.8kHz.
*LINEF = 0 sets the clock frequency to 2.4576MHz and the input sampling frequency to 245.76kHz. LINEF bit = 1 sets the clock
frequency to 2.048MHz and the input sampling frequency to 204.8kHz.
RATE[2:0]
DATA RATE* (sps)
BIPOLAR NFR
(BITS)
BIPOLAR
ENOB
(BITS)
UNIPOLAR
NFR (BITS)
UNIPOLAR
ENOB
(BITS)
OUTPUT
NOISE
(µV
RMS
)
LINEF = 0 LINEF = 1
100 60 50 16.0 16.0 16.0 16.0 0.74
101 120 100 16.0 16.0 16.0 16.0 1.03
110 240 200 16.0 16.0 16.0 16.0 1.45
111 480 400 16.0 16.0 16.0 16.0 2.21
RATE[2:0]
SINGLE-CYCLE DATA RATE*
(sps)
BIPOLAR
NFR (BITS)
BIPOLAR
ENOB
(BITS)
UNIPOLAR
NFR (BITS)
UNIPOLAR
ENOB (BITS)
OUTPUT
NOISE
(µV
RMS
)
LINEF = 0 LINEF = 1
000 1 0.833 16.0 16.0 16.0 16.0 0.21
001 2.5 2.08 16.0 16.0 16.0 16.0 0.27
010 5 4.17 16.0 16.0 16.0 16.0 0.39
011 10 8.33 16.0 16.0 16.0 16.0 0.57
100 15 12.5 16.0 16.0 16.0 16.0 0.74
101 30 25 16.0 16.0 16.0 16.0 1.03
110 60 50 16.0 16.0 16.0 16.0 1.45
111 120 100 16.0 16.0 16.0 16.0 2.21