Datasheet

MAX1192
Ultra-Low-Power, 22Msps, Dual 8-Bit ADC
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Detailed Description
The MAX1192 uses a seven-stage, fully differential,
pipelined architecture (Figure 1) that allows for high-
speed conversion while minimizing power consump-
tion. Samples taken at the inputs move progressively
through the pipeline stages every half-clock cycle.
Including the delay through the output latch, the total
clock-cycle latency is 5 clock cycles for channel A and
5.5 clock cycles for channel B.
At each stage, flash ADCs convert the held input volt-
ages into a digital code. The following digital-to-analog
converter (DAC) converts the digitized result back into
an analog voltage, which is then subtracted from the
original held input signal. The resulting error signal is
then multiplied by two, and the product is passed along
to the next pipeline stage where the process is repeated
until the signal has been processed by all stages. Digital
error correction compensates for ADC comparator off-
sets in each pipeline stage and ensures no missing
codes. Figure 2 shows the MAX1192 functional diagram.
Pin Description (continued)
PIN NAME FUNCTION
23 PD0 Power-Down Digital Input 0. See Table 3.
24 REFIN Reference Input. Internally pulled up to V
DD
.
25 COM Common-Mode Voltage I/O. Bypass COM to GND with a 0.33µF capacitor.
26 REFN
Negative Reference I/O. Conversion range is ±(V
REFP
- V
REFN
). Bypass REFN to GND with a 0.33µF
capacitor.
27 REFP
Positive Reference I/O. Conversion range is ±(V
REFP
- V
REFN
). Bypass REFP to GND with a 0.33µF
capacitor.
— EP Exposed Paddle. Internally connected to pin 3. Externally connect EP to GND.
INA+
INA-
T/H
DIGITAL ERROR CORRECTION
/
D0–D7
FLASH
ADC
T/H
DAC
∑
-
+
x2
1.5 BITS
STAGE 1 STAGE 2 STAGE 7
Figure 1. Pipeline Architecture—Stage Blocks
INA+
INA-
DEC
/T/H
INB+
INB-
DEC/T/H
/
REFERENCE
SYSTEM AND
BIAS
CIRCUITS
PIPELINE
ADC
A
COM
REFIN
REFN
REFP
CLK
TIMING
OV
DD
OGND
MULTIPLEXER
OUTPUT
DRIVERS
POWER
CONTROL
D0–D7
/
/
V
DD
GND
A/B
PD0
PD1
PIPELINE
ADC
B
MAX1192
Figure 2. MAX1192 Functional Diagram