MAX44205 Datasheet, PDF (1/29 Pages) Maxim Integrated Products – Fully Differential Op Amp/SAR ADC Driver

MAX44205
180MHz, Low-Noise, Low-Distortion,
Fully Differential Op Amp/SAR ADC Driver
General Description
The MAX44205 is a low-noise, low-distortion fully differ-
ential operational amplifier suitable for driving high-speed,
high-resolution, 20-/18-/16-bit SAR ADCs, including the
MAX11905 ADC family. Featuring a combination of wide
2.7V to 13.2V supply voltage range and wide 400MHz
bandwidth, the MAX44205 is suitable for low-power, high-
performance data acquisition systems.
The MAX44205 offers a VOCM input to adjust the out-
put common-mode voltage, eliminating the need for a
coupling transformer or AC-coupling capacitors. This
adjustable output common-mode voltage allows the
MAX44205 to match the input common-mode voltage
range of the ADC following it. A proprietary output voltage
clamping solution ensures that the buffer output does not
violate the ADC’s maximum input voltage range, even if
the MAX44205’s supply rails are higher than the ADC’s
full-scale range. Shutdown mode consumes only 6.8µA
and extends battery life in battery-powered applications
or reduces average power in systems cycling between
shutdown and periodic data readings.
The MAX44205 is available in 12-pin, 3mm x 3mm, TQFN
and 10-pin μMAX® packages and is specified for opera-
tion over the -40°C to +125°C temperature range.
For related parts and recommended products to use with this part, refer
to www.maximintegrated.com/MAX44205.related.
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Typical Application Circuit
1kΩ
0.1%
2.2µF
X7R
VCM
1kΩ
0.1%
4.7nF
C0G
4.7nF
C0G
1kΩ
0.1%
-
VSIG
+
-
VSIG
+
1kΩ
0.1%
1kΩ
+5V 0.1%
VS+
VCLPH
OUT+
1.5V _VOCM
0.1µF
MAX44205
OUT-
VCLPL
VS-
-5V
1kΩ
0.1%
4.7nF
C0G
4.7nF
C0G
3.2V TO 12.6V
3V
OUT
IN
MAX6126
GND
10µF
10Ω 0.1%
2.2nF
COG
10Ω 0.1%
ADC INPUT FILTER
3.3V
3.3V
REFVDD VREFIN AVDD
AIN+
MAX11905
AIN-
GND
Features and Benefits
●● Low Input Noise to Drive Precision SAR ADCs
• 3.1nV/√Hz at 1kHz
• 200nV_P-P from 0.1Hz to 10Hz
●● High Speed for DC and AC Applications
• Gain-Bandwidth Product 400MHz
• -3dB Gain-Bandwidth Product 180MHz
• Slew Rate 180V/µs
●● Ultra-Low Distortion Drives AC Inputs to 20-Bit SAR
ADCs
• THD = -130dBc at 10kHz, V_OUT,DIFF = 2V_P-P
• THD = -84dBc at 1MHz, V_OUT,DIFF = 2V_P-P
●● Wide Supply Range (2.7V to 13.2V) Drives Unipolar
or Bipolar (±6.6V) Signals
●● 3.7mA Quiescent Supply Current with Only 6.8µA
Shutdown Current
●● Input Pins for Output(s) Voltage Clamping Avoids
ADC Saturation
●● 12-Pin, 3mm x 3mm TQFN and 10-Pin μMAX
Packages Save Board Space
Applications
●● Single-Ended to Differential Conversion
●● High-Speed Process Control
●● Medical Imaging
●● Fully-Differential Signal Conditioning
●● Active Filters
Ordering Information appears at end of data sheet.
0.0
-10.0
-20.0
-30.0
-40.0
-50.0
-60.0
-70.0
-80.0
-90.0
-100.0
-110.0
-120.0
-130.0
-140.0
0
MAX44205 DRIVING MAX11905
(fSAMPLE = 1Msps, fIN = 10kHz,
65,536-Point FFT)
Dual ±5V Supplies
VOUTDIFF = 6VP-P
THD = -112.9dBc
SFDR = 114.7dBc
SNR = 97.5dB
SINAD = 97.3dB
50
100
150 200 250
300
350
400 450 500
FREQUENCY (kHz)
19-6951; Rev 0; 6/14