ADA4950-2 Low Power Selectable Gain Differential ADC Driver, G = 1, 2, 3

The ADA4950-1/ADA4950-2 are gain-selectable versions of the ADA4932-1/ADA4932-2 with on-chip feedback and gain resistors It is an ideal choice for driving high performance ADCs as a single-ended-to-differential or differential-to-differential amplifier. The output common-mode voltage is user adjustable by means of an internal common-mode feedback loop, allowing the ADA4950-x output to match the input of the ADC. The internal feedback loop also provides exceptional output balance as well as suppression of even-order harmonic distortion products. ADC drivers Single-ended-to-differential converters IF and baseband gain blocks Differential buffers Line drivers

Differential gain configurations of 1, 2, and 3 are easily realized with internal feedback networks that are connected externally to set the closed-loop gain of the amplifier.

The ADA4950-x is fabricated using the Analog Devices, Inc., proprietary silicon-germanium (SiGe) complementary bipolar process, enabling it to achieve low levels of distortion and noise at low power consumption. The low offset and excellent dynamic performance of the ADA4950-x make it well suited for a wide variety of data acquisition and signal processing applications.

The ADA4950-x is available in a Pb-free, 3 mm × 3 mm, 16-lead LFCSP (ADA4950-1, single) or a Pb-free 4 mm × 4 mm, 24-lead LFCSP (ADA4950-2, dual). The pinout has been optimized to facilitate PCB layout and minimize distortion. The ADA4950-1/ADA4950-2 are specified to operate over the -40°C to +105°C temperature range; both operate on supplies from +3 V to ±5 V.

Features and Benefits

High performance at low power

High speed
-3 dB bandwidth of 750 MHz, G = 1
0.1 dB flatness to 210 MHz, V_{OUT, dm} = 2 V p-p, R_{L, dm} = 200 Ω
Slew rate: 2900 V/µs, 25% to 75%
Fast 0.1% settling time of 9 ns

Low power: 9.5 mA per amplifier

Low harmonic distortion
108 dB SFDR @ 10 MHz
98 dB SFDR @ 20 MHz

Low output voltage noise: 9.2 nV/√Hz, G = 1, RTO

±0.2 mV typical input offset voltage

Selectable differential gains of 1, 2, and 3

Differential-to-differential or single-ended-to-differential operation

Adjustable output common-mode voltage

Input common-mode range shifted down by one VBE

Wide supply range: +3 V to ±5 V

Available in 16-lead and 24-lead LFCSP packages

Amplifiers

SPICE Models

ADA4950 SPICE Macro Model .CIR

Data Sheets

Document	note
ADA4950-1/ADA4950-2: Low Power, Selectable GainDifferential ADC Driver, G = 1, 2, 3 Data Sheet (Rev. B)	PDF 812 kB

Application Notes

Document	note
AN-1363: Meeting Biasing Requirements of Externally Biased RF/Microwave Amplifiers with Active Bias Controllers (Rev. 0)	PDF 804.11 K
AN-282: Fundamentals of Sampled Data Systems	PDF 2131 kB
AN-0990: Terminating a Differential Amplifier in Single-Ended Input Applications (Rev. 0)	PDF 181 kB
AN-0992: Active Filter Evaluation Board for Differential Amplifiers (Rev. 0)	PDF 85 kB
AN-1026: High Speed Differential ADC Driver Design Considerations (Rev. A)	PDF 355 kB
AN-649: Using the Analog Devices Active Filter Design Tool (Rev. 0)	PDF 5.3 M
AN-584: Using the AD813X Differential Amplifier (Rev. 0)	PDF 174 kB
AN-589: Ways to Optimize the Performance of a Difference Amplifier (Rev. B)	PDF 115 kB

User Guides

Document	note
UG-107: Evaluation Board for Dual High Speed Selectable Gain Differential Amplifiers (24-Lead, 4 mm × 4 mm LFCSP)	PDF 326 kB

Order Information

Part Number	Package	Packing Qty	Temp Range	Price 100-499	Price 1000+	RoHS
ADA4950-2YCPZ-R2 Production	24 ld LFCSP (4x4mm w/2.10mm EP)	REEL 250	-40 to 105C	6.57	6.57	Y
ADA4950-2YCPZ-R7 Production	24 ld LFCSP (4x4mm w/2.10mm EP)	REEL 1500	-40 to 105C	0	5.29	Y
ADA4950-2YCPZ-RL Production	24 ld LFCSP (4x4mm w/2.10mm EP)	REEL 5000	-40 to 105C	0	5.29	Y