LT1993-4
900MHz Low Distortion, Low
Noise Differential Ampli er/
ADC Driver (A = 4V/V)
V
DESCRIPTIO
FEATURES
900MHz 3dB Bandwidth The LT 1993-4 is a low distortion, low noise Differential
Fixed Gain of 4V/V (12dB) Ampli er/ADC driver for use in applications from DC to
Low Distortion: 900MHz. The LT1993-4 has been designed for ease of
40dBm OIP3, 73dBc HD3 (70MHz 2V ) use, with minimal support circuitry required. Exception-
P-P
51dBm OIP3, 94dBc HD3 (10MHz 2V ) ally low input-referred noise and low distortion products
P-P
Low Noise: 14.5dB NF, e = 2.35nV/Hz (70MHz) (with either single-ended or differential inputs) make the
n
Differential Inputs and Outputs LT1993-4 an excellent solution for driving high speed 12-
Additional Filtered Outputs bit and 14-bit ADCs. In addition to the normal un ltered
Adjustable Output Common Mode Voltage outputs (+OUT and OUT), the LT1993-4 has a built-in
DC- or AC-Coupled Operation 175MHz differential lowpass lter and an additional pair
Minimal Support Circuitry Required of ltered outputs (+OUTFILTERED, OUTFILTERED) to
Small 0.75mm Tall 16-Lead 3 3 QFN Package reduce external ltering components when driving high
speed ADCs. The output common mode voltage is easily set
U
APPLICATIO S via the V pin, eliminating either an output transformer
OCM
or AC-coupling capacitors in many applications.
Differential ADC Driver for:
The LT1993-4 is designed to meet the demanding require-
Imaging
ments of communications transceiver applications. It can
Communications
be used as a differential ADC driver, a general-purpose
Differential Driver/Receiver
differential gain block, or in any other application requir-
Single Ended to Differential Conversion
ing differential drive. The LT1993-4 can be used in data
Differential to Single Ended Conversion
acquisition systems required to function at frequencies
Level Shifting
down to DC.
IF Sampling Receivers
SAW Filter Interfacing/Buffering
The LT1993-4 operates on a 5V supply and consumes
, LTC and LT are registered trademarks of Linear Technology Corporation.
100mA. It comes in a compact 16-lead 3 3 QFN package
All other trademarks are the property of their respective owners.
and operates over a 40C to 85C temperature range.
TYPICAL APPLICATIO 4-Tone WCDMA Waveform,
LT1993-4 Driving LTC2255
14-Bit ADC at 92.16Msps
ADC Driver with Single-Ended to Differential Conversion
0
32768 POINT FFT
10
TONE CENTER FREQUENCIES
1:1
0.1F
20
AT 62.5MHz, 67.5MHz,
Z-RATIO
70MHz 72.5MHz, 77.5MHz
30
INB
12.2
IF IN
OUT
AIN 40
INA
OUTFILTERED
50
LTC2255
100
LT1993-4 82nH 52.3pF
60
ADC
+OUTFILTERED
70
+INB
AIN+
+OUT
MA/COM
80
12.2
+INA
0.1F V
OCM
ETC1-1-13
LTC2255 125Msps
90
ENABLE
14-BIT ADC SAMPLING
100
AT 92.16Msps
2.2V 12dB GAIN
110
19934 TA01
120
0 5 10 15 20 25 30 35 40 45
FREQUENCY (MHz)
LT19934 TA02
19934fa
1
AMPLITUDE (dBFS)
U
ULT1993-4
UUW
ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO
(Note 1)
TOP VIEW
Total Supply Voltage (V /V /V to
CCA CCB CCC
V /V /V ) ...................................................5.5V
EEA EEB EEC
16 15 14 13
Input Current (+INA, INA, +INB, INB,
V 1 12 V
CCC EEC
V , ENABLE) ................................................10mA
OCM
V 2 11 ENABLE
OCM
17
Output Current (Continuous) (Note 6)
V V
3 10
CCA CCB
+OUT, OUT (DC) ..........................................100mA V 4 9 V
EEA EEB
5 6 7 8
(AC) ..........................................100mA
+OUTFILTERED, OUTFILTERED (DC) .............15mA
(AC) .............45mA
Output Short Circuit Duration (Note 2) ............ Inde nite
Operating Temperature Range (Note 3) ... 40C to 85C
UD PACKAGE
16-LEAD (3mm 3mm) PLASTIC QFN
Speci ed Temperature Range (Note 4) .... 40C to 85C
T = 125C, = 68C/W, = 4.2C/W
JMAX JA JC
Storage Temperature Range ................... 65C to 125C EXPOSED PAD IS V (PIN 17)
EE
MUST BE SOLDERED TO THE PCB
Junction Temperature ........................................... 125C
UD PART MARKING*
ORDER PART NUMBER
Lead Temperature Range (Soldering 10 sec) ........ 300C
LT1993CUD-4 LBNS
LT1993IUD-4 LBNS
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking: