LT1993-4 Linear Technology, LT1993-4 Datasheet - Page 14

• Manufacturer Part Number: LT1993-4
• Description: 900MHz Low Distortion - Low Noise Differential Amplifier/ADC Driver
• Manufacturer: Linear Technology

PACKAGE DESCRIPTIO
APPLICATIO S I FOR ATIO
LT1993-4
Large Output Voltage Swings
The LT1993-4 has been designed to provide the 3.2V
output swing needed by the LTC1748 family of 14-bit
low-noise ADCs. This additional output swing improves
system SNR by up to 4dB. Typical performance curves
and AC specifi cations have been included for these
applications.
Input Bias Voltage and Bias Current
The input pins of the LT1993-4 are internally biased to
the voltage applied to the V
resistors are needed, even for AC-coupled operation. The
14
3.50 ± 0.05
IF IN
Figure 9. Level Shifting 3V ADC V
Improved SFDR
2.10 ± 0.05
1.45 ± 0.05
NOTE:
1. DRAWING CONFORMS TO JEDEC PACKAGE OUTLINE MO-220 VARIATION (WEED-2)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
(4 SIDES)
13
14
15
16
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
–INB
–INA
+INB
+INA
+OUTFILTERED
–OUTFILTERED
U
LT1993-4
V
2
OCM
U
OCM
6
7
pin. No external biasing
W
0.50 BSC
CM
0.25 ±0.05
U
1
2
0.70 ±0.05
Voltage for
AIN
AIN
PACKAGE
OUTLINE
+
–
4.02k
11k
LTC22xx
16-Lead Plastic QFN (3mm × 3mm)
31
V
3V
CM
(Reference LTC DWG # 05-08-1691)
1.5V
1.9V
U
19934 F09
PIN 1
TOP MARK
(NOTE 6)
3.00 ± 0.10
(4 SIDES)
UD Package
P-P
input bias current is determined by the voltage difference
between the input common mode voltage and the V
(which sets the output common mode voltage). At both
the positive and negative inputs, any voltage difference is
imposed across 100Ω, generating an input bias current.
For example, if the inputs are tied to 2.5V with the V
pin at 2.2V, then a total input bias current of 3mA will fl ow
into the LT1993-4’s +INA and +INB pins. Furthermore, an
additional input bias current totaling 3mA will fl ow into
the –INA and –INB inputs.
Application (Demo) Boards
The DC800A Demo Board has been created for stand-alone
evaluation of the LT1993-4 with either single-ended or
differential input and output signals. As shown, it accepts
a single-ended input and produces a single-ended output
so that the LT1993-4 can be evaluated using standard
laboratory test equipment. For more information on this
Demo Board, please refer to the Demo Board section of
this datasheet.
There are also additional demo boards available that
combine the LT1993-4 with a variety of different Linear
Technology ADCs. Please contact the factory for more
information on these demo boards.
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
ON THE TOP AND BOTTOM OF PACKAGE
0.75 ± 0.05
1.45 ± 0.10
(4-SIDES)
0.200 REF
0.00 – 0.05
BOTTOM VIEW—EXPOSED PAD
R = 0.115
TYP
15 16
www.DataSheet4U.com
0.50 BSC
0.25 ± 0.05
1
2
(UD16) QFN 0904
0.40 ± 0.10
PIN 1 NOTCH R = 0.20 TYP
OR 0.25 × 45° CHAMFER
OCM
19934fa
OCM
pin