LT6221 Linear Technology Corporation, LT6221 Datasheet - Page 17

• Manufacturer Part Number: LT6221
• Description: Single/dual/quad 60mhz, 20v/?s Low Power, Rail-to-rail Input And Output Precision Op Amp
• Manufacturer: Linear Technology Corporation

PACKAGE DESCRIPTIO
and the output of the lower path is:
Note that the input common mode voltage does not appear
in the output as either a common mode or a difference
mode term. However the voltage V
output terms, and with the same polarity, so it sets up the
output DC level. Also, the differential input voltage V
appears fully at both outputs with opposite polarity, giving
3.5 ±0.05
PACKAGE DESCRIPTIO
+OUT = 3 • (2/3 • V
2.15 ±0.05
• (V
= 2V
= V
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
1.65 ±0.05
(2 SIDES)
ICM
0.25 ± 0.05
OCM
ICM
– V
+ V
+ V
DIFF
DIFF
OCM
ICM
/2)
2.38 ±0.05
(2 SIDES)
– 2V
+ 1/3 • V
0.50
BSC
ICM
+ V
OCM
OCM
0.675 ±0.05
DIFF
U
U
does appear in the
) – 2
PACKAGE
OUTLINE
8-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1698)
TOP MARK
(NOTE 6)
PIN 1
0.200 REF
DIFF
DD Package
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-1)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
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 TOP AND BOTTOM OF PACKAGE
rise to the effective differential gain of 2. Calculations show
that using 1% resistors gives worst-case input common
mode feedthrough better than –31dB, whether looking at
the output common mode or difference mode. Consider-
ing the 6dB of gain, worst-case common mode rejection
ratio is 37dB. (Remember this is assuming 1% resistors.
Of course, this can be improved with more precise resis-
tors.) Results achieved on the bench with typical 1%
resistors showed 67dB of CMRR at low frequency and
40dB CMRR at 1MHz. Gains other than 2 can be achieved
by setting R3 = α • (R1||R2), R5 = α • R4 and R7 = α • R6
where gain = α.
LT6220/LT6221/LT6222
0.75 ±0.05
3.00 ±0.10
(4 SIDES)
0.00 – 0.05
1.65 ± 0.10
(2 SIDES)
BOTTOM VIEW—EXPOSED PAD
0.25 ± 0.05
R = 0.115
TYP
4
5
2.38 ±0.10
(2 SIDES)
8
1
0.50 BSC
0.38 ± 0.10
17
622012fa
(DD8) DFN 1203