LTC6911-2_15 Datasheet, PDF (1/20 Pages) Linear Technology – Dual Matched Amplifiers with Digitally Programmable Gain in MSOP

LTC6911-1/LTC6911-2
Dual Matched Amplifiers
with Digitally Programmable
Gain in MSOP
FEATURES
s _{3-Bit Digital Gain Control:}
(Inverting Gains of 0, 1, 2, 5, 10, 20, 50
and 100V/V) -1 Option
(Inverting Gains of 0, 1, 2, 4, 8, 16, 32
and 64V/V) -2 Option
s _{Two Matched Programmable Gain Amplifiers}
s _{Channel-to-Channel Gain Matching of 0.1dB (Max)}
s _{Rail-to-Rail Input Range}
s _{Rail-to-Rail Output Swing}
s _{Single or Dual Supply: 2.7V to 10.5V Total}
s _{11MHz Gain Bandwidth Product}
s _{Input Noise: 10nV/√Hz}
s _{Total System Dynamic Range to 120dB}
s _{Input Offset Voltage: 2mV, Gain of 10}
s _{Low Profile 10-Lead MSOP Package}
U
APPLICATIO S
s _{Data Acquisition Systems}
s _{Dynamic Gain Changing}
s _{Automatic Ranging Circuits}
s _{Automatic Gain Control}
DESCRIPTIO
The LTC^®6911 is a family of low noise digitally program-
mable gain amplifiers (PGAs) that are easy to use and
occupy very little PC board space. The matched gain of
both channels is adjustable using a 3-bit parallel interface
to select voltage gains of 0, 1, 2, 5, 10, 20, 50 and 100V/
V (LTC6911-1) and 0, 1, 2, 4, 8, 16, 32 and 64V/V
(LTC6911-2). All gains are inverting.
The LTC6911 family consists of two matched inverting
amplifiers with rail-to-rail outputs. When operated with
unity gain, they will also process rail-to-rail input signals.
A half-supply reference generated internally at the AGND
pin supports single power supply applications. Operating
from single or split supplies from 2.7V to 10.5V, the
LTC6911 family is offered in a 10-lead MSOP package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
V⁺
2.7V TO 10.5V 0.1µF
7
9
DIGITAL
INPUT
GAIN IN V/V
G2 G1 G0 LTC6911-1 LTC6911-2
000
0
0
001
–1
–1
010
–2
–2
011
–5
–4
1 0 0 –10
–8
1 0 1 –20
–16
1 1 0 –50
–32
1 1 1 –100
–64
AGND
1
V_INA
≥1µF
2
3
V_INB
LTC6911-X
10 _{VOUTA =}
GAIN • V_INA
8 _{VOUTB =}
GAIN • V_INB
691112 TA01
4
5
6
G0 G1 G2
Frequency Response (LTC6911-1)
50
V_S = 10V, V_IN = 5mV_RMS
GAIN OF –100 (DIGITAL INPUT 111)
40
30 _{GAIN OF –50 (DIGITAL INPUT 110)}
GAIN OF –20 (DIGITAL INPUT 101)
20
GAIN OF –10 (DIGITAL INPUT 100)
10 ^{GAIN OF –5 (DIGITAL INPUT 011)}
GAIN OF –2 (DIGITAL INPUT 010)
0 _{GAIN OF –1 (DIGITAL INPUT 001)}
–10
100
1k
10k 100k 1M 10M
FREQUENCY (Hz)
691112 TA02
sn691112 691112fs
1