Linear Technology DC1833A Demo Manual

DESCRIPTION
The LTC ® 6362 is a low power, low noise differential op amp
with rail-to-rail input and output swing that has been
optimized to drive low power SAR ADCs. The amplifier may
be configured to buffer a fully differential input signal or
convert a single-ended input signal to a differential output
signal. Demo circuit 1833A contains the LTC6362 amplifier
configured as a unity gain amplifier with 1kΩ feedback
and input resistors, where both inputs are AC-coupled by
a 1μF capacitor. The differential outputs of the DC1833A
can be configured with a first order RC network for driving
PERFORMANCE SUMMARY
differential input, as given in Table 1. (T
Table 1. LTC6362 Noise and Distortion
Differential Input, Referred Noise Voltage Density
Distortion, 8V Differential Input, V
P-P
R6, 1k
–
V
IN
V
OCM
0.1μF
R5, 1k
+
V
IN
Arrow.com.
Downloaded from
This demo board is factory tested by measuring distortion with an 8V
= 25°C)
A
= 5V, F = 2kHz, R
S IN LOAD
R3, 1k
+
V
0.1μF
R15
–
+
C18
LTC6362
C
DIFF
R14
–
+
R4, 1k
Figure 1. Typical Application for an LTC6362
DEMO MANUAL DC1833A
Fully Differential Amplifier
the differential inputs of an ADC. The LTC6362 differential
output can be DC-coupled or AC-coupled (AC-coupled is
the default configuration). Onboard jumpers configure
the DC1833A for dual or single power supply. In addition,
there are several optional surface mount pads that can be
used to change the LTC6362 configuration.
Design files for this circuit board are available at
http://www.linear.com/demo
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
= 1000Ω 2nd Harmonic
3rd Harmonic
0
–10
–20
–30
–40
–50
–60
–70
+
V
OUT
–80
C19
–90
C15
–
–100
V
OUT
–110
–120
DC1833A F01a
–130
–140
–150
0
LTC6362
2kHz Sine Wave,
V Diff 8V 16384 –Point FFT
IN P-P
+
V = 5V
–
V = 0V
HD2 = –128dBc
HD3 = –114dBc
4 6 8 16
2 10 12 14
FREQUENCY (kHz)
, 2kHz
P-P
3.9nV/√Hz
–128dBc
–114dBc
18 20
DC1833A FO1b
dc1833af
1