LTC1740_15 Datasheet, PDF (1/16 Pages) Linear Technology – 14-Bit, 6Msps, Sampling ADC

FEATURES
s _{6Msps Sample Rate}
s _{79dB S/(N + D) and 91dB SFDR at 2.5MHz fIN}
s _{Single 5V Supply or ±5V Supplies}
s _{Integral Nonlinearity Error: < 1LSB}
s _{Differential Nonlinearity: < 0.5LSB}
s _{80MHz Full-Power Bandwidth Sampling}
s _{±2.5V and ±1.25V Bipolar Input Ranges}
s _{2.5V Signal Ground Available}
s _{Out-of-Range Indicator}
s _{True Differential Inputs with 75dB CMRR}
s _{Power Dissipation: 245mW}
s _{36-Pin SSOP Package (0.209 Inch Width)}
U
APPLICATIO S
s _{Telecommunications}
s _{Multiplexed Data Acquisition Systems}
s _{High Speed Data Acquisition}
s _{Spectral Analysis}
s _{Imaging Systems}
, LTC and LT are registered trademarks of Linear Technology Corporation.
LTC1740
14-Bit, 6Msps,
Sampling ADC
DESCRIPTIO
The LTC^®1740 is a 6Msps, 14-bit sampling A/D converter
that draws only 245mW from either a single 5V or dual
±5V supplies. This easy-to-use device includes a high
dynamic range sample-and-hold and a programmable
precision reference.
The LTC1740 has a flexible input circuit that allows differ-
ential full-scale input ranges of ±2.5V and ±1.25V with the
internal reference, or any full-scale input range up to
±2.5V with an external reference. The input common
mode voltage is arbitrary, though a 2.5V reference is
provided for single supply applications.
DC specifications include 1LSB typical INL, 0.5LSB typical
DNL and no missing codes over temperature. Outstanding
AC performance includes 79dB S/(N␣ +␣ D) and 91dB SFDR
at an input frequency of 2.5MHz.
The unique differential input sample-and-hold can acquire
single-ended or differential input signals up to its 80MHz
bandwidth. The 75dB common mode rejection allows
users to eliminate ground loops and common mode noise
by measuring signals differentially from the source. A
separate output logic supply allows direct connection to
3V components.
BLOCK DIAGRA
5V
5V
3V TO 5V
+
V_IN 1000pF
–
1µF
1µF
1µF
1µF
+A_IN
1
8
9
V_DD
V_DD
32
33
V_DD
V_DD
S/H
–A_IN
2
V_CM
3
PIPELINED 14-BIT ADC
MODE SELECT
SENSE
4
5 ^VREF
DIGITAL CORRECTION
LOGIC
2.5V
REFERENCE
2.250V
1µF
19
OV_DD
OF
36
D13 (MSB)
12
OUTPUT
BUFFERS
D7
18
D6
20
DIGITAL
OUTPUT
D0 (LSB)
26
BUSY
27
CLK
35
6MHz CLK
V_SS V_SS
30
29
GND GND GND GND GND OGND OGND
6
7
10
34
31
11
28
1740 TA01
1µF
0V OR –5V
4096-Point FFT
0
f_SMPL = 6MHz
f_IN = 2.5MHz, 5V_P-P
–20 5V SUPPLY
–40
–60
–80
–100
–120
0
0.5 1.0 1.5 2.0 2.5 3.0
FREQUENCY (MHz)
1740 TA02
1740f
1