LTC1420 Datasheet, PDF (1/20 Pages) Linear Technology – 12-Bit, 10Msps, Sampling ADC

FEATURES
s _{10Msps Sample Rate}
s _{Single 5V Supply or ±5V Supplies}
s _{Integral Nonlinearity Error <0.35LSB}
s _{Differential Nonlinearity <0.25LSB}
s _{71dB S/(N + D) and 83dB SFDR at Nyquist}
s _{100MHz Full-Power Bandwidth Sampling}
s _{±2.048V, ±1.024V and ±0.512V Bipolar Input Range}
s _{Input PGA}
s _{Out-of-Range Indicator}
s _{True Differential Inputs with 75dB CMRR}
s _{Power Dissipation: 250mW}
s _{28-Pin Narrow SSOP Package}
U
APPLICATIO S
s _{Telecommunications}
s _{Digital Signal Processing}
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.
LTC1420
12-Bit, 10Msps,
Sampling ADC
DESCRIPTIO
The LTC^®1420 is a 10Msps, 12-bit sampling A/D converter
that draws only 250mW from either single 5V or dual ±5V
supplies. This easy-to-use device includes a high dynamic
range sample-and-hold, a precision reference and a PGA
input circuit.
The LTC1420 has a flexible input circuit that allows full-
scale input ranges of ±2.048V ±1.024V and ±0.512V. The
input common mode voltage is arbitrary, though a 2.5V
reference is provided for single supply applications. The
input PGA has a digitally selectable 1x or 2x gain.
Maximum DC specs include ±1LSB INL and ±1LSB DNL
over temperature. Outstanding AC performance includes
71dB S/(N + D) and 83dB SFDR at the Nyquist input
frequency of 5MHz.
The unique differential input sample-and-hold can acquire
single-ended or differential input signals up to its 100MHz
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.
TYPICAL APPLICATIO
5V
+ ^{1 +AIN}
VIN
– ^{2 –AIN}
28
GAIN
S/H
3 VCM
1µF
MODE SELECT
4 SENSE
5 VREF
1µF
5V
5V
1µF
1µF
7
23
V_DD
V_DD
1µF
22
OV_DD
OPTIONAL 3V
LOGIC SUPPLY
PIPELINED 12-BIT ADC
DIGITAL CORRECTION
LOGIC
2.5V
REFERENCE
2.048V
OF 27
D11 (MSB) 10
OUTPUT
BUFFERS
D0 (LSB) 20
DIGITAL
OUTPUT
CLK 26 _{10MHz CLK}
V_SS
25
1µF
0V OR –5V
GND
GND
6
8
GND
24
OGND
21
1420 TA01
1.00
0.75
0.50
0.25
0
–0.25
–0.50
–0.75
–1.00
0
Typical INL Curve
1024
2048
CODE
3072
4096
1420 TA02
1