
1
LTC1282
S
FEATURE
D
U
ESCRIPTIO
The LTC
1282 is a 6
s, 140ksps, sampling 12-bit A/D
converter that draws only 12mW from a single 3V or dual
±3Vsupply.Thiseasy-to-usedevicecomescompletewith
1.14
s sample-and-hold, precision reference and inter-
nally trimmed clock. Unipolar and bipolar conversion
modes provide flexibility for various applications. They are
built with LTBiCMOS
TM switched capacitor technology.
The LTC1282 has a 25ppm/
°C (max) internal reference
and converts 0V to 2.5V unipolar inputs from a single 3V
supply. With
±3V supplies its input range is ±1.25V with
two’s complement output format. Maximum DC specifica-
tions include
±0.5LSB INL, ±0.75LSB DNL and 25ppm/°C
full-scale drift over temperature. Outstanding AC perfor-
mance includes 69dB S/(N + D) and 77dB THD at the
Nyquist input frequency of 70kHz.
The internal clock is trimmed for 6
s maximum conver-
sion time. The clock automatically synchronizes to each
sample command eliminating problems with asynchro-
nous clock noise found in competitive devices. A high
speed parallel interface eases connections to FIFOs, DSPs
and microprocessors.
3V 140ksps 12-Bit
Sampling A/D Converter
with Reference
s
Single Supply 3V or
±3V Operation
s
140ksps Throughput Rate
s
12mW (Typ) Power Dissipation
s
On-Chip 25ppm/
°C Reference
s
Internal Synchronized Clock; No Clock Required
s
High Impedance Analog Input
s
69dB S/(N + D) and 77dB THD at Nyquist
s
±0.5LSB INL and ±0.75LSB DNL Max (A Grade)
s
2.7V Guaranteed Minimum Supply Voltage
s
ESD Protected On All Pins
s
24-Pin Narrow PDIP and SW Packages
s
0V to 2.5V or
±1.25V Input Ranges
U
S
A
O
PPLICATI
s
3V Powered Systems
s
High Speed Data Acquisition
s
Digital Signal Processing
s
Multiplexed Data Acquisition Systems
s
Audio and Telecom Processing
s
Spectrum Analysis
INPUT FREQUENCY (Hz)
1k
0
ENOBs
(EFFECTIVE
NUMBER
OF
BITS)
3
5
7
10
10k
LTC1282 TA02
1
4
6
9
12
11
8
2
100k
62
56
74
68
50
S/(N
+
D)
(dB)
fSAMPLE = 140kHz
NYQUIST
FREQUENCY
Effective Bits and Signal-to-(Noise + Distortion)
vs Input Frequency
, LTC and LT are registered trademarks of Linear Technology Corporation.
LTBiCMOS is a trademark of Linear Technology Corporation
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24
23
22
21
20
19
18
17
16
15
14
13
AIN
VREF
AGND
D11(MSB)
D10
D9
D8
D7
D6
D5
D4
DGND
VDD
VSS
BUSY
CS
RD
HBEN
NC
D0/8
D1/9
D2/10
D3/11
LTC1282
+
0.1
F
10
F
1.20V
VREF
OUTPUT
ANALOG INPUT
(0V TO 2.5V)
+
10
F
0.1
F
3V
8- OR 12-BIT
PARALLEL BUS
P CONTROL
LINES
1282 TA01
Single 3V Supply, 140ksps, 12-Bit Sampling A/D Converter
U
A
O
PPLICATI
TYPICAL