
1
LTC1409
12-Bit, 800ksps Sampling
A/D Converter with Shutdown
S
FEATURE
D
U
ESCRIPTIO
The LTC
1409 is a 1
s, 800ksps, sampling 12-bit A/D
converter that draws only 80mW from
±5V supplies. This
easy-to-use device includes a high dynamic range sample-
and-hold and a precision reference. Two digitally selectable
power Shutdown modes provide flexibility for low power
systems.
The LTC1409 full-scale input range is
±2.5V. Maximum
DC specs include
±1LSB INL and ±1LSB DNL over tem-
perature. Outstanding AC performance includes 72.5dB
S/(N + D) at the Nyquist input frequency of 400kHz.
The unique differential input sample-and-hold can acquire
single-ended or differential input signals up to its 20MHz
bandwidth. The 60dB common mode rejection allows
users to eliminate ground loops and common mode noise
by measuring signals differentially from the source.
The ADC has a
P compatible, 12-bit parallel output port.
There is no pipeline delay in the conversion results.
A separate convert start input and a data ready signal
(BUSY) ease connections to FIFOs, DSPs and micropro-
cessors. A digital output driver power supply pin allows
direct connection to 3V logic.
s
Sample Rate: 800ksps
s
Power Dissipation: 80mW
s
72.5dB S/(N + D) and 86dB THD at Nyquist
s
No Pipeline Delay
s
Nap (4mW) and Sleep (10
W) Shutdown Modes
s
Operates with Internal 15ppm/
°C Reference
or External Reference
s
True Differential Inputs Reject Common Mode Noise
s
20MHz Full Power Bandwidth Sampling
s
±2.5V Bipolar Input Range
s
28-Pin SO Wide and SSOP Package
U
S
A
O
PPLICATI
s
Telecommunications
s
Digital Signal Processing
s
Multiplexed Data Acquisition Systems
s
High Speed Data Acquisition
s
Spectrum Analysis
s
Imaging Systems
, LTC and LT are registered trademarks of Linear Technology Corporation.
U
A
O
PPLICATI
TYPICAL
800kHz, 12-Bit Sampling A/D Converter
Effective Bits and Signal-to-(Noise + Distortion)
vs Input Frequency
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
+AIN
–AIN
VREF
REFCOMP
AGND
D11(MSB)
D10
D9
D8
D7
D6
D5
D4
DGND
AVDD
OVDD
VSS
BUSY
CS
CONVST
RD
SHDN
NAP/SLP
OGND
D0
D1
D2
D3
LTC1409
10
F
DIFFERENTIAL
ANALOG INPUT
(–2.5V TO 2.5V)
2.50V
VREF OUTPUT
10
F
10
F
–5V
5V
12-BIT
PARALLEL
BUS
P CONTROL
LINES
LTC1409 TA01
INPUT FREQUENCY (Hz)
2
EFFECTIVE
BITS
S/(N
+
D)
(dB)
4
6
8
10
10k
100k
1M
10M
LTC1409 TA02
0
1k
12
74
68
62
56
50
NYQUIST
FREQUENCY
fSAMPLE = 800ksps