LTC1609
16-Bit, 200ksps, Serial ADC
with Multiple Input Ranges
FEATURES
s
s
DESCRIPTIO
s
s
s
s
s
s
s
s
s
Sample Rate: 200ksps
Input Ranges
Unipolar: 0V to 10V, 0V to 5V and 0V to 4V
Bipolar:
±10V, ±5V
and
±3.3V
Guaranteed No Missing Codes
Serial I/O
Single 5V Supply
Power Dissipation: 65mW Typ
Power Down Mode: 50µW
SNR: 87dB Typ
Operates with Internal or External Reference
28-Pin SSOP and 20-Pin SO Packages
Improved 2nd Source to ADS7809 and AD977A
The LTC
®
1609 is a 200ksps, serial sampling 16-bit A/D
converter that draws only 65mW (typical) from a single 5V
supply. This easy-to-use device includes a sample-and-
hold, a precision reference, a switched capacitor succes-
sive approximation A/D and trimmed internal clock.
The input range is specified for bipolar inputs of
±10V,
±5V
and
±3.3V
and unipolar inputs of 0V to 10V, 0V to 5V
and 0V to 4V. Maximum DC specs include
±2LSB
INL and
16-bit no missing codes over temperature. It has a typical
signal-to-noise ratio of 87dB.
The ADC has a high speed serial interface. The serial
output data can be clocked out using either the internal
serial shift clock or be clocked out by an external shift
clock. A separate convert start input (R/C) and a data ready
signal (BUSY) ease connections to FIFOs, DSPs and
microprocessors.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
s
s
s
s
Industrial Process Control
Multiplexed Data Acquisition Systems
High Speed Data Acquisition for PCs
Digital Signal Processing
TYPICAL APPLICATIO
ANALOG INPUT
– 10V TO 10V
200Ω
1
2
100Ω
33.2k
3
4
5
2.5V
200kHz, 16-Bit Serial Sampling ADC Configured for
±10V
Inputs
R1
IN
AGND1
R2
IN
R3
IN
NC
CAP
REF
NC
AGND2
NC
NC
SB/BTC
V
DIG
V
ANA
PWRD
BUSY
LTC1609
CS
NC
NC
R/C
NC
TAG
NC
DATA
28
27
26
25
24
–20
+
10µF
0.1µF
5V
2.2µF
2.5V
+
2.2µF
7
8
9
10
11
12
13
14
22
21
20
19
18
17
16
15
1609 TA01
MAGNITUDE (dB)
+
6
23
SERIAL INTERFACE
EXT/INT DATACLK
DGND
SYNC
U
Nonaveraged 4096 Point FFT Plot
0
f
SAMPLE
= 200kHz
f
IN
= 1kHz
SINAD = 87.2dB
THD = –100.1dB
–40
–60
–80
–100
–120
–130
0
25
50
FREQUENCY (kHz)
1609 G06
U
U
75
100
1609fa
1
LTC1609
ABSOLUTE
MAXIMUM
RATINGS
V
ANA
.......................................................................... 7V
V
DIG
to V
ANA
........................................................... 0.3V
V
DIG
........................................................................... 7V
Ground Voltage Difference
DGND, AGND1 and AGND2 ..............................
±0.3V
Analog Inputs (Note 3)
R1
IN
, R2
IN
, R3
IN
................................................
±25V
CAP ............................ V
ANA
+ 0.3V to AGND2 – 0.3V
REF .................................... Indefinite Short to AGND2
Momentary Short to V
ANA
PACKAGE/ORDER INFORMATION
TOP VIEW
R1
IN
AGND1
R2
IN
R3
IN
NC
CAP
REF
NC
AGND2
1
2
3
4
5
6
7
8
9
28 V
DIG
27 V
ANA
26 PWRD
25 BUSY
24 CS
23 NC
22 NC
21 R/C
20 NC
19 TAG
18 NC
17 DATA
16 DATACLK
15 SYNC
ORDER PART
NUMBER
LTC1609CG
LTC1609IG
TOP VIEW
R1
IN
1
AGND1 2
R2
IN
3
R3
IN
4
CAP 5
REF 6
AGND2 7
SB/BTC 8
EXT/INT 9
DGND 10
SW PACKAGE
20-LEAD PLASTIC SO
T
JMAX
= 125°C,
θ
JA
= 130°C/W
20 V
DIG
19 V
ANA
18 PWRD
17 BUSY
16 CS
15 R/C
14 TAG
13 DATA
12 DATACLK
11 SYNC
NC 10
NC 11
SB/BTC 12
EXT/INT 13
DGND 14
G PACKAGE
28-LEAD PLASTIC SSOP
T
JMAX
= 125°C,
θ
JA
= 95°C/W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
CONVERTER CHARACTERISTICS
PARAMETER
Resolution
No Missing Codes
Transition Noise
Integral Linearity Error
Differential Linearity Error
Bipolar Zero Error
(Note 7)
CONDITIONS
The
q
indicates specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. With external reference (Notes 5, 6).
LTC1609
MIN
TYP
MAX
q
q
External Reference = 2.5V (Note 8), Bipolar Ranges
2
U
U
W
W W
U
W
(Notes 1, 2)
Digital Input Voltage (Note 4) ........ DGND – 0.3V to 10V
Digital Output Voltage ........ DGND – 0.3V to V
DIG
+ 0.3V
Power Dissipation .............................................. 500mW
Operating Ambient Temperature Range
LTC1609AC/LTC1609C ............................ 0°C to 70°C
LTC1609AI/LTC1609I ......................... – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
LTC1609CSW
LTC1609ISW
LTC1609ACSW
LTC1609AISW
U
LTC1609A
MIN
TYP
MAX
16
16
UNITS
Bits
Bits
16
15
0.9
±3
–2
3
±10
0.9
±2
–1
1.75
±10
LSB
RMS
LSB
LSB
mV
1609fa
q
q
q
LTC1609
CONVERTER CHARACTERISTICS
PARAMETER
Bipolar Zero Error Drift
Unipolar Zero Error
Unipolar Zero Error Drift
Full-Scale Error Drift
Full-Scale Error
Full-Scale Error Drift
Power Supply Sensitivity
V
ANA
= V
DIG
= V
DD
External Reference = 2.5V (Notes 12, 13)
External Reference = 2.5V
V
DD
= 5V
±5%
(Note 9)
q
The
q
indicates specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. With external reference (Notes 5, 6).
CONDITIONS
Bipolar Ranges
External Reference = 2.5V, Unipolar Ranges
Unipolar Ranges
q
A ALOG I PUT
SYMBOL
V
IN
C
IN
R
IN
PARAMETER
The
q
indicates specifications which apply over the full operating temperature range,
otherwise specifications are at T
A
= 25°C. (Note 5)
CONDITIONS
4.75V
≤
V
ANA
≤
5.25V, 4.75V
≤
V
DIG
≤
5.25V,
q
Analog Input Range (Note 9)
Analog Input Capacitance
Analog Input Impedance
DY A IC ACCURACY
SYMBOL
S/(N + D)
PARAMETER
Signal-to-(Noise
+ Distortion) Ratio
Total Harmonic
Distortion
Peak Harmonic or
Spurious Noise
Full-Power Bandwidth
–3dB Input Bandwidth
Aperture Delay
Aperture Jitter
Transient Response
Overvoltage Recovery
THD
INTERNAL REFERENCE CHARACTERISTICS
PARAMETER
V
REF
Output Voltage
V
REF
Output Tempco
Internal Reference Source Current
External Reference Voltage for Specified Linearity
External Reference Current Drain
CAP Output Voltage
(Notes 9, 10)
CONDITIONS
I
OUT
= 0
I
OUT
= 0
The
q
indicates specifications which apply over the full
operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 5)
LTC1609/LTC1609A
MIN
TYP
MAX
q
U
U
W U
U
U
LTC1609
MIN
TYP
MAX
±2
±10
±2
±7
±0.50
±2
±8
LTC1609A
MIN
TYP
MAX
±2
±10
±2
±7
±0.25
±2
±8
UNITS
ppm/°C
mV
ppm/°C
ppm/°C
%
ppm/°C
LSB
U
MIN
LTC1609/LTC1609A
TYP
MAX
UNITS
V
pF
kΩ
±10,
0V to 5V, etc.
(See Tables 1a and 1b)
10
See Tables 1a and 1b
(Notes 5, 14)
LTC1609
MIN
TYP
MAX
87.5
87
30
– 100
– 94
– 102
– 94
275
1
40
LTC1609A
MIN
TYP
MAX
85
87.5
87
30
– 100
– 94
– 102
– 94
275
1
40
2
150
150
2
–96
UNITS
dB
dB
dB
dB
dB
dB
dB
kHz
MHz
ns
µs
ns
CONDITIONS
1kHz Input Signal (Note 14)
10kHz Input Signal
20kHz, – 60dB Input Signal
1kHz Input Signal, First 5 Harmonics
10kHz Input Signal, First 5 Harmonics
1kHz Input Signal
10kHz Input Signal
(Note 15)
Sufficient to Meet AC Specs Sufficient to Meet AC Specs
Full-Scale Step (Note 9)
(Note 16)
U
UNITS
V
ppm/°C
µA
2.470
2.500
±5
1
2.520
2.30
q
2.50
2.50
2.70
100
V
µA
V
1609fa
External Reference = 2.5V (Note 9)
I
OUT
= 0
3
LTC1609
DIGITAL I PUTS A D DIGITAL OUTPUTS
SYMBOL
V
IH
V
IL
I
IN
C
IN
V
OH
V
OL
I
SOURCE
I
SINK
PARAMETER
High Level Input Voltage
Low Level Input Voltage
Digital Input Current
Digital Input Capacitance
High Level Output Voltage
Low Level Output Voltage
Output Source Current
Output Sink Current
V
DD
= 4.75V
V
DD
= 4.75V
V
OUT
= 0V
V
OUT
= V
DD
I
O
= –10µA
I
O
= – 200µA
I
O
= 160µA
I
O
= 1.6mA
q
q
The
q
indicates specifications which apply over the full
operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 5)
CONDITIONS
V
DD
= 5.25V
V
DD
= 4.75V
V
IN
= 0V to V
DD
q
q
q
TI I G CHARACTERISTICS
SYMBOL
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
6
+ t
7
t
8
t
9
t
10
t
11
t
12
t
13
t
14
t
15
t
16
t
17
t
18
t
19
t
20
t
21
t
22
t
23
t
24
PARAMETER
Convert Pulse Width
R/C, CS to BUSY Delay
BUSY Low Time
BUSY Delay After End of Conversion
Aperture Delay
Conversion Time
Acquisition Time
Throughput Time
R/C Low to DATACLK Delay
DATACLK Period
DATA Valid Setup Time
DATA Valid Hold Time
External DATACLK Period
External DATACLK High
External DATACLK Low
The
q
indicates specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 5)
CONDITIONS
(Note 11)
C
L
= 25pF
q
q
q
R/C, CS to External DATACLK Setup Time
R/C to CS Setup Time
External DATACLK to SYNC Delay
External DATACLK to DATA Valid Delay
CS to External DATACLK Rising Edge Delay
Previous DATA Valid After CS, R/C Low
BUSY to External DATACLK Setup Time
BUSY Falling Edge to Final External DATACLK
TAG Valid Setup Time
TAG Valid Hold Time
(Note 9)
(Note 9)
(Notes 10, 17)
4
U
U
MIN
2.4
LTC1609/LTC1609A
TYP
MAX
0.8
±10
5
4.5
UNITS
V
V
µA
pF
V
V
V
4.0
0.05
0.10
–10
10
0.4
V
mA
mA
UW
LTC1609/LTC1609A
MIN
TYP
MAX
40
80
3
100
5
q
q
q
UNITS
ns
ns
µs
ns
ns
3
2
5
260
150
µs
µs
µs
ns
ns
ns
ns
ns
ns
ns
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
15
40
50
20
20
15
10
6
10
10
2.2
5
1.2
0
15
50
50
t
12
ns
ns
ns
ns
ns
µs
ns
µs
ns
ns
1609fa
LTC1609
POWER REQUIREMENTS
SYMBOL
V
DD
I
DD
P
DIS
PARAMETER
Positive Supply Voltage
Positive Supply Current
Power Dissipation
The
q
indicates specifications which apply over the full operating temperature range,
otherwise specifications are at T
A
= 25°C. (Note 5)
CONDITIONS
(Notes 9, 10)
PWRD = Low
PWRD = Low
PWRD = High
q
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
All voltage values are with respect to ground with DGND, AGND1
and AGND2 wired together (unless otherwise noted).
Note 3:
When these pin voltages are taken below ground or above V
ANA
=
V
DIG
= V
DD
, they will be clamped by internal diodes. This product can
handle input currents of greater than 100mA below ground or above V
DD
without latch-up.
Note 4:
When these pin voltages are taken below ground, they will be
clamped by internal diodes. This product can handle input currents of
90mA below ground without latchup. These pins are not clamped to V
DD
.
Note 5:
V
DD
= 5V, f
SAMPLE
= 200kHz, t
r
= t
f
= 5ns unless otherwise
specified.
Note 6:
Linearity, offset and full-scale specifications apply for a V
IN
input
with respect to ground.
Note 7:
Integral nonlinearity is defined as the deviation of a code from a
straight line passing through the actual end points of the transfer curve.
The deviation is measured from the center of the quantization band.
Note 8:
Bipolar zero error is the offset voltage measured from – 0.5 LSB
when the output code flickers between 0000 0000 0000 0000 and 1111
1111 1111 1111. Unipolar zero error is the offset voltage measured from
0.5LSB when the output codes flickers between 0000. . .0000 and 0000. .
.0001.
U W
LTC1609/LTC1609A
MIN
TYP
MAX
4.75
13
65
50
5.25
20
100
UNITS
V
mA
mW
µW
Note 9:
Guaranteed by design, not subject to test.
Note 10:
Recommended operating conditions.
Note 11:
With CS low the falling R/C edge starts a conversion. If R/C
returns high at a critical point during the conversion it can create small
errors. For best results ensure that R/C returns high within 1.2µs after the
start of the conversion.
Note 12:
As measured with fixed 1% resistors shown in Figures 3a and
3b. Adjustable to zero with external potentiometer.
Note 13:
Full-scale error is the worst-case of –FS or +FS untrimmed
deviation from ideal first and last code transitions, divided by the transition
voltage (not divided by the full-scale range) and includes the effect of
offset error. For unipolar input ranges full-scale error is the deviation of
the last code transition from ideal divided by the transiton voltage and
includes the effect of offset error.
Note 14:
All specifications in dB are referred to a full-scale
±5V
input.
Note 15:
Full-power bandwidth is defined as full-scale input frequency at
which a signal-to-(noise + distortion) degrades to 60dB or 10 bits of
accuracy.
Note 16:
Recovers to specified performance after (2 • FS) input
overvoltage.
Note 17:
When data is shifted out during a conversion, with an external
data clock, complete the process within 1.2µs from the start of the
conversion (BUSY falling). This will help keep any external disturbances
from causing an error in the conversion result.
1609fa
5
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