1
LTC1404
Complete SO-8, 12-Bit,
600ksps ADC with Shutdown
TYPICAL APPLICATIO
N
U
Power Consumption vs Sample Rate
V
CC
A
IN
V
REF
GND
V
SS
CONV
CLK
D
OUT
MPU
P1.4
P1.3
P1.2
LTC1404
+
0.1
µ
F
10
µ
F
+
0.1
µ
F
10
µ
F*
*AVX TPSD106M035R0300
REF
OUT
2.43V
ANALOG INPUT
(0V TO 4.096V)
4
3
2
1
5
6
7
8
SERIAL
DATA LINK
5V
LTC1404 · TA01
Single 5V Supply, 600kHz, 12-Bit Sampling A/D Converter
The LTC
®
1404 is a complete 600ksps, 12-bit A/D con-
verter which draws only 75mW from a 5V or
±
5V supplies.
This easy-to-use device comes complete with a 160ns
sample-and-hold and a precision reference. Unipolar and
bipolar conversion modes add to the flexibility of the ADC.
The LTC1404 has two power saving modes: Nap and
Sleep. In Nap mode, it consumes only 7.5mW of power
and can wake up and convert immediately. In the Sleep
mode, it consumes 60
µ
W of power typically. Upon power-
up from Sleep mode, a reference ready (REFRDY) signal
is available in the serial data word to indicate that the
reference has settled and the chip is ready to convert.
The LTC1404 converts 0V to 4.096V unipolar inputs from
a single 5V supply and
±
2.048V bipolar inputs from
±
5V
supplies. Maximum DC specs include
±
1LSB INL,
±
1LSB
DNL and 45ppm/
°
C full-scale drift over temperature.
Guaranteed AC performance includes 69dB S/(N + D)
and 76dB THD at an input frequency of 100kHz over
temperature.
The 3-wire serial port allows compact and efficient data
transfer to a wide range of microprocessors, microcontrollers
and DSPs.
DESCRIPTIO
N
U
FEATURES
s
Complete 12-Bit ADC in SO-8
s
Single Supply 5V or
±
5V Operation
s
Sample Rate: 600ksps
s
Power Dissipation: 75mW (Typ)
s
72dB S/(N + D) and 80dB THD at Nyquist
s
No Missing Codes over Temperature
s
Nap Mode with Instant Wake-Up: 7.5mW
s
Sleep Mode: 60
µ
W
s
High Impedance Analog Input
s
Input Range (1mV/LSB): 0V to 4.096V or
±
2.048V
s
Internal Reference Can Be Overdriven Externally
s
3-Wire Interface to DSPs and Processors (SPI and
MICROWIRE
TM
Compatible)
s
High Speed Data Acquisition
s
Digital Signal Processing
s
Multiplexed Data Acquisition Systems
s
Audio and Telecom Processing
s
Digital Radio
s
Spectrum Analysis
s
Low Power and Battery-Operated Systems
s
Handheld or Portable Instruments
APPLICATIO
N
S
U
MICROWIRE is a trademark of National Semiconductor Corp.
SAMPLE RATE (Hz)
0.01
SUPPLY CURRENT (mA)
100
10
1
0.1
0.01
0.001
10
1k
1M
LTC1404 · TA02
0.1
1
100
10k 100k
NORMAL CONVERSION
9.6MHz CLOCK
SLEEP MODE
BETWEEN CONVERSION
NAP MODE
BETWEEN CONVERSION
, LTC and LT are registered trademarks of Linear Technology Corporation.
2
LTC1404
ABSOLUTE
M
AXI
M
U
M
RATINGS
W
W
W
U
(Notes 1, 2)
Supply Voltage (V
CC
) ................................................. 7V
Negative Supply Voltage (V
SS
).................... 6V to GND
Total Supply Voltage (V
CC
to V
SS
)
Bipolar Operation Only ........................................ 12V
Analog Input Voltage (Note 3)
Unipolar Operation .................. 0.3V to (V
CC
+ 0.3V)
Bipolar Operation........... (V
SS
0.3V) to (V
CC
+ 0.3V)
Digital Input Voltage (Note 4)
Unipolar Operation ................................ 0.3V to 12V
Bipolar Operation.........................(V
SS
0.3V) to 12V
Digital Output Voltage
Unipolar Operation .................. 0.3V to (V
CC
+ 0.3V)
Bipolar Operation........... (V
SS
0.3V) to (V
CC
+ 0.3V)
Power Dissipation .............................................. 300mW
Operating Ambient Temperature Range
LTC1404C................................................ 0
°
C to 70
°
C
LTC1404I ............................................ 40
°
C to 85
°
C
Junction Temperature .......................................... 125
°
C
Storage Temperature Range ................. 65
°
C to 150
°
C
Lead Temperature (Soldering, 10 sec).................. 300
°
C
PACKAGE/ORDER I
N
FOR
M
ATIO
N
W
U
U
LTC1404CS8
LTC1404IS8
ORDER PART
NUMBER
S8 PART MARKING
1404
1404I
T
JMAX
= 125
°
C,
JA
= 130
°
C/ W
TOP VIEW
V
CC
A
IN
V
REF
GND
V
SS
CONV
CLK
D
OUT
S8 PACKAGE
8-LEAD PLASTIC SO
1
2
3
4
8
7
6
5
Consult factory for PDIP packages and Military grade parts.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
CC
Positive Supply Voltage
Unipolar
4.75
5.25
V
Bipolar
4.75
5.25
V
V
SS
Negative Supply Voltage
Bipolar Only
2.45
5.25
V
I
CC
Positive Supply Current
f
SAMPLE
= 600ksps
q
15
30
mA
Nap Mode
q
1.3
3.0
mA
Sleep Mode
q
8.0
20.0
µ
A
I
SS
Negative Supply Current
f
SAMPLE
= 600ksps, V
SS
= 5V
q
0.2
0.6
mA
Nap Mode
q
0.2
0.5
mA
Sleep Mode
q
4
10
µ
A
P
D
Power Dissipation
f
SAMPLE
= 600ksps
q
75
160
mW
Nap Mode
q
7.5
20
mW
Sleep Mode
q
60
150
µ
W
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
IN
Analog Input Range
4.75V
V
CC
5.25V (Unipolar)
0 to 4.096
V
4.75V
V
CC
5.25V, 5.25V
V
SS
2.45V (Bipolar)
0 to
±
2.048
V
I
IN
Analog Input Leakage Current
During Conversions (Hold Mode)
q
±
1
µ
A
C
IN
Analog Input Capacitance
Between Conversions (Sample Mode)
45
pF
During Conversions (Hold Mode)
5
pF
PUT
U
I
A
A
U
LOG
(Note 5)
POWER REQUIRE E TS
W
U
(Note 5)
3
LTC1404
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Resolution (No Missing Codes)
q
12
Bits
Integral Linearity Error
(Note 8)
q
±
1
LSB
Differential Linearity Error
q
±
1
LSB
Offset Error
(Note 9)
±
6
LSB
q
±
8
LSB
Full-Scale Error
±
15
LSB
Full-Scale Tempco
I
OUT(REF)
= 0
q
±
10
±
45
ppm/
°
C
With internal reference (Notes 5, 7)
C
C
HARA TERISTICS
CO
U
VERTER
V
CC
= 5V, V
SS
= 5V, f
SAMPLE
= 600kHz
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
S/(N + D) Signal-to-Noise
100kHz Input Signal
q
69
72
dB
300kHz Input Signal
72
dB
THD
Total Harmonic Distortion
100kHz Input Signal
q
82
76
dB
Up to 5th Harmonic
300kHz Input Signal
80
dB
Peak Harmonic or
100kHz Input Signal
q
84
76
dB
Spurious Noise
300kHz Input Signal
82
dB
IMD
Intermodulation Distortion
f
IN1
= 99.17kHz, f
IN2
= 102.69kHz
82
dB
f
IN1
= 298.68kHz, f
IN2
= 304.83kHz
70
dB
Full Power Bandwidth
5
MHz
Full Linear Bandwidth (S/(N + D)
68dB)
1
MHz
ACCURACY
IC
DY
U
W
A
I TER AL REFERE CE CHARACTERISTICS
U
U
U
(Note 5)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
REF
Output Voltage
I
OUT
= 0
2.410
2.430
2.450
V
V
REF
Output Tempco
I
OUT
= 0
q
±
10
±
45
ppm/
°
C
V
REF
Line Regulation
4.75V
V
CC
5.25V
0.5
LSB/ V
5.25V
V
SS
0V
0.01
LSB/ V
V
REF
Load Regulation
0
I
OUT
1mA
1
LSB/mA
V
REF
Wake-Up Time from Sleep Mode
C
VREF
= 10
µ
F
2.5
ms
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
IH
High Level Input Voltage
V
CC
= 5.25V
q
2.0
V
V
IL
Low Level Input Voltage
V
CC
= 4.75V
q
0.8
V
I
IN
Digital Input Current
V
IN
= 0V to V
CC
q
±
10
µ
A
C
IN
Digital Input Capacitance
5
pF
V
OH
High Level Output Voltage
V
CC
= 4.75V, I
O
= 10
µ
A
4.7
V
V
CC
= 4.75V, I
O
= 200
µ
A
q
4.0
V
V
OL
Low Level Output Voltage
V
CC
= 4.75V, I
O
= 160
µ
A
0.05
V
V
CC
= 4.75V, I
O
= 1.6mA
q
0.10
0.4
V
(Note 5)
DIGITAL I PUTS A
N
D OUTPUTS
U
U
4
LTC1404
(Note 5)
DIGITAL I PUTS A
N
D OUTPUTS
U
U
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
I
OZ
Hi-Z Output Leakage D
OUT
V
OUT
= 0V to V
CC
q
±
10
µ
A
C
OZ
Hi-Z Output Capacitance D
OUT
15
pF
I
SOURCE
Output Source Current
V
OUT
= 0V
10
mA
I
SINK
Output Sink Current
V
OUT
= V
CC
10
mA
TI I G CHARACTERISTICS
W U
(Note 5, see Figures 12, 13, 14)
The
q
denotes specifications which apply over the full operating
temperature range; all other limits and typicals apply to T
A
= 25
°
C.
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 GND.
Note 3: When these pin voltages are taken below V
SS
(ground for unipolar
mode) or above V
CC
, they will be clamped by internal diodes. This product
can handle input currents greater than 60mA without latch-up if the pin is
driven below V
SS
(ground for unipolar mode) or above V
CC
.
Note 4: When these pin voltages are taken below V
SS
(ground for unipolar
mode), they will be clamped by internal diodes. This product can handle
input currents greater than 60mA without latch-up if the pin is driven
below V
SS
(ground for unipolar mode). These pins are not clamped to V
CC
.
Note 5: V
CC
= 5V, f
SAMPLE
= 600kHz, t
r
= t
f
= 5ns unless otherwise
specified.
Note 6: Guaranteed by design, not subject to test.
Note 7: Linearity, offset and full-scale specifications apply for unipolar and
bipolar modes.
Note 8: Integral nonlinearity is defined as the deviation of a code from a
straight line passing through the actual endpoints of the transfer curve.
The deviation is measured from the center of the quantization band.
Note 9: Bipolar offset is the offset voltage measured from 0.5LSB when
the output code flickers between 0000 0000 0000 and 1111 1111 1111.
Note 10: The rising edge of CONV starts a conversion. If CONV returns
low at a bit decision point during the conversion, it can create small errors.
For best performance, ensure that CONV returns low either within 100ns
after the conversion starts (i.e., before the first bit decision) or after the 14
clock cycles. (Figure 13 Timing Diagram).
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
f
SAMPLE(MAX)
Maximum Sampling Frequency
q
600
kHz
t
CONV
Conversion Time
f
CLK
= 9.6MHz
1.36
µ
s
t
ACQ
Acquisition Time (Unipolar Mode)
200
ns
(Bipolar Mode V
SS
= 5V)
160
ns
f
CLK
CLK Frequency
q
0.1
9.6
MHz
t
CLK
CLK Pulse Width
(Note 6)
q
40
ns
t
WK(NAP)
Time to Wake Up from Nap Mode
350
ns
t
1
CLK Pulse Width to Return to Active Mode
q
40
ns
t
2
CONV
to CLK
Setup Time
q
70
ns
t
3
CONV
After Leading CLK
q
0
ns
t
4
CONV Pulse Width
(Note 10)
q
40
ns
t
5
Time from CLK
to Sample Mode
60
ns
t
6
Aperture Delay of Sample-and-Hold
Jitter < 50ps
40
ns
t
7
Minimum Delay Between Conversion (Unipolar Mode)
(Note 6)
q
220
310
ns
(Bipolar Mode V
SS
= 5V)
q
180
300
ns
t
8
Delay Time, CLK
to D
OUT
Valid
C
LOAD
= 20pF
q
40
70
ns
t
9
Delay Time, CLK
to D
OUT
Hi-Z
C
LOAD
= 20pF
q
40
70
ns
t
10
Time from Previous Data Remains Valid After CLK
C
LOAD
= 20pF
q
10
30
ns
5
LTC1404
TYPICAL PERFOR
M
A
N
CE CHARACTERISTICS
U
W
Bipolar Mode Differential
Nonlinearity vs Output Code
OUTPUT CODE
2048
DIFFERENTIAL NONLINEARITY (LSBs)
2048
1404 G03
1024
0
1024
1.00
0.75
0.50
0.25
0
0.25
0.50
0.75
1.00
1536
512
512
1536
f
SAMPLE
= 600kHz
OUTPUT CODE
0
DIFFERENTIAL NONLINEARITY (LSBs)
4096
1404 G01
1024
2048
3072
1.00
0.75
0.50
0.25
0
0.25
0.50
0.75
1.00
512
1536
2560
3584
f
SAMPLE
= 600kHz
Unipolar Mode Differential
Nonlinearity vs Output Code
OUTPUT CODE
0
INTEGRAL NONLINEARITY (LSBs)
4096
1404 G02
1024
2048
3072
1.00
0.75
0.50
0.25
0
0.25
0.50
0.75
1.00
512
1536
2560
3584
f
SAMPLE
= 600kHz
Unipolar Mode Integral
Nonlinearity vs Output Code
Unipolar Mode 4096 Nonaverage
FFT with 300kHz Signal
Unipolar Mode 4096 Nonaverage
FFT with 100kHz Signal
OUTPUT CODE
2048
INTEGRAL NONLINEARITY (LSBs)
2048
1404 G04
1024
0
1024
1.00
0.75
0.50
0.25
0
0.25
0.50
0.75
1.00
1536
512
512
1536
f
SAMPLE
= 600kHz
Bipolar Mode Integral
Nonlinearity vs Output Code
Unipolar Mode
ENOB and Signal/(Noise +
Distortion) vs Input Frequency
INPUT FREQUENCY (kHz)
10
EFFECTIVE NUMBER OF BITS
SIGNAL/(NOISE + DISTORTION) (dB)
12
11
10
9
8
7
6
5
4
3
2
1
0
74
68
62
56
50
100
1000
1404 G07
f
SAMPLE
= 600kHz
NYQUIST
FREQUENCY
INPUT FREQUENCY (kHz)
80
70
60
50
40
30
20
10
0
100
1404 G08
10
1000
SIGNAL-TO-NOISE RATIO (dB)
f
SAMPLE
= 600kHz
INPUT FREQUENCY (kHz)
80
70
60
50
40
30
20
10
0
100
1404 G09
10
1000
SIGNAL-TO-NOISE RATIO (dB)
f
SAMPLE
= 600kHz
Unipolar Mode
Signal-to-Noise Ratio (Without
Harmonics) vs Input Frequency
Bipolar Mode
Signal-to-Noise Ratio (Without
Harmonics) vs Input Frequency
FREQUENCY (kHz)
0
60 90 120 150 180 210 240 270 300
AMPLITUDE (dB)
1404 G05
0
10
20
30
40
50
60
70
80
90
100
110
120
30
f
SAMPLE
= 600kHz
f
IN
= 99.1699kHz
SINAD = 71dB
THD = 77dB
FREQUENCY (kHz)
0
60 90 120 150 180 210 240 270 300
AMPLITUDE (dB)
1404 G06
0
10
20
30
40
50
60
70
80
90
100
110
120
30
f
SAMPLE
= 600kHz
f
IN
= 298.681kHz
SINAD = 71dB
THD = 73dB
PDF 
ZIP