LTC1404
Complete SO-8, 12-Bit,
600ksps ADC with Shutdown
FEATURES
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DESCRIPTION
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 60µW 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.
, LTC and LT are registered trademarks of Linear Technology Corporation.
MICROWIRE is a trademark of National Semiconductor Corp.
Complete 12-Bit ADC in SO-8
Single Supply 5V or
±
5V Operation
Sample Rate: 600ksps
Power Dissipation: 75mW (Typ)
72dB S/(N + D) and – 80dB THD at Nyquist
No Missing Codes over Temperature
Nap Mode with Instant Wake-Up: 7.5mW
Sleep Mode: 60µW
High Impedance Analog Input
Input Range (1mV/LSB): 0V to 4.096V or
±
2.048V
Internal Reference Can Be Overdriven Externally
3-Wire Interface to DSPs and Processors (SPI and
MICROWIRE
TM
Compatible)
APPLICATIONS
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High Speed Data Acquisition
Digital Signal Processing
Multiplexed Data Acquisition Systems
Audio and Telecom Processing
Digital Radio
Spectrum Analysis
Low Power and Battery-Operated Systems
Handheld or Portable Instruments
TYPICAL APPLICATION
Single 5V Supply, 600kHz, 12-Bit Sampling A/D Converter
5V
Power Consumption vs Sample Rate
100
NORMAL CONVERSION
10
SUPPLY CURRENT (mA)
+
10µF*
ANALOG INPUT
(0V TO 4.096V)
REF
OUT
2.43V
+
10µF
0.1µF
1
0.1µF
V
CC
LTC1404
V
SS
8
MPU
7
6
5
SERIAL
DATA LINK
LTC1404 • TA01
2
3
4
1
SLEEP MODE
BETWEEN CONVERSION
A
IN
V
REF
GND
CONV
CLK
D
OUT
P1.4
P1.3
P1.2
0.1
0.01
9.6MHz CLOCK
0.001
0.01 0.1
1
10 100 1k 10k 100k 1M
SAMPLE RATE (Hz)
LTC1404 • TA02
*AVX TPSD106M035R0300
U
U
U
NAP MODE
BETWEEN CONVERSION
1
LTC1404
ABSOLUTE
MAXIMUM
RATINGS
(Notes 1, 2)
PACKAGE/ORDER INFORMATION
TOP VIEW
V
CC
1
A
IN
2
V
REF
3
GND 4
8 V
SS
7 CONV
6 CLK
5 D
OUT
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
ORDER PART
NUMBER
LTC1404CS8
LTC1404IS8
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 125°C,
θ
JA
= 130°C/ W
S8 PART MARKING
1404
1404I
Consult factory for PDIP packages and Military grade parts.
POWER REQUIRE E TS
SYMBOL
V
CC
V
SS
I
CC
PARAMETER
Positive Supply Voltage
Negative Supply Voltage
Positive Supply Current
(Note 5)
CONDITIONS
Unipolar
Bipolar
Bipolar Only
f
SAMPLE
= 600ksps
Nap Mode
Sleep Mode
f
SAMPLE
= 600ksps, V
SS
= – 5V
Nap Mode
Sleep Mode
f
SAMPLE
= 600ksps
Nap Mode
Sleep Mode
MIN
4.75
4.75
– 2.45
q
q
q
q
q
q
q
q
q
TYP
I
SS
Negative Supply Current
P
D
Power Dissipation
15
1.3
8.0
0.2
0.2
4
75
7.5
60
MAX
5.25
5.25
– 5.25
30
3.0
20.0
0.6
0.5
10
160
20
150
UNITS
V
V
V
mA
mA
µA
mA
mA
µA
mW
mW
µW
A ALOG I PUT
SYMBOL PARAMETER
V
IN
I
IN
C
IN
Analog Input Range
(Note 5)
CONDITIONS
4.75V
≤
V
CC
≤
5.25V (Unipolar)
4.75V
≤
V
CC
≤
5.25V, – 5.25V
≤
V
SS
≤
– 2.45V (Bipolar)
During Conversions (Hold Mode)
Between Conversions (Sample Mode)
During Conversions (Hold Mode)
q
MIN
TYP
0 to 4.096
0 to
±2.048
MAX
UNITS
V
V
Analog Input Leakage Current
Analog Input Capacitance
±1
45
5
2
U
W
U
U
UW
W W
W
U
U
µA
pF
pF
LTC1404
CO VERTER CHARACTERISTICS
PARAMETER
Resolution (No Missing Codes)
Integral Linearity Error
Differential Linearity Error
Offset Error
Full-Scale Error
Full-Scale Tempco
I
OUT(REF)
= 0
q
DY A IC ACCURACY
SYMBOL PARAMETER
S/(N + D) Signal-to-Noise
THD
Total Harmonic Distortion
Up to 5th Harmonic
Peak Harmonic or
Spurious Noise
IMD
Intermodulation Distortion
Full Power Bandwidth
I TER AL REFERE CE CHARACTERISTICS
PARAMETER
V
REF
Output Voltage
V
REF
Output Tempco
V
REF
Line Regulation
V
REF
Load Regulation
V
REF
Wake-Up Time from Sleep Mode
CONDITIONS
I
OUT
= 0
I
OUT
= 0
4.75V
≤
V
CC
≤
5.25V
– 5.25V
≤
V
SS
≤
0V
0
≤
I
OUT
≤
1mA
C
VREF
= 10µF
DIGITAL I PUTS AND OUTPUTS
SYMBOL PARAMETER
V
IH
V
IL
I
IN
C
IN
V
OH
V
OL
High Level Input Voltage
Low Level Input Voltage
Digital Input Current
Digital Input Capacitance
High Level Output Voltage
Low Level Output Voltage
U
U
U
W U
U
U
With internal reference (Notes 5, 7)
MIN
q
CONDITIONS
(Note 8)
(Note 9)
q
q
q
TYP
MAX
±1
±1
±6
±8
±15
UNITS
Bits
LSB
LSB
LSB
LSB
LSB
ppm/°C
12
±10
±45
V
CC
= 5V, V
SS
= – 5V, f
SAMPLE
= 600kHz
CONDITIONS
100kHz Input Signal
300kHz Input Signal
100kHz Input Signal
300kHz Input Signal
100kHz Input Signal
300kHz Input Signal
f
IN1
= 99.17kHz, f
IN2
= 102.69kHz
f
IN1
= 298.68kHz, f
IN2
= 304.83kHz
q
q
q
MIN
69
TYP
72
72
– 82
– 80
– 84
– 82
– 82
– 70
5
1
MAX
UNITS
dB
dB
– 76
– 76
dB
dB
dB
dB
dB
dB
MHz
MHz
Full Linear Bandwidth (S/(N + D)
≥
68dB)
U
(Note 5)
MIN
2.410
q
TYP
2.430
±10
0.5
0.01
1
2.5
MAX
2.450
±45
UNITS
V
ppm/°C
LSB/ V
LSB/ V
LSB/mA
ms
(Note 5)
MIN
q
q
q
CONDITIONS
V
CC
= 5.25V
V
CC
= 4.75V
V
IN
= 0V to V
CC
V
CC
= 4.75V, I
O
= – 10µA
V
CC
= 4.75V, I
O
= – 200µA
V
CC
= 4.75V, I
O
= 160µA
V
CC
= 4.75V, I
O
= 1.6mA
TYP
MAX
0.8
±10
UNITS
V
V
µA
pF
V
V
2.0
5
4.7
q
q
4.0
0.05
0.10
0.4
V
V
3
LTC1404
DIGITAL I PUTS AND OUTPUTS
SYMBOL PARAMETER
I
OZ
C
OZ
I
SOURCE
I
SINK
Hi-Z Output Leakage D
OUT
Hi-Z Output Capacitance D
OUT
Output Source Current
Output Sink Current
TI I G CHARACTERISTICS
SYMBOL
f
SAMPLE(MAX)
t
CONV
t
ACQ
f
CLK
t
CLK
t
WK(NAP)
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
8
t
9
t
10
PARAMETER
Maximum Sampling Frequency
Conversion Time
Acquisition Time (Unipolar Mode)
(Bipolar Mode V
SS
= – 5V)
CLK Frequency
CLK Pulse Width
Time to Wake Up from Nap Mode
CLK Pulse Width to Return to Active Mode
CONV↑ to CLK↑ Setup Time
CONV↑ After Leading CLK↑
CONV Pulse Width
Time from CLK↑ to Sample Mode
Aperture Delay of Sample-and-Hold
Minimum Delay Between Conversion (Unipolar Mode)
(Note 6)
(Bipolar Mode V
SS
= – 5V)
Delay Time, CLK↑ to D
OUT
Valid
Delay Time, CLK↑ to D
OUT
Hi-Z
Time from Previous Data Remains Valid After CLK↑
C
LOAD
= 20pF
C
LOAD
= 20pF
C
LOAD
= 20pF
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.
4
U
U
(Note 5)
MIN
q
CONDITIONS
V
OUT
= 0V to V
CC
V
OUT
= 0V
V
OUT
= V
CC
TYP
15
– 10
10
MAX
±10
UNITS
µA
pF
mA
mA
UW
(Note 5, see Figures 12, 13, 14)
CONDITIONS
q
MIN
600
TYP
1.36
200
160
MAX
UNITS
kHz
µs
ns
ns
f
CLK
= 9.6MHz
q
0.1
40
350
40
70
0
40
60
40
9.6
MHz
ns
ns
ns
ns
ns
ns
ns
ns
(Note 6)
q
q
q
q
(Note 10)
Jitter < 50ps
q
q
q
q
q
q
220
180
40
40
10
30
310
300
70
70
ns
ns
ns
ns
ns
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).
LTC1404
TYPICAL PERFORMANCE CHARACTERISTICS
Unipolar Mode Differential
Nonlinearity vs Output Code
1.00
1.00
INTEGRAL NONLINEARITY (LSBs)
DIFFERENTIAL NONLINEARITY (LSBs)
0.75
0.50
0.25
0
–0.25
–0.50
–0.75
–1.00
0
512 1024 1536 2048 2560 3072 3584 4096
OUTPUT CODE
1404 G01
0.75
0.50
0.25
0
–0.25
–0.50
–0.75
–1.00
0
512 1024 1536 2048 2560 3072 3584 4096
OUTPUT CODE
1404 G02
DIFFERENTIAL NONLINEARITY (LSBs)
f
SAMPLE
= 600kHz
Bipolar Mode Integral
Nonlinearity vs Output Code
1.00
f
SAMPLE
= 600kHz
0
–10
–20
–30
INTEGRAL NONLINEARITY (LSBs)
0.75
0.50
AMPLITUDE (dB)
0.25
0
–0.25
–0.50
–0.75
–1.00
0
–2048
2048
–1024
1024
1536
–1536
–512
512
OUTPUT CODE
1404 G04
–50
– 60
–70
–80
–90
–100
–110
–120
0
30 60 90 120 150 180 210 240 270 300
FREQUENCY (kHz)
1404 G05
AMPLITUDE (dB)
Unipolar Mode
ENOB and Signal/(Noise +
Distortion) vs Input Frequency
12
11
EFFECTIVE NUMBER OF BITS
9
8
7
6
5
4
3
2
1
0
10
56
50
SIGNAL-TO-NOISE RATIO (dB)
SIGNAL-TO-NOISE RATIO (dB)
10
NYQUIST
FREQUENCY
f
SAMPLE
= 600kHz
100
INPUT FREQUENCY (kHz)
1000
1404 G07
U W
Unipolar Mode Integral
Nonlinearity vs Output Code
1.00
f
SAMPLE
= 600kHz
0.75
0.50
0.25
0
–0.25
–0.50
–0.75
Bipolar Mode Differential
Nonlinearity vs Output Code
f
SAMPLE
= 600kHz
–1.00
0
–2048
2048
–1024
1024
1536
–1536
–512
512
OUTPUT CODE
1404 G03
Unipolar Mode 4096 Nonaverage
FFT with 100kHz Signal
f
SAMPLE
= 600kHz
f
IN
= 99.1699kHz
SINAD = 71dB
THD = –77dB
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
Unipolar Mode 4096 Nonaverage
FFT with 300kHz Signal
f
SAMPLE
= 600kHz
f
IN
= 298.681kHz
SINAD = 71dB
THD = –73dB
–40
0
30 60 90 120 150 180 210 240 270 300
FREQUENCY (kHz)
1404 G06
Unipolar Mode
Signal-to-Noise Ratio (Without
Harmonics) vs Input Frequency
74
68
62
SIGNAL/(NOISE + DISTORTION) (dB)
80
70
60
50
40
30
20
10
f
SAMPLE
= 600kHz
0
10
100
INPUT FREQUENCY (kHz)
1000
1404 G08
Bipolar Mode
Signal-to-Noise Ratio (Without
Harmonics) vs Input Frequency
80
70
60
50
40
30
20
10
f
SAMPLE
= 600kHz
0
10
100
INPUT FREQUENCY (kHz)
1000
1404 G09
5
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