LTC1605-1/LTC1605-2
Single Supply 16-Bit, 100ksps,
Sampling ADCs
FEATURES
s
s
s
s
s
s
s
s
s
DESCRIPTIO
Sample Rate: 100ksps
Complete 16-Bit Solution on a Single 5V Supply
Unipolar Input Range: 0V to 4V (LTC1605-1)
Bipolar Input Range:
±
4V (LTC1605-2)
Power Dissipation: 55mW Typ
Signal-to-Noise Ratio: 86dB Typ
Operates with Internal or External Reference
Internal Synchronized Clock
28-Pin 0.3" PDIP and SSOP Packages
The LTC
®
1605-1/LTC1605-2 are 100ksps, sampling
16-bit A/D converters that draw only 55mW (typical) from
a single 5V supply. These easy-to-use devices include a
sample-and-hold, precision reference, switched capacitor
successive approximation A/D and trimmed internal clock.
The LTC1605-1’s input range is 0V to 4V while the
LTC1605-2’s input range is
±4V.
An external reference
can be used if greater accuracy over temperature is
needed.
The ADC has a microprocessor compatible, 16-bit or two
byte parallel output port. A convert start input 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
LTC1605-1 Low Power, 100kHz, 16-Bit Sampling ADC on 5V Supply
5V
10µF
28
27
V
DIG
V
ANA
0V TO 4V 200Ω
INPUT
33.2k
4 CAP
BUSY 26
BUFFER
2.5V
2.2µF
AGND1
2
AGND2
5
DGND
14
1605-1/2 TA01
0.1µF
1 V
IN
4k
6 TO 13
15 TO 22
16-BIT
SAMPLING ADC
20k
10k
D15 TO D0
INL (LSBs)
16-BIT
OR 2 BYTE
PARALLEL
BUS
2.5V
2.2µF
3 REF
4k
2.5V
REFERENCE
CONTROL
LOGIC AND
TIMING
CS 25
R/C 24
BYTE 23
DIGITAL
CONTROL
SIGNALS
U
Typical INL Curve
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
0
16384
32768
CODE
1605-1/2 TA02/G04
U
U
49152
65535
1
LTC1605-1/LTC1605-2
ABSOLUTE
(Notes 1, 2)
AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
V
IN
1
AGND1 2
REF 3
CAP 4
AGND2 5
D15 (MSB) 6
D14 7
D13 8
D12 9
D11 10
D10 11
D9 12
D8 13
DGND 14
G PACKAGE
28-LEAD PLASTIC SSOP
28 V
DIG
27 V
ANA
26 BUSY
25 CS
24 R/C
23 BYTE
22 D0
21 D1
20 D2
19 D3
18 D4
17 D5
16 D6
15 D7
N PACKAGE
28-LEAD PDIP
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)
V
IN
.....................................................................
±25V
CAP ............................ V
ANA
+ 0.3V to AGND2 – 0.3V
REF .................................... Indefinite Short to AGND2
Momentary Short to V
ANA
Digital Input Voltage (Note 4) ........ V
DGND
– 0.3V to 10V
Digital Output Voltage ........ V
DGND
– 0.3V to V
DIG
+ 0.3V
Power Dissipation .............................................. 500mW
Operating Ambient Temperature Range
LTC1605-1C/LTC1605-2C ....................... 0°C to 70°C
LTC1605-1I/LTC1605-2I .................... – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
LTC1605-1CG
LTC1605-1IG
LTC1605-2CG
LTC1605-2IG
LTC1605-1CN
LTC1605-1IN
LTC1605-2CN
LTC1605-2IN
T
JMAX
= 125°C,
θ
JA
= 95°C/W (G)
T
JMAX
= 125°C,
θ
JA
= 130°C/W (N)
Consult factory for Military grade parts.
CO VERTER CHARACTERISTICS
PARAMETER
Resolution
No Missing Codes
Transition Noise
Integral Linearity Error
Zero Error
Zero Error Drift
Full-Scale Error Drift
Full-Scale Error
Full-Scale Error Drift
Power Supply Sensitivity
V
ANA
= V
DIG
= V
DD
(Note 7)
CONDITIONS
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. With external reference (Notes 5, 6).
MIN
q
q
TYP
MAX
UNITS
Bits
Bits
16
15
1
±3
±10
±2
±7
LSB
RMS
LSB
mV
ppm/°C
ppm/°C
±0.50
%
ppm/°C
±8
LSB
q
q
Ext. Reference = 2.5V (Note 8)
Ext. Reference = 2.5V (Notes 12, 13)
Ext. Reference = 2.5V
V
DD
= 5V
±5%
(Note 9)
q
±2
A ALOG I PUT
SYMBOL
V
IN
PARAMETER
The
q
denotes the 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
LTC1605-1
LTC1605-2
q
q
MIN
TYP
0 to 4
±4
10
10
MAX
UNITS
V
V
pF
kΩ
Analog Input Range (Note 9)
C
IN
R
IN
Analog Input Capacitance
Analog Input Impedance
2
U
W
U
U
W W
W
U
U
U
LTC1605-1/LTC1605-2
DY A IC ACCURACY
SYMBOL
S/(N + D)
PARAMETER
The
q
denotes the specifications which apply over the full operating temperature range,
otherwise specifications are at T
A
= 25°C. (Notes 5, 14)
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)
MIN
TYP
87
85
30
– 101
– 92
– 101
– 92
275
40
Sufficient to Meet AC Specs
Full-Scale Step (Note 9)
(Note 16)
150
2
µs
ns
MAX
UNITS
dB
dB
dB
dB
dB
dB
dB
kHz
ns
Signal-to-(Noise + Distortion) Ratio
THD
I TER AL REFERE CE 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)
Ext. Reference = 2.5V (Note 9)
I
OUT
= 0
CONDITIONS
I
OUT
= 0
I
OUT
= 0
The
q
denotes the specifications which apply over the
full operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 5)
MIN
q
DIGITAL I PUTS A D DIGITAL OUTPUTS
SYMBOL
V
IH
V
IL
I
IN
C
IN
V
OH
V
OL
I
OZ
C
OZ
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
Hi-Z Output Leakage D15 to D0
Hi-Z Output Capacitance D15 to D0
Output Source Current
Output Sink Current
V
DD
= 4.75V
V
DD
= 4.75V
V
OUT
= 0V to V
DD
, CS High
CS High (Note 9)
V
OUT
= 0V
V
OUT
= V
DD
CONDITIONS
V
DD
= 5.25V
V
DD
= 4.75V
V
IN
= 0V to V
DD
The
q
denotes the specifications which apply over the
full operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 5)
MIN
q
q
q
U
U
U
W U
U
Total Harmonic Distortion
Peak Harmonic or Spurious Noise
Full-Power Bandwidth
Aperture Delay
Aperture Jitter
Transient Response
Overvoltage Recovery
U
TYP
2.500
±5
1
MAX
2.520
UNITS
V
ppm/°C
µA
2.470
2.30
q
2.50
2.50
2.70
100
V
µA
V
TYP
MAX
0.8
±10
UNITS
V
V
µA
pF
V
V
V
2.4
5
I
O
= –10µA
I
O
= – 200µA
I
O
= 160µA
I
O
= 1.6mA
q
q
q
q
4.5
4.0
0.05
0.10
0.4
±10
15
–10
10
V
µA
pF
mA
mA
3
LTC1605-1/LTC1605-2
The
q
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 5)
SYMBOL
f
SAMPLE(MAX)
t
CONV
t
ACQ
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
8
t
9
t
10
t
11
t
12
PARAMETER
Maximum Sampling Frequency
Conversion Time
Acquisition Time
Convert Pulse Width
Data Valid Delay After R/C↓
BUSY Delay from R/C↓
BUSY Low
BUSY Delay After End of Conversion
Aperture Delay
Bus Relinquish Time
BUSY Delay After Data Valid
Previous Data Valid After R/C↓
R/C to CS Setup Time
Time Between Conversions
Bus Access and Byte Delay
(Notes 9, 10)
(Notes 9, 10)
10
10
10
83
q
q
TI I G CHARACTERISTICS
POWER REQUIRE E TS
SYMBOL
V
DD
I
DD
P
DIS
PARAMETER
Positive Supply Voltage
Positive Supply Current
Power Dissipation
The
q
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 5)
CONDITIONS
(Notes 9, 10)
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
= 100kHz, 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:
Zero error for the LTC1605-1 is the voltage measured from
0.5LSB when the output code flickers between 0000 0000 0000 0000
and 0000 0000 0000 0001. Zero error for the LTC1605-2 is the voltage
measured from – 0.5LSB when the output code flickers between 0000
0000 0000 0000 and 1111 1111 1111 1111.
4
U W
UW
CONDITIONS
q
q
q
MIN
100
TYP
MAX
8
2
UNITS
kHz
µs
µs
ns
µs
ns
µs
ns
ns
(Note 11)
(Note 9)
C
L
= 50pF
q
q
q
40
8
65
8
220
40
10
50
35
200
7.4
83
ns
ns
µs
ns
µs
ns
MIN
4.75
TYP
11
55
MAX
5.25
16
80
UNITS
V
mA
mW
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 3µs after the
start of the conversion.
Note 12:
As measured with fixed resistors shown in Figure 4. Adjustable to
zero with external potentiometer.
Note 13:
Full-scale error is the untrimmed deviation from ideal last code
transition, divided by the full-scale range and includes the effect of offset
error.
Note 14:
All specifications in dB are referred to a full-scale 4V input for the
LTC1605-1 and to
±4V
input for the LTC1605-2.
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 (±20V) input
overvoltage for the LTC1605-1 and
±15V
for the LTC1605-2.
LTC1605-1/LTC1605-2
TYPICAL PERFOR A CE CHARACTERISTICS
Supply Current vs Supply Voltage
12.5
f
SAMPLE
= 100kHz
12.0
f
SAMPLE
= 100kHz
POWER SUPPLY CURRENT (mA)
CHANGE IN CAP VOLTAGE (V)
12.0
SUPPLY CURRENT (mA)
11.5
11.0
10.5
10.0
9.5
4.50
4.75
5.00
5.25
SUPPLY VOLTAGE (V)
1605-1/2 G01
Typical INL Curve
2.0
1.5
1.0
2.0
1.5
1.0
POWER SUPPLY FEEDTHROUGH (dB)
INL (LSBs)
0
–0.5
–1.0
–1.5
–2.0
0
16384
32768
CODE
1605-1/2 TA02/G04
DNL (LSB)
0.5
49152
LTC1605-2 Nonaveraged
4096-Point FFT Plot
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
–130
88
TOTAL HARMONIC DISTORTION (dB)
MAGNITUDE (dB)
SINAD (dB)
f
SAMPLE
= 100kHz
f
IN
= 1kHz
SINAD = 87dB
THD = 101.1dB
SNR = 87.2dB
0
5
10 15 20 25 30 35 40 45 50
FREQUENCY (kHz)
1605-1/2 G07/F11
U W
Supply Current vs Temperature
0.04
0.02
0
–0.02
–0.04
Change in CAP Voltage vs
Load Current
11.5
11.0
LTC1605-2
–0.06
–0.08
LTC1605-1
0
10
10.5
5.50
10.0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
–0.10
–80 –70 –60 –50 –40 –30 –20 –10
LOAD CURRENT (mA)
1605-1/2 G02
1605-1/2 G03
Typical DNL Curve
–20
–30
–40
–50
–60
Power Supply Feedthrough
vs Ripple Frequency
0.5
0
–0.5
–1.0
–1.5
–2.0
LTC1605-2
LTC1605-1
–70
–80
100
65535
0
16384
32768
CODE
49152
65535
1605-1/2 G05
10k
100k
1k
RIPPLE FREQUENCY (Hz)
1M
LTXXXX GXX
SINAD vs Input Frequency
(LTC1605-2)
90
–70
Total Harmonic Distortion vs
Input Frequency (LTC1605-2)
–80
86
–90
84
82
–100
80
1
10
INPUT FREQUENCY (kHz)
100
1605-1/2 G08
–110
1
10
INPUT FREQUENCY (kHz)
100
1605-1/2 G09
5