LTC1273
LTC1275/LTC1276
12-Bit, 300ksps Sampling
A/D Converters with Reference
FEATURES
s
s
s
s
s
s
s
s
s
s
s
DESCRIPTIO
Single Supply 5V or
±5V
Operation
300ksps Sample Rate
75mW (Typ) Power Dissipation
On-Chip 25ppm/°C Reference
Internal Synchronized Clock; No Clock Required
High Impedance Analog Input
70dB S/(N + D) and 77dB THD at Nyquist
±1/2LSB
INL and
±3/4LSB
DNL Max (A Grade)
ESD Protected On All Pins
24-Pin Narrow DIP and SOL Packages
Variety of Input Ranges:
0V to 5V (LTC1273)
±2.5V
(LTC1275)
±5V
(LTC1276)
The LTC1273/LTC1275/LTC1276 are 300ksps, sampling
12-bit A/D converters that draw only 75mW from single
5V or
±5V
supplies. These easy-to-use devices come
complete with 600ns sample-and-holds, precision refer-
ences and internally trimmed clocks. Unipolar and bipo-
lar conversion modes provide flexibility for various appli-
cations. They are built with LTBiCMOS
TM
switched ca-
pacitor technology.
These devices have 25ppm/°C (max) internal references.
The LTC1273 converts 0V to 5V unipolar inputs from a
single 5V supply. The LTC1275/LTC1276 convert
±2.5V
and
±5V
respectively from
±5V
supplies. Maximum DC
specifications include
±1/2LSB
INL,
±3/4LSB
DNL and
25ppm/°C full scale drift over temperature. Outstanding
AC performance includes 70dB S/(N + D) and 77dB THD
at the Nyquist input frequency of 150kHz.
The internal clock is trimmed for 2.7µs maximum conver-
sion time. The clock automatically synchronizes to each
sample command eliminating problems with asynchro-
nous clock noise found in competitive devices. A high
speed parallel interface eases connections to FIFOs, DSPs
and microprocessors.
LTBiCMOS
TM
is a trademark of Linear Technology Corporation
APPLICATI
s
s
s
s
s
S
High Speed Data Acquisition
Digital Signal Processing
Multiplexed Data Acquisition Systems
Audio and Telecom Processing
Spectrum Analysis
TYPICAL APPLICATI
2.42V
V
REF
OUTPUT
Single 5V Supply, 300ksps, 12-Bit Sampling A/D Converter
LTC1273
ANALOG INPUT 1 A
V
DD
(0V TO 5V) 2
IN
V
REF
NC
3
BUSY
AGND
0.1µF
4
CS
D11
5
RD
D10
6
HBEN
D9
7
NC
D8
8
NC
D7
9
D0/8
D6
10
8- OR 12-BIT
D1/9
D5
PARALLEL BUS
11
D2/10
D4
12
D3/11
DGND
5V
24
23
22
21
20
19
18
17
16
15
14
13
Effective Bits and Signal to (Noise + Distortion)
vs Input Frequency
12
11
0.1µF
+
10µF
µP
CONTROL
LINES
+
10µF
10
9
EFFECTIVE BITS
8
7
6
5
4
3
2
1
0
10k
f
SAMPLE
= 300kHz
100k
INPUT FREQUENCY (Hz)
1M
LTC1273/75/76 • TA01
U
74
68
NYQUIST
FREQUENCY
62
56
50
S/(N + D) (dB)
UO
UO
2M
LTC1273/75/76 • TA02
1
LTC1273
LTC1275/LTC1276
ABSOLUTE
AXI U
RATI GS
U
W W
(Note 8)
q
Supply Voltage (V
DD
) .............................................. 12V
Negative Supply Voltage (V
SS
)
LTC1275/LTC1276.................................. – 6V to GND
Total Supply Voltage (V
DD
to V
SS
)
LTC1275/LTC1276............................................... 12V
Analog Input Voltage (Note 3)
LTC1273 .................................... – 0.3V to V
DD
+ 0.3V
LTC1275/LTC1276.............. V
SS
– 0.3V to V
DD
+ 0.3V
Digital Input Voltage (Note 4)
LTC1273 ................................................ – 0.3V to 12V
LTC1275/LTC1276......................... V
SS
– 0.3V to 12V
PACKAGE/ORDER I FOR ATIO
TOP VIEW
A
IN
V
REF
AGND
D11
D10
D9
D8
D7
D6
1
2
3
4
5
6
7
8
9
24 V
DD
23 NC
22 BUSY
21 CS
20 RD
19 HBEN
18 NC
17 NC
16 D0/8
15 D1/9
14 D2/10
13 D3/11
ORDER
PART NUMBER
LTC1273ACN
LTC1273BCN
LTC1273ACS
LTC1273BCS
(For MIL Grade:
Contact Factory)
D5 10
D4 11
DGND 12
N PACKAGE
S PACKAGE
24-LEAD PLASTIC DIP 24-LEAD PLASTIC SOL
T
JMAX
= 110°C,
θ
JA
= 100°C/W (N)
T
JMAX
= 110°C,
θ
JA
= 130°C/W (S)
CO VERTER CHARACTERISTICS
PARAMETER
Resolution (No Missing Codes)
Integral Linearity Error
(Note 7)
Commercial
Military
Commercial
Military
CONDITIONS
q
q
q
q
q
With Internal Reference (Notes 5 and 6)
LTC1273A/LTC1275A/LTC1276A
MIN
TYP
MAX
12
±1/2
±1/2
±3/4
±3/4
±1
±3
±4
±10
±5
±25
±10
LTC1273B/LTC1275B/LTC1276B
MIN
TYP
MAX
12
±1
±1
±1
±1
±1
±4
±6
±15
±45
UNITS
Bits
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
ppm/°C
Differential Linearity Error
Offset Error
Full Scale Error
Full Scale Tempco
I
OUT(REFERENCE)
= 0
q
2
U
W
U
W
(Notes 1 and 2)
Digital Output Voltage (Note 3)
LTC1273 .................................... – 0.3V to V
DD
+ 0.3V
LTC1275/LTC1276 .............. V
SS
– 0.3V to V
DD
+ 0.3V
Power Dissipation ............................................. 500mW
Operating Temperature Range
LTC1273AC, LTC1273BC, LTC1275AC
LTC1275BC, LTC1276AC, LTC1276BC .... 0°C to 70°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
TOP VIEW
A
IN
V
REF
AGND
D11
D10
D9
D8
D7
D6
1
2
3
4
5
6
7
8
9
24 V
DD
23 V
SS
22 BUSY
21 CS
20 RD
19 HBEN
18 NC
17 NC
16 D0/8
15 D1/9
14 D2/10
13 D3/11
ORDER
PART NUMBER
LTC1275ACN
LTC1275BCN
LTC1275ACS
LTC1275BCS
LTC1276ACN
LTC1276BCN
LTC1276ACS
LTC1276BCS
(For MIL Grade:
Contact Factory)
D5 10
D4 11
DGND 12
N PACKAGE
S PACKAGE
24-LEAD PLASTIC DIP 24-LEAD PLASTIC SOL
T
JMAX
= 110°C,
θ
JA
= 100°C/W (N)
T
JMAX
= 110°C,
θ
JA
= 130°C/W (S)
U
LTC1273
LTC1275/LTC1276
DY A IC ACCURACY
(Note 5)
SYMBOL
THD
PARAMETER
Total Harmonic Distortion
Up to 5th Harmonic
Peak Harmonic or Spurious Noise
IMD
Intermodulation Distortion
Full Power Bandwidth
Full Linear Bandwidth (S/(N + D)
≥
68dB)
CONDITIONS
50kHz/150kHz Input Signal
50kHz/150kHz Input Signal
50kHz/150kHz Input Signal
f
IN1
= 29.37kHz, f
IN2
= 32.446kHz
LTC1273A/LTC1275A/LTC1276A
LTC1273B/LTC1275B/LTC1276B
MIN
TYP
MAX
72/70
– 83/– 74
– 85/– 76
– 80
4.5
200
UNITS
dB
dB
dB
dB
MHz
kHz
S/(N + D) Signal-to-Noise Plus Distortion Ratio
A ALOG I PUT
(Note 5)
SYMBOL PARAMETER
V
IN
Analog Input Range (Note 9)
CONDITIONS
4.95V
≤
V
DD
≤
5.25V (LTC1273)
4.75V
≤
V
DD
≤
5.25V, – 5.25V
≤
V
SS
≤
– 2.45V (LTC1275)
4.95V
≤
V
DD
≤
5.25V, – 5.25V
≤
V
SS
≤
– 4.95V (LTC1276)
CS = High
Between Conversions (Sample Mode)
During Conversions (Hold Mode)
Commercial
Military
q
q
q
q
q
q
I
IN
C
IN
t
ACQ
Analog Input Leakage Current
Analog Input Capacitance
Sample-and-Hold
Acquisition Time
I TER AL REFERE CE CHARACTERISTICS
(Note 5)
PARAMETER
V
REF
Output Voltage
V
REF
Output Tempco
V
REF
Line Regulation
V
REF
Load Regulation
CONDITIONS
I
OUT
= 0
I
OUT
= 0
4.95V
≤
V
DD
≤
5.25V
– 5.25V
≤
V
SS
≤
– 4.95V
0V
≤
|
I
OUT
|
≤
1mA
q
DIGITAL I PUTS A D DIGITAL OUTPUTS
(Note 5)
SYMBOL PARAMETER
V
IH
V
IL
I
IN
C
IN
V
OH
High Level Input Voltage
Low Level Input Voltage
Digital Input Current
Digital Input Capacitance
High Level Output Voltage
V
DD
= 4.95V
I
O
= – 10µA
I
O
= – 200µA
CONDITIONS
V
DD
= 5.25V
V
DD
= 4.95V
V
IN
= 0V to V
DD
q
q
q
U
U
U
U
W U
U
U
LTC1273A/LTC1275A/LTC1276A
LTC1273B/LTC1275B/LTC1276B
MIN
TYP
MAX
UNITS
0 to 5
±2.5
±5
±1
50
5
600
1000
V
V
V
µA
pF
pF
ns
ns
U
LTC1273A/LTC1275A/LTC1276A
MIN
TYP
MAX
2.400
2.420
±5
0.01
0.01
2
2.440
±25
LTC1273B/LTC1275B/LTC1276B
MIN
TYP
MAX
2.400
2.420
±10
0.01
0.01
2
2.440
±45
UNITS
V
ppm/°C
LSB/V
LSB/V
LSB/mA
LTC1273A/LTC1275A/LTC1276A
LTC1273B/LTC1275B/LTC1276B
MIN
TYP
MAX
UNITS
2.4
0.8
±10
5
4.7
q
V
V
µA
pF
V
V
4.0
3
LTC1273
LTC1275/LTC1276
DIGITAL I PUTS A D DIGITAL OUTPUTS
(Note 5)
SYMBOL PARAMETER
V
OL
Low Level Output Voltage
CONDITIONS
V
DD
= 4.95V
I
O
= 160µA
I
O
= 1.6mA
V
OUT
= 0V to V
DD
, CS High
CS High (Note 9 )
V
OUT
= 0V
V
OUT
= V
DD
LTC1273A/LTC1275A/LTC1276A
LTC1273B/LTC1275B/LTC1276B
MIN
TYP
MAX
UNITS
0.05
0.10
V
V
µA
pF
mA
mA
I
OZ
C
OZ
I
SOURCE
I
SINK
High Z Output Leakage D11-D0/8
High Z Output Capacitance D11-D0/8
Output Source Current
Output Sink Current
POWER REQUIRE E TS
(Note 5)
SYMBOL PARAMETER
V
DD
V
SS
I
DD
I
SS
P
D
Positive Supply Voltage
Negative Supply Voltage
Positive Supply Current
Negative Supply Current
Power Dissipation
LTC1275/LTC1276
CONDITIONS
LTC1273/LTC1276 (Notes 10, 11)
LTC1275 (Note 10)
LTC1275 (Note 10)
LTC1276 (Notes 10, 11)
q
q
TI I G CHARACTERISTICS
See Timing Characteristics Figures (Note 5)
SYMBOL
f
SAMPLE(MAX)
PARAMETER
Maximum Sampling Frequency
CONDITIONS
(Note 10)
Commercial
Military
Commercial
Military
C
L
= 50pF
Commercial
Military
C
L
= 20pF
Commercial
Military
C
L
= 100pF
Commercial
Military
t
4
t
5
t
6
RD Pulse Width
CS to RD Hold Time
Data Setup Time After BUSY↑
Commercial
Military
q
q
q
q
q
q
q
q
q
t
CONV
t
1
t
2
Conversion Time
CS to RD Setup Time
RD to BUSY Delay
t
3
Data Access Time After RD↓
4
U W
U
U
q
q
q
0.4
±10
15
– 10
10
LTC1273A/LTC1275A/LTC1276A
LTC1273B/LTC1275B/LTC1276B
MIN
TYP
MAX
UNITS
4.95
4.75
– 2.45
– 4.95
15
0.065
75
5.25
5.25
– 5.25
– 5.25
25
0.200
V
V
V
V
mA
mA
mW
UW
LTC1273A/LTC1275A/LTC1276A
LTC1273B/LTC1275B/LTC1276B
MIN
TYP
MAX
UNITS
300
250
2.7
3.0
0
80
190
230
270
90
110
120
125
150
170
kHz
kHz
µs
µs
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
40
70
90
100
ns
ns
ns
40
q
q
50
q
q
q
q
t
3
0
LTC1273
LTC1275/LTC1276
TI I G CHARACTERISTICS
See Timing Characteristics Figures (Note 5)
SYMBOL PARAMETER
t
7
Bus Relinquish Time
Commercial
Military
t
8
t
9
t
10
t
11
HBEN to RD Setup Time
HBEN to RD Hold Time
Delay Between RD Operations
Delay Between Conversions
(Note 10)
Commercial
Military
q
q
q
q
q
q
q
t
12
The
q
indicates specifications which apply over the full operating
temperature range; all other limits and typicals 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 ground with DGND and
AGND wired together (unless otherwise noted).
Note 3:
When these pin voltages are taken below V
SS
(ground for
LTC1273) or above V
DD
, they will be clamped by internal diodes. This
product can handle input currents greater than 60mA below V
SS
(ground
for LTC1273) or above V
DD
without latch-up.
Note 4:
When these pin voltages are taken below V
SS
(ground for
LTC1273) they will be clamped by internal diodes. This product can handle
input currents greater than 60mA below V
SS
(ground for LTC1273)
without latch-up. These pins are not clamped to V
DD
.
Note 5:
V
DD
= 5V (V
SS
= – 5V for LTC1275/LTC1276), 300kHz at 70°C and
250kHz at 125°C, t
r
= t
f
= 5ns unless otherwise specified.
TI I G CHARACTERISTICS
(Note 5)
Slow Memory Mode, Parallel Read Timing Diagram
ROM Mode, Parallel Read Timing Diagram
BUSY
t
3
DATA
HOLD
TRACK
t
12
OLD DATA
DB11 TO DB0
t
6
t
7
NEW DATA
DB11 TO DB0
UW
CS
RD
CONDITIONS
LTC1273A/LTC1275A/LTC1276A
LTC1273B/LTC1275B/LTC1276B
MIN
TYP
MAX
UNITS
20
20
20
0
0
40
500
600
1000
25
30
75
85
90
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Aperture Delay of Sample-and-Hold
Note 6:
Linearity, offset and full scale specifications apply for unipolar and
bipolar modes.
Note 7:
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 8:
Bipolar offset (LTC1275/LTC1276) is the different voltage
measured from – 0.5LSB when the LTC1275/LTC1276 output code flickers
between 0000 0000 0000 and 1111 1111 1111.
Note 9:
Guaranteed by design, not subject to test.
Note 10:
Recommended operating conditions.
Note11:
A
IN
must not exceed V
DD
or fall below V
SS
by more than 50mV for
specified accuracy. Therefore the minimum supply voltage for the
LTC1273 is + 4.95V. The minimum supplies for the LTC1275 are +4.75V
and – 2.45V and the minimum supplies for the LTC1276 are
±4.95V.
UW
CS
t
1
t
5
t
10
t
1
t
1
RD
t
4
t
2
t
5
t
11
t
CONV
t
7
t
1
t
4
t
2
t
5
t
2
t
CONV
t
11
t
CONV
t
7
NEW DATA
DB11 TO DB0
BUSY
t
3
DATA
HOLD
LTC1273/75/76 • TA03
t
3
OLD DATA
DB11 TO DB0
t
12
t
12
TRACK
LTC1273/75/76 • TA04
5
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