LTC2249
14-Bit, 80Msps
Low Power 3V ADC
FEATURES
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DESCRIPTIO
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Sample Rate: 80Msps
Single 3V Supply (2.7V to 3.4V)
Low Power: 222mW
73dB SNR at 70MHz Input
90dB SFDR at 70MHz Input
No Missing Codes
Flexible Input: 1V
P-P
to 2V
P-P
Range
575MHz Full Power Bandwidth S/H
Clock Duty Cycle Stabilizer
Shutdown and Nap Modes
Pin Compatible Family
80Msps: LTC2229 (12-Bit), LTC2249 (14-Bit)
65Msps: LTC2228 (12-Bit), LTC2248 (14-Bit)
40Msps: LTC2227 (12-Bit), LTC2247 (14-Bit)
25Msps: LTC2226 (12-Bit), LTC2246 (14-Bit)
10Msps: LTC2225 (12-Bit), LTC2245 (14-Bit)
32-Pin (5mm
×
5mm) QFN Package
The LTC
®
2249 is a 14-bit 80Msps, low power 3V A/D
converter designed for digitizing high frequency, wide
dynamic range signals. The LTC2249 is perfect for de-
manding imaging and communications applications with
AC performance that includes 73dB SNR and 90dB SFDR
for signals well beyond the Nyquist frequency.
DC specs include
±1LSB
INL (typ),
±0.5LSB
DNL (typ) and
no missing codes over temperature. The transition noise
is a low 1.2LSB
RMS
.
A single 3V supply allows low power operation. A separate
output supply allows the outputs to drive 0.5V to 3.3V
logic.
A single-ended CLK input controls converter operation. An
optional clock duty cycle stabilizer allows high perfor-
mance at full speed for a wide range of clock duty cycles.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
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Wireless and Wired Broadband Communication
Imaging Systems
Ultrasound
Spectral Analysis
Portable Instrumentation
TYPICAL APPLICATIO
REFH
REFL
FLEXIBLE
REFERENCE
OV
DD
SNR (dBFS)
+
ANALOG
INPUT
INPUT
S/H
–
14-BIT
PIPELINED
ADC CORE
CORRECTION
LOGIC
OUTPUT
DRIVERS
D13
•
•
•
D0
OGND
CLOCK/DUTY
CYCLE
CONTROL
2229 TA01
CLK
U
SNR vs Input Frequency,
–1dB, 2V Range
75
74
73
72
71
70
69
68
67
66
65
0
100
50
150
INPUT FREQUENCY (MHz)
200
2249 G09
U
U
2249f
1
LTC2249
ABSOLUTE
AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
SENSE
MODE
V
CM
D13
D12
D11
V
DD
OF
OV
DD
= V
DD
(Notes 1, 2)
Supply Voltage (V
DD
) ................................................. 4V
Digital Output Ground Voltage (OGND) ....... –0.3V to 1V
Analog Input Voltage (Note 3) ..... –0.3V to (V
DD
+ 0.3V)
Digital Input Voltage .................... –0.3V to (V
DD
+ 0.3V)
Digital Output Voltage ................ –0.3V to (OV
DD
+ 0.3V)
Power Dissipation ............................................ 1500mW
Operating Temperature Range
LTC2249C ............................................... 0°C to 70°C
LTC2249I .............................................–40°C to 85°C
Storage Temperature Range ..................–65°C to 125°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
24 D10
23 D9
22 D8
32 31 30 29 28 27 26 25
AIN
+
1
AIN
–
2
REFH 3
REFH 4
REFL 5
REFL 6
V
DD
7
GND 8
9 10 11 12 13 14 15 16
OE
D0
D1
D2
D3
CLK
SHDN
D4
LTC2249CUH
LTC2249IUH
33
21 OV
DD
20 OGND
19 D7
18 D6
17 D5
QFN PART*
MARKING
2249
UH PACKAGE
32-LEAD (5mm
×
5mm) PLASTIC QFN
T
JMAX
= 125°C,
θ
JA
= 34°C/W
EXPOSED PAD IS GND (PIN 33)
MUST BE SOLDERED TO PCB
Consult LTC Marketing for parts specified with wider operating temperature ranges.
*The temperature grade is identified by a label on the shipping container.
CO VERTER CHARACTERISTICS
PARAMETER
Resolution (No Missing Codes)
Integral Linearity Error
Differential Linearity Error
Offset Error
Gain Error
Offset Drift
Full-Scale Drift
Transition Noise
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 4)
CONDITIONS
●
MIN
14
–4
–1
–12
–2.5
●
●
●
●
TYP
±1
±0.5
±2
±0.5
±10
±30
±15
1
MAX
4
1
12
2.5
UNITS
Bits
LSB
LSB
mV
%FS
µV/°C
ppm/°C
ppm/°C
LSB
RMS
Differential Analog Input (Note 5)
Differential Analog Input
(Note 6)
External Reference
Internal Reference
External Reference
SENSE = 1V
A ALOG I PUT
SYMBOL
V
IN
V
IN,CM
I
IN
I
SENSE
I
MODE
t
AP
t
JITTER
CMRR
PARAMETER
The
●
denotes the specifications which apply over the full operating temperature range, otherwise
specifications are at T
A
= 25°C. (Note 4)
CONDITIONS
2.7V < V
DD
< 3.4V (Note 7)
Differential Input (Note 7)
0V < A
IN+
, A
IN–
< V
DD
0V < SENSE < 1V
●
●
●
●
●
MIN
1
–1
–3
–3
TYP
1V to 2V
1.5
MAX
1.9
1
3
3
UNITS
V
V
µA
µA
µA
ns
ps
RMS
dB
2249f
Analog Input Range (A
IN+
–A
IN–
)
Analog Input Common Mode
Analog Input Leakage Current
SENSE Input Leakage
MODE Pin Leakage
Sample-and-Hold Acquisition Delay Time
Sample-and-Hold Acquisition Delay Time Jitter
Analog Input Common Mode Rejection Ratio
0
0.2
80
2
U
W
U
U
W W
W
U
U
U
LTC2249
DY A IC ACCURACY
SYMBOL
SNR
PARAMETER
Signal-to-Noise Ratio
The
●
denotes the specifications which apply over the full operating temperature range,
otherwise specifications are at T
A
= 25°C. A
IN
= –1dBFS. (Note 4)
CONDITIONS
5MHz Input
40MHz Input
70MHz Input
140MHz Input
SFDR
Spurious Free Dynamic Range
2nd or 3rd Harmonic
5MHz Input
40MHz Input
70MHz Input
140MHz Input
SFDR
Spurious Free Dynamic Range
4th Harmonic or Higher
5MHz Input
40MHz Input
70MHz Input
140MHz Input
S/(N+D)
Signal-to-Noise Plus Distortion Ratio
5MHz Input
40MHz Input
70MHz Input
140MHz Input
I
MD
Intermodulation Distortion
Full Power Bandwidth
f
IN1
= 28.2MHz, f
IN2
= 26.8MHz
Figure 8 Test Circuit
●
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●
I TER AL REFERE CE CHARACTERISTICS
PARAMETER
V
CM
Output Voltage
V
CM
Output Tempco
V
CM
Line Regulation
V
CM
Output Resistance
CONDITIONS
I
OUT
= 0
U
W U
U
MIN
70.8
TYP
73
73
73
72.6
90
MAX
UNITS
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
MHz
75
90
90
85
95
81
95
95
90
72.9
70.2
72.8
72.8
72.1
90
575
U
(Note 4)
MIN
1.475
TYP
1.500
±30
3
4
MAX
1.525
UNITS
V
ppm/°C
mV/V
Ω
2.7V < V
DD
< 3.4V
–1mA < I
OUT
< 1mA
2249f
3
LTC2249
DIGITAL I PUTS A D DIGITAL OUTPUTS
SYMBOL
V
IH
V
IL
I
IN
C
IN
LOGIC OUTPUTS
OV
DD
= 3V
C
OZ
I
SOURCE
I
SINK
V
OH
V
OL
OV
DD
= 2.5V
V
OH
V
OL
OV
DD
= 1.8V
V
OH
V
OL
High Level Output Voltage
Low Level Output Voltage
I
O
= –200µA
I
O
= 1.6mA
1.79
0.09
V
V
High Level Output Voltage
Low Level Output Voltage
I
O
= –200µA
I
O
= 1.6mA
2.49
0.09
V
V
Hi-Z Output Capacitance
Output Source Current
Output Sink Current
High Level Output Voltage
Low Level Output Voltage
OE = High (Note 7)
V
OUT
= 0V
V
OUT
= 3V
I
O
= –10µA
I
O
= –200µA
I
O
= 10µA
I
O
= 1.6mA
●
●
The
●
denotes the specifications which apply over the
full operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 4)
PARAMETER
High Level Input Voltage
Low Level Input Voltage
Input Current
Input Capacitance
CONDITIONS
V
DD
= 3V
V
DD
= 3V
V
IN
= 0V to V
DD
(Note 7)
●
●
●
LOGIC INPUTS (CLK, OE, SHDN)
2
0.8
–10
3
10
V
V
µA
pF
POWER REQUIRE E TS
SYMBOL
V
DD
OV
DD
IV
DD
P
DISS
P
SHDN
P
NAP
PARAMETER
Analog Supply Voltage
Output Supply Voltage
Supply Current
Power Dissipation
Shutdown Power
Nap Mode Power
The
●
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 8)
CONDITIONS
(Note 9)
(Note 9)
●
●
●
●
4
U W
U
U
MIN
TYP
MAX
UNITS
3
50
50
2.7
2.995
2.99
0.005
0.09
0.4
pF
mA
mA
V
V
V
V
MIN
2.7
0.5
TYP
3
3
74
222
2
15
MAX
3.4
3.6
86
258
UNITS
V
V
mA
mW
mW
mW
SHDN = H, OE = H, No CLK
SHDN = H, OE = L, No CLK
2249f
LTC2249
The
●
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 4)
SYMBOL
f
s
t
L
t
H
t
AP
t
D
PARAMETER
Sampling Frequency
CLK Low Time
CLK High Time
Sample-and-Hold Aperture Delay
CLK to DATA Delay
Data Access Time After OE↓
BUS Relinquish Time
Pipeline
Latency
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 GND and OGND
wired together (unless otherwise noted).
Note 3:
When these pin voltages are taken below GND or above V
DD
, they
will be clamped by internal diodes. This product can handle input currents
of greater than 100mA below GND or above V
DD
without latchup.
Note 4:
V
DD
= 3V, f
SAMPLE
= 80MHz, input range = 2V
P-P
with differential
drive, unless otherwise noted.
C
L
= 5pF (Note 7)
C
L
= 5pF (Note 7)
(Note 7)
●
●
●
TI I G CHARACTERISTICS
TYPICAL PERFOR A CE CHARACTERISTICS
Typical INL, 2V Range
2.0
1.5
1.0
DNL ERROR (LSB)
INL ERROR (LSB)
0.5
0
–0.5
–1.0
–1.5
–2.0
0
4096
8192
CODE
2249 G01
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
AMPLITUDE (dB)
12288
U W
UW
CONDITIONS
(Note 9)
Duty Cycle Stabilizer Off
Duty Cycle Stabilizer On (Note 7)
Duty Cycle Stabilizer Off
Duty Cycle Stabilizer On (Note 7)
●
●
●
●
●
MIN
1
5.9
5
5.9
5
1.4
TYP
6.25
6.25
6.25
6.25
0
2.7
4.3
3.3
6
MAX
80
500
500
500
500
5.4
10
8.5
UNITS
MHz
ns
ns
ns
ns
ns
ns
ns
ns
Cycles
Note 5:
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 6:
Offset error is the offset voltage measured from –0.5 LSB when
the output code flickers between 00 0000 0000 0000 and
11 1111 1111 1111.
Note 7:
Guaranteed by design, not subject to test.
Note 8:
V
DD
= 3V, f
SAMPLE
= 80MHz, input range = 1V
P-P
with
differential drive.
Note 9:
Recommended operating conditions.
Typical DNL, 2V Range
1.0
0.8
0.6
0.4
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
0
4096
8192
CODE
2249 G02
8192 Point FFT, f
IN
= 5MHz,
–1dB, 2V Range
16384
12288
16384
0
5
10
15 20 25 30
FREQUENCY (MHz)
35
40
2249 G03
2249f
5
