NSC ADC12DC080CISQ

September 2007
ADC12DC080/ADC12DC105
Dual 12-Bit, 80/105 MSPS A/D Converter with CMOS
Outputs
General Description
Features
NOTE: This is Advance Information for products currently in development. ALL specifications are design targets
and are subject to change.
The ADC12DC080 and ADC12DC105 are high-performance
CMOS analog-to-digital converters capable of converting two
analog input signals into 12-bit digital words at rates up to
80/105 Mega Samples Per Second (MSPS) respectively.
These converters use a differential, pipelined architecture
with digital error correction and an on-chip sample-and-hold
circuit to minimize power consumption and the external component count, while providing excellent dynamic performance. A unique sample-and-hold stage yields a full-power
bandwidth of 1 GHz. The ADC12DC080/105 may be operated
from a single +3.3V power supply. A power-down feature reduces the power consumption to very low levels while still
allowing fast wake-up time to full operation. The differential
inputs provide a 2V full scale differential input swing. A stable
1.2V internal voltage reference is provided, or the ADC12DC080/105 can be operated with an external 1.2V reference. Output data format (offset binary versus 2's complement) and duty cycle stabilizer are pin-selectable. The duty
cycle stabilizer maintains performance over a wide range of
clock duty cycles.
The ADC12DC080/105 is available in a 60-lead LLP package
and operates over the industrial temperature range of −40°C
to +85°C.
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1 GHz Full Power Bandwidth
Internal sample-and-hold circuit and precision reference
Low power consumption
Clock Duty Cycle Stabilizer
Single +3.3V supply operation
Power-down mode
Offset binary or 2's complement output data format
60-pin LLP package, (9x9x0.8mm, 0.5mm pin-pitch)
Key Specifications
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For ADC12DC105
Resolution
Conversion Rate
SNR (fIN = 240 MHz)
SFDR (fIN = 240 MHz)
Full Power Bandwidth
Power Consumption
12 Bits
105 MSPS
67 dBFS (typ)
83 dBFS (typ)
1 GHz (typ)
800 mW (typ)
Applications
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High IF Sampling Receivers
Wireless Base Station Receivers
Test and Measurement Equipment
Communications Instrumentation
Portable Instrumentation
Connection Diagram
30015401
© 2007 National Semiconductor Corporation
300154
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ADC12DC080/ADC12DC105 Dual 12-Bit, 80/105 MSPS A/D Converter with CMOS Outputs
ADVANCE INFORMATION
ADC12DC080/ADC12DC105
Block Diagram
30015402
Ordering Information
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Industrial (−40°C ≤ TA ≤ +85°C)
Package
ADC12DC080CISQ
60 Pin LLP
ADC12DC105CISQ
60 Pin LLP
2
Pin No.
Symbol
Equivalent Circuit
Description
ANALOG I/O
3
13
VINA+
VINB+
2
14
VINAVINB-
5
11
VRPA
VRPB
7
9
VCMOA
VCMOB
6
10
VRNA
VRNB
Differential analog input pins. The differential full-scale input signal
level is 2VP-P with each input pin signal centered on a common
mode voltage, VCM.
These pins should each be bypassed to AGND with a low ESL
(equivalent series inductance) 0.1 µF capacitor placed very close
to the pin to minimize stray inductance. An 0201 size 0.1 µF
capacitor should be placed between VRP and VRN as close to the
pins as possible, and a 1 µF capacitor should be placed in parallel.
VRP and VRN should not be loaded. VCMO may be loaded to 1mA
for use as a temperature stable 1.5V reference.
It is recommended to use VCMO to provide the common mode
voltage, VCM, for the differential analog inputs.
VREF
Reference Voltage. This device provides an internally developed
1.2V reference. When using the internal reference, VREF should be
decoupled to AGND with a 0.1 µF and a 1µF, low equivalent series
inductance (ESL) capacitor.
This pin may be driven with an external 1.2V reference voltage.
This pin should not be used to source or sink current.
19
OF/DCS
This is a four-state pin controlling the input clock mode and output
data format.
OF/DCS = VA, output data format is 2's complement without duty
cycle stabilization applied to the input clock
OF/DCS = AGND, output data format is offset binary, without duty
cycle stabilization applied to the input clock.
OF/DCS = (2/3)*VA, output data is 2's complement with duty cycle
stabilization applied to the input clock
OF/DCS = (1/3)*VA, output data is offset binary with duty cycle
stabilization applied to the input clock.
18
CLK
The clock input pin.
The analog inputs are sampled on the rising edge of the clock input.
59
DIGITAL I/O
57
20
This is a two-state input controlling Power Down.
PD = VA, Power Down is enabled and power dissipation is reduced.
PD = AGND, Normal operation.
PD_A
PD_B
3
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ADC12DC080/ADC12DC105
Pin Descriptions and Equivalent Circuits
ADC12DC080/ADC12DC105
Pin No.
Symbol
Equivalent Circuit
Description
42-49,
52-55
DA0-DA7,
DA8-DA11
Digital data output pins that make up the 12-bit conversion result
for Channel A. DA0 (pin 42) is the LSB, while DA11 (pin 55) is the
MSB of the output word. Output levels are CMOS compatible.
23-24,
27-36
DB0-DB1,
DB3-DB11
Digital data output pins that make up the 12-bit conversion result
for Channel B. DB0 (pin 23) is the LSB, while DB11 (pin 36) is the
MSB of the output word. Output levels are CMOS compatible.
39
DRDY
Data Ready Strobe. The data output transition is synchronized with
the falling edge of this signal. This signal switches at the same
frequency as the CLK input.
8, 16, 17, 58,
60
VA
Positive analog supply pins. These pins should be connected to a
quiet source and be bypassed to AGND with 0.1 µF capacitors
located close to the power pins.
1, 4, 12, 15,
Exposed Pad
AGND
ANALOG POWER
The ground return for the analog supply.
DIGITAL POWER
26, 38,50
VDR
25, 37, 51
DRGND
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Positive driver supply pin for the output drivers. This pin should be
connected to a quiet voltage source and be bypassed to DRGND
with a 0.1 µF capacitor located close to the power pin.
The ground return for the digital output driver supply. This pins
should be connected to the system digital ground, but not be
connected in close proximity to the ADC's AGND pins.
4
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (VA, VDR)
Voltage on Any Pin
(Not to exceed 4.2V)
Input Current at Any Pin other
than Supply Pins (Note 4)
Package Input Current (Note 4)
Max Junction Temp (TJ)
(Notes 1, 3)
Operating Temperature
Supply Voltage (VA)
Output Driver Supply (VDR)
Clock Duty Cycle
(DCS Enabled)
(DCS disabled)
VCM
|AGND-DRGND|
−0.3V to 4.2V
−0.3V to (VA +0.3V)
±5 mA
±50 mA
+150°C
30°C/W
−40°C ≤ TA ≤ +85°C
+2.7V to +3.6V
+2.4V to VA
30/70 %
45/55 %
1.4V to 1.6V
≤100mV
Thermal Resistance (θJA)
ESD Rating
Human Body Model (Note 6)
2500V
Machine Model (Note 6)
250V
Storage Temperature
−65°C to +150°C
Soldering process must comply with National
Semiconductor's Reflow Temperature Profile
specifications. Refer to www.national.com/packaging.
(Note 7)
ADC12DC080 Converter Electrical Characteristics
This product is currently under development. As such, the parameters specified are DESIGN TARGETS. The specifications cannot be guaranteed until device characterization has taken place.
Unless otherwise specified, the following specifications apply: AGND = DRGND = 0V, VA = +3.0V, VDR = +2.5V, Internal VREF =
+1.2V, fCLK = 80 MHz, VCM = VCMO, CL = 5 pF/pin. Typical values are for TA = 25°C. Boldface limits apply for TMIN ≤ TA ≤
TMAX. All other limits apply for TA = 25°C (Notes 8, 9)
Symbol
Parameter
Conditions
Typical
(Note 10)
Limits
Units
(Limits)
12
Bits (min)
STATIC CONVERTER CHARACTERISTICS
Resolution with No Missing Codes
INL
Integral Non Linearity (Note 11)
±0.5
LSB (max)
LSB (min)
DNL
Differential Non Linearity
±0.4
LSB (max)
LSB (min)
Under Range Output Code
0
0
Over Range Output Code
4095
4095
REFERENCE AND ANALOG INPUT CHARACTERISTICS
VCMO
Common Mode Output Voltage
1.5
1.45
1.55
V (min)
V (max)
VCM
Analog Input Common Mode Voltage
1.5
1.4
1.6
V (min)
V (max)
CIN
VIN Input Capacitance (each pin to
GND) (Note 12)
VREF
VIN = 1.5 Vdc
± 0.5 V
External Reference Voltage
(CLK LOW)
8.5
(CLK HIGH)
3.5
1.20
5
pF
pF
1.176
1.224
V (min)
V (max)
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ADC12DC080/ADC12DC105
Operating Ratings
Absolute Maximum Ratings (Notes 1, 3)
ADC12DC080/ADC12DC105
ADC12DC080 Dynamic Converter Electrical Characteristics
Unless otherwise specified, the following specifications apply: AGND = DRGND = 0V, VA = +3.0V, VDR = +2.5V, Internal VREF =
+1.2V, fCLK = 80 MHz, VCM = VCMO, CL = 5 pF/pin, . Typical values are for TA = 25°C. Boldface limits apply for TMIN ≤ TA ≤
TMAX. All other limits apply for TA = 25°C (Notes 8, 9)
Symbol
Parameter
Conditions
Typical
Limits
(Note 10)
Units
(Limits)
(Note 2)
DYNAMIC CONVERTER CHARACTERISTICS, AIN = -1dBFS
FPBW
Full Power Bandwidth
SNR
Signal-to-Noise Ratio
SFDR
ENOB
THD
H2
H3
SINAD
-1 dBFS Input, −3 dB Corner
Spurious Free Dynamic Range
Effective Number of Bits
Total Harmonic Disortion
Second Harmonic Distortion
Third Harmonic Distortion
Signal-to-Noise and Distortion Ratio
1.0
GHz
fIN = 10 MHz
71.2
dBFS
fIN = 70 MHz
70
dBFS
fIN = 170 MHz
68
dBFS
fIN = 10 MHz
90
dBFS
fIN = 70 MHz
88
dBFS
fIN = 170 MHz
83
dBFS
fIN = 10 MHz
11.5
Bits
fIN = 70 MHz
11.3
Bits
fIN = 170 MHz
11
Bits
fIN = 10 MHz
−88
dBFS
fIN = 70 MHz
−85
dBFS
fIN = 170 MHz
−80
dBFS
fIN = 10 MHz
−100
dBFS
fIN = 70 MHz
−95
dBFS
fIN = 170 MHz
−85
dBFS
fIN = 10 MHz
−90
dBFS
fIN = 70 MHz
−88
dBFS
fIN = 170 MHz
−83
dBFS
fIN = 10 MHz
71.1
dBFS
fIN = 70 MHz
69.8
dBFS
fIN = 170 MHz
67.7
dBFS
ADC12DC080 Logic and Power Supply Electrical Characteristics
Unless otherwise specified, the following specifications apply: AGND = DRGND = 0V, VA = +3.0V, VDR = +2.5V, Internal VREF =
+1.2V, fCLK = 80 MHz, VCM = VCMO, CL = 5 pF/pin. Typical values are for TA = 25°C. Boldface limits apply for TMIN ≤ TA ≤
TMAX. All other limits apply for TA = 25°C (Notes 8, 9)
Symbol
Parameter
Conditions
Typical
(Note 10)
Limits
Units
(Limits)
2.0
V (min)
0.8
V (max)
DIGITAL INPUT CHARACTERISTICS (CLK, PD_A,PD_B)
VIN(1)
Logical “1” Input Voltage
VD = 3.6V
VIN(0)
Logical “0” Input Voltage
VD = 3.0V
IIN(1)
Logical “1” Input Current
VIN = 3.3V
10
µA
IIN(0)
Logical “0” Input Current
VIN = 0V
−10
µA
CIN
Digital Input Capacitance
5
pF
DIGITAL OUTPUT CHARACTERISTICS (DA0-DA11,DB0-DB11,DRDY)
VOUT(1)
Logical “1” Output Voltage
IOUT = −0.5 mA , VDR = 2.4V
VOUT(0)
Logical “0” Output Voltage
IOUT = 1.6 mA, VDR = 2.4V
+ISC
Output Short Circuit Source Current
VOUT = 0V
−10
mA
−ISC
Output Short Circuit Sink Current
VOUT = VDR
10
mA
COUT
Digital Output Capacitance
5
pF
POWER SUPPLY CHARACTERISTICS
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6
1.2
V (min)
0.4
V (max)
Parameter
Conditions
Typical
(Note 10)
Limits
Units
(Limits)
IA
Analog Supply Current
Full Operation
200
mA (max)
IDR
Digital Output Supply Current
Full Operation (Note 13)
26
mA
Power Consumption
Excludes IDR (Note 13)
600
mW (max)
Power Down Power Consumption
PD_A=PD_B=VA
30
mW
ADC12DC080 Timing and AC Characteristics
Unless otherwise specified, the following specifications apply: AGND = DRGND = 0V, VA = +3.0V, VDR = +2.5V, Internal VREF =
+1.2V, fCLK = 80 MHz, VCM = VCMO, CL = 5 pF/pin. Typical values are for TA = 25°C. Timing measurements are taken at 50% of
the signal amplitude. Boldface limits apply for TMIN ≤ TA ≤ TMAX. All other limits apply for TA = 25°C (Notes 8, 9)
Typical
(Note 10)
Limits
Units
(Limits)
Maximum Clock Frequency
80
MHz (max)
Minimum Clock Frequency
20
MHz (min)
Symb
Parameter
Conditions
tCH
Clock High Time
6
tCL
Clock Low Time
6
tCONV
Conversion Latency
tOD
Output Delay of CLK to DATA
Relative to rising edge of CLK
4
tSU
Data Output Setup Time
Relative to DRDY
5
ns (min)
tH
Data Output Hold Time
Relative to DRDY
5
ns (min)
tAD
Aperture Delay
0.6
ns
tAJ
Aperture Jitter
0.1
ps rms
7
ns
ns
7
Clock Cycles
2
6
ns (min)
ns (max)
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ADC12DC080/ADC12DC105
Symbol
ADC12DC080/ADC12DC105
ADC12DC105 Converter Electrical Characteristics
This product is currently under development. As such, the parameters specified are DESIGN TARGETS. The specifications cannot be guaranteed until device characterization has taken place.
Unless otherwise specified, the following specifications apply: AGND = DRGND = 0V, VA = +3.3V, VDR = +2.5V, Internal VREF =
+1.2V, fCLK = 105 MHz, VCM = VCMO, CL = 5 pF/pin. Typical values are for TA = 25°C. Boldface limits apply for TMIN ≤ TA ≤
TMAX. All other limits apply for TA = 25°C (Notes 8, 9)
Symbol
Parameter
Conditions
Typical
Limits
(Note 10)
Units
(Limits)
STATIC CONVERTER CHARACTERISTICS
Resolution with No Missing Codes
12
Bits (min)
INL
Integral Non Linearity (Note 11)
±0.5
LSB (max)
LSB (min)
DNL
Differential Non Linearity
±0.4
LSB (max)
LSB (min)
Under Range Output Code
0
0
Over Range Output Code
4095
4095
REFERENCE AND ANALOG INPUT CHARACTERISTICS
VCMO
Common Mode Output Voltage
1.5
1.45
1.55
V (min)
V (max)
VCM
Analog Input Common Mode Voltage
1.5
1.4
1.6
V (min)
V (max)
CIN
VIN Input Capacitance (each pin to GND) VIN = 1.5 Vdc
(Note 12)
± 0.5 V
VREF
(CLK LOW)
8.5
(CLK HIGH)
3.5
External Reference Voltage
1.20
pF
pF
1.176
1.224
V (min)
V (max)
ADC12DC105 Dynamic Converter Electrical Characteristics
Unless otherwise specified, the following specifications apply: AGND = DRGND = 0V, VA = +3.3V, VDR = +2.5V, Internal VREF =
+1.2V, fCLK = 105 MHz, VCM = VCMO, CL = 5 pF/pin, . Typical values are for TA = 25°C. Boldface limits apply for TMIN ≤ TA ≤
TMAX. All other limits apply for TA = 25°C (Notes 8, 9)
Symbol
Parameter
Conditions
Typical
Limits
(Note 10)
Units
(Limits)
(Note 2)
DYNAMIC CONVERTER CHARACTERISTICS, AIN = -1dBFS
FPBW
Full Power Bandwidth
SNR
Signal-to-Noise Ratio
SFDR
ENOB
THD
H2
Spurious Free Dynamic Range
Effective Number of Bits
Total Harmonic Disortion
Second Harmonic Distortion
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-1 dBFS Input, −3 dB Corner
1.0
GHz
fIN = 10 MHz
70.1
dBFS
fIN = 70 MHz
69.1
dBFS
fIN = 240 MHz
67
dBFS
fIN = 10 MHz
88
dBFS
fIN = 70 MHz
85
dBFS
fIN = 240 MHz
83
dBFS
fIN = 10 MHz
11.3
Bits
fIN = 70 MHz
11.2
Bits
fIN = 240 MHz
10.8
Bits
fIN = 10 MHz
−86
dBFS
fIN = 70 MHz
−85
dBFS
fIN = 240 MHz
−80
dBFS
fIN = 10 MHz
−95
dBFS
fIN = 70 MHz
−90
dBFS
fIN = 240 MHz
−85
dBFS
8
H3
SINAD
Parameter
Conditions
Third Harmonic Distortion
Signal-to-Noise and Distortion Ratio
Typical
Limits
(Note 10)
Units
(Limits)
(Note 2)
fIN = 10 MHz
−88
dBFS
fIN = 70 MHz
−85
dBFS
fIN = 240 MHz
−83
dBFS
fIN = 10 MHz
70
dBFS
fIN = 70 MHz
69
dBFS
fIN = 240 MHz
66.8
dBFS
ADC12DC105 Logic and Power Supply Electrical Characteristics
Unless otherwise specified, the following specifications apply: AGND = DRGND = 0V, VA = +3.3V, VDR = +2.5V, Internal VREF =
+1.2V, fCLK = 105 MHz, VCM = VCMO, CL = 5 pF/pin. Typical values are for TA = 25°C. Boldface limits apply for TMIN ≤ TA ≤
TMAX. All other limits apply for TA = 25°C (Notes 8, 9)
Symbol
Parameter
Conditions
Typical
(Note 10)
Limits
Units
(Limits)
DIGITAL INPUT CHARACTERISTICS (CLK, PD_A,PD_B)
VIN(1)
Logical “1” Input Voltage
VD = 3.6V
2.0
V (min)
VIN(0)
Logical “0” Input Voltage
VD = 3.0V
0.8
V (max)
IIN(1)
Logical “1” Input Current
VIN = 3.3V
10
µA
IIN(0)
Logical “0” Input Current
VIN = 0V
−10
µA
CIN
Digital Input Capacitance
5
pF
DIGITAL OUTPUT CHARACTERISTICS (DA0-DA11,DB0-DB11,DRDY)
VOUT(1)
Logical “1” Output Voltage
IOUT = −0.5 mA , VDR = 2.4V
1.2
V (min)
VOUT(0)
Logical “0” Output Voltage
IOUT = 1.6 mA, VDR = 2.4V
0.4
V (max)
+ISC
Output Short Circuit Source Current
VOUT = 0V
−10
mA
−ISC
Output Short Circuit Sink Current
VOUT = VDR
10
mA
COUT
Digital Output Capacitance
5
pF
242
mA (max)
POWER SUPPLY CHARACTERISTICS
IA
Analog Supply Current
Full Operation
IDR
Digital Output Supply Current
Full Operation (Note 13)
32
mA
Power Consumption
Excludes IDR (Note 13)
800
mW (max)
Power Down Power Consumption
PD_A=PD_B=VA
33
mW
ADC12DC105 Timing and AC Characteristics
Unless otherwise specified, the following specifications apply: AGND = DRGND = 0V, VA = +3.3V, VDR = +2.5V, Internal VREF =
+1.2V, fCLK = 105 MHz, VCM = VCMO, CL = 5 pF/pin. Typical values are for TA = 25°C. Timing measurements are taken at 50% of
the signal amplitude. Boldface limits apply for TMIN ≤ TA ≤ TMAX. All other limits apply for TA = 25°C (Notes 8, 9)
Symb
Parameter
Conditions
Typical
(Note 10)
Maximum Clock Frequency
Minimum Clock Frequency
Limits
Units
(Limits)
105
MHz (max)
20
MHz (min)
tCH
Clock High Time
4
ns
tCL
Clock Low Time
4
ns
tCONV
Conversion Latency
7
Clock Cycles
tOD
Output Delay of CLK to DATA
Relative to rising edge of CLK
4
2
6
ns (min)
ns (max)
tSU
Data Output Setup Time
Relative to DRDY
3
ns (min)
tH
Data Output Hold Time
Relative to DRDY
3
ns (min)
tAD
Aperture Delay
0.6
ns
tAJ
Aperture Jitter
0.1
ps rms
9
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ADC12DC080/ADC12DC105
Symbol
ADC12DC080/ADC12DC105
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
guaranteed to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.
The guaranteed specifications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under
the listed test conditions. Operation of the device beyond the maximum Operating Ratings is not recommended.
Note 2: This parameter is specified in units of dBFS - indicating the value that would be attained with a full-scale input signal.
Note 3: All voltages are measured with respect to GND = AGND = DRGND = 0V, unless otherwise specified.
Note 4: When the input voltage at any pin exceeds the power supplies (that is, VIN < AGND, or VIN > VA), the current at that pin should be limited to ±5 mA. The
±50 mA maximum package input current rating limits the number of pins that can safely exceed the power supplies with an input current of ±5 mA to 10.
Note 5: The maximum allowable power dissipation is dictated by TJ,max, the junction-to-ambient thermal resistance, (θJA), and the ambient temperature, (TA), and
can be calculated using the formula PD,max = (TJ,max - TA )/θJA. The values for maximum power dissipation listed above will be reached only when the device is
operated in a severe fault condition (e.g. when input or output pins are driven beyond the power supply voltages, or the power supply polarity is reversed). Such
conditions should always be avoided.
Note 6: Human Body Model is 100 pF discharged through a 1.5 kΩ resistor. Machine Model is 220 pF discharged through 0 Ω
Note 7: Reflow temperature profiles are different for lead-free and non-lead-free packages.
Note 8: The inputs are protected as shown below. Input voltage magnitudes above VA or below GND will not damage this device, provided current is limited per
(Note 4). However, errors in the A/D conversion can occur if the input goes above 2.6V or below GND as described in the Operating Ratings section.
30015411
Note 9: With a full scale differential input of 2VP-P , the 12-bit LSB is 488 µV.
Note 10: Typical figures are at TA = 25°C and represent most likely parametric norms at the time of product characterization. The typical specifications are not
guaranteed.
Note 11: Integral Non Linearity is defined as the deviation of the analog value, expressed in LSBs, from the straight line that passes through positive and negative
full-scale.
Note 12: The input capacitance is the sum of the package/pin capacitance and the sample and hold circuit capacitance.
Note 13: IDR is the current consumed by the switching of the output drivers and is primarily determined by load capacitance on the output pins, the supply voltage,
VDR, and the rate at which the outputs are switching (which is signal dependent). IDR=VDR(C0 x f0 + C1 x f1 +....C11 x f11) where VDR is the output driver power
supply voltage, Cn is total capacitance on the output pin, and fn is the average frequency at which that pin is toggling.
Note 14: This parameter is guaranteed by design and/or characterization and is not tested in production.
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10
APERTURE DELAY is the time after the falling edge of the
clock to when the input signal is acquired or held for conversion.
APERTURE JITTER (APERTURE UNCERTAINTY) is the
variation in aperture delay from sample to sample. Aperture
jitter manifests itself as noise in the output.
CLOCK DUTY CYCLE is the ratio of the time during one cycle
that a repetitive digital waveform is high to the total time of
one period. The specification here refers to the ADC clock
input signal.
COMMON MODE VOLTAGE (VCM) is the common DC voltage applied to both input terminals of the ADC.
CONVERSION LATENCY is the number of clock cycles between initiation of conversion and when that data is presented
to the output driver stage. Data for any given sample is available at the output pins the Pipeline Delay plus the Output
Delay after the sample is taken. New data is available at every
clock cycle, but the data lags the conversion by the pipeline
delay.
CROSSTALK is coupling of energy from one channel into the
other channel.
DIFFERENTIAL NON-LINEARITY (DNL) is the measure of
the maximum deviation from the ideal step size of 1 LSB.
EFFECTIVE NUMBER OF BITS (ENOB, or EFFECTIVE
BITS) is another method of specifying Signal-to-Noise and
Distortion Ratio or SINAD. ENOB is defined as (SINAD 1.76) / 6.02 and says that the converter is equivalent to a
perfect ADC of this (ENOB) number of bits.
FULL POWER BANDWIDTH is a measure of the frequency
at which the reconstructed output fundamental drops 3 dB
below its low frequency value for a full scale input.
GAIN ERROR is the deviation from the ideal slope of the
transfer function. It can be calculated as:
Gain Error = Positive Full Scale Error − Negative Full Scale
Error
It can also be expressed as Positive Gain Error and Negative
Gain Error, which are calculated as:
PGE = Positive Full Scale Error - Offset Error
NGE = Offset Error - Negative Full Scale Error
INTEGRAL NON LINEARITY (INL) is a measure of the deviation of each individual code from a best fit straight line. The
deviation of any given code from this straight line is measured
from the center of that code value.
INTERMODULATION DISTORTION (IMD) is the creation of
additional spectral components as a result of two sinusoidal
frequencies being applied to the ADC input at the same time.
It is defined as the ratio of the power in the intermodulation
products to the total power in the original frequencies. IMD is
usually expressed in dBFS.
LSB (LEAST SIGNIFICANT BIT) is the bit that has the smallest value or weight of all bits. This value is VFS/2n, where
“VFS” is the full scale input voltage and “n” is the ADC resolution in bits.
MISSING CODES are those output codes that will never appear at the ADC outputs. The ADC is guaranteed not to have
any missing codes.
where f1 is the RMS power of the fundamental (output) frequency and f2 through f10 are the RMS power of the first 9
harmonic frequencies in the output spectrum.
SECOND HARMONIC DISTORTION (2ND HARM) is the difference expressed in dB, between the RMS power in the input
frequency at the output and the power in its 2nd harmonic
level at the output.
THIRD HARMONIC DISTORTION (3RD HARM) is the difference, expressed in dB, between the RMS power in the
input frequency at the output and the power in its 3rd harmonic
level at the output.
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ADC12DC080/ADC12DC105
MSB (MOST SIGNIFICANT BIT) is the bit that has the largest
value or weight. Its value is one half of full scale.
NEGATIVE FULL SCALE ERROR is the difference between
the actual first code transition and its ideal value of ½ LSB
above negative full scale.
OFFSET ERROR is the difference between the two input
voltages [(VIN+) – (VIN-)] required to cause a transition from
code 2047 to 2048.
OUTPUT DELAY is the time delay after the falling edge of the
clock before the data update is presented at the output pins.
PIPELINE DELAY (LATENCY) See CONVERSION LATENCY.
POSITIVE FULL SCALE ERROR is the difference between
the actual last code transition and its ideal value of 1½ LSB
below positive full scale.
POWER SUPPLY REJECTION RATIO (PSRR) is a measure
of how well the ADC rejects a change in the power supply
voltage. PSRR is the ratio of the Full-Scale output of the ADC
with the supply at the minimum DC supply limit to the FullScale output of the ADC with the supply at the maximum DC
supply limit, expressed in dB.
SIGNAL TO NOISE RATIO (SNR) is the ratio, expressed in
dB, of the rms value of the input signal to the rms value of the
sum of all other spectral components below one-half the sampling frequency, not including harmonics or DC.
SIGNAL TO NOISE PLUS DISTORTION (S/N+D or
SINAD) Is the ratio, expressed in dB, of the rms value of the
input signal to the rms value of all of the other spectral components below half the clock frequency, including harmonics
but excluding d.c.
SPURIOUS FREE DYNAMIC RANGE (SFDR) is the difference, expressed in dB, between the rms values of the input
signal and the peak spurious signal, where a spurious signal
is any signal present in the output spectrum that is not present
at the input.
TOTAL HARMONIC DISTORTION (THD) is the ratio, expressed in dB, of the rms total of the first nine harmonic levels
at the output to the level of the fundamental at the output. THD
is calculated as
Specification Definitions
ADC12DC080/ADC12DC105
Timing Diagrams
30015409
FIGURE 1. Output Timing
Transfer Characteristic
30015410
FIGURE 2. Transfer Characteristic
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ADC12DC080/ADC12DC105
Physical Dimensions inches (millimeters) unless otherwise noted
TOP View...............................SIDE View...............................BOTTOM View
60-Lead LLP Package
Ordering Numbers:
ADC12DC080CISQ / ADC12DC105CISQ
NS Package Number SQA60A
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ADC12DC080/ADC12DC105 Dual 12-Bit, 80/105 MSPS A/D Converter with CMOS Outputs
Notes
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