Dual 8-Bit, 60 MSPS A/D Converter AD9059

Dual 8-Bit, 60 MSPS A/D Converter AD9059
Dual 8-Bit, 60 MSPS A/D Converter
AD9059
FEATURES
Dual 8-Bit ADCs on a Single Chip
Low Power: 400 mW Typical
On-Chip 2.5 V Reference and Track-and-Hold
1 V p-p Analog Input Range
Single 5 V Supply Operation
5 V or 3 V Logic Interface
120 MHz Analog Bandwidth
Power-Down Mode: <12 mW
APPLICATIONS
Digital Communications (QAM Demodulators)
RGB and YC/Composite Video Processing
Digital Data Storage Read Channels
Medical Imaging
Digital Instrumentation
FUNCTIONAL BLOCK DIAGRAM
PWRDN
VD
VDD
AD9059
AINA
T/H
ADCA
8
D7A–D0A
VREF
ENCODE
2.5V
AINB
T/H
ADCB
8
D7B–D0B
GND
PIN CONFIGURATION
PRODUCT DESCRIPTION
The AD9059 is a dual 8-bit monolithic analog-to-digital converter
optimized for low cost, low power, small size, and ease of use.
With a 60 MSPS encode rate capability and full-power analog
bandwidth of 120 MHz typical, the component is ideal for
applications requiring multiple ADCs with excellent dynamic
performance.
AINA 1
28 AINB
VREF 2
27 GND
26 ENCODE
PWRDN 3
25 VD
VD 4
GND 5
AD9059
24 GND
VDD 6
TOP VIEW 23 VDD
D7A (MSB) 7 (Not to Scale) 22 D7B (MSB)
To minimize system cost and power dissipation, the AD9059
includes an internal 2.5 V reference and dual track-and-hold
circuits. The ADC requires only a 5 V power supply and an
encode clock. No external reference or driver components are
required for many applications.
D6A 8
21 D6B
D5A 9
20 D5B
D4A 10
19 D4B
D3A 11
18 D3B
D2A 12
17 D2B
The AD9059’s single encode input is TTL/CMOS compatible
and simultaneously controls both internal ADC channels. The
parallel 8-bit digital outputs can be operated from 5 V or 3 V
supplies. A power-down function may be exercised to bring
total consumption to <12 mW when ADC data is not required
for lengthy periods of time. In power-down mode, the digital
outputs are driven to a high impedance state.
D1A 13
16 D1B
D0A (LSB) 14
15 D0B (LSB)
Fabricated on an advanced BiCMOS process, the AD9059
is available in a space-saving 28-lead shrink small outline
package (28-lead SSOP) and is specified over the industrial
temperature range (–40°C to +85°C).
Customers desiring single-channel digitization may consider the
AD9057, a single 8-bit, 60 MSPS monolithic based on the
AD9059 ADC core. The AD9057 is available in a 20-lead shrink
small outline package (20-lead SSOP) and is specified over the
industrial temperature range.
REV. A
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective companies.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
www.analog.com
Fax: 781/326-8703
© 2003 Analog Devices, Inc. All rights reserved.
AD9059–SPECIFICATIONS
(V = 5 V, V
ELECTRICAL CHARACTERISTICS
D
Parameter
DD
= 3 V, external reference, ENCODE = 60 MSPS, unless otherwise noted.)
Temp
Test Level
Min
RESOLUTION
AD9059BRS
Typ
Max
8
DC ACCURACY
Differential Nonlinearity
25°C
Full
25°C
Full
Full
25°C
Full
Full
I
VI
I
VI
VI
I
VI
V
25°C
25°C
Full
25°C
25°C
25°C
25°C
V
I
VI
V
V
I
V
CHANNEL MATCHING (A to B)
Gain Delta
Input Offset Voltage Delta
25°C
25°C
V
V
BAND GAP REFERENCE
Output Voltage
Temperature Coefficient
Full
Full
VI
V
2.4
SWITCHING PERFORMANCE
Maximum Conversion Rate
Minimum Conversion Rate
Aperture Delay (tA)
Aperture Uncertainty (Jitter)
Output Valid Time (tV)2
Output Propagation Delay (tPD)2
Full
Full
25°C
25°C
Full
Full
VI
IV
V
V
IV
IV
60
25°C
25°C
V
V
25°C
25°C
I
V
25°C
25°C
Integral Nonlinearity
No Missing Codes
Gain Error1
Gain Temperature Coefficient1
ANALOG INPUT
Input Voltage Range (Centered at 2.5 V)
Input Offset Voltage
Input Resistance
Input Capacitance
Input Bias Current
Analog Bandwidth
0.75
0.75
–6
–8
–15
–25
Bits
2.0
2.5
2.0
2.5
Guaranteed
–2.5
+6
+8
± 70
1.0
0
150
2
6
120
+15
+25
16
±1
±4
2.5
± 10
4.0
LSB
LSB
LSB
LSB
% FS
% FS
ppm/°C
V p-p
mV
mV
kΩ
pF
µA
MHz
% FS
mV
2.6
5
2.7
5
6.6
9.5
Unit
14.2
V
ppm/°C
MSPS
MSPS
ns
ps, rms
ns
ns
3
DYNAMIC PERFORMANCE
Transient Response
Overvoltage Recovery Time
Signal-to-Noise Ratio (SINAD) (with Harmonics)
fIN = 10.3 MHz
fIN = 76 MHz
Effective Number of Bits (ENOB)
fIN = 10.3 MHz
fIN = 76 MHz
Signal-to-Noise Ratio (SNR) (Without Harmonics)
fIN = 10.3 MHz
fIN = 76 MHz
Second Harmonic Distortion
fIN = 10.3 MHz
fIN = 76 MHz
Third Harmonic Distortion
fIN = 10.3 MHz
fIN = 76 MHz
Two-Tone Intermodulation Distortion (IMD)
Channel Crosstalk Rejection
Differential Phase
Differential Gain
9
9
ns
ns
40
44.5
43.5
dB
dB
I
V
6.35
7.1
6.9
Bits
Bits
25°C
25°C
I
V
42
46
45
dB
dB
25°C
25°C
I
V
–50
–62
–54
dBc
dBc
25°C
25°C
25°C
25°C
25°C
25°C
I
V
V
V
V
V
–46
–60
–54
–52
–50
0.8
1.0
dBc
dBc
dBc
dBc
Degrees
%
–2–
REV. A
AD9059
SPECIFICATIONS (continued)
Parameter
Temp
Test Level
Min
DIGITAL INPUTS
Logic 1 Voltage
Logic 0 Voltage
Logic 1 Current
Logic 0 Current
Input Capacitance
Encode Pulsewidth High (tEH)
Encode Pulsewidth Low (tEL)
Full
Full
Full
Full
25°C
25°C
25°C
VI
VI
VI
VI
V
IV
IV
2.0
Full
Full
Full
VI
IV
VI
Full
Full
Full
Full
25°C
VI
VI
VI
VI
I
DIGITAL OUTPUTS
Logic 1 Voltage (VDD = 3 V)
Logic 1 Voltage (VDD = 5 V)
Logic 0 Voltage (VDD = 3 V or 5 V)
Output Coding
POWER SUPPLY
VD Supply Current (VD = 5 V)
VDD Supply Current (VDD = 3 V)4
Power Dissipation5, 6
Power-Down Dissipation
Power Supply Rejection Ratio (PSRR)
AD9059BRS
Typ
Max
0.8
±1
±1
4.5
6.7
6.7
166
166
2.95
4.95
0.05
Offset Binary Code
72
13
400
6
3
92
15
505
12
Unit
V
V
µA
µA
pF
ns
ns
V
V
V
mA
mA
mW
mW
mV/V
NOTES
1
Gain error and gain temperature coefficient are based on the ADC only (with a fixed 2.5 V external reference).
2
tV and tPD are measured from the 1.5 V level of the ENCODE to the 10%/90% levels of the digital output swing. The digital output load during test is not to exceed
an ac load of 10 pF or a dc current of ± 40 µA.
3
SNR/harmonics based on an analog input voltage of –0.5 dBFS referenced to a 1.0 V full-scale input range.
4
Digital supply current based on V DD = 3 V output drive with <10 pF loading under dynamic test conditions.
5
Power dissipation is based on 60 MSPS encode and 10.3 MHz analog input dynamic test conditions (V D = 5 V ± 5%, VDD = 3 V ± 5%).
6
Typical thermal impedance for the RS style (SSOP) 28-lead package: θJC = 39°C/W, θCA = 70°C/W, and θJA = 109°C/W.
Specifications subject to change without notice.
EXPLANATION OF TEST LEVELS
ABSOLUTE MAXIMUM RATINGS*
Test Level
I – 100% production tested.
VD, VDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
Analog Inputs . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to VD + 0.5 V
Digital Inputs . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to VD + 0.5 V
VREF Input . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to VD + 0.5 V
Digital Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA
Operating Temperature . . . . . . . . . . . . . . . . . . –55°C to +125°C
Storage Temperature . . . . . . . . . . . . . . . . . . . . –65°C to +150°C
II –
100% production tested at +25°C and sample tested at
specified temperatures.
III –
Sample tested only.
IV –
Parameter is guaranteed by design and characterization
testing.
V –
Parameter is a typical value only.
VI –
100% production tested at +25°C; guaranteed by design
and characterization testing for industrial temperature range.
*Stresses above those listed under Absolute Maximum Ratings may cause permanent
damage to the device. This is a stress rating only; functional operation of the device
at these or any other conditions above those indicated in the operational sections of
this specification is not implied. Exposure to absolute maximum ratings for extended
periods may affect device reliability.
ORDERING GUIDE
Model
Temperature Range
Package Option
AD9059BRS
AD9059/PCB
–40°C to +85°C
25°C
RS-28
Evaluation Board
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although the
AD9059 features proprietary ESD protection circuitry, permanent damage may occur on devices
subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended
to avoid performance degradation or loss of functionality.
REV. A
–3–
AD9059
PIN FUNCTION DESCRIPTIONS
N
N+3
N+5
N+1
AIN
N+2
N+4
Pin No.
Mnemonic
1, 28
AINA, AINB Analog Inputs for ADC A and B.
2
VREF
Internal Voltage Reference (2.5 V
Typical); Bypass with 0.1 µF to
Ground or Overdrive with External
Voltage Reference.
3
PWRDN
Power-Down Function Select; Logic
HIGH for Power-Down Mode
(Digital Outputs Go to HighImpedance State).
4, 25
VD
Analog 5 V Power Supply.
tA
ENCODE
tEH
tEL
tV
DIGITAL
OUTPUTS
N–3
N–2
N–1
N
N+1
N+2
tPD
MIN
tA
tEH
tEL
tV
tPD
TYP
MAX
2.7ns
APERTURE DELAY
PULSEWIDTH HIGH
6.7ns
PULSEWIDTH LOW
6.7ns
OUTPUT VALID TIME
4.0ns
OUTPUT PROP DELAY
166ns
5, 24, 27
GND
Ground.
6, 23
VDD
Digital Output Power Supply.
Nominally 3 V to 5 V.
7–14
D7A–D0A
Digital Outputs of ADC A.
22–15
D7B–D0B
Digital Outputs of ADC B.
26
ENCODE
Encode Clock for ADCs A and B
(ADCs Sample Simultaneously on
the Rising Edge of ENCODE).
166ns
6.6n
9.5ns
14.2ns
Figure 1. Timing Diagram
PIN CONFIGURATION
AINA 1
28 AINB
VREF 2
27 GND
AD9059
24 GND
VDD 6
23 VDD
D6A 8
21 D6B
D5A 9
20 D5B
D4A 10
19 D4B
D3A 11
18 D3B
D2A 12
17 D2B
D1A 13
16 D1B
TOP VIEW
D7A (MSB) 7 (Not to Scale) 22 D7B (MSB)
D0A (LSB) 14
Analog Input (V)
Voltage Level
Digital Output
3.0
2.502
2.498
2.0
Positive Full Scale
Midscale + 1/2 LSB
Midscale – 1/2 LSB
Negative Full Scale
1111 1111
1000 0000
0111 1111
0000 0000
25 VD
VD 4
GND 5
Table I. Digital Coding (VREF = 2.5 V)
26 ENCODE
PWRDN 3
Function
15 D0B (LSB)
–4–
REV. A
Typical Performance Characteristics–AD9059
–30
0
ENCODE = 60MSPS
ANALOG IN = 10.3MHz, –0.5dBFS
SINAD = 43.9dB
ENOB = 7.0 BITS
SNR = 45.1dB
–10
–20
–30
ENCODE = 60MSPS
AIN = –0.5dBFS
–35
–40
–45
SECOND HARMONIC
dB
dB
–40
–50
–50
–55
–60
–60
–70
THIRD HARMONIC
–65
–80
–90
0
–70
30
FREQUENCY (MHz)
20
60
80
100
120
140
160
TPC 4. Harmonic Distortion vs. AIN Frequency
0
0
ENCODE = 60MSPS
–10
ANALOG IN = 76MHz, –0.5dBFS
–20 SINAD = 43.0dB
ENOB = 6.85 BITS
–30 SNR = 44.1dB
–10
–40
–40
ENCODE = 60MSPS
F1 IN = 9.5MHz @ –7.0dBFS
F2 IN = 9.9MHz @ –7.0dBFS
2F1 - F2 = –52.0dBc
2F2 - F1 = –53.0dBc
–20
dB
–30
–50
–50
–60
–60
–70
–70
–80
–80
–90
0
–90
30
FREQUENCY (MHz)
0
10
TPC 2. Spectral Plot 60 MSPS, 76 MHz
30
54
SNR
AIN = 10.3MHz, –0.5dBFS
44
SNR
48
42
42
SINAD
SINAD
40
36
dB
38
ENCODE = 60MSPS
AIN = –0.5dBFS
36
30
24
34
18
32
12
30
0
20
40
60
80
100
120
140
ANALOG INPUT FREQUENCY (MHz)
6
160
5
TPC 3. SINAD/SNR vs. AIN Frequency
REV. A
20
FREQUENCY (MHz)
TPC 5. Two-Tone IMD
46
dB
40
ANALOG INPUT FREQUENCY (MHz)
TPC 1. FFT Spectral Plot 60 MSPS, 10.3 MHz
dB
0
10
20
30
40
50
60
ENCODE RATE (MSPS)
70
80
TPC 6. SINAD/SNR vs. Encode Rate
–5–
90
AD9059
600
12
AIN = 10.3MHz, –0.5dBFS
11
550
10
VDD = 3V
9.5
450
9.0
VDD = 5V
tPD (ns)
POWER (mW)
500
400
8.5
8.0
7.5
350
VDD = 3V
300
VDD = 5V
7.0
6.5
250
5
10
20
30
40
50
60
ENCODE RATE (MSPS)
70
80
6.0
–45
90
TPC 7. Power Dissipation vs. Encode Rate
0
25
TEMPERATURE (°C)
70
90
TPC 10. tPD vs. Temperature/Supply (3 V/5 V)
45.5
46.0
SNR
45.5
45.0
SNR
45.0
44.5
44.5
SINAD
44.0
43.5
43.5
dB
dB
44.0
SINAD
43.0
43.0
42.5
ENCODE = 60MSPS
AIN = 10.3MHz, –0.5dBFS
42.5
42.0
ENCODE = 60MSPS
AIN = 10.3MHz, –0.5dBFS
41.5
42.0
41.0
41.5
–45
0
25
70
TEMPERATURE (°C)
40.5
5.8
90
6.7
7.5
8.4
9.2
10
10.9
ENCODE HIGH PULSEWIDTH (ns)
TPC 8. SINAD/SNR vs. Temperature
TPC 11. SINAD/SNR vs. Encode Pulsewidth
0
0
–1
–0.2
–2
–0.4
ADC GAIN (dB)
GAIN ERROR (%)
–3
–0.6
–0.8
–1.0
–1.2
–1.4
–5
–6
ENCODE = 60MSPS
AIN = –0.5dBFS
–7
–8
–9
–1.6
–1.8
–45
–4
–10
0
25
70
TEMPERATURE (°C)
90
1
2
5
10
20
50
100
200
500
ANALOG FREQUENCY (MHz)
TPC 12. ADC Frequency Response
TPC 9. ADC Gain vs. Temperature (With External
2.5 V Reference)
–6–
REV. A
AD9059
Figure 3 shows typical connections for high performance dc
biasing using the ADC’s internal voltage reference. All components may be powered from a single 5 V supply (analog input
signals are referenced to ground).
THEORY OF OPERATION
The AD9059 combines Analog Devices’ proprietary MagAmp
gray code conversion circuitry with flash converter technology to
provide dual high performance 8-bit ADCs in a single low cost
monolithic device. The design architecture ensures low power,
high speed, and 8-bit accuracy.
1k⍀
The AD9059 provides two linked ADC channels that are clocked
from a single ENCODE input (see Functional Block Diagram).
The two ADC channels simultaneously sample the analog inputs
(AINA and AINB) and provide noninterleaved parallel digital
outputs (D0A–D7A and D0B–D7B). The voltage reference
(VREF) is internally connected to both ADCs so channel gains
and offsets will track if external reference control is desired.
1k⍀
1 AINA
10k⍀
3 VREF
10k⍀
AD9059
AD8041
VINB
(–0.5V TO +0.5V)
Figure 3. DC-Coupled AD9059 (VIN Inverted)
A stable and accurate 2.5 V voltage reference is built into the
AD9059 (VREF). The reference output is used to set the ADC
gain/offset and can provide dc bias for the analog input signals.
The internal reference is tied to the ADC circuitry through an
800 Ω internal impedance and is capable of providing 300 µA
external drive current (for dc biasing the analog input or other
user circuitry).
Some applications may require greater accuracy, improved
temperature performance, or gain adjustments that cannot be
obtained using the internal reference. An external voltage may
be applied to the VREF pin to overdrive the internal voltage
reference for gain adjustment of up to ± 10% (the VREF pin is
internally tied directly to the ADC circuitry). ADC gain and
offset will vary simultaneously with external reference adjustment with a 1:1 ratio (a 2% or 50 mV adjustment to the 2.5 V
reference varies ADC gain by 2% and ADC offset by 50 mV).
Theoretical input voltage range versus reference input voltage
may be calculated using the following equations.
VRANGE ( p − p ) = VREF 2.5
VMIDSCALE = VREF
VTOP −OF − RANGE = VREF + VRANGE 2
VBOTTOM −OF − RANGE = VREF – VRANGE 2
0.1µF
1 AINA
AD9059
3 VREF
The external reference should have a 1 mA minimum sink/
source current capability to ensure complete overdrive of the
internal voltage reference.
0.1µF
1k⍀
28 AINB
0.1µF
Figure 2. Capacity Coupled AD9059
REV. A
1k⍀
Voltage Reference
5V
VINB
(1V p-p)
28 AINB
1k⍀
The AD9059 provides independent single-ended high impedance
(150 kΩ) analog inputs for the dual ADCs. Each input requires a
dc bias current of 6 µA (typical) centered near 2.5 V (±10%). The
dc bias may be provided by the user or may be derived from the
ADC’s internal voltage reference. Figure 2 shows a low cost dc
bias implementation that allows the user to capacitively couple
ac signals directly into the ADC without additional active circuitry. For best dynamic performance, the VREF pin should
be decoupled to ground with a 0.1 µF capacitor (to minimize
modulation of the reference voltage), and the bias resistor should
be approximately 1 kΩ.
EXTERNAL VREF
(OPTIONAL)
0.1µF
5V
USING THE AD9059
Analog Inputs
1k⍀
AD8041
VIN A
The analog input signal is buffered at the input of each ADC
channel and applied to a high speed track-and-hold. The trackand-hold circuit holds the analog input value during the
conversion process (beginning with the rising edge of the
ENCODE command). The track-and-hold’s output signal passes
through the gray code and flash conversion stages to generate
coarse and fine digital representations of the held analog input
level. Decode logic combines the multistage data and aligns the
8-bit word for strobed outputs on the rising edge of the ENCODE
command. The MagAmp/Flash architecture of the AD9059
results in three pipeline delays for the output data.
VINA
(1V p-p)
+5V
+5V
–7–
AD9059
Digital Logic (5 V/3 V Systems)
Applications
The digital inputs and outputs of the AD9059 can easily be
configured to interface directly with 3 V or 5 V logic systems.
The encode and power-down (PWRDN) inputs are CMOS
stages with TTL thresholds of 1.5 V, making the inputs compatible with TTL, 5 V CMOS, and 3 V CMOS logic families. As
with all high speed data converters, the encode signal should be
clean and jitter free to prevent degradation of ADC dynamic
performance.
The wide analog bandwidth of the AD9059 makes it attractive for
a variety of high performance receiver and encoder applications.
Figure 4 shows the dual ADC in a typical low cost I and Q
demodulator implementation for cable, satellite, or wireless
LAN modem receivers. The excellent dynamic performance of
the ADC at higher analog input frequencies and encode rates
empowers users to employ direct IF sampling techniques (see
TPC 2). IF sampling eliminates or simplifies analog mixer and
filter stages to reduce total system cost and power.
The AD9059’s digital outputs will also interface directly with 5 V
or 3 V CMOS logic systems. The voltage supply pins (VDD) for
these CMOS stages are isolated from the analog VD voltage
supply. By varying the voltage on these supply pins, the digital
output high levels will change for 5 V or 3 V systems. The VDD
pins are internally connected on the AD9059 die. Care should
be taken to isolate the VDD supply voltages from the 5 V analog
supply to minimize noise coupling into the ADCs.
AD9059
ADC
BPF
ADC
90°
IF IN
The AD9059 provides high impedance digital output operation
when the ADC is driven into power-down mode (PWRDN,
logic high). A 200 ns (minimum) power-down time should be
provided before a high impedance characteristic is required. A
200 ns power-up period should be provided to ensure accurate
ADC output data after reactivation (valid output data is available three clock cycles after the 200 ns delay).
BPF
VCO
VCO
Figure 4. I and Q Digital Receiver
The high sampling rate and analog bandwidth of the AD9059
are ideal for computer RGB video digitizer applications. With a
full-power analog bandwidth of 2× the maximum sampling rate,
the ADC provides sufficient pixel-to-pixel transient settling time
to ensure accurate 60 MSPS video digitization. Figure 5 shows
a typical RGB video digitizer implementation for the AD9059.
Timing
The AD9059 is guaranteed to operate with conversion rates
from 5 MSPS to 60 MSPS. At 60 MSPS, the ADC is designed
to operate with an encode duty cycle of 50%, but performance
is insensitive to moderate variations. Pulsewidth variations of up
to ± 10% (allowing the encode signal to meet the minimum/
maximum high/low specifications) will cause no degradation in
ADC performance (see Figure 1).
AD9059
RED
ADC
GREEN
ADC
8
8
PIXEL CLOCK
Due to the linked ENCODE architecture of the ADCs, the
AD9059 cannot be operated in a 2-channel ping-pong mode.
H-SYNC
Power Dissipation
BLUE
The power dissipation of the AD9059 is specified to reflect a
typical application setup under the following conditions: encode
is 60 MSPS, analog input is –0.5 dBFS at 10.3 MHz, VD is 5 V,
VDD is 3 V, and digital outputs are loaded with 7 pF typical
(10 pF maximum). The actual dissipation will vary as these
conditions are modified in user applications. TPC 7 shows typical power consumption for the AD9059 versus ADC encode
frequency and VDD supply voltage.
PLL
ADC
8
ADC
AD9059
Figure 5. RGB Video Encoder
A power-down function allows users to reduce power dissipation
when ADC data is not required. A TTL/CMOS high signal
(PWRDN) shuts down portions of the dual ADC and brings total
power dissipation to less than 10 mW. The internal band gap
voltage reference remains active during power-down mode to
minimize ADC reactivation time. If the power-down function is
not desired, Pin 3 should be tied to ground. Both ADC channels
are controlled simultaneously by the PWRDN pin; they cannot
be shut down or turned on independently.
–8–
REV. A
AD9059
+VD
800⍀
+VD
3k⍀
VREF
2.5V
+VDD
3V TO 5V
+VD
500⍀
ENCODE
PWRDN
D0–D7
AIN
VREF
2.5k⍀
VOLTAGE REFERENCE
DIGITAL INPUTS
DIGITAL OUTPUTS
ANALOG INPUTS
Figure 6. Equivalent Circuits
Analog input signals to the board should be 1 V p-p into 50 Ω
for full-scale ADC drive. For ac-coupled operation, connect E7
to E8 (analog input A to C12 feedthrough capacitor), E13 to
E15 (C12 to R15 termination resistor for Channel A), E4 to E6
(analog input B to C11 feedthrough capacitor), and E10 to E12
(C11 to R14 termination resistor for Channel B) using the
board jumper connectors.
Evaluation Board
The AD9059/PCB evaluation board provides an easy-to-use
analog/digital interface for the dual 8-bit, 60 MSPS ADC. The
board includes typical hardware configurations for a variety of high
speed digitization evaluations. On-board components include the
AD9059 (in the 28-lead SSOP package), optional analog input
buffer amplifiers, digital output latches, board timing drivers, and
configurable jumpers for ac coupling, dc coupling, and powerdown function testing. The board is configured at shipment for
dc coupling using the AD9059’s internal reference.
The on-board reference voltage may be used to drive the ADC or
an external reference may be applied. The standard configuration
employs the internal voltage reference without any external
connection requirements. An external voltage reference may be
applied at board connector input REF to overdrive the limited
current output of the AD9059’s internal voltage reference. The
external voltage reference should be 2.5 V typical.
For dc-coupled analog input applications, amplifiers U3 and U4
are configured to operate as unity gain inverters with adjustable
offset for the analog input signals. For full-scale ADC drive,
each analog input signal should be 1 V p-p into 50 Ω referenced
to ground. Each amplifier offsets its analog signal by +VREF
(2.5 V typical) to center the voltage for proper ADC input drive.
For dc-coupled operation, connect E7 to E9 (analog input A to
R11), E14 to E13 (amplifier output to analog input A of
AD9059), E4 to E5 (analog input B to R10), and E11 to E10
(amplifier output to analog input B of AD9059) using the board
jumper connectors.
The power-down function of the AD9059 can be exercised
through a board jumper connection. Connect E2 to E1 (5 V to
PWRDN) for power-down mode operation. For normal operation,
connect E3 to E1 (ground to PWRDN).
The encode signal source should be TTL/CMOS compatible
and capable of driving a 50 Ω termination. The digital outputs
of the AD9059 are buffered through latches on the evaluation
board (U5 and U6) and are available for the user at connector
Pins 30–37 and Pins 22–29. Latch timing is derived from the
ADC ENCODE clock and a digital clocking signal is provided
for the board user at connector Pins 2 and 21.
For ac-coupled analog input applications, amplifiers U3 and U4
are removed from the analog signal paths. The analog signals
are coupled through Capacitors C11 and C12, each terminated
to the VREF voltage through separate 1 kΩ resistors (providing
bias current for the AD9059 analog inputs, AINA and AINB).
REV. A
–9–
AD9059
J9, VDD
ANALOG IN–A
BNC
J5
U4
AD8041Q
E8
E7
R13
50⍀
E9
R11
1k⍀
C12
0.1µF
8
DIS
7
+VS
5V
6
5
NC
1
NC
2
3
4
–VS
C16
10µF
R5
10⍀
E14
E13
E15
R15
1k⍀
R7
1k⍀
R8
10k⍀
5V
C10
0.1µF
C17
10µF
R9
10k⍀
C8
0.1µF
J1, REF
E2
5V
R14
1k⍀
C9
0.1µF
U1
AD9059RS
E1
E3
PWRDN
D7A
D6A
D5A
D4A
D3A
D2A
D1A
D0A
1
2
3
4
5
6
7
8
9
10
11
12
13
14
AINA
VREF
PWRDN
VD
GND
VDD
D7A
D6A
D5A
D4A
D3A
D2A
D1A
D0A
P2
C37DRPF
28
AINB
27
GND
26
ENC
VD 25 5V
24
GND
23
VDD
22
D7B
D7B
21
D6B
D6B
20
D5B
D5B
19
D4B
D4B
18
D3B
D3B
17
D2B
D2B
16
D1B
D1B
15
D0B
D0B
U5
74ACQ574
D0B
D1B
D2B
D3B
D4B
D5B
D6B
D7B
9
8
7
6
5
4
3
2
E12
R8
1k⍀
BNC
J4
E5
R10
1k⍀
E4
E6
R12
50⍀
1
NC
2
3
4 –V
S
8
DIS
7 5V
+VS
6
5
NC
D7A
D6A
D5A
D4A
D3A
D2A
D1A
U7
74AC00
C6
0.1µF
C7
0.1µF
C4
0.1µF
C5
0.1µF
3
2
ENCODE
C14
0.1µF
C13
0.1µF
1
U7
74AC00
R15
50⍀
4
5
C15
10µF
6
U7
74AC00
DECOUPLING CAPS
12
13
J12, GND
9
8
7
6
5
4
8D
7D
6D
5D
4D
3D
3
2D
2
1D
D0A
CK
C11
0.1µF
5V
C3
0.1µF
DB0
DB1
DB2
DB3
DB4
DB5
DB6
DB7
U6
74ACQ574
R4
10⍀
BNC
J10
J11, VD
12
13
14
15
16
17
18
19
E10
E11
U3
AD8041Q
ANALOG IN–B
8D
8Q
7Q
7D
6Q
6D
5D
5Q
4Q
4D
3Q
3D
2Q
2D
1Q
1D
CK OE
11 1
11
8Q
7Q
6Q
5Q
4Q
3Q
2Q
1Q
OE
1
12
13
14
15
16
17
DA7
DA6
DA5
DA4
DA3
DA2
18
DA1
19
DA0
DB0
DB1
DB2
DB3
DB4
DB5
DB6
DB7
DA0
DA1
DA2
DA3
DA4
DA5
DA6
DA7
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
11
Figure 7. AD9059 Dual Evaluation Board Schematic
–10–
REV. A
AD9059
Figure 8. Evaluation Board Layout (Top)
Figure 9. Evaluation Board Layout (Bottom)
REV. A
–11–
AD9059
OUTLINE DIMENSIONS
28-Lead Shrink Small Outline Package [SSOP]
(RS-28)
C00563–0–4/03(A)
Dimensions shown in millimeters
10.50
10.20
9.90
28
15
5.60
5.30
5.00
8.20
7.80
7.40
14
1
1.85
1.75
1.65
2.00 MAX
0.10
COPLANARITY
0.25
0.09
0.05
MIN
0.38
0.22
0.65
BSC
SEATING
PLANE
8ⴗ
4ⴗ
0ⴗ
0.95
0.75
0.55
COMPLIANT TO JEDEC STANDARDS MO-150AH
Revision History
Location
Page
4/03—Data Sheet changed from REV. 0 to REV. A.
Renumbered Figures and TPCs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Universal
Changes to SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Updated OUTLINE DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
–12–
REV. A
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