INTERSIL HI5808_01

HI5808
TM
Data Sheet
April 2001
File Number
4233.5
12-Bit, 9MSPS A/D Converter
Features
The HI5808 is a monolithic, 12-bit, Analog-to-Digital
Converter fabricated in Intersil’s HBC10 BiCMOS process. It
is designed for high speed, high resolution applications
where wide bandwidth and low power consumption are
essential.
• Sampling Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9MSPS
The HI5808 is designed in a fully differential pipelined
architecture with a front end differential-in-differential-out
sample-and-hold (S/H). The HI5808 has excellent dynamic
performance while consuming 325mW power at 9MSPS.
• Full Power Input Bandwidth . . . . . . . . . . . . . . . . . 100MHz
The 100MHz full power input bandwidth is ideal for
communication systems and document scanner
applications. Data output latches are provided which present
valid data to the output bus with a latency of 3 clock cycles.
The digital outputs have a separate supply pin which can be
powered from a 3V to 5V supply.
• TTL/CMOS Compatible Digital I/O
HI5808BIB
HI5808EVAL1
SAMPLE
RATE
TEMP.
RANGE (oC)
9MSPS
-40 to 85
25
• Internal Sample and Hold
• Fully Differential Architecture
• Low Distortion
• Internal Voltage Reference
• Digital Outputs . . . . . . . . . . . . . . . . . . . . . . . . . 5V to 3.0V
Applications
• Digital Communication Systems
• Undersampling Digital IF
Ordering Information
PART
NUMBER
• Low Power
• Document Scanners
PKG.
NO.
PACKAGE
28 Ld SOIC
M28.3
• Additional Reference Documents
- AN9214 Using Intersil High Speed A/D Converters
- AN9724 Using the HI5808EVAL1 Evaluation Board
Evaluation Board
Pinout
HI5808
(SOIC)
TOP VIEW
1
CLK
1
28 D0
DVCC1
2
27 D1
DGND1
3
26 D2
DVCC1
4
25 D3
DGND1
5
24 D4
AVCC
6
23 D5
AGND
7
22 DVCC2
VIN+
8
21 DGND2
VIN -
9
20 D6
VDC 10
19 D7
VROUT 11
18 D8
VRIN 12
17 D9
AGND 13
16 D10
AVCC 14
15 D11
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil and Design is a trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2001, All Rights Reserved
HI5808
Functional Block Diagram
BIAS
VDC
VINVIN+
CLOCK
REF
S/H
CLK
VROUT
VRIN
STAGE 1
DVCC2
4-BIT
FLASH
4-BIT
DAC
+
∑
-
D11 (MSB)
D10
DIGITAL DELAY
AND
DIGITAL ERROR CORRECTION
X8
STAGE 3
4-BIT
FLASH
4-BIT
DAC
+
∑
-
D9
D8
D7
D6
D5
D4
D3
D2
D1
X8
D0 (LSB)
STAGE 4
4-BIT
FLASH
AVCC
AGND
DGND2
DVCC1
DGND1
Typical Applications Schematic
(LSB) (28) D0
(27) D1
VROUT (11) (26) D2
(25) D3
VRIN (12)
(24) D4
AGND (7)
(23) D5
AGND (13)
(20) D6
DGND1 (3)
(19) D7
DGND1 (5)
(18) D8
DGND2 (21)
(17) D9
(16) D10
(MSB) (15) D11
VIN+
VIN+ (8)
VIN -
BNC
D11
(2) DVCC1
VIN- (9)
(22) DVCC2
+5V
0.1µF
+
10µF
0.1µF
+5V
+
10µF
(6) AVCC
(14) AVCC
HI5808
2
AGND
DGND
(4) DVCC1
VDC (10)
CLK (1)
CLOCK
D0
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
10µF AND 0.1µF CAPS ARE PLACED
AS CLOSE TO PART AS POSSIBLE
HI5808
Absolute Maximum Ratings
Thermal Information
Supply Voltage, AVCC or DVCC to AGND or DGND . . . . . . . . . +6.0V
DGND to AGND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3V
Digital I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DGND to DVCC
Analog I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AGND to AVCC
Thermal Resistance (Typical, Note 1)
θJA (oC/W)
SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
70
Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . .150oC
Maximum Storage Temperature Range . . . . . . . . . . -65oC to 150oC
Lead Temperature (Soldering, 10s) . . . . . . . . . . . . . . . . . . . . . 300oC
(SOIC - Lead Tips Only)
Operating Conditions
Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . -40oC to 85oC
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE:
1. θJA is measured with the component mounted on a low effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
Electrical Specifications
AVCC = DVCC1 = DVCC2 = +5V, fS = 9MSPS at 50% Duty Cycle, VRIN = 3.5V, CL = 10pF,
TA = -40oC to 85oC, Differential Analog Input, Typical Values are Test Results at 25oC,
Unless Otherwise Specified
HI5808BIB
-40oC TO 85oC
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
12
-
-
Bits
ACCURACY
Resolution
Integral Linearity Error, INL
fIN = DC
-
±1
±2
LSB
Differential Linearity Error, DNL
(Guaranteed No Missing Codes)
fIN = DC
-
±0.5
±1
LSB
Offset Error, VOS
fIN = DC
-
19
-
LSB
Full Scale Error, FSE
fIN = DC
-
32
-
LSB
DYNAMIC CHARACTERISTICS
Minimum Conversion Rate
No Missing Codes
-
0.5
-
MSPS
Maximum Conversion Rate
No Missing Codes
9
-
-
MSPS
Effective Number of Bits, ENOB
fIN = 1MHz
10.0
10.8
-
Bits
Signal to Noise and Distortion Ratio, SINAD
fIN = 1MHz
-
66.5
-
dB
Signal to Noise Ratio, SNR
RMS Signal
= ------------------------------RMS Noise
fIN = 1MHz
-
67.3
-
dB
Total Harmonic Distortion, THD
fIN = 1MHz
-
-75
-
dBc
2nd Harmonic Distortion
fIN = 1MHz
-
-80
3rd Harmonic Distortion
fIN = 1MHz
-
-77
-
dBc
RMS Signal
= -------------------------------------------------------------RMS Noise + Distortion
dBc
Spurious Free Dynamic Range, SFDR
fIN = 1MHz
-
77
-
dBc
Intermodulation Distortion, IMD
f1 = 1MHz, f2 = 1.02MHz
-
-65
-
dBc
-
1
-
Cycle
-
2
-
Cycle
-
±2.0
-
V
Transient Response
Overvoltage Recovery
0.2V Overdrive
ANALOG INPUT
Maximum Peak-to-Peak Differential Analog Input Range
(VIN+ - VIN-)
Maximum Peak-to-Peak Single-Ended Analog Input Range
(Notes 2, 3)
Analog Input Resistance, RIN
Analog Input Capacitance, C IN
-
4.0
-
V
1
-
-
MΩ
-
10
-
pF
-10
-
+10
µA
Differential Analog Input Bias Current
IB DIFF = (IB+ - IB-)
-
±0.5
-
µA
Full Power Input Bandwidth, FPBW
-
100
-
MHz
Analog Input Bias Current, IB+ or IB-
3
(Note 3)
HI5808
Electrical Specifications
AVCC = DVCC1 = DVCC2 = +5V, fS = 9MSPS at 50% Duty Cycle, VRIN = 3.5V, CL = 10pF,
TA = -40oC to 85oC, Differential Analog Input, Typical Values are Test Results at 25oC,
Unless Otherwise Specified (Continued)
HI5808BIB
-40oC TO 85oC
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
1
2.3
4
V
Reference Output Voltage, VROUT (Loaded)
-
3.5
-
V
Reference Output Current
-
-
1
mA
Reference Temperature Coefficient
-
50
-
ppm/oC
Reference Voltage Input, VRIN
-
3.5
-
V
Total Reference Resistance, RL
-
7.8
-
kΩ
Reference Current
-
450
-
µA
DC Bias Voltage Output, VDC
-
2.3
-
V
Max Output Current (Not To Exceed)
-
-
1
mA
2.0
-
-
V
Analog Input Common Mode Voltage Range (VIN+ + VIN-)/2
Differential Mode (Note 2)
INTERNAL VOLTAGE REFERENCE
REFERENCE VOLTAGE INPUT
DC BIAS VOLTAGE
DIGITAL INPUTS (CLK)
Input Logic High Voltage, VIH
-
-
0.8
V
Input Logic High Current, IIH
VCLK = 5V
-
-
10.0
µA
Input Logic Low Current, IIL
VCLK = 0V
-
-
10.0
µA
-
7
-
pF
1.6
-
-
mA
Input Logic Low Voltage, VIL
Input Capacitance, C IN
DIGITAL OUTPUTS (D0-D11)
VO = 0.4V (Note 2)
Output Logic Sink Current, IOL
DVCC3 = 3.0V, VO = 0.4V
Output Logic Source Current, IOH
VO = 2.4V (Note 2)
DVCC3 = 3.0V, VO = 2.4V
-
1.6
-
mA
-0.2
-
-
mA
-
-0.2
-
mA
-
5
-
pF
Aperture Delay, tAP
-
5
-
ns
Aperture Jitter, tAJ
-
5
-
ps (RMS)
Data Output Delay, tOD
-
8
-
ns
-
8
-
ns
-
-
3
Cycles
Output Capacitance, COUT
TIMING CHARACTERISTICS
Data Output Hold, t H
For a Valid Sample (Note 2)
Data Latency, tLAT
Clock Pulse Width (Low)
9MSPS Clock
45
50
55
ns
Clock Pulse Width (High)
9MSPS Clock
45
50
55
ns
POWER SUPPLY CHARACTERISTICS
Total Supply Current, ICC
VIN+ - VIN- = 2V
-
65
73
mA
Analog Supply Current, AICC
VIN+ - VIN- = 2V
-
46
-
mA
Digital Supply Current, DICC1
VIN+ - VIN- = 2V
-
17
-
mA
Output Supply Current, DICC2
VIN+ - VIN- = 2V
-
2
-
mA
Power Dissipation
VIN+ - VIN- = 2V
-
325
365
mW
Offset Error PSRR, ∆V OS
AVCC or DVCC = 5V ±5%
-
2
-
LSB
Gain Error PSRR, ∆FSE
AVCC or DVCC = 5V ±5%
-
30
-
LSB
NOTES:
2. Parameter guaranteed by design or characterization and not production tested.
3. With the clock off (clock low, hold mode).
4
HI5808
Timing Waveforms
ANALOG
INPUT
CLOCK
INPUT
SN - 1
HN - 1
SN
HN
SN + 1
H N + 1 SN + 2
HN + 2
S N + 3 HN + 3 S N + 4 HN + 4 S N + 5
HN + 5
SN + 6
HN + 6
INPUT
S/H
1ST
STAGE
2ND
STAGE
B1, N - 1
B2, N - 2
3RD
STAGE
4TH
STAGE
B1, N
B2, N - 1
B3, N - 2
B4, N - 3
DATA
OUTPUT
B1, N + 1
B2, N
B3, N - 1
B4, N - 2
DN - 3
B1, N + 2
B2, N + 1
B3, N
B4, N - 1
DN - 2
B2, N + 2
B3, N + 1
B4, N
DN - 1
B1, N + 3
B2, N + 3
B3, N + 2
B4, N + 1
DN
DN + 1
NOTES:
4. SN : N-th sampling period.
5. HN : N-th holding period.
6. BM , N : M-th stage digital output corresponding to N-th sampled input.
7. DN : Final data output corresponding to N-th sampled input.
FIGURE 1. INTERNAL CIRCUIT TIMING
ANALOG
INPUT
tAP
tAJ
1.5V
1.5V
tOD
tH
2.0V
DATA
OUTPUT
DATA N - 1
DATA N
0.8V
FIGURE 2. INPUT-TO-OUTPUT TIMING
5
B1, N + 5
B2, N + 4
B3, N + 3
B 4, N + 2
tLAT
CLOCK
INPUT
B1, N + 4
B3, N + 4
B4, N + 3
DN + 2
DN + 3
HI5808
Typical Performance Curves
11
70
fS = 9MSPS
fS = 9MSPS
10
TEMPERATURE = 25 oC
TEMPERATURE = 25oC
60
SINAD (dB)
ENOB
9
8
50
7
40
6
30
5
10
INPUT FREQUENCY (MHz)
1
100
INPUT FREQUENCY (MHz)
FIGURE 3. EFFECTIVE NUMBER OF BITS (ENOB) vs INPUT
FREQUENCY
FIGURE 4. SIGNAL TO NOISE AND DISTORTION (SINAD) vs
INPUT FREQUENCY
-40
70
fS = 9MSPS
fS = 9MSPS
TEMPERATURE = 25oC
TEMPERATURE = 25 oC
-50
THD (dBc)
60
SNR (dB)
10
1
100
50
-60
-70
40
-80
30
10
1
10
1
100
100
INPUT FREQUENCY (MHz)
INPUT FREQUENCY (MHz)
FIGURE 5. SIGNAL TO NOISE RATIO (SNR) vs INPUT
FREQUENCY
FIGURE 6. TOTAL HARMONIC DISTORTION (THD) vs INPUT
FREQUENCY
80
11
2MHz
fS = 9MSPS
10
TEMPERATURE = 25oC
1MHz
5MHz
10MHz
9
ENOB
SFDR (dBc)
70
60
8
7
fS = 9MSPS
TEMPERATURE = 25oC
20MHz
50MHz
50
6
100MHz
40
1
10
INPUT FREQUENCY (MHz)
100
FIGURE 7. SPURIOUS FREE DYNAMIC RANGE (SFDR) vs
INPUT FREQUENCY
6
5
0.4
0.5
DUTY CYCLE (tCLK-LOW/tCLK)
0.6
FIGURE 8. EFFECTIVE NUMBER OF BITS (ENOB) vs CLOCK
DUTY CYCLE AND INPUT FREQUENCY
HI5808
Typical Performance Curves
(Continued)
11
3.525
2MHz
1MHz
10
9
VREFNOM
10MHz
VROUT (V)
ENOB
3.515
5MHz
20MHz
8
fS = 9MSPS
3.505
3.495
VREFLD
7
50MHz
3.485
6
100MHz
5
-40
-20
0
40
20
TEMPERATURE (oC)
60
3.475
-40
80
FIGURE 9. EFFECTIVE NUMBER OF BITS (ENOB) vs
TEMPERATURE AND INPUT FREQUENCY
0
20
40
TEMPERATURE (oC)
60
80
FIGURE 10. INTERNAL VOLTAGE REFERENCE OUTPUT
(VROUT) vs TEMPERATURE AND LOAD
70
326
60
ITOT
CURRENT (mA)
324
fS = 9MSPS
322
VIN + = VIN- = VDC
320
50
AI CC
40
fS = 9MSPS
VIN+ = VIN- = VDC
30
20
DICC1
318
10
DICC2
316
-40
-20
0
20
40
60
0
-40
80
-20
TEMPERATURE (oC)
FIGURE 11. POWER DISSIPATION vs TEMPERATURE
0
0
20
40
TEMPERATURE (oC)
fIN = 1MHz, fS = 9MSPS
-20
-30
-40
-50
-60
-70
-80
-90
-100
0
1024
FREQUENCY BIN
FIGURE 13. 4096 POINT FFT SPECTRAL PLOT
7
60
80
FIGURE 12. POWER SUPPLY CURRENT vs TEMPERATURE
-10
OUTPUT LEVEL (dB)
POWER DISSIPATION (mW)
-20
2048
HI5808
Pin Descriptions
PIN NO.
NAME
DESCRIPTION
1
CLK
Sample Clock Input.
2
DVCC1
Digital Supply (5.0V).
3
DGND1
Digital Ground.
4
DVCC1
Digital Supply (5.0V).
5
DGND1
Digital Ground.
6
AVCC
Analog Supply (5.0V).
7
AGND
Analog Ground.
8
VIN+
Positive Analog Input.
9
VIN-
Negative Analog Input.
10
VDC
DC Bias Voltage Output.
11
VROUT
12
VRIN
Reference Voltage Input.
13
AGND
Analog Ground.
14
AVCC
Analog Supply (5.0V).
15
D11
Data Bit 11 Output (MSB).
16
D10
Data Bit 10 Output.
17
D9
Data Bit 9 Output.
18
D8
Data Bit 8 Output.
19
D7
Data Bit 7 Output.
20
D6
Data Bit 6 Output.
21
DGND2
Digital Output Ground.
22
DVCC2
Digital Output Supply (3.0V to 5.0V).
23
D5
Data Bit 5 Output.
24
D4
Data Bit 4 Output.
25
D3
Data Bit 3 Output.
26
D2
Data Bit 2 Output.
27
D1
Data Bit 1 Output.
28
D0
Data Bit 0 Output (LSB).
fully-differential output for the converter core. During the
sampling phase, the VIN pins see only the on-resistance of a
switch and CS . The relatively small values of these
components result in a typical full power input bandwidth of
100MHz for the converter.
φ1
VIN +
φ1
φ1
φ1
CS
VOUT +
-+
+-
φ2
VIN -
CH
VOUT -
CS
φ1
CH
φ1
Reference Voltage Output.
Detailed Description
Theory of Operation
The HI5808 is a 12-bit fully differential sampling pipeline A/D
converter with digital error correction. Figure 14 depicts the
circuit for the front end differential-in-differential-out sampleand-hold (S/H). The switches are controlled by an internal
clock which is a non-overlapping two phase signal, φ1 and φ2 ,
derived from the master clock. During the sampling phase,
φ1 , the input signal is applied to the sampling capacitors,
CS . At the same time the holding capacitors, CH , are
discharged to analog ground. At the falling edge of φ1 the
input signal is sampled on the bottom plates of the sampling
capacitors. In the next clock phase, φ2 , the two bottom
plates of the sampling capacitors are connected together
and the holding capacitors are switched to the op-amp
output nodes. The charge then redistributes between CS
and CH completing one sample-and-hold cycle. The output
is a fully-differential, sampled-data representation of the
analog input. The circuit not only performs the sample-andhold function but will also convert a single-ended input to a
8
FIGURE 14. ANALOG INPUT SAMPLE-AND-HOLD
As illustrated in the functional block diagram and the timing
diagram in Figure 1, three identical pipeline subconverter
stages, each containing a four-bit flash converter, a four-bit
digital-to-analog converter and an amplifier with a voltage gain
of 8, follow the S/H circuit with the fourth stage being only a 4bit flash converter. Each converter stage in the pipeline will be
sampling in one phase and amplifying in the other clock phase.
Each individual sub-converter clock signal is offset by 180
degrees from the previous stage clock signal, with the result
that alternate stages in the pipeline will perform the same
operation.
The digital output of each of the three identical 4-bit
subconverter stages is a four-bit digital word containing a
supplementary bit to be used by the digital error correction
logic. The output of each subconverter stage is input to a digital
delay line which is controlled by the internal sampling clock.
The function of the digital delay line is to time align the digital
outputs of the three identical four-bit subconverter stages with
the corresponding output of the fourth stage flash converter
before applying the sixteen bit result to the digital error
correction logic. The digital error correction logic uses the
supplementary bits to correct any error that may exist before
generating the final twelve bit digital data output of the
converter.
Because of the pipeline nature of this converter, the digital
data representing an analog input sample is output to the
digital data bus on the 3rd cycle of the clock after the analog
sample is taken. This time delay is specified as the data
latency. After the data latency time, the digital data
representing each succeeding analog sample is output on
the following clock pulse. The digital output data is
synchronized to the external sampling clock with an output
latch. The output of the digital error correction circuit is
available in offset binary format (see Table 1, A/D Code
Table).
HI5808
TABLE 1. A/D CODE TABLE
CODE CENTER
DESCRIPTION
DIFFERENTIAL
INPUT VOLTAGE †
(USING INTERNAL
REFERENCE)
OFFSET BINARY OUTPUT CODE
MSB
LSB
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
+Full Scale (+FS) - 1/4 LSB
+1.99976V
1
1
1
1
1
1
1
1
1
1
1
1
+FS - 11/4 LSB
1.99878V
1
1
1
1
1
1
1
1
1
1
1
0
+ 3/4 LSB
732.4µV
1
0
0
0
0
0
0
0
0
0
0
0
- 1/4 LSB
-244.1µV
0
1
1
1
1
1
1
1
1
1
1
1
-FS + 13/4 LSB
-1.99829V
0
0
0
0
0
0
0
0
0
0
0
1
-Full Scale (-FS) + 3/4 LSB
-1.99927V
0
0
0
0
0
0
0
0
0
0
0
0
† The voltages listed above represent the ideal center of each offset binary output code shown.
Internal Reference Generator, VROUT and VRIN
The HI5808 has an internal reference generator, therefore, no
external reference voltage is required. VROUT must be
connected to VRIN when using the internal reference voltage.
The HI5808 can be used with an external reference. The
converter requires only one external reference voltage
connected to the VRIN pin with VROUT left open.
The HI5808 is tested with VRIN equal to 3.5V. Internal to the
converter, two reference voltages of 1.3V and 3.3V are
generated for a fully differential input signal range of ±2V.
In order to minimize overall converter noise, it is
recommended that adequate high frequency decoupling be
provided at the reference voltage input pin, V RIN .
Analog Input, Differential Connection
The analog input to the HI5808 can be configured in various
ways depending on the signal source and the required level
of performance. A fully differential connection (Figure 15) will
give the best performance for the converter.
using a differential input. This low output impedance voltage
source is not designed to be a reference but makes an
excellent bias source and stays within the analog input
common mode voltage range over temperature.
The difference between the converter’s two internal voltage
references is 2V. For the AC coupled differential input, (Figure
15), if VIN is a 2VP-P sinewave with -VIN being 180 degrees out
of phase with VIN , then VIN+ is a 2VP-P sinewave riding on a
DC bias voltage equal to VDC and VIN- is a 2VP-P sinewave
riding on a DC bias voltage equal to VDC . Consequently, the
converter will be at positive full scale, all 1’s digital data output
code, when the VIN+ input is at VDC +1V and the VIN- input is
at V DC -1V (V IN+- VIN - = 2V). Conversely, the ADC will be
at negative full scale, all 0’s digital data output code, when
the VIN + input is equal to VDC -1V and V IN- is at VDC + 1V
(VIN + -VIN - = -2V). From this, the converter is seen to have
a peak-to-peak differential analog input voltage range of ±2V.
The analog input can be DC coupled (Figure 16) as long as
the inputs are within the analog input common mode voltage
range (1.0V ≤ VDC ≤ 4.0V).
VIN
VIN+
VIN
VIN+
VDC
HI5808
R
VDC
VIN-
HI5808
VDC
-VIN
-VIN
C
VDC
R
VIN -
FIGURE 15. AC COUPLED DIFFERENTIAL INPUT
FIGURE 16. DC COUPLED DIFFERENTIAL INPUT
Since the HI5808 is powered off a single +5V supply, the
analog input must be biased so it lies within the analog input
common mode voltage range of 1.0V to 4.0V. The
performance of the ADC does not change significantly with
the value of the analog input common mode voltage.
The resistors, R, in Figure 16 are not absolutely necessary
but may be used as load setting resistors. A capacitor, C,
connected from VIN+ to VIN - will help filter any high
frequency noise on the inputs, also improving performance.
Values around 20pF are sufficient and can be used on AC
coupled inputs as well. Note, however, that the value of
capacitor C chosen must take into account the highest
frequency component of the analog input signal.
A 2.3V DC bias voltage source, VDC , half way between the
top and bottom internal reference voltages, is made
available to the user to help simplify circuit design when
9
HI5808
Analog Input, Single-Ended Connection
Digital I/O and Clock Requirements
The configuration shown in Figure 17 may be used with a
single ended AC coupled input. Sufficient headroom must be
provided such that the input voltage never goes above +5V
or below AGND .
The HI5808 provides a standard high-speed interface to
external TTL/CMOS logic families. The digital CMOS clock
input has TTL level thresholds. The low input bias current
allows the HI5808 to be driven by CMOS logic.
VIN+
VIN
HI5808
VDC
VIN-
FIGURE 17. AC COUPLED SINGLE ENDED INPUT
Again, the difference between the two internal voltage
references is 2V. If V IN is a 4VP-P sinewave, then V IN + is a
4V P- P sinewave riding on a positive voltage equal to VDC.
The converter will be at positive full scale when V IN + is at
VDC + 2V (VIN + - V IN - = 2V) and will be at negative full
scale when VIN + is equal to VDC - 2V (VIN+ - V IN - = -2V).
In this case, VDC could range between 2V and 3V without
a significant change in ADC performance. The simplest
way to produce VDC is to use the VDC bias voltage output
of the HI5808.
The single ended analog input can be DC coupled (Figure
18) as long as the input is within the analog input common
mode voltage range.
The digital CMOS outputs have a separate digital supply. This
allows the digital outputs to operate from a 3.0V to 5.0V supply.
When driving CMOS logic, the digital outputs will swing to the
rails. When driving standard TTL loads, the digital outputs will
meet standard TTL level requirements even with a 3.0V supply.
In order to ensure rated performance of the HI5808, the duty
cycle of the clock should be held at 50% ±5%. It must also
have low jitter and operate at standard TTL levels.
Performance of the HI5808 will only be guaranteed at
conversion rates above 0.5MSPS. This ensures proper
performance of the internal dynamic circuits.
Supply and Ground Considerations
The HI5808 has separate analog and digital supply and
ground pins to keep digital noise out of the analog signal path.
The part should be mounted on a board that provides
separate low impedance connections for the analog and
digital supplies and grounds. For best performance, the
supplies to the HI5808 should be driven by clean, linear
regulated supplies. The board should also have good high
frequency decoupling capacitors mounted as close as
possible to the converter. If the part is powered off a single
supply then the analog supply and ground pins should be
isolated by ferrite beads from the digital supply and ground
pins.
VIN
VIN+
VDC
R
C
VDC
HI5808
Static Performance Definitions
VIN -
FIGURE 18. DC COUPLED SINGLE ENDED INPUT
The resistor, R, in Figure 18 is not absolutely necessary but
may be used as a load setting resistor. A capacitor, C,
connected from VIN+ to VIN - will help filter any high
frequency noise on the inputs, also improving performance.
Values around 20pF are sufficient and can be used on AC
coupled inputs as well. Note, however, that the value of
capacitor C chosen must take into account the highest
frequency component of the analog input signal.
A single ended source will give better overall system
performance if it is first converted to differential before
driving the HI5808.
10
Refer to the Application Note AN9214, “Using Intersil High
Speed A/D Converters” for additional considerations when
using high speed converters.
Offset Error (VOS)
The midscale code transition should occur at a level 1/4 LSB
above half-scale. Offset is defined as the deviation of the
actual code transition from this point.
Full-Scale Error (FSE)
The last code transition should occur for an analog input that
is 3/4 LSB below positive full scale with the offset error
removed. Full-scale error is defined as the deviation of the
actual code transition from this point.
Differential Linearity Error (DNL)
DNL is the worst case deviation of a code width from the
ideal value of 1 LSB.
Integral Linearity Error (INL)
INL is the worst case deviation of a code center from a best
fit straight line calculated from the measured data.
HI5808
Each of the power supplies are moved plus and minus 5%
and the shift in the offset and gain error (in LSBs) is noted.
distortion terms is calculated. The terms included in the
calculation are (f1 + f2), (f1 - f2), (2f1), (2f2), (2f1 + f2), (2f1 - f2),
(f1 + 2f2), (f1 - 2f2). The ADC is tested with each tone 6dB
below full scale.
Dynamic Performance Definitions
Transient Response
Fast Fourier Transform (FFT) techniques are used to
evaluate the dynamic performance of the HI5808. A low
distortion sine wave is applied to the input, it is coherently
sampled, and the output is stored in RAM. The data is then
transformed into the frequency domain with an FFT and
analyzed to evaluate the dynamic performance of the A/D.
The sine wave input to the part is -0.5dB down from full scale
for all these tests. SNR and SINAD are quoted in dB. The
distortion numbers are quoted in dBc (decibels with respect
to carrier) and DO NOT include any correction factors for
normalizing to full scale.
Transient response is measured by providing a full-scale
transition to the analog input of the ADC and measuring the
number of cycles it takes for the output code to settle within
12-bit accuracy.
Signal-to-Noise Ratio (SNR)
Full power input bandwidth is the analog input frequency at
which the amplitude of the digitally reconstructed output has
decreased 3dB below the amplitude of the input sinewave.
The input sinewave has an amplitude which swings from -fS to
+fS . The bandwidth given is measured at the specified
sampling frequency.
Power Supply Rejection Ratio (PSRR)
SNR is the measured RMS signal to RMS noise at a
specified input and sampling frequency. The noise is the
RMS sum of all of the spectral components except the
fundamental and the first five harmonics.
Signal-to-Noise + Distortion Ratio (SINAD)
SINAD is the measured RMS signal to RMS sum of all
other spectral components below the Nyquist frequency,
fS/2, excluding DC.
Overvoltage Recovery
Overvoltage Recovery is measured by providing a full-scale
transition to the analog input of the ADC which overdrives the
input by 200mV, and measuring the number of cycles it takes
for the output code to settle within 12-bit accuracy.
Full Power Input Bandwidth (FPBW)
Timing Definitions
Refer to Figure 1, Internal Circuit Timing, and Figure 2, InputTo-Output Timing, for these definitions.
Effective Number Of Bits (ENOB)
Aperture Delay (t AP)
The effective number of bits (ENOB) is calculated from the
SINAD data by:
Aperture delay is the time delay between the external sample
command (the falling edge of the clock) and the time at which
the signal is actually sampled. This delay is due to internal
clock path propagation delays.
ENOB = ( SINAD + V C ORR -1.76 )/6.02,
Aperture Jitter (tAJ)
where: VCORR = 0.5dB.
VCORR adjusts the ENOB for the amount the input is below
full scale.
Total Harmonic Distortion (THD)
THD is the ratio of the RMS sum of the first 5 harmonic
components to the RMS value of the fundamental input
signal.
Aperture Jitter is the RMS variation in the aperture delay due
to variation of internal clock path delays.
Data Hold Time (tH)
Data hold time is the time to where the previous data (N - 1)
is no longer valid.
Data Output Delay Time (tOD)
2nd and 3rd Harmonic Distortion
Data output delay time is the time to where the new data (N)
is valid.
This is the ratio of the RMS value of the applicable
harmonic component to the RMS value of the fundamental
input signal.
Data Latency (t LAT)
Spurious Free Dynamic Range (SFDR)
SFDR is the ratio of the fundamental RMS amplitude to the
RMS amplitude of the next largest spur or spectral
component in the spectrum below fS/2.
Intermodulation Distortion (IMD)
Nonlinearities in the signal path will tend to generate
intermodulation products when two tones, f1 and f2 , are
present at the inputs. The ratio of the measured signal to the
11
After the analog sample is taken, the digital data is output on
the bus at the third cycle of the clock. This is due to the
pipeline nature of the converter where the data has to ripple
through the stages. This delay is specified as the data
latency. After the data latency time, the data representing
each succeeding sample is output at the following clock
pulse. The digital data lags the analog input sample by 3
clock cycles.
HI5808
Small Outline Plastic Packages (SOIC)
M28.3 (JEDEC MS-013-AE ISSUE C)
N
28 LEAD WIDE BODY SMALL OUTLINE PLASTIC PACKAGE
INDEX
AREA
0.25(0.010) M
H
B M
INCHES
E
-B1
2
3
L
SEATING PLANE
-A-
h x 45o
A
D
-C-
e
A1
B
0.25(0.010) M
C
0.10(0.004)
C A M
MIN
MAX
MIN
MAX
NOTES
A
0.0926
0.1043
2.35
2.65
-
A1
0.0040
0.0118
0.10
0.30
-
B
0.013
0.0200
0.33
0.51
9
C
0.0091
0.0125
0.23
0.32
-
D
0.6969
0.7125
17.70
18.10
3
E
0.2914
0.2992
7.40
7.60
4
e
µα
B S
0.05 BSC
1.27 BSC
-
H
0.394
0.419
10.00
10.65
-
h
0.01
0.029
0.25
0.75
5
L
0.016
0.050
0.40
1.27
6
8o
0o
N
α
NOTES:
MILLIMETERS
SYMBOL
28
0o
28
7
8o
Rev. 0 12/93
1. Symbols are defined in the “MO Series Symbol List” in Section 2.2
of Publication Number 95.
2. Dimensioning and tolerancing per ANSI Y14.5M-1982.
3. Dimension “D” does not include mold flash, protrusions or gate
burrs. Mold flash, protrusion and gate burrs shall not exceed
0.15mm (0.006 inch) per side.
4. Dimension “E” does not include interlead flash or protrusions. Interlead flash and protrusions shall not exceed 0.25mm (0.010
inch) per side.
5. The chamfer on the body is optional. If it is not present, a visual
index feature must be located within the crosshatched area.
6. “L” is the length of terminal for soldering to a substrate.
7. “N” is the number of terminal positions.
8. Terminal numbers are shown for reference only.
9. The lead width “B”, as measured 0.36mm (0.014 inch) or greater
above the seating plane, shall not exceed a maximum value of
0.61mm (0.024 inch)
10. Controlling dimension: MILLIMETER. Converted inch dimensions are not necessarily exact.
All Intersil products are manufactured, assembled and tested utilizing ISO9000 quality systems.
Intersil Corporation’s quality certifications can be viewed at website www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design and/or specifications at any time without notice.
Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No
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12
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