ETC BW1217X

10BIT 30MSPS ADC
BW1217X
GENERAL DESCRIPTION
FEATURES
The BW1217X is a CMOS 10-bit A/D converter for
video applications. It is a three-step pipelined A/D
converter which consists of sample & hold, two
multiplying DACs, and three 4-bit flash ADCs.
The maximum conversion rate of BW1217X is
30MSPS and supply voltage is 3.3V single.
-
Resolution : 10Bit
Differential Linearity Error : ±1.0 LSB
Integral Linearity Error : ±2.0 LSB
Maximum Conversion Rate : 30MSPS
Sample & Hold Function Implemented
Low Power Consumption : 82.5mW(Typ)
Power Supply : 3.3V Single
Operation Temperature Range : 0ºC ~70ºC
TYPICAL APPLICATIONS
- PC or computer based video signal processing such
as multi-media, scanner, etc.
- General Purpose video applications including
camcorder, digital video, broad-casting and studio
equipments.
- Medical electronics such as digital scope, transit
recorder, radar.
FUNCTIONAL BLOCK DIAGRAM
AINT
AINC
SHA
MDAC
1
VDDA
VSSA
VBBA
VDDD
MDAC
2
REFTOP
REFBOT
VSSD
VBBD
REFMID
CML
ITEST
STBY
CKIN
FLASH
1
FLASH
2
CML
GEN.
MAIN
BIAS
CLOCK
GEN.
DIGITAL
LOGIC
Ver 1.1 (Feb. 2000)
No responsibility is assumed by SEC for its use nor for any
infringements of patents or other rights of third parties that may
result from its use. The content of this datasheet is subject to
change without any notice
FLASH
3
OVF
UDF
DO[9]
DO[8]
DO[7]
DO[6]
DO[5]
DO[4]
DO[3]
DO[2]
DO[1]
DO[0]
BW1217X
10BIT 30MSPS ADC
CORE PIN DESCRIPTION
NAME
I/O TYPE
I/O PAD
AINT
AI
piar50_bb
Analog Input +
(Input Range : 0.5V ~ 2.5V)
AINC
AI
piar50_bb
Analog Input : (DC=1.5V)
REFMID
AB
pia_bb
Reference Mid Point (Test Pin)
REFTOP
AI
pia_bb
Reference Top (2.0V)
REFBOT
AI
pia_bb
Reference Bottom(1.0V)
VDDA
AP
vdda
Analog Power ( 3.3V )
VSSA
AG
vssa
Analog Ground
VBBA
AG
vbba
Analog Sub Bias
ITEST
AB
pia_bb
open=use internal bias point
STBY
DI
picc_bb
high=power saving standby mode
(normally = gnd)
CKIN
DI
picc_bb
Sampling Clock Input
CML
AB
pia_bb
Internal Bias Point(Test Pin)
DO[9:0]
DO
pot2_bb
Digital Output
OVF
DO
pot2_bb
Overflow
UDF
DO
pot2_bb
Underflow
VBBD
DG
vbba
Digital Sub Bias
VSSD
DG
vssd
Digital Ground
VDDD
DP
vddd
Digital Power
CORE CONFIGURATION
PIN DESCRIPTION
VDDA
I/O TYPE ABBR.
-
AI : Analog Input
DI : Digital Input
AO : Analog Output
DO : Digital Output
AB : Analog Bidirectional
DB : Digital Bidirectional
-
AP
DP
AG
DG
:
:
:
:
Analog Power
Digital Power
Analog Ground
Digital Ground
VSSA
VDDD
VBBD
VBBA
VSSD
AINT
OVF
UDF
AINC
DO[9:0]
REFTOP
bw1217x
REFBOT
CKIN
STBY
REFMID ITEST CML
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ANALOG
BW1217X
10BIT 30MSPS ADC
ABSOLUTE MAXIMUM RATINGS
Characteristic
Value
Symbol
Unit
Supply Voltage
VDD
4.5
V
Analog Input Voltage
AIN
VSS to VDD
V
Digital Input Voltage
CLK
VSS to VDD
V
VOH, VOL
VSS to VDD
V
-45 to 125
ºC
Digital Output Voltage
Storage Temperature Range
Tstg
NOTES
1. ABSOLUTE MAXIMUM RATING specifies the values beyond which the device may be damaged permanently.
Exposure to ABSOLUTE MAXIMUM RATING conditions for extended periods may affect reliability. Each
condition value is applied with the other values kept within the following operating conditions and function
operation under any of these conditions is not implied.
2. All voltages are measured with respect to VSS unless otherwise specified.
3. 100pF capacitor is discharged through a 1.5KΩ resistor (Human body model)
RECOMMENDED OPERATING CONDITIONS
Characteristics
Symbol
Min
Typ
Max
Unit
Supply Voltage
VDDA - VSSA
VDDD - VSSD
3.15
3.3
3.45
V
Supply Voltage Difference
VDDA - VDDD
-0.1
0.0
0.1
V
REFTOP
REFBOT
-
2.0
1.0
-
V
Analog Input Voltage (+)
AINT
0.5
-
2.5
V
Analog Input Voltage (-)
AINC
Operating Temperature
Topr
Reference Input Voltage(Externally)
1.5
0
-
V
70
ºC
NOTES
1. It is strongly recommended that all the supply pins (VDDA, VDDD) be powered from the same source to avoid
power latch-up.
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ANALOG
BW1217X
10BIT 30MSPS ADC
DC ELECTRICAL CHARACTERISTICS
Characteristics
Symbol
Min
Typ
Max
Unit
-
-
-
10
Bits
Reference Current
IREF
-
2
3
mA
Differential Linearity Error
DLE
-
-
±1.0
LSB
AINT : 0.5 ~ 2.5V
(Ramp Input)
Integral Linearity Error
ILE
-
-
±2.0
LSB
Fck : 1MHz
Bottom Offset Voltage Error
EOB
-
-
20
LSB
Top Offset Voltage Error
EOT
-
-
20
LSB
Resolution
Conditions
-
NOTES
1. Converter Specifications (unless otherwise specified)
VDDA=3.3V VDDD=3.3V
VSSA=GND VSSD=GND
Ta=25ºC
2. TBD : To Be Determined
AC ELECTRICAL CHARACTERISTICS
Characteristics
Symbol
Min
Typ
Max
Unit
Maximum Conversion Rate
fc
30
-
-
MSPS
Dynamic Supply Current
Ivdd
-
25
30
mA
fc=30MHz
(without system load)
Signal - to - Noise Ratio
SNR
48
52
-
dB
AINT = 1MHz
fc = 30MHz
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Conditions
AINT : 1MHz Sine Signal
(source resolution > 12bit)
ANALOG
BW1217X
10BIT 30MSPS ADC
TIMING DIAGRAM( Main Function )
AIN
CLOCK
SHA
track
hold
ref sample
FLASH1
MDAC1
amplify
precharge
input
sample
ref sample
FLASH2
MDAC2
track
hold
latch
track
residue
amplify
amplify
precharge
input
sample
ref sample
FLASH3
track
hold
track
hold
track
latch
encoding
input
sample
latch
track
residue
amplify
latch
encoding
residue
amplify
amplify
precharge
DATA
SEC ASIC
hold
input
sample
latch
track
residue
amplify
latch
encoding
DATA
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ANALOG
BW1217X
10BIT 30MSPS ADC
bias to protect interruption of any other circuit.
SAH amp is designed that open-loop dc gain is
higher than 70dB, phase margin is higher than
60degree. Its input block is designed to be the
rail-to-rail architecture using complementary
differential pair.
FUNCTIONAL DESCRIPTION
1. BW1217X is a three step A/D Converter
comprising three 4-bit flash ADC and two
multiplying DAC. The N-bit flash ADC is
composed of 2(n-1) latching comparators, and
multiplying DAC is composed of 2*(N+2)
capacitors and two fully-differential amplifier.
2. BW1217X operates as follows. During the first
"L" cycle of external clock the analog input data
is tracked and sampled, and the input is held
from the rising edge of the external clock, which
is fed to the first 4-bit flash ADC, and the first
multiplying DAC. Multiplying DAC reconstructs
a voltage corresponding to the first 4-bit ADC's
output, and finally amplifies a residue voltage by
23. The second 4-bit flash ADC, and MDAC are
worked as same manner, finally amplifiers a
residue voltage, which is the difference between
first MDAC's output and reconstructed voltage by
22. The third 4-bit flash ADC, and MDAC are
worked as previous stages.
3. BW1217X has the error correction scheme,
which handles the output from mismatch in the
first, second and third flash ADC.
MAIN BLOCK DESCRIPTION
1. SAH
SAH(track and hold) is the circuit that samples
the analog input signal and holds that value until
next sample-time. It is good as small as its
different value between analog input signal and
output signal. SAH amp gain must be higher
than 66dB at least for less than 1/2LSB of SAH
error voltage at 10bit ADC and its conversion
frequency is 30MHz, its settling-time must be
shorten than 12ns. This SAH is consist of fully
differential op amp, switching tr. and sampling
capacitor.
The
sampling
clock
are
non-overlapping clocks(Q1,Q2) and sampling
capacitor value is 1.2pF. SAH uses independent
SEC ASIC
2. FLASH
The 4-bit flash converter compares analog
signal(SAH output) with reference voltage, and
that result transfers to MDAC and digital
correction logic block. It is realized fully
differential comparators of 15EA. Considering
self-offset, dynamic feed through error, it should
distinguish 40mV at least. First, the comparators
charge the reference voltage at the sampling
capacitors before transferred SAH output. Q2
works this process and Q1 discharges this
sampling capacitors. That is, the comparators
compare relative different values dual input
voltage with dual reference voltage. Its output
during Q1 operation is stored at the pre-latch
block by Q1P.
3. MDAC
MDAC is the most important block at this
ADC and it decides the characteristics. MDAC
is consist of amp1,amp2, selection logic and
capacitor array(c_array). C_array's compositions
are the capacitors to charge the analog input
and the reference voltage, Switches to control
the path. Selection logic controls the c_array
internal switches. If Q1 is high, selection's
output is all low, the switches of tsw1 are off,
the switches of tsw2 are all on. Therefore the
capacitors of c_array charges analog input values
held at SAH. If Q2 is high, it is reversed and
final MDAC output voltage is described the
following equation.
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Vout = (AIN - Vref)*8-Vref/2
AIN=AINT-1.5V
ANALOG
BW1217X
10BIT 30MSPS ADC
CORE EVALUATION GUIDE
1. ADC function is evaluated by external check on the bidirectional pads connected to input nodes of
HOST DSP back-end circuit.
2. The reference voltages may be biased internally through resistor divider.
2.0V
1.0V
REFTOP
DO[9:0]
REFBOT
Power Used
:VDDA,VDDD,VBBD
VSSA,VSSD,VBBA
STBY
NOTES
: 10uF Electronic Capacitor
unless Otherwise Specified
: 0.1uF Ceramic Capacitor
unless Otherwise Specified
DO[9:0]
Digital Mux
AINT
bw1217x
AINC
OVF
HOST
DSP
CORE
UDF
CKIN
ITEST REFMID CML
DO[9:0]
Bidirectional
PAD
(ADC Function Test &
externally forced Digital Input)
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ANALOG
BW1217X
10BIT 30MSPS ADC
PACKAGE CONFIGURATION
NOTES
1. You can test ADC function by checking external bidirectional pad connected to internal signal path.
2. ESD (Electro Static Discharge) sensitive device. Although the digital control inputs are diode protected, permanent
damage may occur on devices subjected to high electrostatic discharges. It is recommended that unused devices be
stored in conductive foam or shunts to avoid performance degradation or loss of functionality. The protective foam
should be discharged to the destination socket before devices are inserted.
3. NC denotes "No Connection".
2.0V
1.0V
Reference Reference
Top
Bottom
GND
45 VSSD
46 VSSD
NC
47 VDDD
1
REFTOP
48 VDDD
2
44
NC
43
NC
42
VBBA
NC
41
9
VSSA
NC
40
10
VSSA
NC
39
11
AINT
OVF
38
12
NC
UDF
37
13
AINC
D<9>
36
14
REFMID
D<8>
35
15
NC
D<7> 34
CML
6
VDDA
7
VDDA
8
bw1217l_top
BW1217X
STBY
D<5> 32
18
VDDR
19
VSSR
20
CKIN
D<4> 31
D<1> 28
D<0> 27
NC 26
TRISTATE 25
17
NC 24
D<6> 33
NC 23
ITEST
NC 22
16
D<3> 30
D<2> 29
Digital Output Bits 0 and 1
NOTES
: 10uF ELECTROLYTIC CAPACITOR
UNLESS OTHERWISE SPECIFIED
: 0.1uF CERAMIC CAPACITOR
UNLESS OTHERWISE SPECIFIED
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ANALOG
Digital Output Bits 2 Through 9
VBBD
5
NC 21
Clock Signal
REFBOT
3.3V
PAD Power
3
DC 1.5V
NC
GND
Video-In
(Input Range:0.5~2.5V)
4
3.3V
Analog Power
3.3V
Digital
Power
BW1217X
10BIT 30MSPS ADC
PACKAGE PIN DESCRIPTION
NAME
PIN NO.
I/O TYPE
PIN DESCRIPTION
REFTOP
2
AI
External Reference Top Bias.(2.0V)
REFBOT
3
AI
External Reference Bottom Bias.(1.0V)
CML
5
AB
Internal Bias Point ( Test Pin )
VDDA
6,7
AP
3.3V Analog Power
VBBA
8
AG
Analog Sub Bias
VSSA
9,10
AG
Analog Ground
AINT
11
AI
Analog Input (+)
Input Range : 0.5~2.5V
AINC
13
AI
Analog Input. (-)
DC 1.5V
REFMID
14
AB
Reference Mid Point ( Test Pin )
ITEST
16
AB
open=use internal bias point
STBY
17
DI
High = power saving standby mode
(normally gnd)
VDDR
18
PP
Ouput Driver Power(3.3V)
VSSR
19
PG
Output Driver Ground
CKIN
20
DI
Sampling Clock Input
TRISTATE
25
DI
high = high impedance digital output
(normally gnd)
DO[9:0]
27~36
DO
Digital Output
UDF
37
DO
Underflow
OVF
38
DO
Overflow
VBBD
44
DG
Digital Substrate Bias
VSSD
45,46
DG
Digital Ground
VDDD
47,48
DP
Digital Power(3.3V)
NOTES
1. I/O TYPE PP and PG denote PAD Power and PAD Ground respectively.
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ANALOG
BW1217X
10BIT 30MSPS ADC
USER GUIDE
1. Resolution Control.
- Modular structure is the most important feature of BW1217X.
- You can get any resolution you want by combining each primary module (MDAC + FLASH) without major
circuit change.
- It means you don't have to redesign the most difficult analog block for another resolution.
- But this simple resolution control method has a limit up to 10bits, otherwise the internal op-amp must be
redesigned.
module
ain
sha
mdac1
flash1
mdac2
flash2
flash3
dclogic
10bit
2. Speed Up
- The initial target speed of BW1217X was 30MHz, but it proved to operate well at 35MHz or more
due to a lot of design margin.
3. Input Range Variation.
- The default of the input of this ADC is differential -1.0V ~ +1.0V.
- The bias voltages of both AINT and AINC are 0.5V~2.5V, and their offset is 1.5V.
- In order to change to another input voltage range, alter the voltage values of AINT and AINC after setting
Reftop and Refbot to the maximum value of input range.
- If you want single ended input, fix AINC to 1.5V as a ground and the internal input voltage level is
V(aint)-1.5V.
4. Verilog Modeling
- Verilog modeling needs 64bits for only one analog real signal.
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ANALOG
BW1217X
10BIT 30MSPS ADC
FEEDBACK REQUEST
It should be quite helpful to our ADC core development if you specify your system requirements on
ADC in the following characteristic cheking table and fill out the additional questions.
We appreciate your interest in our products. Thank you very much.
Characteristic
Min
Typ
Max
Unit
Analog Power Supply Voltage
V
Digital Power Supply Voltage
V
Bit Resolution
Bit
Reference Input Voltage
V
Analog Input Voltage
Vpp
Operating Temperature
ºC
Integral Non-linearity Error
LSB
Differential Non-linearity Error
LSB
Bottom Offset Voltage Error
mV
Top Offset Voltage Error
mV
Maximum Conversion Rate
Remarks
MSPS
Dynamic Supply Current
mA
Power Dissipation
mW
Signal-to-noise Ratio
dB
Pipeline Delay
CLK
Digital Output Format
(Provide detailed description &
timing diagram)
1. Between single input-output and differential input-output configurations, which one is suitable for your
system and why?
2. Please comment on the internal/external pin configurations you want our ADC to have, if you have
any reason to prefer some type of configuration.
3. Freely list those functions you want to be implemented in our ADC, if you have any.
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ANALOG