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m 10-BIT 80MSPS DUAL DAC

BW1221L_2CLK

GENERAL DESCRIPTION

The BW1221L_2CLK is a CMOS Dual 10Bit D/A converter for general & video applications. Its typical conversion
rate is 80MSPS (maximum 100MSPS) and supply voltage is 3.3V single. An external 1.0V voltage
reference(VREF) and a single resistor (RSET) control the full_scale output current.

TYPICAL APPLICATIONS

-- High Definition Television(DTV,HDTV)

-- High Resolution Color Graphics

-- Hard Disk Driver(HDD)

-- CAE/CAD/CAM

-- Image Processing

-- Instrumentation

-- Conventional Digital to Analog Conversion

FEATURES

-- 80MSPS 1CLK pipeline delay operation

-- +3.3V CMOS monolothic construction

-- 1.0LSB differential linearity error(Max)

2.5LSB integral linearity error(Max)

External voltage reference

-- Dual Channel DAC

-- 10-Bit voltage parallel input per channel

-- High impedance single current output

-- Bineary coding input

-- High impedance analog output current source

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BW1221L_2CLK

CORE PIN DESCRIPTION

Name

I/O Type

I/O Pad

Pin Description

D1[9:0]

picc_bb

1st Channel Digital input

D2[9:0]

picc_bb

2nd Channel Digital input

IO1

poa_bb

1st Channel Current Output

IO2

poa_bb

2nd Channel Current Output

CLK1

picc_bb

Clock Input of 1st channel

CLK2

picc_bb

Clock Input of 2nd channel

VREF

pia_bb

Reference voltage input

COMP

pia_bb

External capacitance connection

picc_bb

Power-Down High Enable

IREF

pia_bb

external resistor connection

VDDA

vdda

Analog Power

VDDD

vddd

Digital Power

VSSA

vssa

Analog Ground

VSSD

vssd

Digital Ground

VBB

vbba

Bulk Bias

I/O Type Abbr.

-- AI: Analog Input

-- DI: Digital Input

-- AO: Analog Output

-- DO: Digital Output

-- AB: Analog Bidirectional

-- DB: Digital Bidirectional

-- AP: Analog Power

-- DP: Digital Power

-- AG: Analog Ground

-- DG: Digital Ground

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BW1221L_2CLK

ABSOLUTE MAXIMUM RATINGS

Characteristics

Symbol

Values

Unit

Supply Voltage

VDDA

VDDD

Voltage on any Digital Voltage

Vin

VSSD-0.3 to VDDD+0.3

Storage Temperature Range

Tstg

-45 to 125

°C

NOTES

It is strongly recommended that to avoid power latch-up all the supply Pins(VDDA,VDDD) be driven from the same
source, and all ground Pins(VSSA,VSSD,VBB) be driven from the same source.

Absolute Maximum Rating values should be applied individually while all other parameters are within specified
operating conditions. Function operation under any of these conditions is not implied.

Applied voltage must be limited to specified range.

Absolute Maximum Ratings are values beyond which the device may be damaged permanently. Normal operation is
not guaranteed.

RECOMMENDED OPERATING CONDITIONS

Characteristics

Symbol

Min

Typ

Max

Unit

Operating Supply Voltage

VDDA,VDDD

3.15

3.3

3.45

Digital input Voltage HIGH

LOW

0.7VDDD

3.3
0.0

0.3VDDD

Operating Temperature Range

opr

°C

Output Load(effective)

249

Data Input Setup Time

Data Input Hold Time

Clock Cycle Time

CLK

12.5

Clock Pulse Width High

PWH

Clock Pulse Width Low

PWL

IREF Current

REF

0.33

Zero_level Voltage

-10.0

-1.2

10.0

External Reference Voltage

REF

1.0

NOTES:
1.

It is strongly recommended that all the supply pins(VDDA,VDDD) should be driven from the same source to avoid
power latch-up.

All data above could be available with less than 10pF parasitic load capacitance at IO1 and IO3 node.

BW1221L_2CLK

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DC ELECTRICAL CHARACTERISTICS

Characteristics

Symbol

Min

Typ

Max

Unit

Resolution

Bits

Differential Linearity Error

DLE

±0.6

±1.0

LSB

Integral Linearity Error

ILE

±1.8

±2.5

LSB

Full Scale Current per Channel

4.2

4.9

5.4

Monotonicity

Guaranteed

LSB Size

4.1

4.9

5.3

Maximum Output Compliance

1.0

1.2

Exteranl Refence Voltage

1.0

Power Supply Current

NOTES:
1.

Converter Specifications (unless otherwise specified)
VDDA=3.3V VDDD=3.3V VSSA=VSSD=VBB=GND
Ta=25

C RL1=RL2=249

, VREF=1.0V, Rset = 3K

TBD: To Be Determined

AC ELECTRICAL CHARACTERISTICS

Characteristics

Symbol

Min

Typ

Max

Unit

Conversion Speed

MAX

MHz

Analog Output Delay

Analog Output Rising Time

Analog Output Falling Time

Analog Output Settling Time

set

100

150

Glitch Impulse

±120

±200

pVsec

Pipeline Delay

Clock

Power Supply Rejection Ratio

(f=1KHz, COMP=0.1uF)

PSS

0.0

1.0

Feedthrough

fdth

-33

-28

Power_Down On Time

Power_Down Off Time

0.1

0.3

NOTE:
1.

The above pararameters are not tested through the temperature range.

Clock and data feedthrough is a function of the amount of overshoot and undershoot on the digital inputs.
Settling time does not include clock and data feedthrough. Glitch impulse include clock and data feedthrough.

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BW1221L_2CLK

FUCTION DESCRIPTION

This is dual 10bit 80MSPS digital to analog data converter and uses segment architecture for 5bits of MSB sides
and binerary-weighted architecture for 5bits of LSB side. It contains of 1st latch block, decoder block, 2nd latch
block, OPA block, CM(current mirror)block and analog switch block. This core uses reference current to decide the
1LSB current size by dividing the reference current by 68times. So the reference current must be constant and the
reference curretn of CM can be constant by using OPA block with high DC gain. The most significant block of this
core is analog switch block and it must maintain the uniformity at each switch, so layout designer must care of the
matching characteristic on analog switch and CM block. And more than 80% of supply current is dissipated at
analog switch block and OPA block. And it uses samsung(SEC) standard cell as all digital cell of latch,decoder and
buffer. And to adjust full current output, you must decide the "Rset" resistor value(connected to IREF pin) and
"Vbias" voltage value(connected to VREF pin). Its voltage output can be obtained by connecting R

(connected to

IO1 pin), and R

(connected to IO2 pin). Its maximum output voltage limit is 1.2V. So you must decide the R

and

, Vbias and Rset carefully not Vout(p-p) to exceed 1.2V. It contains PD pin for power-save but regretfuly it isn't

complete. If you want more complete power-save mode, call back us(SEC). We can provide you more complete
power-save mode control scheme.

BW1221L_2CLK

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TIMING DIAGRAM

CLK

D[9:0]

1 Clocks Pipeline Delay

data(1111111111)

0000000000

p wh

p wl

0000000000

c lk

set

High
Low

Vout(p-p)

CLK

D[9:0]

data[2]

data[3]

data[1]

Vout[2]

Vout[1]

CLK

D[9:0]

data1(1111111111)

Vout(pp)

NOTES:
1.

The Behavioral Modeling is provided by Verilog HDL modeling file which includes the spec of pipeline delay,
setup_time, hold_time, rising time, falling time, and clock frequency, and so on.

Output delay(Td) measured from the 50% point of the rising edge of CLK to the full scale trasition

Settling time(Tset) measured from the 50% point of full scale transition to the output remaining within

1LSB.

Output rising(Tr)/falling(Tf) time measured between the 10% and 90% points of full scale transition.

Power_down doesn't need clock signal.

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BW1221L_2CLK

CORE EVALUATION GUIDE

PATH

SELECT

bw1221l_2clk

TEST PATH

HOST

DSP

CORE

IO2

CHANNEL

SELECT

VDDD VSSD VDDA VSSA VBB

3.3V

CLK1 input

CLK1

CLK2

1.0V

VREF

SET

IREF

COMP

VDDA

CLK2 input

D1[9]

D1[8]

D1[7]

D1[6]
D1[5]

D1[4]

D1[3]
D1[2]

D1[1]

D1[0]

D2[9]

D2[8]

D2[7]

D2[6]

D2[5]

D2[4]

D2[3]

D2[2]

D2[1]

D2[0]

IO1

LOCATION

DESCRIPTION

COMP

0.1uF CERAMIC CAPACITOR

10uF TANTALUM CAPACITOR

SET

249

REF

1.0V DC Voltage Supply

BW1221L_2CLK

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How to change the resolution

If it is needed to change the resolution, you can use as many as more significant bits, and the rest (less significant
bits) can be grounded or supplied by VDDD power. That is, if you need only 8bits, you have to use MSB 8bit digital
input pin, and the LSB 2 digital input pin have to be grounded or supplied by VDDD power.

How to change the output range

You can change the output swing using the following equation:
V

out

= { V

ref

/ ( R

set

*68) } * 1023 * R

This equation implies that you can determine the output swing by changing the value of Vref,
Rset, and RL where the output swing is limited up to 1.2V.

1. ABOUT TESTABILITY
If you want to test it over full spec via all channel in main chip(that is, when it is used as a block of main chip) you
must add many pins(for 20pins of digital inputs, 2pins of analog outputs, etc) at the main chip to test this DAC
block. But usually it is nearly impossble 'cause the total number of pins at main chip is limited. So more efficient
method for testing this DAC block is needed. We offer two ways of testing efficiently here as a reference. But
remember this is not the best way. You can test it by your own testing method.

2. FIRST METHOD OF TESTABILITY
The first way is adding only extra 10PADs for 10bit parallel digital inputs and 2PADs for channel selecting and path
selecting. You can check three channels one by one, that is you can test only one channel at one time. Therefore
you can test all three channels by turn but cannot check all channel at one time. And this method needs extra MUX
and switch blocks for testing. Furthermore we can confirm all channels by testing only one channel because the
two channels have same architecture and share the same analog reference block(OPAMP, CM, BGR). This
characteristic makes it simple to test this DAC block(when it is embedded in main chip) by adding another 10PADs
for parallel digital inputs and 2PADs for selecting one channel analog switch block of DAC out of three channels.

3. SECOND METHOD OF TESTABILITY
If above extra 12PADs are burden on you, then you can test it by this second method to reduce the extra PADs for
testing. What is different from above method is that this way needs only 2 extra PADs(one for 1bit serial digital
input and the other for clock signal), but you must insert extra serial to parallel converter block for converting 1bit
10times high speed digital input to 10bit parallel digital inputs. And this block needs considerable area. Further this
method also needs extra 2PADs for channel selecting and path selecting.

4 ANALYSIS
The voltage applied to VREF is measured at IREF node . And the voltage value is proportioned to the reference
current value of resistor which is connected to IREF node. So you can estimate the full scale current value by
measuring the voltage, and check the DC characteristics of the OPAMP. For reference, as VREF voltage applied
to VREF pin is given at IREF node, the current flowing through RSET resistor(connected to IREF pin) is given as
VREF/RSET. If the voltage applied to VREF pin is not same with IREF node, you can say "This DAC chip does not
work properly", because the internal OPAMP block makes the two node voltage(IFEF pin, VREF pin) equal. And
you have to check the COMP node to see the desired voltage on it. If the desired voltage is not measured, you can
check the DAC output by appling a desired voltage to the COMP pin instead of compensation capacitor directly.
If you use internal reference voltage(BGR's output voltage) instead of external Vbias by setting the BGRSW low,
you can check the BGR's output by checking the VREF pin voltage.

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BW1221L_2CLK

CORE LAYOUT GUIDE

Layout DAC core replacement

-- It is recommended that you use thick analog power metal(larger than 40um in width).

When connecting to PAD, the path should be kept as short as possible, and use branch metal to connect to
the center of analog switch block.

-- It is recommended that you use thick analog output metal(at least more than 50um) when connecting to PAD,

and also the path length should be kept as short as possible. If the metal width is less than 50um, you
should use double or triple PADs.

-- Digital power and analog power are separately used.

-- When it is connected to other blocks, it must be double shielded using N-well and P+ active to remove the

substrate and coupling noise. In that case, the power metal should be connected to PAD directly.

-- Bulk power is used to reduce the influence of substrate noise.

-- You must use more than two pins for VDDA because it requires much current dissipation.

BW1221L_2CLK

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FEEDBACK REQUEST

We appreciate your interest in our products. If you have further questions, please specify in the attached form.
Thank you very much.

DC / AC ELECTRICAL CHARACTERISTIC

Characteristics

Min

Typ

Max

Unit

Remarks

Supply

Voltage

Power

dissipation

Resolution

Bits

Analog

Output

Voltage

Operating

Temperature

°C

Output

Load

Capacitor

Output

Load

Resistor

Integral

Non-Linearity

Error

LSB

Differential

Non-Linearity

Error

LSB

Maximum

Conversion

Rate

MHz

VOLTAGE OUTPUT DAC

Reference Voltage TOP

BOTTOM

Analog Output Voltage Range

Digital Input Format

Binary Code or 2's Complement Code

CURRENT OUTPUT DAC

Analog

Output

Maximum

Current

Analog

Output

Maximum

Signal

Frequency

MHz

Reference

Voltage

External

Resistor

for

Current

Setting

(RSET)

Pipeline

Delay

sec

-- Do you want to Power down mode?

-- Do you want to Interal Reference Voltage(BGR)?

-- Which do you want to Serial Input TYPE or parallel Input TYPE?

-- Do you need 3.3v and 5v power supply in your system?

-- How many channels do you need(BW1221L_2CLK is dual channel DAC)?

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