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LTC1666/LTC1667/LTC1668

APPLICATIO S

FEATURES

DESCRIPTIO

12-Bit, 14-Bit, 16-Bit,

50Msps DACs

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50Msps Update Rate

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Pin Compatible 12-Bit, 14-Bit and 16-Bit Devices

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5pV-s Glitch Impulse

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Differential Current Outputs

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20ns Settling Time

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Low Power: 180mW from

±5V Supplies

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TTL/CMOS (3.3V or 5V) Inputs

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Small Package: 28-Pin SSOP

The LTC

50Msps differential current output DACs implemented on

a high performance BiCMOS process with laser trimmed,

thin-film resistors. The combination of a novel current-

steering architecture and a high performance process

produces DACs with exceptional AC and DC performance.

The LTC1668 is the first 16-bit DAC in the marketplace to

exhibit an SFDR (spurious free dynamic range) of 87dB

for an output signal frequency of 1MHz.

Operating from

±5V supplies, the LTC1666/LTC1667/

LTC1668 can be configured to provide full-scale output

currents up to 10mA. The differential current outputs of

the DACs allow single-ended or true differential operation.

The – 1V to 1V output compliance of the LTC1666/

LTC1667/LTC1668 allows the outputs to be connected

directly to external resistors to produce a differential out-

put voltage without degrading the converter’s linearity. Al-

ternatively, the outputs can be connected to the summing

junction of a high speed operational amplifier, or to a

transformer.

The LTC1666/LTC1667/LTC1668 are pin compatible and

are available in a 28-pin SSOP and are fully specified over

the industrial temperature range.

, LTC and LT are registered trademarks of Linear Technology Corporation.

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Cellular Base Stations

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Multicarrier Base Stations

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Wireless Communication

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Direct Digital Synthesis (DDS)

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xDSL Modems

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Arbitrary Waveform Generation

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Automated Test Equipment

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Instrumentation

LTC1668, 16-Bit, 50Msps DAC

–

+

–5V

CLOCK

INPUT

16-BIT DATA

INPUT

LADCOM

AGND DGND

CLK

DB15

DB0

1666/7/8 TA01

0.1

µF

LTC1668

5V

52.3

Ω

REFOUT

COMP1

COMP2

C2

0.1

µF

0.1

µF

C1

0.1

µF

2k

52.3

Ω

DIFFERENTIAL

+

–

0.1

µF

16-BIT

HIGH SPEED

DAC

2.5V

REFERENCE

0.1

100

90

80

70

60

50

1.0

10

100

1666/7/8 G05

5MSPS

25MSPS

50MSPS

DIGITAL AMPLITUDE = 0dBFS