LTC2656
Octal 16-/12-Bit Rail-to-Rail
DACs with 10ppm/°C
Max Reference
FEATURES
DESCRIPTION
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The LTC®2656 is a family of octal 16-/12-bit rail-to-rail
DACs with a precision integrated reference. The DACs have
built-in high performance, rail-to-rail, output buffers and
are guaranteed monotonic. The LTC2656-L has a full-scale
output of 2.5V with the integrated 10ppm/°C reference and
operates from a single 2.7V to 5.5V supply. The LTC2656-H
has a full-scale output of 4.096V with the integrated reference and operates from a 4.5V to 5.5V supply. Each DAC can
also operate with an external reference, which sets the DAC
full-scale output to two times the external reference voltage.
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Precision 10ppm/°C Max Reference
Maximum INL Error: ±4LSB at 16 Bits
Guaranteed Monotonic over Temperature
Selectable Internal or External Reference
2.7V to 5.5V Supply Range (LTC2656-L)
Integrated Reference Buffers
Ultralow Crosstalk Between DACs(<1nV•s)
Power-On-Reset to Zero-Scale/Mid-scale
Asynchronous LDAC Update Pin
Tiny 20-Lead 4mm × 5mm QFN and 20-Lead
Thermally Enhanced TSSOP Packages
These DACs communicate via a SPI/MICROWIRE™ compatible 4-wire serial interface which operates at clock rates
up to 50MHz. The LTC2656 incorporates a power-on reset
circuit that is controlled by the PORSEL pin. If PORSEL
is tied to GND the DACs reset to zero-scale. If PORSEL is
tied to VCC, the DACs reset to mid-scale.
APPLICATIONS
Mobile Communications
Process Control and Industrial Automation
n Instrumentation
n Automatic Test Equipment
n Automotive
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L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Protected by U.S. Patents, including 5396245, 6891433.
BLOCK DIAGRAM
REFIN/OUT
INTERNAL REFERENCE
REF
REF
GND
REGISTER
REGISTER
REGISTER
DAC B
REGISTER
VOUTB
REGISTER
REF
REGISTER
DAC A
REGISTER
VOUTA
REGISTER
VCC
REFLO
4
3
DAC G
REGISTER
REGISTER
DAC F
CONTROL LOGIC
DECODE
SCK
2
VOUTG
VOUTF
1
0
–1
DAC E
DAC A
DAC B
DAC C
DAC D
–2
–3
–4
128
VOUTE
16384
32768
DAC E
DAC F
DAC G
DAC H
49152
65535
CODE
2656 TA01b
POWER-ON RESET
CS/LD
LDAC
REGISTER
DAC D
INL vs Code
REF
REF
REGISTER
VOUTD
REGISTER
REF
REGISTER
DAC C
REGISTER
VOUTC
VOUTH
REF
REGISTER
REF
DAC H
INL (LSB)
REFCOMP
PORSEL
SDO
SDI
32-BIT SHIFT REGISTER
CLR
2656 TA01a
2656fa
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