FEATURES
n
LTC2640
Single 12-/10-/8-Bit SPI
V
OUT
DACs with
10ppm/°C Reference
DESCRIPTION
The LTC
®
2640 is a family of 12-, 10-, and 8-bit voltage-
output DACs with an integrated, high-accuracy, low-drift
reference in an 8-lead TSOT-23 package. It has a rail-to-rail
output buffer that is guaranteed monotonic.
The LTC2640-L has a full-scale output of 2.5V, and operates
from a single 2.7V to 5.5V supply. The LTC2640-H has a
full-scale output of 4.096V, and operates from a 4.5V to
5.5V supply. A 10ppm/°C reference output is available at
the REF pin.
Each DAC can also operate in External Reference mode,
in which a voltage supplied to the REF pin sets the full-
scale output.
The LTC2640 DACs use a SPI/MICROWIRE™ compatible
3-wire serial interface which operates at clock rates up
to 50MHz.
The LTC2640 incorporates a power-on reset circuit. Op-
tions are available for Reset to Zero-Scale or Reset to
Mid-Scale after power-up.
L,
LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property
of their respective owners. Protected by U.S. Patents including 5396245, 5859606, 6891433,
6937178 and 7414561.
n
n
n
n
n
n
n
n
n
n
n
n
Integrated Precision Reference
2.5V Full-Scale 10ppm/°C (LTC2640-L)
4.096V Full-Scale 10ppm/°C (LTC2640-H)
Maximum INL Error: 1LSB (LTC2640A-12)
Bidirectional Reference: Input or 10ppm/°C Output
Low Noise (0.7mVpp, 0.1Hz to 200kHz)
Guaranteed Monotonic Over Temperature
2.7V to 5.5V Supply Range (LTC2640-L)
Low Power Operation: 180μA at 3V
Power Down to 1.8μA Maximum (C and I Grades)
Asynchronous DAC Clear Pin (LTC2640-Z)
Power-On Reset to Zero or Mid-Scale options
Double-Buffered Data Latches
Guaranteed Operation from –40°C to 125°C (H-Grade)
8-Lead TSOT-23 (ThinSOT™) Package
APPLICATIONS
n
n
n
n
n
n
Mobile Communications
Process Control and Industrial Automation
Automatic Test Equipment
Portable Equipment
Automotive
Optical Networking
BLOCK DIAGRAM
V
CC
(LTC2640-Z)
REF
INTERNAL
REFERENCE
Integral Nonlinearity (LTC2640A-LZ12)
1.0
V
CC
= 3V
V
FS
= 2.5V
SDI
SWITCH
0.5
INL (LSB)
V
OUT
–1.0
GND
2640 TA01
SCK
24-BIT
SHIFT
REGISTER
CONTROL
DECODE LOGIC
RESISTOR
DIVIDER
0
DACREF
CS/LD
INPUT
REGISTER
DAC
REGISTER
DAC
–0.5
0
1024
2048
CODE
3072
4095
2640 TA01b
CLR
2640fb
1
LTC2640
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 2)
Supply Voltage (V
CC
) ................................... –0.3V to 6V
CLR, CS/LD,
REF_SEL, SCK, SDI ................. –0.3V to 6V
V
OUT
, REF ......................... –0.3V to Min(V
CC
+ 0.3V, 6V)
Operating Temperature Range
LTC2640C ................................................ 0°C to 70°C
LTC2640I.............................................. –40°C to 85°C
LTC2640H (Note 3) ............................ –40°C to 125°C
Maximum Junction Temperature........................... 150°C
Storage Temperature Range................... –65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
PIN CONFIGURATION
LTC2640-Z
CS/LD
1
SCK 2
SDI 3
GND 4
TOP VIEW
8
CLR
7 V
OUT
6 REF
5 V
CC
LTC2640-M
CS/LD
1
SCK 2
SDI 3
GND 4
TOP VIEW
8 REF_SEL
7 V
OUT
6 REF
5 V
CC
TS8 PACKAGE
8-LEAD PLASTIC TSOT-23
T
JMAX
= 150°C (NOTE 6),
θ
JA
= 195°C/W
TS8 PACKAGE
8-LEAD PLASTIC TSOT-23
T
JMAX
= 150°C (NOTE 6),
θ
JA
= 195°C/W
2640fb
2
LTC2640
ORDER INFORMATION
LTC2640 A
C
TS8 –L
M
12
#TRM PBF
LEAD FREE DESIGNATOR
TAPE AND REEL
TR = 2,500-Piece Tape and Reel
TRM = 500-Piece Tape and Reel
RESOLUTION
12 = 12-Bit
10 = 10-Bit
8 = 8-Bit
POWER-ON RESET
M = Reset to Mid-Scale
Z = Reset to Zero-Scale
FULL-SCALE VOLTAGE, INTERNAL REFERENCE MODE
L = 2.5V
H = 4.096V
PACKAGE TYPE
TS8 = 8-Lead Plastic TSOT-23
TEMPERATURE GRADE
C = Commercial Temperature Range (0°C to 70°C)
I = Industrial Temperature Range (–40°C to 85°C)
H = Automotive Temperature Range (–40°C to 125°C)
ELECTRICAL GRADE (OPTIONAL)
A = ±1LSB Maximum INL (12-Bit)
PRODUCT PART NUMBER
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
2640fb
3
LTC2640
PRODUCT SELECTION GUIDE
PART NUMBER
LTC2640A-LM12
LTC2640A-LZ12
LTC2640A-HM12
LTC2640A-HZ12
LTC2640-LM12
LTC2640-LM10
LTC2640-LM8
LTC2640-LZ12
LTC2640-LZ10
LTC2640-LZ8
LTC2640-HM12
LTC2640-HM10
LTC2640-HM8
LTC2640-HZ12
LTC2640-HZ10
LTC2640-HZ8
V
FS
WITH INTERNAL
PART MARKING* REFERENCE
LTDHV
LTDHW
LTDHX
LTDHY
LTDHV
LTDHZ
LTDJF
LTDHW
LTDJB
LTDJG
LTDHX
LTDJC
LTDJH
LTDHY
LTDJD
LTDJJ
2.5V • (4095/4096)
2.5V • (4095/4096)
4.096V • (4095/4096)
4.096V • (4095/4096)
2.5V • (4095/4096)
2.5V • (1023/1024)
2.5V • (255/256)
2.5V • (4095/4096)
2.5V • (1023/1024)
2.5V • (255/256)
4.096V • (4095/4096)
4.096V • (1023/1024)
4.096V • (255/256)
4.096V • (4095/4096)
4.096V • (1023/1024)
4.096V • (255/256)
POWER-ON RESET
TO CODE
PIN 8
Mid-Scale
Zero
Mid-Scale
Zero
Mid-Scale
Mid-Scale
Mid-Scale
Zero
Zero
Zero
Mid-Scale
Mid-Scale
Mid-Scale
Zero
Zero
Zero
REF_SEL
CLR
REF_SEL
CLR
REF_SEL
REF_SEL
REF_SEL
CLR
CLR
CLR
REF_SEL
REF_SEL
REF_SEL
CLR
CLR
CLR
RESOLUTION
12-Bit
12-Bit
12-Bit
12-Bit
12-Bit
10-Bit
8-Bit
12-Bit
10-Bit
8-Bit
12-Bit
10-Bit
8-Bit
12-Bit
10-Bit
8-Bit
V
CC
2.7V – 5.5V
2.7V – 5.5V
4.5V – 5.5V
4.5V – 5.5V
2.7V – 5.5V
2.7V – 5.5V
2.7V – 5.5V
2.7V – 5.5V
2.7V – 5.5V
2.7V – 5.5V
4.5V – 5.5V
4.5V – 5.5V
4.5V – 5.5V
4.5V – 5.5V
4.5V – 5.5V
4.5V – 5.5V
MAXIMUM INL
±1LSB
±1LSB
±1LSB
±1LSB
±2.5LSB
±1LSB
±0.5LSB
±2.5LSB
±1LSB
±0.5LSB
±2.5LSB
±1LSB
±0.5LSB
±2.5LSB
±1LSB
±0.5LSB
*The temperature grade is identified by a label on the shipping container.
2640fb
4
LTC2640
ELECTRICAL CHARACTERISTICS
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 2.7V to 5.5V, V
OUT
unloaded unless otherwise specified.
LTC2640-LM12/-LM10/-LM8/-LZ12/-LZ10/-LZ8, LTC2640A-LM12/-LZ12 (V
FS
= 2.5V)
LTC2640-8
SYMBOL PARAMETER
DC Performance
Resolution
Monotonicity
DNL
INL
ZSE
V
OS
V
OSTC
FSE
V
FSTC
Differential
Nonlinearity
Integral
Nonlinearity
Zero-Scale Error
Offset Error
l
LTC2640-10
LTC2640-12
LTC2640A-12
UNITS
Bits
Bits
±1
±0.5
0.5
±0.5
±10
±0.08 ±0.4
±10
±10
±10
±1
5
±5
LSB
LSB
mV
mV
μV/°C
%FSR
ppm/°C
ppm/°C
ppm/°C
CONDITIONS
MIN
8
8
TYP
MAX MIN TYP MAX MIN TYP
10
10
±0.5
±0.5
±0.2
0.5
±0.5
±10
±0.08 ±0.4
±10
±10
±10
0.035 0.064
0.035 0.064
±1
5
±5
±1
0.5
±0.5
±10
12
12
MAX MIN TYP MAX
12
12
±1
±2.5
5
±5
V
CC
= 3V, Internal Ref. (Note 4)
l
V
CC
= 3V, Internal Ref. (Note 4)
l
V
CC
= 3V, Internal Ref. (Note 4)
l
V
CC
= 3V, Internal Ref.,
Code = 0
l
±0.05 ±0.5
0.5
±0.5
±10
5
±5
V
CC
= 3V, Internal Ref. (Note 5)
l
V
OS
Temperature V
CC
= 3V, Internal Ref. (Note 5)
Coefficient
Full-Scale Error
V
CC
= 3V, Internal Ref. (Note 11)
l
±0.08 ±0.4
±10
±10
±10
±0.08 ±0.4
±10
±10
±10
0.14 0.256
0.14 0.256
Full-Scale Voltage V
CC
= 3V, Internal Ref. (Note 10)
Temperature
C-Grade
Coefficient
I-Grade
H-Grade
Load Regulation
Internal Ref., Mid-Scale,
V
CC
= 3V ±10%,
–5mA ≤ I
OUT
≤ 5mA,
V
CC
= 5V ±10%,
–10mA ≤ I
OUT
≤ 10mA
Internal Ref., Mid-Scale,
V
CC
= 3V ±10%,
–5mA ≤ I
OUT
≤ 5mA,
V
CC
= 5V ±10%,
–10mA ≤ I
OUT
≤ 10mA
l
l
0.009 0.016
0.009 0.016
0.14 0.256 LSB/mA
0.14 0.256 LSB/mA
R
OUT
DC Output
Impedance
l
l
0.09 0.156
0.09 0.156
0.09 0.156
0.09 0.156
0.09 0.156
0.09 0.156
0.09 0.156
0.09 0.156
Ω
Ω
SYMBOL
V
OUT
PSR
I
SC
PARAMETER
DAC Output Span
Power Supply Rejection
Short-Circuit Output Current (Note 6)
Sinking
Sourcing
Positive Supply Voltage
Supply Current (Note 7)
CONDITIONS
External Reference
Internal Reference
V
CC
= 3V ±10% or 5V ±10%
V
FS
= V
CC
= 5.5V
Zero-Scale; V
OUT
shorted to V
CC
Full-Scale; V
OUT
shorted to GND
For Specified Performance
V
CC
= 3V, V
REF
= 2.5V, External Reference
V
CC
= 3V, Internal Reference
V
CC
= 5V, V
REF
= 2.5V, External Reference
V
CC
= 5V, Internal Reference
V
CC
= 5V, C-Grade, I-Grade
V
CC
= 5V, H-Grade
l
l
l
l
l
l
l
l
l
MIN
TYP
0 to V
REF
0 to 2.5
–80
27
–28
MAX
UNITS
V
V
dB
48
–48
5.5
mA
mA
V
μA
μA
μA
μA
μA
μA
Power Supply
V
CC
I
CC
2.7
150
180
160
190
0.6
0.6
200
240
210
260
1.8
4
I
SD
Supply Current in Power-Down Mode
(Note 7)
2640fb
5
综合技术交流
