LTC1662
Ultralow Power, Dual
10-Bit DAC in MSOP
Features
n
n
Description
The LTC
®
1662 is an ultralow power, fully buffered voltage
output, dual 10-bit digital-to-analog converter (DAC). Each
DAC channel draws just 1.7µA (typ) total supply-plus-
reference operating current, yet is capable of supplying
DC output currents in excess of 1mA and reliably driving
capacitive loads of up to 1000pF A programmable sleep
.
mode further reduces total operating current to 0.05µA.
Linear Technology’s proprietary, inherently monotonic
architecture provides excellent linearity and an exception-
ally small external form factor. The double-buffered input
logic provides simultaneous update capability and can be
used to write to the DACs without interrupting sleep mode.
With its tiny operating current and exceptionally small
size, the LTC1662 is ideal for use in the most power-
constrained products. For most designs, there is no
perceptible impact on the power budget; the LTC1662
draws many times less current than even a trimpot,
while providing buffered, low impedance (0.5Ω typical,
V
CC
= 5V) rail-to-rail outputs.
The LTC1662 is pin and software compatible with the
LTC1661 dual, 60µA 10-bit DAC. It is available in 8-pin
MSOP and PDIP packages and is specified over the in-
dustrial temperature range.
n
n
n
n
n
n
n
Ultralow Power: 1.5µA (Typ) I
CC
per DAC Plus
0.05µA Sleep Mode for Extended Battery Life
Tiny: Two 10-Bit DACs in an 8-Lead MSOP—
Half the Size of an SO-8
Wide 2.7V to 5.5V Supply Range
Double Buffered for Simultaneous DAC Updates
Rail-to-Rail Voltage Outputs Drive 1000pF
Reference Range Includes Supply for Ratiometric
0V to V
CC
Output
Reference Input Impedance Is Code-Independent
(7.1MΩ Typ)—Eliminates External Buffers
3-Wire Serial Interface with Schmitt Trigger Inputs
Differential Nonlinearity: ±0.75LSB Max
applications
n
n
n
n
n
Mobile Communications
Portable Battery-Powered Instruments
Remote or Inaccessible Adjustments
Digitally Controlled Amplifiers and Attenuators
Factory or Field Calibration
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.
Block Diagram
V
OUT A
8
GND
7
V
CC
6
V
OUT B
5
5.0
LATCH
LATCH
LATCH
10-BIT
DAC A
LATCH
10-BIT
DAC B
I
CC
+ I
REF
(µA)
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
SHIFT REGISTER
0.5 V
REF
= V
CC
CODE = 1023
0
–55 –35 –15 5 25 45 65 85 105 125
TEMPERATURE (°C)
3
SDI
4
REF
1662 BD
1662 TA01b
Total Supply-Plus-Reference
Operating Current
5.5V
4.5V
3.6V
V
CC
= 2.7V
CONTROL
LOGIC
ADDRESS
DECODER
1
CS/LD
2
SCK
1662fa
1
LTC1662
aBsolute maximum ratings
(Note 1)
V
CC
to GND ............................................... –0.3V to 7.5V
Logic Inputs to GND ................................. –0.3V to 7.5V
V
OUT A
, V
OUT B
, REF to GND ......... –0.3V to (V
CC
+ 0.3V)
Maximum Junction Temperature .......................... 125°C
Storage Temperature Range .................. –65°C to 150°C
Operating Temperature Range
LTC1662C ............................................... 0°C to 70°C
LTC1662I ............................................ –40°C to 85°C
Lead Temperature (Soldering, 10 sec).................. 300°C
pin conFiguration
TOP VIEW
TOP VIEW
CS/LD
SCK
SDI
REF
1
2
3
4
8
7
6
5
V
OUT A
GND
V
CC
V
OUT B
CS/LD
1
SCK 2
SDI 3
REF 4
8
7
6
5
V
OUT A
GND
V
CC
V
OUT B
MS8 PACKAGE
8-LEAD PLASTIC MSOP
T
JMAX
= 125°C,
θ
JA
= 150°C/W
N8 PACKAGE
8-LEAD PLASTIC DIP
T
JMAX
= 125°C,
θ
JA
= 100°C/W
orDer inFormation
LEAD FREE FINISH
LTC1662CMS8#PBF
LTC1662IMS8#PBF
LTC1662CN8#PBF
LTC1662IN8#PBF
LEAD BASED FINISH
LTC1662CMS8
LTC1662IMS8
LTC1662CN8
LTC1662IN8
TAPE AND REEL
LTC1662CMS8#TRPBF
LTC1662IMS8#TRPBF
LTC1662CN8#TRPBF
LTC1662IN8#TRPBF
TAPE AND REEL
LTC1662CMS8#TR
LTC1662IMS8#TR
LTC1662CN8#TR
LTC1662IN8#TR
PART MARKING
LTKB
LTKC
LTC1662CN8
LTC1662IN8
PART MARKING
LTKB
LTKC
LTC1662CN8
LTC1662IN8
PACKAGE DESCRIPTION
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic DIP
8-Lead Plastic DIP
PACKAGE DESCRIPTION
8-Lead Plastic MSOP
8-Lead Plastic MSOP
8-Lead Plastic DIP
8-Lead Plastic DIP
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
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/
1662fa
2
LTC1662
electrical characteristics
SYMBOL
Accuracy
Resolution
Monotonicity
DNL
INL
V
OS
V
OS
TC
GE
GE TC
PSR
Differential Nonlinearity
Integral Nonlinearity
Offset Error
V
OS
Temperature Coefficient
Gain Error
Gain Error Temperature Coefficient
Power Supply Rejection
Input Voltage Range
Input Resistance
Input Capacitance
Power Supply
V
CC
I
CC
Positive Supply Voltage
Supply Current
For Specified Performance
V
CC
= 3V (Note 3)
V
CC
= 5V (Note 3)
V
CC
= 3V (Note 3)
V
CC
= 5V (Note 3)
Supply Plus Reference Current, V
CC
= V
REF
= 5V (Note 3)
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range (T
A
= T
MIN
to T
MAX
), otherwise specifications are at T
A
= 25°C. V
CC
= 2.7V to 5.5V, V
REF
≤ V
CC
, V
OUT
unloaded
unless otherwise noted.
PARAMETER
CONDITIONS
MIN
10
10
±0.12
±0.8
±5
±15
V
CC
= 5V, V
REF
= 4.096V
V
REF
= 2.5V
l
l
TYP
MAX
UNITS
Bits
Bits
(Note 2)
(Note 2)
(Note 2)
V
CC
= 5V, V
REF
= 4.096V, Measured at Code 20
l
l
l
l
±0.75
±4
±25
±8
LSB
LSB
mV
µV/°C
LSB
µV/°C
LSB/V
±1
±12
0.18
0
3.9
7.1
2.5
10
2.7
3.0
3.5
Reference Input
V
CC
V
MΩ
GΩ
pF
5.5
4.0
4.5
5.0
5.5
0.10
0.18
70
80
V
µA
µA
µA
µA
µA
µA
mA
mA
V/ms
V/ms
ms
ms
pF
V
V
0.8
0.6
±0.05
1.5
±1.0
V
V
µA
pF
Active Mode
Sleep Mode
l
l
l
Sleep Mode Operating Current
DC Performance
Short-Circuit Current Low
Short-Circuit Current High
AC Performance
Voltage Output Slew Rate
Voltage Output Settling Time
Capacitive Load Driving
Digital I/O
V
IH
V
IL
I
LK
C
IN
Digital Input High Voltage
Digital Input Low Voltage
Digital Input Leakage
Digital Input Capacitance
0.05
V
OUT
= 0V, V
CC
= V
REF
= 5V, Code = 1023 (Note 7)
V
OUT
= V
CC
= V
REF
= 5V, Code = 0 (Note 7)
Rising (Notes 4, 5)
Falling (Notes 4, 5)
Rising 0.1V
FS
to 0.9V
FS
±0.5LSB (Notes 4, 5)
Falling 0.9V
FS
to 0.1V
FS
±0.5LSB (Notes 4, 5)
l
l
5
3
12
10
20
7
0.40
0.75
1000
V
CC
= 2.7V to 5.5V
V
CC
= 2.7V to 3.6V
V
CC
= 4.5V to 5.5V
V
CC
= 2.7V to 5.5V
V
IN
= GND to V
CC
l
l
l
l
l
2.4
2.0
1662fa
3
LTC1662
timing characteristics
range, otherwise specifications are at T
A
= 25°C.
PARAMETER
SDI Setup
SDI Hold
SCK High Time
SCK Low Time
CS/LD
Pulse Width
LSB SCK High to
CS/LD
High
CS/LD
Low to SCK High
SCK Low to
CS/LD
Low
CS/LD
High to SCK Positive Edge
SCK Frequency
V
CC
= 2.7V to 5.5V
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
9
t
11
SDI Setup
SDI Hold
SCK High Time
SCK Low Time
CS/LD
Pulse Width
LSB SCK High to
CS/LD
High
CS/LD
Low to SCK High
SCK Low to
CS/LD
Low
CS/LD
High to SCK Positive Edge
SCK Frequency
Relative to SCK Positive Edge (Note 6)
Relative to SCK Positive Edge (Note 6)
(Note 6)
(Note 6)
(Note 6)
(Note 6)
(Note 6)
(Note 6)
(Note 6)
Square Wave (Note 6)
l
l
l
l
l
l
l
l
l
l
The
l
denotes the specifications which apply over the full operating temperature
CONDITIONS
Relative to SCK Positive Edge
Relative to SCK Positive Edge
(Note 6)
(Note 6)
(Note 6)
(Note 6)
(Note 6)
(Note 6)
(Note 6)
Square Wave (Note 6)
l
l
l
l
l
l
l
l
l
l
SYMBOL
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
9
t
11
MIN
55
0
30
30
100
30
20
0
20
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
V
CC
= 4.5V to 5.5V
16.7
75
0
50
50
150
50
30
0
30
10
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
MHz
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2:
Nonlinearity and monotonicity are defined and tested at V
CC
= 5V,
V
REF
= 4.096V, from code 20 to code 1023. See Figure 2.
Note 3:
Digital inputs at 0V or V
CC
.
Note 4:
Load is 10kΩ in parallel with 100pF
.
Note 5:
V
CC
= V
REF
= 5V. DAC switched between 0.1V
FS
and 0.9V
FS
;
i.e., codes k = 102 and k = 922.
Note 6:
Guaranteed by design, not subject to test.
Note 7:
One DAC output loaded.
1662fa
4
LTC1662
typical perFormance characteristics
Supply Current vs Temperature
5.0
4.5
4.0
3.5
I
CC
(µA)
3.0
2.5
2.0
1.5
1.0
0.5
0
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
1662 G01
Total Supply-Plus-Reference
Operating Current
5.0
4.5
4.0
5.5V
4.5V
V
REF
= V
CC
CODE = 1023
5.5V
4.5V
I
CC
+ I
REF
(µA)
1000
Supply Current
vs Clock Frequency
CS/LD
= LOGIC LOW
CODE = 0
V
CC
= 5V
3.5
2.5
2.0
1.5
1.0
0.5 V
REF
= V
CC
CODE = 1023
0
–55 –35 –15 5 25 45 65 85 105 125
TEMPERATURE (°C)
1662 G02
100
3.6V
V
CC
= 2.7V
I
CC
(µA)
3.0
3.6V
V
CC
= 2.7V
10
V
CC
= 3V
1
10
100
1k
10k 100k 1M
FREQUENCY (Hz)
10M 100M
1662 G03
Supply Current
vs Logic Input Voltage
1.0
0.9
0.8
0.7
I
CC
(mA)
0.6
0.5
0.4
0.3
0.2
0.1
0
0
1.5
1 1.5 2 2.5 3 3.5 4
LOGIC INPUT VOLTAGE (V)
4.5
5
V
CC
= 5V
ALL DIGITAL INPUTS
SHORTED TOGETHER
4
3
2
1
0
–1
–2
–3
–4
Integral Nonlinearity (INL)
DIFFERENTIAL NONLINEARITY (LSB)
Differential Nonlinearity (DNL)
0.75
0.60
0.40
0.20
0
–0.20
–0.40
–0.60
–0.75
INTEGRAL NONLINEARITY (LSB)
0
256
512
CODE
768
1023
1662 G05
0
256
512
CODE
768
1023
1662 G06
1662 G04
Integral Nonlinearity (INL)
vs Reference Voltage
4
3
2
1
0
–1
–2
–3
–4
0
1
2
3
V
REF
(V)
1662 G07
Differential Nonlinearity (DNL)
vs Reference Voltage
0.75
0.50
PEAK DNL (LSB)
0.25
0
MAX NEG DNL
–0.25
–0.50
–0.75
OFFSET ERROR (mV)
V
CC
= 5.5V
0
–1
MAX POS DNL
–2
–3
–4
Offset Voltage vs Temperature
V
CC
= 5V
V
REF
= 4.096V
V
CC
= 5.5V
PEAK INL (LSB)
MAX POS INL
MAX NEG INL
4
5
6
0
1
2
3
V
REF
(V)
4
5
6
1662 G08
–5
25 45 65
–55 –35 –15 5
TEMPERATURE (°C)
85
105
1662 G09
1662fa
5
京公网安备 11010802033920号
EEWORLD
