LTC1662
Ultralow Power, Dual
10-Bit DAC in MSOP
DESCRIPTIO
The LTC
®
1662 is an ultralow power, fully buffered volt-
age 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 sup-
plying DC output currents in excess of 1mA and reliably
driving capacitive loads of up to 1000pF. A program-
mable Sleep mode further reduces total operating cur-
rent 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
industrial temperature range.
, LTC and LT are registered trademarks of Linear Technology Corporation.
FEATURES
s
s
s
s
s
s
s
s
s
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
APPLICATIO S
s
s
s
s
s
Mobile Communications
Portable Battery-Powered Instruments
Remote or Inaccessible Adjustments
Digitally Controlled Amplifiers and Attenuators
Factory or Field Calibration
BLOCK DIAGRA
V
OUT A
8
GND
7
V
CC
6
V
OUT B
5
LATCH
LATCH
LATCH
10-BIT
DAC A
LATCH
10-BIT
DAC B
I
CC
+ I
REF
(µA)
CONTROL
LOGIC
ADDRESS
DECODER
SHIFT REGISTER
1
CS/LD
2
SCK
3
SDI
4
REF
1662 BD
U
W
U
Total Supply-Plus-Reference
Operating Current
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
V
REF
= V
CC
CODE = 1023
5 25 45 65 85 105 125
TEMPERATURE (°C)
1662 G02
5.5V
4.5V
3.6V
V
CC
= 2.7V
0
–55 –35 –15
1
LTC1662
ABSOLUTE
(Note 1)
AXI U
RATI GS
Operating Temperature Range
LTC1662C ............................................. 0°C to 70°C
LTC1662I ........................................... – 40°C to 85°C
Lead Temperature (Soldering, 10 sec)................ 300°C
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
PACKAGE/ORDER I FOR ATIO
TOP VIEW
CS/LD
SCK
SDI
REF
1
2
3
4
8
7
6
5
V
OUT A
GND
V
CC
V
OUT B
ORDER PART
NUMBER
CS/LD 1
LTC1662CMS8
LTC1662IMS8
MS8 PART MARKING
LTKB
LTKC
MS8 PACKAGE
8-LEAD PLASTIC MSOP
T
JMAX
= 125°C,
θ
JA
= 150°C/W
Consult factory for Military grade parts.
The
q
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.
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
Active Mode
Sleep Mode
V
REF
= 2.5V
q
q
q
ELECTRICAL CHARACTERISTICS
PARAMETER
CONDITIONS
(Note 2)
(Note 2)
(Note 2)
V
CC
= 5V, V
REF
= 4.096V, Measured at Code 20
V
CC
= 5V, V
REF
= 4.096V
Reference Input
0
3.9
7.1
2.5
10
V
CC
V
MΩ
GΩ
pF
2
U
U
W
W W
U
W
TOP VIEW
8
7
6
5
V
OUT A
GND
V
CC
V
OUT B
ORDER PART
NUMBER
LTC1662CN8
LTC1662IN8
SCK 2
SDI 3
REF 4
N8 PACKAGE
8-LEAD PLASTIC DIP
T
JMAX
= 125°C,
θ
JA
= 100°C/W
MIN
10
10
TYP
MAX
UNITS
Bits
Bits
q
q
q
q
±0.12
±0.8
±5
±15
±1
±12
0.18
±0.75
±4
±25
±8
LSB
LSB
mV
µV/°C
LSB
µV/°C
LSB/V
q
LTC1662
The
q
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.
SYMBOL
V
CC
I
CC
PARAMETER
Positive Supply Voltage
Supply Current
CONDITIONS
For Specified Performance
V
CC
= 3V (Note 3)
V
CC
= 5V (Note 3)
V
CC
= 3V (Note 3)
V
CC
= 5V (Note 3)
q
ELECTRICAL CHARACTERISTICS
MIN
2.7
TYP
MAX
5.5
UNITS
V
µA
µA
µA
µA
µA
µA
mA
mA
V/ms
V/ms
ms
ms
pF
V
V
Power Supply
3.0
3.5
q
q
4.0
4.5
5.0
5.5
0.10
0.18
70
80
Sleep Mode Operating Current Supply Plus Reference Current, V
CC
= V
REF
= 5V (Note 3)
q
0.05
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
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
q
q
q
q
q
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)
q
q
5
3
12
10
20
7
0.40
0.75
1000
2.4
2.0
0.8
0.6
±0.05
1.5
±1.0
V
V
µA
pF
TI I G 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
SDI Setup
SDI Hold
SCK High Time
SCK Low Time
SYMBOL
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
9
t
11
V
CC
= 4.5V to 5.5V
UW
The
q
denotes the specifications which apply over the full operating temperature
MIN
q
q
q
q
q
q
q
q
q
q
q
q
q
q
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)
Relative to SCK Positive Edge (Note 6)
Relative to SCK Positive Edge (Note 6)
(Note 6)
(Note 6)
TYP
15
– 10
14
14
27
2
– 21
–5
0
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
55
0
30
30
100
30
20
0
20
16.7
75
0
50
50
20
– 10
15
15
MHz
ns
ns
ns
ns
3
LTC1662
TI I G CHARACTERISTICS
range, otherwise specifications are at T
A
= 25°C.
PARAMETER
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
SYMBOL
t
5
t
6
t
7
t
9
t
11
Note 1:
Absolute maximum ratings are those values beyond which the life
of a device may be impaired.
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
.
TYPICAL PERFOR A CE 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
V
REF
= V
CC
CODE = 1023
5.5V
4.5V
I
CC
+ I
REF
(µA)
2.5
2.0
1.5
1.0
0.5
3.6V
V
CC
= 2.7V
I
CC
(µA)
3.6V
V
CC
= 2.7V
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
INTEGRAL NONLINEARITY (LSB)
V
CC
= 5V
ALL DIGITAL INPUTS
SHORTED TOGETHER
4
3
2
1
0
–1
–2
–3
–4
DIFFERENTIAL NONLINEARITY (LSB)
4
U W
UW
The
q
denotes the specifications which apply over the full operating temperature
CONDITIONS
(Note 6)
(Note 6)
(Note 6)
(Note 6)
(Note 6)
Square Wave (Note 6)
q
q
q
q
q
q
MIN
150
50
30
0
30
TYP
30
3
– 14
–5
0
MAX
UNITS
ns
ns
ns
ns
ns
10
MHz
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.
Total Supply-Plus-Reference
Operating Current
5.0
4.5
4.0
3.5
3.0
5.5V
4.5V
100
1000
Supply Current vs Clock
Frequency
CS/LD = LOGIC LOW
CODE = 0
V
CC
= 5V
10
V
CC
= 3V
V
REF
= V
CC
CODE = 1023
1
0
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
1662 G02
10
100
1k
10k 100k 1M
FREQUENCY (Hz)
10M 100M
1662 G03
Integral Nonlinearity (INL)
0.75
0.60
0.40
0.20
0
–0.20
–0.40
–0.60
–0.75
0
256
512
CODE
768
1023
1662 G05
Differential Nonlinearity (DNL)
0
256
512
CODE
768
1023
1662 G06
1662 G04
LTC1662
TYPICAL PERFOR A CE CHARACTERISTICS
Integral Nonlinearity (INL) vs
Reference Voltage
4
3
2
1
0
–1
–2
–3
–4
0
1
2
3
V
REF
(V)
1662 G07
V
CC
= 5.5V
0.50
PEAK DNL (LSB)
PEAK INL (LSB)
0.25
0
MAX POS INL
MAX POS DNL
OFFSET ERROR (mV)
MAX NEG INL
4
Gain Error vs Temperature
0
V
CC
= 5V
V
REF
= 4.096V
–1
GAIN ERROR (mV)
1.0
0.8
0.6
0.4
∆V
OUT
(LSB)
–2
∆V
OUT
(LSB)
–3
–4
–5
–55 –35 –15 5
25 45 65
TEMPERATURE (°C)
Output Amplifier Current Sourcing
Capability (Midscale)
5.0
4.5
4.0
3.5
V
OUT
(V)
3.0
2.5
2.0
1.5
1.0
0.5
0
1µ
10µ
100µ
1m
10m
OUTPUT SOURCE CURRENT (A)
100m
1662 G13
V
REF
= V
CC
CODE = 512
T
A
= 25°C
V
OUT
(V)
V
OUT
(V)
V
CC
= 5.5V
V
CC
= 5V
V
CC
= 4.5V
V
CC
= 3.6V
V
CC
= 3V
V
CC
= 2.7V
U W
5
6
Differential Nonlinearity (DNL) vs
Reference Voltage
0.75
V
CC
= 5.5V
Offset Voltage vs Temperature
0
V
CC
= 5V
V
REF
= 4.096V
–1
–2
MAX NEG DNL
–0.25
–0.50
–0.75
0
1
2
3
V
REF
(V)
1662 G08
–3
–4
4
5
6
–5
–55 –35 –15 5
25 45 65
TEMPERATURE (°C)
85
105
1662 G09
Load Regulation vs Output
Current at 5V
1.0
Load Regulation vs Output
Current at 3V
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
V
REF
= V
CC
= 3V
V
OUT
= 1.5V
CODE = 512
T
A
= 25°C
V
REF
= V
CC
= 5V
V
OUT
= 2.5V
CODE = 512
T
A
= 25°C
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
SOURCE
SINK
2
3
4
5
–0.8
–1.0
SOURCE
SINK
1
85
105
–5 –4 –3 –2 –1 0 1
I
OUT
(mA)
–1 –0.8–0.6–0.4– 0.2 0 0.2 0.4 0.6 0.8
I
OUT
(mA)
1662 G10
1662 G11
1662 G12
Output Amplifier Current Sinking
Capability (Midscale)
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
1µ
10µ
100µ
1m
10m
OUTPUT SINK CURRENT (A)
100m
1662 G14
Max/Min Output Voltage vs Source/
Sink Output Current (V
CC
= 5V)
5.0
4.5
CODE = 1023
V
REF
= V
CC
CODE = 512
T
A
= 25°C
V
CC
= 5.5V
V
CC
= 5V
V
CC
= 4.5V
4.0
3.5
3.0
2.5
2.0
1.5
V
REF
= V
CC
T
A
= 25°C
V
CC
= 3.6V
V
CC
= 3V
V
CC
= 2.7V
1.0
0.5
0
0
0.5 1 1.5 2 2.5 3 3.5 4 4.5
OUTPUT SOURCE/SINK CURRENT (mA)
5
CODE = 0
1662 G15
5
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
