LT6660
1
6660f
CHANGE IN V
OUT
(%)
0.09
0
DISTRIBUTION (%)
4
8
16
20
24
32
6660 TA01b
12
28
0.09
0.05
0.01
0.01
0.05
Tiny Micropower
Precision Series References
in 2mm × 2mm DFN
The LT
®
6660 is a family of micropower series references
that combine high accuracy and low drift with low power
dissipation and extremely small package size. These se-
ries references use curvature compensation to obtain
low temperature coeffi cient, and laser trimmed precision
thin-fi lm resistors to achieve high output accuracy. The
LT6660 will supply up to 20mA with excellent line regula-
tion characteristics, making it ideal for precision regulator
applications.
The LT6660 family of series references provide supply
current and power dissipation advantages over shunt
references that must idle the entire load current to oper-
ate. Additionally, the LT6660 does not require an output
compensation capacitor. This feature is important in
applications where PC board space is a premium, fast set-
tling is demanded, or total capacitance must be kept to a
minimum, as in intrinsic safety applications. Reverse-bat-
tery protection keeps these references from conducting
reverse current.
Handheld Instruments
Precision Regulators
A/D and D/A Converters
Power Supplies
Hard Disk Drives
Sensor Modules
3-Lead 2mm × 2mm × 0.75mm DFN Package
No Output Capacitor Required
Low Drift: 20ppm/°C Max
High Accuracy: 0.2% Max
Low Supply Current
20mA Output Current Guaranteed
Reverse-Battery Protection
Low IR Refl ow Induced Stress: 0.02% Typ
Voltage Options: 2.5V, 3V, 3.3V, 5V and 10V
Space-Saving Alternative to the LT1460
APPLICATIO S
U
FEATURES
DESCRIPTIO
U
TYPICAL APPLICATIO
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Basic Connection
LT6660
GND
IN
OUT
V
OUT
+ 0.9V
V
IN
20V
6660 TA01
C1
0.1
µF
V
OUT
LT6660H V
OUT
Shift Due to IR Refl ow
LT6660
2
6660f
Input Voltage .............................................................30V
Reverse Voltage ......................................................15V
Output Short-Circuit Duration, T
A
= 25°C ................5 sec
Specifi ed Temperature Range ...................... 0°C to 70°C
(Note 1)
ABSOLUTE AXI U
RATI GS
W
W
W
U
PACKAGE/ORDER I FOR ATIO
U
U
W
TOP VIEW
OUT
GND
IN
DC PACKAGE
3-LEAD (2mm
× 2mm) PLASTIC DFN
4
3
2
1
T
JMAX
= 125°C,
JA
= 102°C/W
EXPOSED PAD IS GND, MUST BE SOLDERED TO PCB
ORDER PART NUMBER
DFN PART MARKING*
LT6660HCDC-2.5
LT6660JCDC-2.5
LT6660KCDC-2.5
LT6660HCDC-3
LT6660JCDC-3
LT6660KCDC-3
LT6660HCDC-3.3
LT6660JCDC-3.3
LT6660KCDC-3.3
LT6660HCDC-5
LT6660JCDC-5
LT6660KCDC-5
LT6660HCDC-10
LT6660JCDC-10
LT6660KCDC-10
LBXN
LBXN
LBXN
LBYV
LBYV
LBYV
LBYW
LBYW
LBYW
LBYT
LBYT
LBYT
LBYX
LBYX
LBYX
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking:
http://www.linear.com/leadfree/
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container.
Operating Temperature Range
(Note 2) ............................................... 40°C to 85°C
Storage Temperature Range (Note 3) ..... 65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
AVAILABLE OPTIONS
OUTPUT VOLTAGE
(V)
SPECIFIED TEMPERATURE
RANGE
ACCURACY
(%)
TEMPERATURE
COEFFICIENT (ppm/°C)
PART ORDER
NUMBER
2.5
2.5
2.5
0°C to 70°C
0°C to 70°C
0°C to 70°C
0.2
0.4
0.5
20
20
50
LT6660HCDC-2.5
LT6660JCDC-2.5
LT6660KCDC-2.5
3
3
3
0°C to 70°C
0°C to 70°C
0°C to 70°C
0.2
0.4
0.5
20
20
50
LT6660HCDC-3
LT6660JCDC-3
LT6660KCDC-3
3.3
3.3
3.3
0°C to 70°C
0°C to 70°C
0°C to 70°C
0.2
0.4
0.5
20
20
50
LT6660HCDC-3.3
LT6660JCDC-3.3
LT6660KCDC-3.3
LT6660
3
6660f
The
denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
IN
= V
OUT
+ 2.5V, I
OUT
= 0 unless otherwise specifi ed.
ELECTRICAL CHARACTERISTICS
OUTPUT VOLTAGE
(V)
SPECIFIED TEMPERATURE
RANGE
ACCURACY
(%)
TEMPERATURE
COEFFICIENT (ppm/°C)
PART ORDER
NUMBER
5
5
5
0°C to 70°C
0°C to 70°C
0°C to 70°C
0.2
0.4
0.5
20
20
50
LT6660HCDC-5
LT6660JCDC-5
LT6660KCDC-5
10
10
10
0°C to 70°C
0°C to 70°C
0°C to 70°C
0.2
0.4
0.5
20
20
50
LT6660HCDC-10
LT6660JCDC-10
LT6660KCDC-10
AVAILABLE OPTIONS
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Output Voltage Tolerance
LT6660HCDC
0.2
0.2
%
LT6660JCDC
0.4
0.4
%
LT6660KCDC
0.5
0.5
%
Output Voltage Temperature Coeffi cient (Note 4)
LT6660HCDC
LT6660JCDC
LT6660KCDC
10
10
25
20
20
50
ppm/°C
ppm/°C
ppm/°C
Line Regulation
V
OUT
+ 0.9V V
IN
V
OUT
+ 2.5V
150
800
1000
ppm/V
ppm/V
V
OUT
+ 2.5V V
IN
20V
50
100
130
ppm/V
ppm/V
Load Regulation Sourcing (Note 5)
I
OUT
= 100µA
1000
3000
4000
ppm/mA
ppm/mA
I
OUT
= 10mA
50
200
300
ppm/mA
ppm/mA
I
OUT
= 20mA
20
70
100
ppm/mA
ppm/mA
Thermal Regulation (Note 6)
P = 200mW
2.5
10
ppm/mW
Dropout Voltage (Note 7)
V
IN
V
OUT
, V
OUT
0.2%, I
OUT
= 0
0.9
V
V
IN
V
OUT
, V
OUT
0.2%, I
OUT
= 10mA
1.3
1.4
V
V
Output Current
Short V
OUT
to GND
40
mA
Reverse Leakage
V
IN
= 15V
0.5
10
µA
Output Voltage Noise (Note 8)
0.1Hz f 10Hz
10Hz f 1kHz
4
4
ppm (P-P)
ppm (RMS)
Long-Term Stability of Output Voltage (Note 9)
100
ppm/kHr
Hysteresis (Note 10)
T = 0°C to 70°C
T = 40°C to 85°C
50
250
ppm
ppm
Supply Current
LT6660-2.5
115
145
175
µA
µA
LT6660-3
145
180
220
µA
µA
LT6660-3.3
145
180
220
µA
µA
LT6660-5
160
200
240
µA
µA
LT6660-10
215
270
350
µA
µA
LT6660
4
6660f
OUTPUT CURRENT (mA)
0
0
OUTPUT VOLTAGE CHANGE (mV)
20
40
60
80
100
120
1
2
3
4
55
°C
6660 G03
5
125
°C
25
°C
OUTPUT CURRENT (mA)
0.1
2.0
OUTPUT VOLTAGE CHANGE (mV)
1.0
0
1
10
100
6660 G02
3.0
2.5
1.5
0.5
3.5
4.0
55
°C
25
°C
125
°C
INPUT-OUTPUT VOLTAGE (V)
0
0.1
OUTPUT CURRENT (mA)
10
125
°C
25
°C
100
0.5
1.0
1.5
2.0
2.5
6660 G01
1
55
°C
Characteristic curves are similar for all voltage
options of the LT6660. Curves from the LT6660-2.5 and the LT6660-10 represent the extremes of the voltage options. Characteristic
curves for other output voltages fall between these curves, and can be estimated based on their voltage output.
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
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: The LT6660 is guaranteed functional over the operating
temperature range of 40°C to 85°C.
Note 3: If the parts are stored outside of the specifi ed temperature range,
the output may shift due to hysteresis.
Note 4: Temperature coeffi cient is measured by dividing the change in
output voltage by the specifi ed temperature range. Incremental slope is
also measured at 25°C.
Note 5: Load regulation is measured on a pulse basis from no load to the
specifi ed load current. Output changes due to die temperature change
must be taken into account separately.
Note 6: Thermal regulation is caused by die temperature gradients created
by load current or input voltage changes. This effect must be added to
normal line or load regulation. This parameter is not 100% tested.
Note 7: Excludes load regulation errors.
Note 8: Peak-to-peak noise is measured with a single pole highpass fi lter
at 0.1Hz and 2-pole lowpass fi lter at 10Hz. The unit is enclosed in a still-air
environment to eliminate thermocouple effects on the leads. The test time
is 10 sec. RMS noise is measured with a single pole highpass fi lter at
10Hz and a 2-pole lowpass fi lter at 1kHz. The resulting output is full wave
rectifi ed and then integrated for a fi xed period, making the fi nal reading an
average as opposed to RMS. A correction factor of 1.1 is used to convert
from average to RMS and a second correction of 0.88 is used to correct
for the nonideal bandpass of the fi lters.
Note 9: Long-term stability typically has a logarithmic characteristic
and therefore, changes after 1000 hours tend to be much smaller than
before that time. Total drift in the second thousand hours is normally less
than one third that of the fi rst thousand hours with a continuing trend
toward reduced drift with time. Long-term stability will also be affected by
differential stresses between the IC and the board material created during
board assembly.
Note 10: Hysteresis in output voltage is created by package stress that
differs depending on whether the IC was previously at a higher or lower
temperature. Output voltage is always measured at 25°C, but the IC
is cycled to 70°C or 0°C before successive measurements. Hysteresis
is roughly proportional to the square of the temperature change. For
instruments that are stored at well-controlled temperatures (within 20 or
30 degrees of operational temperature) hysteresis is not a problem.
ELECTRICAL CHARACTERISTICS
2.5V Minimum Input-Output
Voltage Differential
2.5V Load Regulation, Sourcing
2.5V Load Regulation, Sinking
LT6660
5
6660f
FREQUENCY (Hz)
100
1000
10
1k
10k
6660 G10
100
100k
NOISE VOLTAGE (nV/
Hz)
200
µs/DIV
C
LOAD
= 0
µF
20
10
1
0.1
LOAD CURRENT (mA)
6660 G09
TIME (2 SEC/DIV)
OUTPUT NOISE (20
µ
V/DIV)
6660 G11
TEMPERATURE (
°C)
50
OUTPUT VOLTAGE (V)
2.501
2.502
2.503
25
75
6660 G04
2.500
2.499
25
0
50
100
125
2.498
2.497
THREE TYPICAL PARTS
INPUT VOLTAGE (V)
0
SUPPLY CURRENT (
µ
A)
100
150
125
°C
25
°C
55
°C
20
6660 G05
50
0
5
10
15
250
200
INPUT VOLTAGE (V)
0
OUTPUT VOLTAGE (V)
2.502
2.501
2.500
2.499
2.498
2.497
2.496
2.495
2.494
16
6660 G06
4
8
12
20
14
2
6
10
18
25
°C
125
°C
55
°C
FREQUENCY (kHz)
20
POWER SUPPLY REJECTION RATIO (dB)
40
50
70
80
0.1
10
100
1000
6660 G07
0
1
60
30
10
FREQUENCY (kHz)
1
OUTPUT IMPEDANCE (
)
10
100
1000
0.01
1
10
100
0.1
0.1
1000
6660 G08
C
L
= 0
µF
C
L
= 0.1
µF
C
L
= 1
µF
Characteristic curves are similar for all voltage
options of the LT6660. Curves from the LT6660-2.5 and the LT6660-10 represent the extremes of the voltage options. Characteristic
curves for other output voltages fall between these curves, and can be estimated based on their voltage output.
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
2.5V Output Voltage
Temperature Drift
2.5V Supply Current
vs Input Voltage
2.5V Line Regulation
2.5V Power Supply Rejection
Ratio vs Frequency
2.5V Output Impedance
vs Frequency
2.5V Transient Response
2.5V Output Voltage
Noise Spectrum
2.5V Output Noise 0.1Hz to 10Hz
LT6660
6
6660f
INPUT-OUTPUT VOLTAGE (V)
0
0.1
OUTPUT CURRENT (mA)
10
125
°C
25
°C
100
0.5
1.0
1.5
2.0
2.5
6660 G12
1
55
°C
OUTPUT CURRENT (mA)
0.1
15
OUTPUT VOLTAGE CHANGE (mV)
20
25
30
35
1
10
100
6660 G13
10
5
5
10
0
125
°C
25
°C
55
°C
OUTPUT CURRENT (mA)
0
OUTPUT VOLTAGE CHANGE (mV)
150
200
250
4
6660 G14
100
50
0
1
2
3
5
125
°C
55
°C
25
°C
INPUT VOLTAGE (V)
0
0
SUPPLY CURRENT (
µ
A)
50
150
200
250
350
2
10
14
6660 G16
100
300
8
18 20
4
6
12
16
125
°C
55
°C
25
°C
TEMPERATURE (
°C)
50
OUTPUT VOLTAGE (V)
10.002
10.004
10.006
0
50
75
6660 G15
9.998
10.000
9.996
9.994
9.992
9.990
9.988
9.986
9.984
9.982
25
25
100
125
THREE TYPICAL PARTS
INPUT VOLTAGE (V)
6
OUTPUT VOLTAGE (V)
10.000
10.005
10.010
12
16
6660 G17
9.995
9.990
8
10
14
18
20
9.985
9.980
125
°C
55
°C
25
°C
Characteristic curves are similar for all voltage
options of the LT6660. Curves from the LT6660-2.5 and the LT6660-10 represent the extremes of the voltage options. Characteristic
curves for other output voltages fall between these curves, and can be estimated based on their voltage output.
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
10V Minimum Input-Output
Voltage Differential
10V Load Regulation, Sourcing
10V Load Regulation, Sinking
10V Output Voltage
Temperature Drift
10V Supply Current
vs Input Voltage
10V Line Regulation
LT6660
7
6660f
FREQUENCY (kHz)
0.01
0.1
1
10
1
10
0.1
100
6660 G21
NOISE VOLTAGE (
µ
V/
Hz)
200
µs/DIV
C
LOAD
= 0
µF
20
10
1
0.1
LOAD CURRENT (mA)
6660 G20
FREQUENCY (kHz)
30
POWER SUPPLY REJECTION RATIO (dB)
90
100
20
10
80
50
70
60
40
0.1
10
100
1000
6660 G18
0
1
FREQUENCY (kHz)
1
OUTPUT IMPEDANCE (
)
10
100
1000
0.01
1
10
100
0.1
0.1
1000
6660 G19
C
L
= 0
µF
C
L
= 0.1
µF
C
L
= 1
µF
TIME (2 SEC/DIV)
OUTPUT NOISE (20
µ
V/DIV)
6660 G22
Characteristic curves are similar for all voltage
options of the LT6660. Curves from the LT6660-2.5 and the LT6660-10 represent the extremes of the voltage options. Characteristic
curves for other output voltages fall between these curves, and can be estimated based on their voltage output.
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
10V Output Voltage
Noise Spectrum
10V Output Noise 0.1Hz to 10Hz
10V Power Supply Rejection
Ratio vs Frequency
10V Output Impedance
vs Frequency
10V Transient Response
LT6660
8
6660f
APPLICATIO S I FOR ATIO
W
U
U
U
Longer Battery Life
Series references have a large advantage over older shunt
style references. Shunt references require a resistor
from the power supply to operate. This resistor must be
chosen to supply the maximum current that can ever be
demanded by the circuit being regulated. When the circuit
being controlled is not operating at this maximum current,
the shunt reference must always sink this current, resulting
in high dissipation and short battery life.
The LT6660 series references do not require a current
setting resistor and can operate with any supply voltage
from V
OUT
+ 0.9V to 20V. When the circuitry being regu-
lated does not demand current, the LT6660s reduce their
dissipation and battery life is extended. If the references
are not delivering load current, they dissipate only several
mW, yet the same connection can deliver 20mA of load
current when demanded.
Capacitive Loads
The LT6660 family of references are designed to be stable
with a large range of capacitive loads. With no capacitive
load, these references are ideal for fast settling or applica-
tions where PC board space is a premium. The test circuit
shown in Figure 1 is used to measure the response time
and stability of various load currents and load capacitors.
This circuit is set for the 2.5V option. For other voltage
options, the input voltage must be scaled up and the
output voltage generator offset voltage must be adjusted.
The 1V step from 2.5V to 1.5V produces a current step of
10mA or 1mA for R
L
= 100 or R
L
= 1k. Figure 2 shows
the response of the reference to these 1mA and 10mA
load steps with no load capacitance, and Figure 3 shows
a 1mA and 10mA load step with a 0.1µF output capaci-
tor. Figure 4 shows the response to a 1mA load step with
C
L
= 1µF and 4.7µF.
Figure 2. C
L
= 0µF
Figure 3. C
L
= 0.1µF
Figure 4. I
OUT
= 1mA
1
µs/DIV
V
GEN
V
OUT
V
OUT
2.5V
1.5V
1mA
10mA
6660 F02
100
µs/DIV
V
GEN
V
OUT
V
OUT
2.5V
1.5V
1mA
10mA
6660 F03
100
µs/DIV
V
GEN
V
OUT
V
OUT
2.5V
1.5V
1
µF
4.7
µF
6660 F04
Figure 1. Response Time Test Circuit
LT6660-2.5
R
L
V
OUT
V
GEN
6660 F01
C
IN
0.1
µF
2.5V
1.5V
C
L
V
IN
= 2.5V
LT6660
9
6660f
HYSTERESIS (ppm)
240
160
80
0
NUMBER OF UNITS
8
70
°C TO 25°C
0
°C TO 25°C
10
12
6660 F06
6
4
80
160
200
120
40
40
120
200
2
0
18
16
14
240
WORST-CASE HYSTERESIS
ON 40 UNITS
HYSTERESIS (ppm)
600
400
200
0
NUMBER OF UNITS
4
85
°C TO 25°C
40
°C TO 25°C
5
6
6660 F07
3
2
200
400
500
300
100
100
300
500
1
0
9
8
7
600
WORST-CASE HYSTERESIS
ON 34 UNITS
Figure 6. 0°C to 70°C Hysteresis
Figure 7. 40°C to 85°C Hysteresis
Figure 5. Typical Long-Term Drift
HOURS
150
ppm
50
50
150
100
0
100
200
400
600
800
6660 F05
1000
100
0
300
500
700
900
APPLICATIO S I FOR ATIO
W
U
U
U
Table 1 gives the maximum output capacitance for vari-
ous load currents and output voltages to avoid instability.
Load capacitors with low ESR (effective series resistance)
cause more ringing than capacitors with higher ESR such
as polarized aluminum or tantalum capacitors.
Table 1. Maximum Output Capacitance
VOLTAGE
OPTION
I
OUT
= 100µA
I
OUT
= 1mA
I
OUT
= 10mA
I
OUT
= 20mA
2.5V
>10µF
>10µF
2µF
0.68µF
3V
>10µF
>10µF
2µF
0.68µF
3.3V
>10µF
>10µF
1µF
0.68µF
5V
>10µF
>10µF
1µF
0.68µF
10V
>10µF
1µF
0.15µF
0.1µF
Long-Term Drift
Long-term drift cannot be extrapolated from accelerated
high temperature testing. This erroneous technique
gives drift numbers that are wildly optimistic. The only
way long-term drift can be determined is to measure it
over the time interval of interest. The LT6660 long-term
drift data was taken on over 100 parts that were soldered
into PC boards similar to a "real world" application. The
boards were then placed into a constant temperature oven
with T
A
= 30°C, their outputs were scanned regularly and
measured with an 8.5 digit DVM. Figure 5 shows typical
long-term drift of the LT6660s.
Hysteresis
Hysteresis data shown in Figure 6 and Figure 7 represents
the worst-case data taken on parts from 0°C to 70°C and
from 40°C to 85°C. The output is capable of dissipat-
ing relatively high power, i.e., for the LT6660-2.5, P
D
=
17.5V · 20mA = 350mW. The thermal resistance of the
DFN package is 102°C/W and this dissipation causes a
36°C internal rise. This elevated temperature may cause
the output to shift due to thermal hysteresis. For highest
performance in precision applications, do not let the
LT6660's junction temperature exceed 85°C.
Input Capacitance
It is recommended that a 0.1µF or larger capacitor be
added to the input pin of the LT6660. This can help with
stability when large load currents are demanded.
LT6660
10
6660f
Output Accuracy
Like all references, either series or shunt, the error budget
of the LT6660s is made up of primarily three components:
initial accuracy, temperature coeffi cient and load regulation.
Line regulation is neglected because it typically contributes
only 150ppm/V. The LT6660s typically shift 0.02% when
soldered into a PCB, so this is also neglected. The output
errors are calculated as follows for a 100µA load and 0°C
to 70°C temperature range:
LT6660HCDC
Initial Accuracy = 0.2%
For I
OUT
= 100µA
V
OUT
= (4000ppm/mA)(0.1mA) = 0.04%
For Temperature 0°C to 70°C the maximum T = 70°C
V
OUT
= (20ppm/°C)(70°C) = 0.14%
Total worst-case output error is:
0.2% + 0.04% + 0.14% = 0.380%
Table 2 gives the worst-case accuracy for LT6660HC,
LT6660JC and LT6660KC from 0°C to 70°C, and shows
that if the LT6660HC is used as a reference instead of a
regulator, it is capable of 8 bits of absolute accuracy over
temperature without a system calibration.
Table 2. Worst-Case Output Accuracy over Temperature
I
OUT
LT6660HCDC
LT6660JCDC
LT6660KCDC
0µA
0.340%
0.540%
0.850%
100µA
0.380%
0.580%
0.890%
10mA
0.640%
0.840%
1.15%
20mA
0.540%
0.740%
1.05%
APPLICATIO S I FOR ATIO
W
U
U
U
LT6660
11
6660f
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
PACKAGE DESCRIPTIO
U
2.00
±0.10
(4 SIDES)
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (W-TBD)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE
TOP AND BOTTOM OF PACKAGE
BOTTOM VIEW--EXPOSED PAD
1.00
± 0.05
(2 SIDES)
1.35
± 0.05
(2 SIDES)
0.75
±0.05
0.40
±0.05
0.70
±0.05
1
3
PIN 1 BAR
TOP MARK
(SEE NOTE 6)
0.200 REF
0.00 0.05
(DC3) DFN 1205 REV Ø
0.25
± 0.05
R = 0.05
TYP
R = 0.115 TYP
0.50 BSC
0.25
± 0.05
1.35
±0.05
(2 SIDES)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
1.00
±0.05
(2 SIDES)
1.30
±0.05
2.00
±0.05
PACKAGE
OUTLINE
0.50 BSC
PIN 1 NOTCH
R = 0.20 OR
0.25
× 45°
CHAMFER
DC Package
3-Lead Plastic DFN (2mm × 2mm)
(Reference LTC DWG # 05-08-1717 Rev Ø)
LT6660
12
6660f
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
FAX: (408) 434-0507
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2006
LT 0106 · PRINTED IN USA
V
+
(V
OUT
+ 1.8V)
LT6660
OUT
GND
IN
6660 TA03
2N2905
V
OUT
100mA
47
µF
2
µF
SOLID
TANT
R1
220
+
+
3
2
1
6660 TA04
2N2905
V
OUT
100mA
2
µF
SOLID
TANT
D1*
LED
V
+
V
OUT
+ 2.8V
8.2
R1
220
GLOWS IN CURRENT LIMIT,
DO NOT OMIT
*
47
µF
+
+
LT6660
OUT
GND
IN
3
2
1
6660 TA02
R
L
40mA
V
+
R1*
V
OUT
TYPICAL LOAD
CURRENT = 50mA
SELECT R1 TO DELIVER 80% OF TYPICAL LOAD CURRENT.
LT1460 WILL THEN SOURCE AS NECESSARY TO MAINTAIN
PROPER OUTPUT. DO NOT REMOVE LOAD AS OUTPUT WILL
BE DRIVEN UNREGULATED HIGH. LINE REGULATION IS
DEGRADED IN THIS APPLICATION
*
10mA
47
µF
+
LT6660
OUT
GND
IN
R1 =
V
+
V
OUT
40mA
3
2
1
TYPICAL APPLICATIO
U
RELATED PARTS
Handling Higher Load Currents
Boosted Output Current with No Current Limit
Boosted Output Current with Current Limit
PART NUMBER
DESCRIPTION
COMMENTS
LT1019
Precision Bandgap Reference
0.05% Max, 5ppm/°C Max
LT1027
Precision 5V Reference
0.02%, 2ppm/°C Max
LT1236
Precision Low Noise Reference
0.05% Max, 5ppm/°C Max, SO Package
LT1460
Micropower Series References
0.075% Max, 10ppm/°C Max, 20mA Output Current
LT1461
Micropower Precision Low Dropout
0.04% Max, 3ppm/°C Max, 50mA Output Current
LT1634
Micropower Precision Shunt Reference 1.25V, 2.5V Output
0.05%, 25ppm/°C Max
LT1790
Micropower Precision Series References
0.05% Max, 10ppm/°C Max, 60µA Supply, SOT23 Package
LTC
®
1798
Micropower Low Dropout Reference, Fixed or Adjustable
0.15% Max, 40ppm/°C, 6.5µA Max Supply Current
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