LT1610IS8#TR [Linear]
LT1610 - 1.7MHz, Single Cell Micropower DC/DC Converter; Package: SO; Pins: 8; Temperature Range: -40°C to 85°C;型号: | LT1610IS8#TR |
厂家: | Linear |
描述: | LT1610 - 1.7MHz, Single Cell Micropower DC/DC Converter; Package: SO; Pins: 8; Temperature Range: -40°C to 85°C 开关 光电二极管 |
文件: | 总16页 (文件大小:210K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
LT1610
1.7MHz, Single Cell
Micropower
DC/DC Converter
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FEATURES
DESCRIPTIO
The LT®1610 is a micropower fixed frequency DC/DC
converterthatoperatesfromaninputvoltageaslowas1V.
Intended for small, low power applications, it switches at
1.7MHz, allowing the use of tiny capacitors and inductors.
■
Uses Tiny Capacitors and Inductor
■
Internally Compensated
■
Low Quiescent Current: 30µA
■
■
■
■
■
■
■
■
Operates with VIN as Low as 1V
3V at 30mA from a Single Cell
The device can generate 3V at 30mA from a single cell
(1V) supply. An internal compensation network can be
connected to the LT1610’s VC pin, eliminating two exter-
nalcomponents.No-loadquiescentcurrentoftheLT1610
is 30µA, and the internal NPN power switch handles a
300mA current with a voltage drop of 300mV.
5V at 200mA from 3.3V
High Output Voltage Capability: Up to 28V
Low Shutdown Current: <1µA
Automatic Burst ModeTM Switching at Light Load
Low VCESAT Switch: 300mV at 300mA
8-Lead MSOP and SO Packages
TheLT1610isavailablein8-leadMSOPandSOpackages.
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APPLICATIO S
■
Pagers
■
Cordless Phones
■
Battery Backup
LCD Bias
Portable Electronic Equipment
■
, LTC and LT are registered trademarks of Linear Technology Corporation.
Burst Mode is a trademark of Linear Technology Corporation.
■
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TYPICAL APPLICATIO
L1
Efficiency
D1
4.7µH
V
OUT
85
3V
30mA
V
= 3V
OUT
R1
6
5
SW
80
75
70
65
60
55
50
V
= 1.5V
IN
1M
V
V
= 1.25V
IN
IN
2
3
FB
SHDN
+
+
R2
681k
C1
22µF
C2
22µF
LT1610
1 CELL
V
= 1V
IN
8
7
COMP
GND
PGND
V
C
1
4
C1, C2: AVX TAJA226M006R
D1: MOTOROLA MBR0520
L1: MURATA LQH1C4R7
1610 F01
0.1
1
10
100
LOAD CURRENT (mA)
1610 TA01
Figure 1. 1-Cell to 3V Step-Up Converter
1
LT1610
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ABSOLUTE MAXIMUM RATINGS
(Note 1)
Maximum Junction Temperature ......................... 125°C
Operating Temperature Range (Note 1)
Commercial ............................................. 0°C to 70°C
Extended Commercial (Note 2).......... –40°C to 85°C
Industrial ........................................... –40°C to 85°C
Storage Temperature Range ................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
VIN Voltage ................................................................ 8V
SW Voltage ............................................... –0.4V to 30V
FB Voltage ..................................................... VIN + 0.3V
VC Voltage ................................................................ 2V
COMP Voltage .......................................................... 2V
Current into FB Pin .............................................. ±1mA
SHDN Voltage ............................................................ 8V
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PACKAGE/ORDER INFORMATION
ORDER PART
ORDER PART
TOP VIEW
NUMBER
NUMBER
TOP VIEW
V
1
2
3
4
COMP
GND
8
7
6
5
C
V
1
8 COMP
7 GND
C
LT1610CMS8
LT1610CS8
LT1610IS8
FB
SHDN
PGND
FB 2
SHDN 3
PGND 4
6 V
IN
V
IN
5 SW
SW
MS8 PACKAGE
MS8 PART MARKING
LTDT
S8 PART MARKING
8-LEAD PLASTIC MSOP
S8 PACKAGE
8-LEAD PLASTIC SO
TJMAX = 125°C, θJA = 160°C/W
1610
1610I
T
JMAX = 125°C, θJA = 120°C/W
Consult factory for Military grade parts.
The ● denotes specifications which apply over the specified temperature
ELECTRICAL CHARACTERISTICS
(Note 2)
range, otherwise specifications are at TA = 25°C. Commercial grade 0°C to 70°C, VIN = 1.5V, VSHDN = VIN, unless otherwise noted.
PARAMETER
CONDITIONS
MIN
TYP
MAX
1
UNITS
Minimum Operating Voltage
Maximum Operating Voltage
Feedback Voltage
0.9
V
V
8
●
●
1.20
1.23
30
1.26
60
V
Quiescent Current
V
= 1.5V, Not Switching
µA
SHDN
Quiescent Current in Shutdown
V
V
= 0V, V = 2V
= 0V, V = 5V
0.01
0.01
0.5
1.0
µA
µA
SHDN
SHDN
IN
IN
FB Pin Bias Current
27
80
nA
Reference Line Regulation
1V ≤ V ≤ 2V (25°C, 0°C)
0.6
1
2
0.15
0.2
%/V
%/V
%/V
%/V
IN
1V ≤ V ≤ 2V (70°C)
IN
2V ≤ V ≤ 8V (25°C, 0°C)
0.03
IN
2V ≤ V ≤ 8V (70°C)
IN
Error Amp Transconductance
Error Amp Voltage Gain
Switching Frequency
∆I = 2µA
25
100
1.7
80
µmhos
V/V
●
●
1.4
2
MHz
Maximum Duty Cycle
77
75
95
95
%
%
2
LT1610
The ● denotes specifications which apply over the specified temperature
ELECTRICAL CHARACTERISTICS
(Note 2)
range, otherwise specifications are at TA = 25°C. Commercial grade 0°C to 70°C, VIN = 1.5V, VSHDN = VIN, unless otherwise noted.
PARAMETER
CONDITIONS
MIN
TYP
600
300
MAX
UNITS
Switch Current Limit
(Note 3)
450
900
mA
Switch V
I
= 300mA
350
400
mV
mV
CESAT
SW
●
Switch Leakage Current
SHDN Input Voltage High
SHDN Input Voltage Low
SHDN Pin Bias Current
V
= 5V
0.01
1
µA
V
SW
1
0.3
0.1
V
V
V
= 3V
= 0V
10
0.01
µA
µA
SHDN
SHDN
The ● denotes specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C.
Industrial grade –40°C to 85°C, VIN = 1.5V, VSHDN = VIN, unless otherwise noted.
PARAMETER
CONDITIONS
T = 85°C
T = –40°C
A
MIN
TYP
MAX
UNITS
Minimum Operating Voltage
0.9
1
1.25
V
V
A
Maximum Operating Voltage
Feedback Voltage
8
V
V
●
●
1.20
1.23
30
1.26
60
Quiescent Current
µA
Quiescent Current in Shutdown
V
V
= 0V, V = 2V
0.01
0.01
0.5
1.0
µA
µA
SHDN
SHDN
IN
= 0V, V = 5V
IN
FB Pin Bias Current
27
80
nA
Reference Line Regulation
2V ≤ V ≤ 8V (–40°C)
0.03
0.15
0.2
%/V
%/V
IN
2V ≤ V ≤ 8V (85°C)
IN
Error Amp Transconductance
Error Amp Voltage Gain
Switching Frequency
∆I = 2µA
25
100
1.7
80
µmhos
V/V
(Note 4)
(Note 4)
●
●
1.4
2
MHz
Maximum Duty Cycle
77
75
95
95
%
%
Switch Current Limit
450
600
300
900
mA
Switch V
I
= 300mA
= 5V
350
400
mV
mV
CESAT
SW
●
Switch Leakage Current
SHDN Input Voltage High
SHDN Input Voltage Low
SHDN Pin Bias Current
V
0.01
1
µA
V
SW
1
0.3
0.1
V
V
V
= 3V
= 0V
10
0.01
µA
µA
SHDN
SHDN
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LT1610C is guaranteed to meet specified performance from
0°C to 70°C and is designed, characterized and expected to meet these
extended temperature limits, but is not tested at –40°C and 85°C. The
LT1610I is guaranteed to meet the extended temperature limits.
Note 3: Current limit guaranteed by design and/or correlation to static test.
Current limit is affected by duty cycle due to ramp generator. See Block
Diagram.
Note 4: Not 100% tested at 85°C.
3
LT1610
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TYPICAL PERFOR A CE CHARACTERISTICS
Current Limit (DC = 30%)
vs Temperature
VCESAT vs Current
Current Limit vs Duty Cycle
600
500
400
300
800
700
600
500
400
300
200
100
0
800
700
600
500
400
300
200
T
= 25°C
A
T
= 85°C
A
T
= 25°C
A
T
= –40°C
A
200
100
0
200
300
400
500
600
100
–50
0
25
50
75
100
0
10 20 30 40 50 60 70 80 90 100
DUTY CYCLE (%)
–25
SWITCH CURRENT (mA)
TEMPERATURE (°C)
1610 G01
1610 G02
1610 G03
Oscillator Frequency
vs Input Voltage
Quiescent Current
vs Temperature
Feedback Voltage
2.50
2.25
2.00
1.75
1.50
1.25
1.00
0.75
0.50
0.25
0
1.240
1.235
1.230
1.225
1.220
1.215
1.210
40
35
30
25
T
A
= 25°C
20
15
10
5
0
0
4
6
7
–50
0
25
50
75
100
1
2
3
5
8
–25
–25
0
50
–50
75
100
25
INPUT VOLTAGE (V)
TEMPERATURE (°C)
TEMPERATURE (°C)
1610 G04
1610 G05
1610 G06
Burst Mode Operation,
Circuit of Figure 1
SHDN Pin Current
vs SHDN Pin Voltage
Transient Response,
Circuit of Figure 1
50
40
30
VOUT
20mV/DIV
VOUT
50mV/DIV
AC COUPLED
AC COUPLED
SWITCH
VOLTAGE
2V/DIV
SWITCH
CURRENT
50mA/DIV
IL1
100mA/DIV
31mA
ILOAD
1mA
20
10
0
1610 TA08
1610 TA08
VIN = 1.25V
VOUT = 3V
ILOAD = 3mA
20µs/DIV
VIN = 1.25V
OUT = 3V
500µs/DIV
V
4
0
1
2
3
5
6
7
8
SHDN VOLTAGE (V)
1610 G07
4
LT1610
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PIN FUNCTIONS
VC (Pin 1): Error Amplifier Output. Frequency compensa-
tion network must be connected to this pin, either internal
(COMP pin) or external series RC to ground. 220kΩ/
220pF typical value.
SW (Pin 5): Switch Pin. Connect inductor/diode here.
Minimize trace area at this pin to keep EMI down.
VIN (Pin 6): Input Supply Pin. Must be locally bypassed.
GND (Pin 7): Signal Ground. Carries all device ground
current except switch current. Tie to local ground plane.
FB (Pin 2): Feedback Pin. Reference voltage is 1.23V.
Connect resistive divider tap here. Minimize trace area at
FB. Set VOUT according to VOUT = 1.23V (1 + R1/R2).
COMP (Pin 8): Internal Compensation Network. Tie to VC
pin, or let float if external compensation is used. Output
capacitor must be tantalum if COMP pin is used for com-
pensation.
SHDN (Pin 3): Shutdown. Ground this pin to turn off
device. Tie to 1V or more to enable.
PGND (Pin 4): Power Ground. Tie directly to local ground
plane.
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BLOCK DIAGRA
V
IN
6
V
IN
R6
40k
R5
40k
V
OUT
+
–
A1
m
1
8
3
7
V
SHUTDOWN
SHDN
GND
C
g
R1
(EXTERNAL)
COMP
C
Q1
FB
2
Q2
× 10
FB
R
C
R3
30k
C
R2
(EXTERNAL)
R4
140k
+
–
ENABLE
BIAS
SW
5
COMPARATOR
–
FF
DRIVER
RAMP
Q3
A2
R
Q
GENERATOR
+
S
Σ
+
–
0.15Ω
A = 3
1.7MHz
OSCILLATOR
4
PGND
1610 F02
Figure 2. LT1610 Block Diagram
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LT1610
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APPLICATIONS INFORMATION
OPERATION
Iftheoutputloadincreasessufficiently,A1’soutputremains
high, resulting in continuous operation. When the LT1610
is running continuously, peak switch current is controlled
by VC to regulate the output voltage. The switch is turned
on at the beginning of each switch cycle. When the sum-
mation of a signal representing switch current and a ramp
generator(introducedtoavoidsubharmonicoscillationsat
duty factors greater than 50%) exceeds the VC signal,
comparator A2 changes state, resetting the flip-flop and
turning off the switch. Output voltage increases as switch
current is increased. The output, attenuated by a resistor
divider, appears at the FB pin, closing the overall loop.
Frequency compensation is provided by either an external
series RC network connected between the VC pin and
ground or the internal RC network on the COMP pin (Pin
8). The typical values for the internal RC are 50k and 50pF.
The LT1610 combines a current mode, fixed frequency
PWMarchitecturewithBurstModemicropoweroperation
to maintain high efficiency at light loads. Operation can be
best understood by referring to the block diagram in
Figure 2. Q1 and Q2 form a bandgap reference core whose
loop is closed around the output of the converter. When
VIN is 1V, the feedback voltage of 1.23V, along with an
70mV drop across R5 and R6, forward biases Q1 and Q2’s
base collector junctions to 300mV. Because this is not
enough to saturate either transistor, FB can be at a higher
voltage than VIN. When there is no load, FB rises slightly
above 1.23V, causing VC (the error amplifier’s output) to
decrease. When VC reaches the bias voltage on hysteretic
comparator A1, A1’s output goes low, turning off all
circuitry except the input stage, error amplifier and low-
battery detector. Total current consumption in this state is
30µA. As output loading causes the FB voltage to de-
crease, A1’s output goes high, enabling the rest of the IC.
Switch current is limited to approximately 100mA initially
after A1’s output goes high. If the load is light, the output
voltage (and FB voltage) will increase until A1’s output
goes low, turning off the rest of the LT1610. Low fre-
quency ripple voltage appears at the output. The ripple
frequencyisdependentonloadcurrentandoutputcapaci-
tance. This Burst Mode operation keeps the output regu-
lated and reduces average current into the IC, resulting in
high efficiency even at load currents of 1mA or less.
LAYOUT
Although the LT1610 is a relatively low current device, its
high switching speed mandates careful attention to layout
for optimum performance. For boost converters, follow
thecomponentplacementindicatedinFigure3forthebest
results. C2’s negative terminal should be placed close to
Pin4oftheLT1610.Doingthisreducesswitchingcurrents
in the ground copper which keeps high frequency “spike”
noise to a minimum. Tie the local ground into the system
ground plane at one point only, using a few vias, to avoid
introducing dI/dt induced noise into the ground plane.
GROUND PLANE
V
IN
R1
1
2
3
4
8
7
6
5
C1
+
L1
LT1610
R2
SHUTDOWN
MULTIPLE
VIAs
+
D1
C2
GND
V
OUT
1610 F03
Figure 3. Recommended Component Placement for Boost Converter. Note Direct High Current Paths Using
Wide PC Traces. Minimize Trace Area at Pin 1 (VC) and Pin 2 (FB). Use Multiple Vias to Tie Pin 4 Copper to
Ground Plane. Use Vias at One Location Only to Avoid Introducing Switching Currents into the Ground Plane
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LT1610
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APPLICATIONS INFORMATION
A SEPIC (Single-Ended Primary Inductance Converter)
schematic is shown in Figure 4. This converter topology
produces a regulated output over an input voltage range
that spans (i.e., can be higher or lower than) the output.
Recommended component placement for a SEPIC is
shown in Figure 5.
C3
1µF
CERAMIC
L1
22µH
D1
V
INPUT
OUT
•
3.3V
Li-ION
120mA
3V to 4.2V
6
5
SW
1M
•
V
IN
L2
22µH
1
8
2
3
+
C1
22µF
6.3V
V
C
FB
+
C2
22µF
6.3V
LT1610
604k
COMP
SHDN
GND
7
PGND
4
C1, C2: AVX TAJA226M006
C3: AVX 1206YC105 (X7R)
D1: MOTOROLA MBR0520
1610 F04
SHUTDOWN
L1, L2: MURATA LQH3C220 (UNCOUPLED)
OR SUMIDA CLS62-220 (COUPLED)
Figure 4. Li-Ion to 3.3V SEPIC DC/DC Converter
GROUND PLANE
R1
V
IN
1
2
8
7
6
5
C1
+
LT1610
R2
SHUTDOWN
3
4
L1
L2
MULTIPLE
VIAs
C2
C3
D1
+
GND
V
OUT
1610 F05
Figure 5. Recommended Component Placement for SEPIC
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LT1610
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APPLICATIONS INFORMATION
COMPONENT SELECTION
impedance of the output capacitor. The capacitor should
havelowimpedanceatthe1.7MHzswitchingfrequencyof
the LT1610. At this frequency, the impedance is usually
dominated by the capacitor’s equivalent series resistance
(ESR). Choosing a capacitor with lower ESR will result in
lower output ripple.
Inductors
Inductors used with the LT1610 should have a saturation
current rating (–30% of zero current inductance) of ap-
proximately 0.5A or greater. DCR should be 0.5Ω or less.
The value of the inductor should be matched to the power
requirements and operating voltages of the application. In
mostcasesavalueof4.7µHor10µHissuitable.TheMurata
LQH3C inductors specified throughout the data sheet are
small and inexpensive, and are a good fit for the LT1610.
Alternatives are the CD43 series from Sumida and the
DO1608seriesfromCoilcraft. Theseinductorsareslightly
larger but will result in slightly higher circuit efficiency.
Perhaps the best way to decrease ripple is to add a 1µF
ceramic capacitor in parallel with the bulk output capaci-
tor. Ceramic capacitors have very low ESR and 1µF is
enough capacitance to result in low impedance at the
switching frequency. The low impedance can have a
dramatic effect on output ripple voltage. To illustrate,
examine Figure 6’s circuit, a 4-cell to 5V/100mA SEPIC
DC/DCconverter. Thisdesignusesinexpensivealuminum
electrolytic capacitors at input and output to keep cost
down. Figure 7 details converter operation at a 100mA
load, without ceramic capacitor C5. Note the 400mV
Chip inductors, although tempting to use because of their
small size and low cost, generally do not have enough
energy storage capacity or low enough DCR to be used
successfully with the LT1610.
spikes on VOUT
.
After C5 is installed, output ripple decreases by a factor of
8 to about 50mVP-P. The addition of C5 also improves
efficiency by 1 to 2 percent.
Diodes
The Motorola MBR0520 is a 0.5 amp, 20V Schottky diode.
This is a good choice for nearly any LT1610 application,
unless the output voltage or the circuit topology require a
diode rated for higher reverse voltages. Motorola also
offers the MBR0530 (30V) and MBR0540 (40V) versions.
Most one-half amp and one amp Schottky diodes are
suitable; these are available from many manufacturers. If
you use a silicon diode, it must be an ultrafast recovery
type. Efficiency will be lower due to the silicon diode’s
higher forward voltage drop.
Low ESR and the required bulk output capacitance can be
obtained using a single larger output capacitor. Larger
tantalum capacitors, newer capacitor technologies (for
example the POSCAP from Sanyo and SPCAP from
Panasonic) or large value ceramic capacitors will reduce
the output ripple. Note, however, that the stability of the
circuit depends on both the value of the output capacitor
and its ESR. When using low value capacitors or capaci-
tors with very low ESR, circuit stability should be evalu-
ated carefully, as described below.
Capacitors
Loop Compensation
The input capacitor must be placed physically close to the
LT1610. ESR is not critical for the input. In most cases
inexpensive tantalum can be used.
The LT1610 is a current mode PWM switching regulator
that achieves regulation with a linear control loop. The
LT1610 provides the designer with two methods of com-
pensatingthisloop. First, youcanuseaninternalcompen-
sation network by tying the COMP pin to the VC pin. This
results in a very small solution and reduces the circuit’s
total part count. The second option is to tie a resistor RC
andacapacitorCC inseriesfromtheVC pintoground. This
allows optimization of the transient response for a wide
variety of operating conditions and power components.
The choice of output capacitor is far more important. The
quality of this capacitor is the greatest determinant of the
output voltage ripple. The output capacitor performs two
major functions. It must have enough capacitance to
satisfy the load under transient conditions and it must
shunt the AC component of the current coming through
the diode from the inductor. The ripple on the output
results when this AC current passes through the finite
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LT1610
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APPLICATIONS INFORMATION
C3
1µF
CERAMIC
L1
22µH
D1
V
•
OUT
5V
120mA
6
5
SW
•
1M
V
IN
L2
22µH
1
2
3
+
C1
22µF
6.3V
C4
V
C
FB
4 CELLS
1µF
+
C5
C2
22µF
6.3V
LT1610
324k
CERAMIC
1µF
8
COMP
SHDN
CERAMIC
GND
7
PGND
4
C1, C2: ALUMINUM ELECTROLYTIC
C3 TO C5: CERAMIC X7R OR X5R
D1: MBR0520
1610 F06
SHUTDOWN
L1, L2: MURATA LQH3C220 OR SUMIDA CLS62-220
Figure 6. 4-Cell Alkaline to 5V/120mA SEPIC DC/DC Converter
sation network is modified to achieve stable operation.
Linear Technology’s Application Note 19 contains a de-
tailed description of the method. A good starting point for
the LT1610 is CC ~ 220pF and RC ~ 220k.
VOUT
200mV/DIV
IDIODE
500mA/DIV
SWITCH
VOLTAGE
10V/DIV
All Ceramic, Low Profile Design
Largevalueceramiccapacitorsthataresuitableforuseas
the main output capacitor of an LT1610 regulator are now
available. These capacitors have very low ESR and there-
fore offer very low output ripple in a small package.
However, you should approach their use with some
caution.
100ns/DIV
1610 F07
Figure 7. Switching Waveforms Without Ceramic Capacitor C5
VOUT
50mV/DIV
IDIODE
Ceramic capacitors are manufactured using a number of
dielectrics, each with different behavior across tempera-
ture and applied voltage. Y5V is a common dielectric used
for high value capacitors, but it can lose more than 80% of
the original capacitance with applied voltage and extreme
temperatures. The transient behavior and loop stability of
the switching regulator depend on the value of the output
capacitor, so you may not be able to afford this loss. Other
dielectrics (X7R and X5R) result in more stable character-
istics and are suitable for use as the output capacitor. The
X7R type has better stability across temperature, whereas
the X5R is less expensive and is available in higher values.
500mA/DIV
SWITCH
VOLTAGE
10V/DIV
VIN = 4.1V
LOAD = 100mA
100ns/DIV
1610 F08
Figure 8. Switching Waveforms with Ceramic Capacitor C5.
Note the 50mV/DIV Scale for VOUT
Itisbesttochoosethecompensationcomponentsempiri-
cally. Once the power components have been chosen
(based on size, efficiency, cost and space requirements),
a working circuit is built using conservative (or merely
guessed) values of RC and CC. Then the response of the
circuitisobservedunderatransientload,andthecompen-
The second concern in using ceramic capacitors is that
many switching regulators benefit from the ESR of the
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LT1610
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APPLICATIONS INFORMATION
output capacitor because it introduces a zero in the
regulator’s loop gain. This zero may not be effective
because the ceramic capacitor’s ESR is very low. Most
currentmodeswitchingregulators(includingtheLT1610)
can easily be compensated without this zero. Any design
should be tested for stability at the extremes of operating
temperatures; this is particularly so of circuits that use
ceramic output capacitors.
VOUT
100mV/DIV
LOAD
CURRENT
105mA
5mA
500µs/DIV
1610 F10
Figure 10. Tantalum Output Capacitor
and Internal RC Compensation
Figure 9 details a 2.5V to 5V boost converter. Transient
responsetoa5mAto105mAloadstepispicturedinFigure
10. The “double trace” of VOUT at 105mA load is due to the
ESR of C2. This ESR aids stability. In Figure 11, C2 is
replaced by a 10µF ceramic capacitor. Note the low phase
margin; at higher input voltage, the converter may oscil-
late. After replacing the internal compensation network
with an external 220pF/220k series RC, the transient
response is shown in Figure 12. This is acceptable tran-
sient response.
VOUT
100mV/DIV
LOAD
CURRENT
105mA
5mA
500µs/DIV
1610 F11
Table 1
FIGURE C2
Figure 11. 10µF X5R-Type Ceramic Output Capacitor
and Internal RC Compensation has Low Phase Margin
COMPENSATION
Internal
10
11
12
AVX TAJA226M006 Tantalum
Taiyo Yuden JMK316BJ106
Taiyo Yuden JMK316BJ106
Internal
220pF/220k
VOUT
L1
10µH
100mV/DIV
D1
V
OUT
V
IN
5V
2.5V
100mA
LOAD
CURRENT
6
5
SW
1M
105mA
V
IN
5mA
2
3
1
FB
SHDN
500µs/DIV
1610 F12
+
+
C1
R2
324k
C2
22µF
LT1610
Figure 12. Ceramic Output Capacitor with 220pF/220k
External Compensation has Adequate Phase Margin
22µF
7
V
C
GND
PGND
COMP
8
R
C
4
C
C
C1: AVX TAJA226M006
C2: SEE TABLE
1610 F09
D1: MOTOROLA MBR0520
L1: MURATA LQH30100
Figure 9. 2.5V to 5V Boost Converter Can Operate with a
Ceramic Output Capacitor as Long as Proper RC and CC
are Used. Disconnect COMP Pin if External Compensation
Components Are Used
10
LT1610
U
TYPICAL APPLICATIONS
2-Cell to 5V Converter
Efficiency
90
80
70
60
50
L1
D1
4.7µH
V
OUT
V
= 3V
IN
5V
50mA
V
= 2V
IN
6
5
SW
1M
V
IN
2
7
3
8
FB
SHDN
V
= 1.5V
IN
+
+
C1
15µF
C2
15µF
LT1610
2 CELLS
324k
COMP
V
C
GND
PGND
1
4
0.1
1
10
100
1000
1610 TA02
C1, C2: AVX TAJA156M010R
D1: MOTOROLA MBR0520
L1: SUMIDA CD43-4R7
MURATA LQH1C4R7
LOAD CURRENT (mA)
1610 TA03
2-Cell to 3.3V Converter
Efficiency
90
80
70
L1
D1
3.3V
OUT
4.7µH
V
OUT
3.3V
3V
IN
70mA
6
5
R2
1M
V
SW
IN
2
3
1
8
1.5V
FB
V
IN
C
+
+
C1
10µF
R3
604k
C2
33µF
LT1610
2 CELLS
2V
IN
COMP
GND
7
SHDN
PGND
4
60
50
0.1
1
10
100
1000
1610 TA04
C1: AVX TAJA106M010R
C2: AVX TAJB336M006R
D1: MBR0520
LOAD (mA)
SHUTDOWN
1610 TA05
L1: MURATA LQH3C4R7
5V to 12V/100mA Boost Converter
Efficiency
90
85
80
75
70
65
60
55
50
L1
D1
10µH
V
OUT
V
IN
12V
100mA
5V
6
5
R2
1M
V
SW
IN
2
3
1
8
FB
V
C
+
+
C1
15µF
R3
115k
C2
15µF
LT1610
COMP
GND
7
SHDN
PGND
4
0.1
1
10
100
1610 TA06
C1: AVX TAJA156M010
C2: AVX TAJB156M016
LOAD CURRENT (mA)
SHUTDOWN
1610 TA07
D1: MOTOROLA MBR0520
L1: MURATA LQH3C100M24
11
LT1610
TYPICAL APPLICATIONS
U
5V to 9V/150mA Boost Converter
Efficiency
L1
90
85
80
75
70
65
60
55
50
D1
10µH
V
OUT
V
IN
9V
5V
150mA
6
5
R2
1M
V
SW
IN
2
1
8
FB
V
C
+
+
C1
15µF
R3
158k
C2
15µF
LT1610
3
COMP
GND
7
SHDN
PGND
4
1
10
100
300
1610 TA08
C1: AVX TAJA156M010
C2: AVX TAJB156M016
D1: MOTOROLA MBR0520
L1: MURATA LQH3C100M24
SHUTDOWN
LOAD CURRENT (mA)
1610 TA09
5V to 9V Boost Converter Transient Response
VOUT
200mV/DIV
140mA
LOAD
CURRENT
10mA
INDUCTOR
CURRENT
200mA/DIV
200µs/DIV
1610 TA10
12
LT1610
U
TYPICAL APPLICATIONS
3.3V TO 8V/70mA, –8V/5mA, 24V/5mA TFT LCD Bias Supply Uses All Ceramic Capacitors
D2
V
OFF
–8V
5mA
1µF
D3
V
ON
24V
0.22µF
5mA
0.22µF
0.22µF: TAIYO YUDEN EMK212BJ224MG
1µF
1µF
D4
1µF: TAIYO YUDEN LMK212BJ105MG
4.7µF: TAIYO YUDEN LMK316BJ475ML
D1: MOTOROLA MBRO520
0.22µF
D2, D3, D4: BAT54S
L1: SUMIDA CDRH5D185R4
L1
5.4µH
D1
V
IN
3.3V
AV
8V
DD
6
5
V
SW
IN
70mA
8
2
3
1
COMP
SHDN
274k
C1
4.7µF
C2
4.7µF
LT1610
FB
PGND
4
V
C
GND
100k
51pF
48.7k
7
1610 TA18
TFT LCD Bias Supply Transient Response
AVDD
200mV/DIV
VON
500mV/DIV
VOFF
200mV/DIV
70mA
AVDD LOAD
25mA
VON LOAD = 5mA
OFF LOAD = 5mA
200µs/DIV
1610 TA19
V
13
LT1610
U
TYPICAL APPLICATIONS
Single Cell Super Cap Charger
L1
4.7µH
R4
20Ω
D1
V
OUT
4.5V
R1
6
5
200k
CHARGE
V
SW
IN
Q1
8
2
3
1
COMP
SHDN
+
+
+
R2
2M
C2
15µF
C1
LT1610
C
BIG
15µF
SHUTDOWN
V
FB
PGND
4
C
GND
1 AA
15k
R3
845k
ALKALINE
7
3.3nF
1610 TA11
C1, C2: AVX TAJA156M010
D1: MOTOROLA MBR0530T1
L1: MURATA LQH1C4R7
Q1: 2N3906
Super Cap Charger Output Current vs Output Voltage
Super Cap Charger Output Power vs Output Voltage
25
60
50
40
30
20
10
0
20
15
10
5
0
2.0
3.0
3.5
4.0
4.5
5.0
2.5
2.0
3.0
3.5
4.0
4.5
5.0
2.5
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
1610 TA12
1610 TA13
14
LT1610
U
PACKAGE DESCRIPTION
Dimensions in inches (millimeters) unless otherwise noted.
MS8 Package
8-Lead Plastic MSOP
(LTC DWG # 05-08-1660)
0.118 ± 0.004*
(3.00 ± 0.102)
8
7
6
5
0.118 ± 0.004**
(3.00 ± 0.102)
0.192 ± 0.004
(4.88 ± 0.10)
1
2
3
4
0.040 ± 0.006
(1.02 ± 0.15)
0.034 ± 0.004
(0.86 ± 0.102)
0.007
(0.18)
0° – 6° TYP
SEATING
PLANE
0.012
(0.30)
REF
0.021 ± 0.006
(0.53 ± 0.015)
0.006 ± 0.004
(0.15 ± 0.102)
MSOP (MS8) 1197
0.0256
(0.65)
TYP
* DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH,
PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
S8 Package
8-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.189 – 0.197*
(4.801 – 5.004)
7
5
8
6
0.150 – 0.157**
(3.810 – 3.988)
0.228 – 0.244
(5.791 – 6.197)
1
0.053 – 0.069
3
4
2
0.010 – 0.020
(0.254 – 0.508)
× 45°
(1.346 – 1.752)
0.004 – 0.010
(0.101 – 0.254)
0.008 – 0.010
(0.203 – 0.254)
0°– 8° TYP
0.016 – 0.050
(0.406 – 1.270)
0.050
(1.270)
TYP
0.014 – 0.019
(0.355 – 0.483)
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
SO8 0996
15
LT1610
U
TYPICAL APPLICATIONS N
Li-Ion to 3.3V SEPIC DC/DC Converter
Efficiency
80
70
60
50
40
30
C3
V
IN
V
IN
V
IN
= 2.7V
= 3.6V
= 4.2V
1µF
L1
CERAMIC
D1
22µH
V
INPUT
•
OUT
3.3V
Li-ION
120mA
3V to 4.2V
6
5
•
1M
V
SW
IN
L2
22µH
1
8
2
3
+
C1
22µF
6.3V
V
C
FB
+
C2
LT1610
604k
22µF
6.3V
COMP
SHDN
GND
7
PGND
4
0.1
1
10
100
LOAD CURRENT (mA)
C1, C2: AVX TAJB226M006
C3: AVX 1206YC105 (X7R)
D1: MOTOROLA MBR0520
1610 TA14
1610 TA15
SHUTDOWN
L1, L2: MURATA LQH3C220 (UNCOUPLED)
OR SUMIDA CLS62-220 (COUPLED)
4-Cell to 5V/120mA SEPIC DC/DC Converter
4-Cell to 5V Efficiency
80
70
60
50
40
30
C3
V
IN
V
IN
V
IN
V
IN
= 3.6V
= 4.2V
= 5V
1µF
L1
CERAMIC
D1
22µH
V
•
OUT
= 6.5V
5V
120mA
6
5
•
1M
V
SW
IN
L2
22µH
1
8
2
3
+
C1
22µF
6.3V
V
C
FB
4 CELLS
+
C2
LT1610
324k
22µF
6.3V
COMP
SHDN
GND
7
PGND
4
0.1
1
10
100
LOAD CURRENT (mA)
C1, C2: AVX TAJB226M006
C3: AVX 1206YC105 (X7R)
D1: MOTOROLA MBR0520
1610 TA16
1610 TA17
SHUTDOWN
L1, L2: MURATA LQH3C220 (UNCOUPLED)
OR SUMIDA CLS62-220 (COUPLED)
RELATED PARTS
PART NUMBER
LTC®1474
LT1307
DESCRIPTION
COMMENTS
Micropower Step-Down DC/DC Converter
94% Efficiency, 10µA I , 9V to 5V at 250mA
Q
Single Cell Micropower 600kHz PWM DC/DC Converter
Ultralow Power Single/Dual Comparators with Reference
Single Cell to 3.3V Regulated Charge Pump
Micropower Low Dropout Linear Regulator
Inverting 1.4MHz DC/DC Converter
3.3V at 75mA from 1 Cell, MSOP Package
LTC1440/1/2
LTC1502-3.3
LT1521
2.8µA I , Adjustable Hysteresis
Q
40µA I , No Inductors, 3.3V at 10mA from 1V Input
Q
500mV Dropout, 300mA Current, 12µA I
Q
LT1611
5V to –5V at 150mA, Tiny SOT-23 Package
3.3V to 5V at 200mA, Tiny SOT-23 Package
LT1613
Step-Up 1.4MHz DC/DC Converter
LTC1682
Doubler Charge Pump with Low Noise Linear Regulator
Fixed 3.3V and 5V Outputs, 1.8V to 4.4V Input Range, 50mA Output
1610f LT/TP 0699 4K • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
16
●
●
LINEAR TECHNOLOGY CORPORATION 1998
(408)432-1900 FAX:(408)434-0507 www.linear-tech.com
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