LINER LTC1754-3.3 Micropower, regulated 3.3v/5v charge pump with shutdown in sot-23 Datasheet

LTC1754-3.3/LTC1754-5
Micropower, Regulated
3.3V/5V Charge Pump with
Shutdown in SOT-23
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FEATURES
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DESCRIPTIO
Ultralow Power: IIN = 13µA
Regulated Output Voltage: 3.3V ±4%, 5V ±4%
5V Output Current: 50mA (VIN ≥ 3.0V)
3.3V Output Current: 40mA (VIN ≥ 2.5V)
No Inductors Needed
Very Low Shutdown Current: <1µA
Shutdown Disconnects Load from VIN
Internal Oscillator: 600kHz
Short-Circuit and Overtemperature Protected
Ultrasmall Application Circuit: (0.052 Inch2)
6-Pin SOT-23 Package
The LTC®1754 is a micropower charge pump DC/DC
converter that produces a regulated output. The input
voltage range is 2V to 4.4V for 3.3V output and 2.7V to
5.5V for 5V output. Extremely low operating current and a
low external parts count (one flying capacitor and two
small bypass capacitors at VIN and VOUT) make the LTC1754
ideally suited for small, battery-powered applications. The
total component area of the application circuit shown
below is only 0.052 inch2.
The LTC1754 operates as a Burst ModeTM switched capacitor voltage doubler to produce a regulated output. It has
thermal shutdown capability and can survive a continuous
short circuit from VOUT to GND.
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APPLICATIO S
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The LTC1754 is available in a 6-pin SOT-23 package.
SIM Interface Supplies for GSM Cellular Telephones
White LED Power Supplies
Li-Ion Battery Backup Supplies
Handheld Computers
Smart Card Readers
PCMCIA Local 5V Supplies
, 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
10µF
2
ON/OFF
3
VOUT
LTC1754-X
GND
VIN
SHDN C –
LTC1754-3.3
Output Voltage vs Supply Voltage
6
5
3.40
1µF
4
VIN
10µF
1754 TA01
Regulated 3.3V Output from 2V to 4.4V Input
VOUT = 3.3V ± 4%
IOUT = 0mA TO 20mA, VIN > 2.0V
IOUT = 0mA TO 40mA, VIN > 2.5V
5.15
IOUT = 20mA
COUT = 10µf
CFLY = 1µF
5.10
3.35
TA = 85°C
3.30
TA = 25°C
TA = –40°C
3.25
Regulated 5V Output from 2.7V to 5.5V Input
VOUT = 5V ± 4%
IOUT = 0mA TO 25mA, VIN > 2.7V
IOUT = 0mA TO 50mA, VIN > 3.0V
LTC1754-5
Output Voltage vs Supply Voltage
OUTPUT VOLTAGE (V)
VOUT
C+
OUTPUT VOLTAGE (V)
1
IOUT = 25mA
COUT = 10µF
CFLY = 1µF
5.05
TA = 25°C
TA = 85°C
5.00
TA = –40°C
4.95
4.90
3.20
2.0
2.5
3.5
4.0
3.0
SUPPLY VOLTAGE (V)
4.5
1754 TA02
4.85
2.5
3.0
3.5
4.0
4.5
SUPPLY VOLTAGE (V)
5.0
5.5
1574 TA03
1
LTC1754-3.3/LTC1754-5
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ABSOLUTE
RATI GS
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PACKAGE/ORDER I FOR ATIO
(Note 1)
VIN to GND .................................................. – 0.3V to 6V
VOUT to GND ............................................... – 0.3V to 6V
SHDN to GND .............................................. – 0.3V to 6V
IOUT (Note 4) ......................................................... 75mA
VOUT Short-Circuit Duration ............................ Indefinite
Operating Temperature Range (Note 3) ... – 40°C to 85°C
Storage Temperature Range .................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................... 300°C
ORDER PART
NUMBER
TOP VIEW
VOUT 1
6 C+
GND 2
5 VIN
SHDN 3
4 C–
LTC1754ES6-3.3
LTC1754ES6-5
S6 PART MARKING
S6 PACKAGE
6-LEAD PLASTIC SOT-23
TJMAX = 150°C, θJA = 230°C/ W
LTGK
LTLW
Consult factory for Industrial and Military grade parts.
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. CFLY = 1µF (Note 2), CIN = 10µF, COUT = 10µF.
SYMBOL
PARAMETER
LTC1754-3.3
VIN
Input Supply Voltage
VOUT
Output Voltage
ICC
VR
η
fOSC
tON
ISC
LTC1754-5
VIN
VOUT
Operating Supply Current
Output Ripple
Efficiency
Switching Frequency
VOUT Turn-On Time
Output Short-Circuit Current
Input Supply Voltage
Output Voltage
ICC
Operating Supply Current
VR
Output Ripple
η
Efficiency
fOSC
Switching Frequency
tON
VOUT Turn-On Time
ISC
Output Short-Circuit Current
LTC1754-3.3/LTC1754-5
ISHDN
Shutdown Supply Current
VIH
VIL
IIH
IIL
SHDN Input Threshold (High)
SHDN Input Threshold (Low)
SHDN Input Current (High)
SHDN Input Current (Low)
CONDITIONS
●
2.0V ≤ VIN ≤ 4.4V, IOUT ≤ 20mA
2.5V ≤ VIN ≤ 4.4V, IOUT ≤ 40mA
2.0V ≤ VIN ≤ 4.4V, IOUT = 0mA, SHDN = VIN
VIN = 2.5V, IOUT = 40mA
VIN = 2.0V, IOUT = 20mA
Oscillator Free Running
VIN = 2.0V, IOUT = 0mA
VIN = 2.5V, VOUT = 0V, SHDN = 2.5V
●
●
2.0
3.17
3.17
●
●
2.7V ≤ VIN ≤ 5.5V, IOUT ≤ 25mA
3.0V ≤ VIN ≤ 5.5V, IOUT ≤ 50mA
2.7V ≤ VIN ≤ 5.5V, IOUT = 0mA, SHDN = VIN
VIN = 3V, IOUT = 50mA
VIN = 3V, IOUT = 50mA
Oscillator Free Running
VIN = 3V, IOUT = 0mA
VIN = 3V, VOUT = 0V, SHDN = 3V
●
●
VIN ≤ 3.6V, IOUT = 0mA, VSHDN = 0V
3.6V < VIN, IOUT = 0mA, VSHDN = 0V
●
●
2.7
4.8
4.8
●
●
SHDN = VIN
SHDN = 0V
●
●
TYP
3.30
3.30
11
23
82
600
0.8
118
5.0
5.0
13
65
82.7
700
0.4
150
0.01
MAX
UNITS
4.4
3.43
3.43
30
V
V
V
µA
mVP-P
%
kHz
ms
mA
5.5
5.2
5.2
30
V
V
V
µA
mVP-P
%
kHz
ms
mA
1
2.5
1.4
●
Note 1: Absolute Maximum Ratings are those values beyond which the life of
a device may be impaired.
Note 2: 0.6µF is the minimum required CFLY capacitance for rated output
current capability. Depending on the choice of capacitor material, a
somewhat higher value of capacitor may be required to attain 0.6µF over
temperature.
2
MIN
–1
–1
0.3
1
1
Note 3: The LTC1754ES6-X is guaranteed to meet performance
specifications from 0°C to 70°C. Specifications over the –40°C to 85°C
operating temperature range are assured by design, characterization and
correlation with statistical process controls.
Note 4: Based on long term current density limitations.
µA
µA
V
V
µA
µA
LTC1754-3.3/LTC1754-5
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TYPICAL PERFOR A CE CHARACTERISTICS
No Load Supply Current
vs Supply Voltage
20
3.35
SUPPLY CURRENT (µA)
OUTPUT VOLTAGE (V)
TA = 25°C
COUT = 10µF
CFLY = 1µF
VIN = 2.5V
3.30
VIN = 2V
3.25
Supply Current vs VSHDN
20
IOUT = 0µA
CFLY = 1µF
VSHDN = VIN
15
SUPPLY CURRENT (µA)
Output Voltage vs Output Current
3.40
LTC1754-3.3, TA = 25°C unless otherwise noted.
TA = 85°C
TA = 25°C
10
TA = 25°C
IOUT = 0µA
15
VIN = 4.5V
VIN = 2.5V
10
VIN = 2V
5
TA = – 40°C
3.20
5
0
20
60
80
40
OUTPUT CURRENT (mA)
2.0
100
2.5
3.0
3.5
4.0
SUPPLY VOLTAGE (V)
VOUT Short-Circuit Current
vs Supply Voltage
3
4
2
VSHDN CONTROL VOLTAGE (V)
5
1754 G03
Efficiency vs Load Current
100
TA = 25°C
CFLY = 1µF
90
160
80
140
EFFICIENCY (%)
VOUT SHORT-CIRCUIT CURRENT (mA)
1
1754 G02
1754 G01
180
0
4.5
120
100
TA = 25°C
VIN = 2V
CFLY = 1µF
70
60
50
40
30
20
80
10
0
0.001
60
2.0
2.5
3.0
3.5
4.0
SUPPLY VOLTAGE (V)
4.5
0.01
0.1
1
10
LOAD CURRENT (mA)
1754 G05
1735 G04
Output Ripple
Load Transient Response
100
Start-Up Time
IOUT
0mA to 20mA
10mA/DIV
SHDN
1V/DIV
VOUT
AC COUPLED
20mV/DIV
VOUT
1V/DIV
VOUT
AC COUPLED
20mV/DIV
VIN = 2V
COUT = 10µF
50µs/DIV
1754 G07
VIN = 2V
COUT = 10µF
IOUT = 20mA
5µs/DIV
1754 G08
VIN = 2V
COUT = 10µF
200µs/DIV
1754 G9
3
LTC1754-3.3/LTC1754-5
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TYPICAL PERFOR A CE CHARACTERISTICS
No Load Supply Current
vs Supply Voltage
Output Voltage vs Output Current
25
IOUT = 0µA
CFLY = 1µF
VSHDN = VIN
5.05
SUPPLY CURRENT (µA)
OUTPUT VOLTAGE (V)
20
TA = 25°C
COUT = 10µF
CFLY = 1µF
5.10
Supply Current vs VSHDN
VIN = 3V
5.00
VIN = 2.7V
4.95
15
TA = 25°C
10
TA = –40°C
VIN = 5.5V
VIN = 3.3V
15
VIN = 2.7V
10
5
4.90
4.85
0
20
5
2.5
100
40
60
80
OUTPUT CURRENT (mA)
3.0
3.5
4.0
4.5
SUPPLY VOLTAGE (V)
5.0
1574-5 G02
2
4
5
3
VSHDN CONTROL VOLTAGE (V)
6
1574 G12
Efficiency vs Load Current
VIN = 3V
90 TA = 25°C
CFLY = 1µF
80
TA = 25°C
CFLY = 1µF
180
EFFICIENCY (%)
VOUT SHORT-CIRCUIT CURRENT (mA)
1
100
220
200
0
5.5
1754 G11
VOUT Short-Circuit Current
vs Supply Voltage
160
140
70
60
50
40
30
20
120
10
100
2.5
3.0
3.5
4.0
4.5
SUPPLY VOLTAGE (V)
5.0
0
0.001
5.5
0.01
0.1
1
10
LOAD CURRENT (mA)
Load Transient Response
100
1754-5 G05
1754 G13
Output Ripple
Start-Up Time
IOUT
0mA to 50mA
25mA/DIV
SHDN
5V/DIV
VOUT
AC COUPLED
20mV/DIV
VOUT
AC COUPLED
50mV/DIV
VIN = 3V
COUT = 10µF
4
TA = 25°C
IOUT = 0µA
20
TA = 85°C
SUPPLY CURRENT (µA)
5.15
LTC1754-5, TA = 25°C unless otherwise noted.
50µs/DIV
1754 G16
VOUT
1V/DIV
VIN = 3V
COUT = 10µF
IOUT = 50mA
5µs/DIV
1754 G17
VIN = 3V
COUT = 10µF
100µs/DIV
1754 G18
LTC1754-3.3/LTC1754-5
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TYPICAL PERFOR A CE CHARACTERISTICS
LTC1754-3.3. LTC1754-5, TA = 25°C unless otherwise noted.
Oscillator Frequency
vs Supply Voltage
Efficiency vs Supply Voltage
EFFICIENCY (%)
80
OSCILLATOR FREQUENCY (kHz)
90
LTC1754-5
IOUT = 25mA
70
60
50
40
30
2.0
850
TA = 25°C
CFLY = 1µF
LTC1754-3.3
IOUT = 20mA
2.5
0.95
800
0.90
TA = 85°C
750
THRESHOLD VOLTAGE (V)
100
VSHDN Threshold Voltage
vs Supply Voltage
700
TA = 25°C
650
600
550
TA = –40°C
5.0
5.5
TA = 25°C
0.80
TA = 85°C
0.75
0.70
500
4.5
3.0 3.5 4.0
SUPPLY VOLTAGE (V)
TA = –40°C
0.85
450
2.0
2.5
3.5 4.0 4.5
SUPPLY VOLTAGE (V)
5.0
3.0
0.65
2.0
5.5
2.5
3.0 3.5 4.0 4.5
SUPPLY VOLTAGE (V)
1754 G20
1754 G19
5.0
5.5
1754 G21
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PI FU CTIO S
VOUT (Pin 1): Regulated Output Voltage. For best performance, VOUT should be bypassed with a 6.8µF (min) low
ESR capacitor as close as possible to the pin.
GND (Pin 2): Ground. Should be tied to a ground plane for
best performance.
C – (Pin 4): Flying Capacitor Negative Terminal.
VIN (Pin 5): Input Supply Voltage. VIN should be bypassed
with a 6.8µF (min) low ESR capacitor.
C + (Pin 6): Flying Capacitor Positive Terminal.
SHDN (Pin 3): Active Low Shutdown Input. A low on
SHDN disables the LTC1754. SHDN must not be allowed
to float.
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SI PLIFIED BLOCK DIAGRA
*
VOUT
C+
2
COUT
10µF
CFLY
1µF
1
VIN
CIN
10µF
+
COMP1
CONTROL
2
–
C–
VREF
1
SHDN
1754 BD
*CHARGE PUMP SHOWN IN PHASE 1, THE CHARGING PHASE.
PHASE 1 IS ALSO THE SHUTDOWN PHASE
5
LTC1754-3.3/LTC1754-5
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APPLICATIO S I FOR ATIO
Operation (Refer To Block Diagram)
The LTC1754 uses a switched-capacitor charge pump to
boost VIN to a regulated output voltage. Regulation is
achieved by sensing the output voltage through an internal
resistor divider and enabling the charge pump when the
divided output drops below the lower trip point of COMP1.
When the charge pump is enabled, a two-phase
nonoverlapping clock activates the charge pump switches.
The flying capacitor is charged to VIN on phase one of the
clock. On phase two of the clock it is stacked in series with
VIN and connected to VOUT. This sequence of charging and
discharging the flying capacitor continues at a free running frequency of 600kHz (typ). Once the attenuated
output voltage reaches the upper trip point of COMP1, the
charge pump is disabled. When the charge pump is
disabled the LTC1754 draws only 13µA from VIN thus
providing high efficiency under low load conditions.
In shutdown mode all circuitry is turned off and the
LTC1754 draws only leakage current from the VIN supply.
Furthermore, VOUT is disconnected from VIN. The SHDN
pin is a CMOS input with a threshold voltage of approximately 0.8V, but may be driven to a logic level that exceeds
VIN. The LTC1754 is in shutdown when a logic low is
applied to the SHDN pin. Since the SHDN pin is a high
impedance CMOS input, it should never be allowed to
float. To ensure that its state is defined, it must always be
driven with a valid logic level.
Power Efficiency
The efficiency (η) of the LTC1754 is similar to that of a
linear regulator with an effective input voltage of twice the
actual input voltage. This results because the input current
for a voltage doubling charge pump is approximately twice
the output current. In an ideal voltage doubling regulator
the power efficiency would be given by:
( )( )
( )( )
VOUT IOUT
P
V
η = OUT =
= OUT
2VIN
PIN
VIN 2IOUT
At moderate-to-high output power, the switching losses and
quiescent current of the LTC1754 are negligible and the
expression above is valid. For example, an LTC1754-5 with
6
VIN = 3V, IOUT = 25mA and VOUT regulating to 5V, has a
measured efficiency of 82.7%, which is in close agreement
with the theoretical 83.3% calculation. The LTC1754 continues to maintain good efficiency even at fairly light loads
because of its inherently low power design.
Short-Circuit/Thermal Protection
During short-circuit conditions, the LTC1754 will draw
between 100mA and 400mA from VIN causing a rise in the
junction temperature. On-chip thermal shutdown circuitry
disables the charge pump once the junction temperature
exceeds approximately 150°C and reenables the charge
pump once the junction temperature drops back to approximately 140°C. The LTC1754 will cycle in and out of
thermal shutdown indefinitely without latchup or damage
until the short circuit on VOUT is removed.
Capacitor Selection
The style and value of capacitors used with the
LTC1754 determine several important parameters such as
output ripple, charge pump strength and turn-on time.
To reduce noise and ripple, it is recommended that low
ESR (< 0.1Ω) capacitors be used for both CIN and COUT.
These capacitors should be either ceramic or tantalum and
be 6.8µF or greater. Aluminum capacitors are not recommended because of their high ESR. If the source impedance to VIN is very low up to several megahertz, CIN may
not be needed.
A ceramic capacitor is recommended for the flying capacitor with a value in the range of 1µF to 2.2µF. Note that a
large value flying capacitor (> 2.2µF) will increase output
ripple unless COUT is also increased. For very low load
applications, CFLY may be reduced to 0.01µF to 0.047µF.
This will reduce output ripple at the expense of maximum
output current and efficiency.
In order to achieve the rated output current it is necessary
to have at least 0.6µF of capacitance for the flying capacitor. Capacitors of different material lose their capacitance
over temperature at different rates. For example, a ceramic
capacitor made of X7R material will retain most of its
capacitance from – 40°C to 85°C, whereas a Z5U or Y5V
style capacitor will lose considerable capacitance over that
LTC1754-3.3/LTC1754-5
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APPLICATIO S I FOR ATIO
range. The capacitor manufacturer’s data sheet should be
consulted to determine what style and value of capacitor
is needed to ensure 0.6µF at all temperatures.
Output Ripple
Low frequency regulation mode ripple exists due to the
hysteresis in the sense comparator and propagation delay
in the charge pump control circuit. The amplitude and
frequency of this ripple are heavily dependent on the load
current, the input voltage and the output capacitor size.
For large VIN the ripple voltage can become substantial
because the increased strength of the charge pump causes
fast edges that may outpace the regulation circuitry.
Generally the regulation ripple has a sawtooth shape
associated with it.
A high frequency ripple component may also be present
on the output capacitor due to the charge transfer action
of the charge pump. In this case the output can display a
voltage pulse during the charging phase. This pulse
results from the product of the charging current and the
ESR of the output capacitor. It is proportional to the input
voltage, the value of the flying capacitor and the ESR of the
output capacitor.
Typical combined output ripple for the LTC1754-5 with
VIN = 3V under maximum load is 65mVP-P using a low ESR
10µF output capacitor. A smaller output capacitor and/or
larger output current load will result in higher ripple due to
higher output voltage slew rates.
There are several ways to reduce output voltage ripple. For
applications requiring higher VIN or lower peak-to-peak
ripple, a larger COUT capacitor (22µF or greater) is recommended. A larger capacitor will reduce both the low and
high frequency ripple due to the lower charging and
discharging slew rates, as well as the lower ESR typically
found with higher value (larger case size) capacitors. A low
ESR ceramic output capacitor will minimize the high
frequency ripple, but will not reduce the low frequency
ripple unless a high capacitance value is used. To reduce
both the low and high frequency ripple, a reasonable
compromise is to use a 10µF to 22µF tantalum capacitor
in parallel with a 1µF to 3.3µF ceramic capacitor on VOUT.
An R-C filter may also be used to reduce high frequency
voltage spikes (see Figure 1).
VOUT
LTC1754-X
+
VOUT
15µF
TANTALUM
1µF
CERAMIC
2Ω
VOUT
LTC1754-X
+
10µF
TANTALUM
+
VOUT
10µF
TANTALUM
1754 F01
Figure 1. Output Ripple Reduction Techniques
In low load or high VIN applications, smaller values for the
flying capacitor may be used to reduce output ripple. A
smaller flying capacitor (0.01µF to 0.47µF) delivers less
charge per clock cycle to the output capacitor resulting in
lower output ripple. However, with a smaller flying capacitor, the maximum available output current will be reduced
along with the efficiency.
Note that when using a larger output capacitor the turn on
time of the device will increase.
Inrush Currents
During normal operation VIN will experience current transients in the 50mA to 100mA range whenever the charge
pump is enabled. However during start-up, inrush currents may approach 250mA. For this reason it is important
to minimize the source impedance between the input
supply and the VIN pin. Too much source impedance may
result in regulation problems or prevent start-up.
Ultralow Quiescent Current Regulated Supply
The LTC1754 contains an internal resistor divider (refer to
the Simplified Block Diagram) that typically draws 1.5µA
from VOUT. During no-load conditions, this internal load
causes a droop rate of only 150mV per second on VOUT
with COUT = 10µF. Applying a 2Hz to 100Hz, 2% to 5% duty
cycle signal to the SHDN pin ensures that the circuit of
Figure 2 comes out of shutdown frequently enough to
maintain regulation. Since the LTC1754 spends nearly the
entire time in shutdown, the no-load quiescent current is
approximately (VOUT)(1.5µA)/(ηVIN).
The LTC1754 must be out of shutdown for a minimum
duration of 200µs to allow enough time to sense the output
voltage and keep it in regulation. A 2Hz, 2% duty cycle
7
LTC1754-3.3/LTC1754-5
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APPLICATIO S I FOR ATIO
signal will keep VOUT in regulation under no-load conditions. As the VOUT load current increases, the frequency
with which the LTC1754 is taken out of shutdown must
also be increased.
1
VOUT
10µF
2
SHDN PIN
WAVEFORM
3
VOUT
C+
LTC1754-X
GND
SHDN
VIN
C–
6
5
4
1µF
Layout Considerations
Due to high switching frequency and high transient currents produced by the LTC1754, careful board layout is
necessary. A true ground plane and short connections to
all capacitors will improve performance and ensure proper
regulation under all conditions. Figure 4 shows the recommended layout configuration
VIN
VIN
10µF
VOUT
LOW IQ MODE (2Hz TO 100Hz, 2% TO 5% DUTY CYCLE)
1µF
1754 F02
Figure 2. Ultralow Quiescent Current Regulated Supply
10µF
10µF
GND
LTC1754-X
SHDN
1754-5 F04
6
SUPPLY CURRENT (µA)
TA = 25°C
IOUT = 0µA
5 CFLY = 1µF
Figure 4. Recommended Layout
Thermal Management
LTC1754-5
4
3
LTC1754-3.3
2
1
0
2.0
2.5
3.0 3.5 4.0 4.5
SUPPLY VOLTAGE (V)
5.0
5.5
1754 F03
Figure 3. No-Load Supply Current vs Supply Voltage
for the Circuit Shown in Figure 2
8
For higher input voltages and maximum output current,
there can be substaintial power dissipation in the LTC1754.
If the junction temperature increases above approximately
150°C, the thermal shutdown circuitry will automatically
deactivate the output. To reduce the maximum junction
temperature, a good thermal connection to the PC board
is recommended. Connecting the GND pin (Pin 2) to a
ground plane and maintaining a solid ground plane under
the device on at least two layers of the PC board can reduce
the thermal resistance of the package and PC board
system to about 150°C/W.
LTC1754-3.3/LTC1754-5
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TYPICAL APPLICATIO S
Low Power Battery Backup with Autoswitchover and No Reverse Current
3
LTC1521-3.3
1
1µF
2
4
1N4148
VIN
5V
75k
5
+
10µF
10µF
2-CELL
NiCd
BATTERY
6
C–
C+
VIN
VOUT
VOUT = 3.3V
IOUT ≤ 300mA
IOUT ≤ 20mA BACKUP
1
10µF
LTC1754-3.3
SHDN
3
GND
2
7
1.2M
4
8
3
475k
6
HIGH = BACKUP MODE
LTC1540
10k
5
175433 TA03
2
1M
1
USB Port to Regulated 5V Power Supply
1µF
4
6
5
3
1
LTC1754-5
10µF
VOUT
10µF 5V ±4%
50mA
2
1754 TA06
9
LTC1754-3.3/LTC1754-5
U
TYPICAL APPLICATIO S
5V, 100mA Step-Up Generator from 3V
1µF
4
6
C–
5
VIN
3V
VIN
10µF
3
C+
VOUT
LTC1754-5
SHDN
GND
VOUT
5V
100mA
1
2
1µF
4
6
C–
5
3
ON/OFF
VIN
C+
VOUT
LTC1754-5
SHDN
GND
1
10µF
2
1754 TA07
Lithium-Ion Battery to 5V White or Blue LED Driver
1µF
4
5
3V TO 4.4V
Li-Ion
BATTERY
C–
VIN
10µF
SHDN
100Ω
10µF
LTC1754-5
3
ON/OFF
6
C+
1
VOUT
GND
100Ω
100Ω
2
1754 TA08
3.3V and 5V Step-Up Generator from 2V
VOUT1
3.3V
1µF
1µF
4
5
VIN
2V
10µF
ON/OFF
C–
VIN
6
4
C+
1
VOUT
LTC1754-3.3
3
SHDN
GND
I3.3 + 2I5 ≤ 20mA
5
6
C+
1
VOUT
LTC1754-5
10µF
2
C–
VIN
η≅
3
SHDN
GND
VOUT2
5V
10µF
2
1754 TA09
10
3.3I3.3 + 5I5
VIN(2I3.3 + 4I5)
LTC1754-3.3/LTC1754-5
U
PACKAGE DESCRIPTION
Dimensions in inches (millimeters), unless otherwise noted.
S6 Package
6-Lead Plastic SOT-23
(LTC DWG # 05-08-1634)
2.80 – 3.00
(0.110 – 0.118)
(NOTE 3)
2.6 – 3.0
(0.110 – 0.118)
1.50 – 1.75
(0.059 – 0.069)
0.35 – 0.55
(0.014 – 0.022)
0.09 – 0.20
(0.004 – 0.008)
(NOTE 2)
1.90
(0.074)
REF
0.00 – 0.15
(0.00 – 0.006)
0.95
(0.037)
REF
0.90 – 1.45
(0.035 – 0.057)
0.35 – 0.50
0.90 – 1.30
(0.014 – 0.020)
(0.035 – 0.051)
SIX PLACES (NOTE 2)
S6 SOT-23 0898
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DIMENSIONS ARE INCLUSIVE OF PLATING
3. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
4. MOLD FLASH SHALL NOT EXCEED 0.254mm
5. PACKAGE EIAJ REFERENCE IS SC-74A (EIAJ)
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
11
LTC1754-3.3/LTC1754-5
U
TYPICAL APPLICATIO
Low Power Battery Backup with Autoswitchover and No Reverse Current
Si4435DY
1µF
4
1N4148
VIN
5V
75k
5
+
10µF
10µF
3-CELL
NiCd
BATTERY
6
C–
C+
VOUT
VIN
1
VOUT = 5V
IOUT ≤ 50mA
10µF
LTC1754-5
SHDN
3
GND
2
BAT54C
7
1.43M
4
8
3
475k
6
LTC1540
10k
5
1M
2
1
1754 TA05
RELATED PARTS
PART NUMBER
DESCRIPTION
LT1054
High Power Doubler Charge Pump
Up to 100mA Output, VIN = 3.5V to 15V, SO-8 Package
LTC1144
Charge Pump Inverter with Shutdown
VIN = 2V to 18V, 15V to –15V Supply
LTC1262
12V, 30mA Flash Memory Prog. Supply
Regulated 12V ±5% Output, IQ = 500µA
LTC1514/LTC1515
Buck/Boost Charge Pumps with IQ = 60µA
50mA Output at 3V, 3.3V or 5V; 2V to 10V Input
LTC1516
Micropower 5V Charge Pump
IQ = 12µA, Up to 50mA Output, VIN = 2V to 5V
LTC1517-5/LTC1517-3.3
Micropower 5V/3.3V Doubler Charge Pumps
IQ = 6µA, Up to 20mA Output
LTC1522
Micropower 5V Doubler Charge Pump
IQ = 6µA, Up to 20mA Output
LT1615
Step-Up Switching Regulator in SOT-23
IQ = 20µA, VIN = 1.2V to 15V, Up to 34V Output
LTC1682
Low Noise Doubler Charge Pump
Output Noise = 60µVRMS, 2.5V to 5.5V Output
12
Linear Technology Corporation
COMMENTS
175435f LT/TP 0400 4K • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com
 LINEAR TECHNOLOGY CORPORATION 1999