LINER LTC1515CS8-3/5 Step-up/step-down switched capacitor dc/dc converters with reset Datasheet

LTC1515 Series
Step-Up/Step-Down
Switched Capacitor DC/DC
Converters with Reset
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DESCRIPTION
FEATURES
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The LTC®1515, LTC1515-3/5 and LTC1515-3.3/5 are
micropower switched capacitor DC/DC converters that
produce a regulated output voltage by either stepping up
or stepping down the input voltage. Output voltage is
adjustable using an external resistor divider (LTC1515) or
programmable to either 3V/5V (LTC1515-3/5) or 3.3V/5V
(LTC1515-3.3/5) using a logic pin.
Adjustable/Selectable 3V, 3.3V or 5V
Output Voltages
2V to 10V Input Voltage Range
Up to 50mA Output Current
Only Three External Capacitors Required
Soft Start Limits Inrush Current at Turn-On
Low Operating Current: 60µA
Very Low Shutdown Current: < 1µA
Shutdown Disconnects Load from VIN
VOUT Programmable to 3V/5V or 3.3V/5V
Short-Circuit and Overtemperature Protected
650kHz Switching Frequency
Open-Drain Power-On Reset Output
Daisy-Chained Control Outputs
Available in SO-8 Package
A unique architecture allows the parts to accommodate a
wide input voltage range (2V to 10V) while maintaining
±4% regulation. Additional circuitry prevents excessive
inrush current and output voltage ripple when large VIN to
VOUT differentials are present.
An internal power-on reset circuit forces the POR pin low
on initial power-up. The POR output remains low until
200ms (typ) after VOUT is in regulation.
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APPLICATIONS
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The parts are short-circuit and overtemperature protected.
Battery life is maximized by very low operating currents
(ICC = 60µA typ, ICC < 1µA in shutdown). All three parts are
available in an SO-8 package.
SIM Interface in GSM Cellular Telephones
Smart Card Readers
Local Power Supplies
Portable Equipment
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATION
LTC1515-X 5V Output vs Input Voltage
Programmable 3.3V/5V Power Supply with Power-On Reset
5.2
100k
RESET
5V 3.3V
1
SHDN
VOUT
8
VOUT = 3.3V OR 5V
IOUT = 50mA
2
7
POR
VIN
LTC1515-3.3/5
3
6
5/3
C1+
4
GND
C1–
5
+
+
10µF
0.22µF
10µF
VIN
4-CELL
NiCd
OUTPUT VOLTAGE (V)
ON OFF
IOUT = 10mA
5/3 = 3V
5.1
5.0
4.9
LTC1515 • TA01
4.8
2
3
4
5
8
6
7
INPUT VOLTAGE (V)
9
10
LT1515 • TA02
1
LTC1515 Series
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ABSOLUTE MAXIMUM RATINGS
(Note 1)
VIN to GND ................................................ – 0.3V to 12V
VOUT to GND ............................................. – 0.3V to 12V
SHDN, 5/3, FB to GND .............................. – 0.3V to 12V
VOUT Short-Circuit Duration ............................. Indefinite
Operating Temperature Range
Commercial ............................................. 0°C to 70°C
Industrial ............................................ – 40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
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PACKAGE/ORDER I FOR ATIO
ORDER PART
NUMBER
TOP VIEW
SHDN 1
8
VOUT
POR 2
7
VIN
FB 3
6
C1 +
GND 4
5
C1 –
S8 PACKAGE
8-LEAD PLASTIC SO
TOP VIEW
SHDN 1
8
VOUT
POR 2
7
VIN
5/3 3
6
C1 +
GND 4
5
C1 –
LTC1515CS8
LTC1515IS8
S8 PART MARKING
1515
1515I
TJMAX = 125°C, θJA = 110°C/W
ORDER PART NUMBER
LTC1515CS8-3/5
LTC1515CS8-3.3/5
LTC1515IS8-3/5
LTC1515IS8-3.3/5
S8 PART MARKING
S8 PACKAGE
8-LEAD PLASTIC SO
151535
515335
TJMAX = 125°C, θJA = 110°C/W
515I35
15I335
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
VIN = 2V to 10V, SHDN = 3V, C1 = 0.22µF, CIN = COUT = 10µF unless otherwise noted (Note 2).
PARAMETER
CONDITIONS
VIN Operating Voltage
VOUT = 5V
VOUT = 3V/3.3V
VOUT = ADJ
●
●
●
MIN
2.7
2.0
2.0
VOUT = 3V (LTC1515-3/5)
2V ≤ VIN ≤ 8V, IOUT ≤ 15mA
3V ≤ VIN ≤ 8V, IOUT ≤ 50mA
●
●
2.88
2.88
VOUT = 3.3V (LTC1515-3.3/5)
2V ≤ VIN ≤ 8V, IOUT ≤ 15mA
3V ≤ VIN ≤ 8V, IOUT ≤ 50mA
●
●
VOUT = 5V (LTC1515-3/5, LTC1515-3.3/5)
2.7V ≤ VIN ≤ 10V, IOUT ≤ 15mA
3.3V ≤ VIN ≤ 10V, IOUT ≤ 50mA
VFB Feedback Voltage
LTC1515, VFB Ramping Negative
TYP
MAX
UNITS
10
8
10
V
V
V
3.0
3.0
3.12
3.12
V
V
3.17
3.17
3.3
3.3
3.43
3.43
V
V
●
●
4.8
4.8
5.0
5.0
5.2
5.2
V
V
●
1.190
1.232
1.275
V
VFB Feedback Hysteresis
LTC1515
Effective Output Resistance
LTC1515, VIN = 3V, Step-Up Mode
●
1
VIN Operating Current
VIN ≤ 5V, IOUT = 0, SHDN = 3V
VIN > 5V, IOUT = 0, SHDN = 3V
●
●
VIN Shutdown Current
SHDN = 0V, VIN ≤ 5V
SHDN = 0V, VIN > 5V
●
Output Ripple
Full Load (Note 2)
60
75
%
30
Ω
100
135
µA
µA
1
25
µA
µA
100
mVP-P
Switching Frequency
Full Load
●
500
650
800
kHz
5/3, SHDN Input Threshold
VIL
VIH
●
●
0.4
1.0
1.0
1.6
V
V
5/3, SHDN = VIN
5/3, SHDN = 0V
●
●
–1
–1
1
1
µA
µA
FB Input Current
FB = 1.232V
●
– 50
50
nA
POR Output Low Voltage
ISINK = 100µA, VIN = 3V
●
0.4
V
5/3, SHDN Input Current
2
0.05
LTC1515 Series
ELECTRICAL CHARACTERISTICS
VIN = 2V to 10V, SHDN = 3V, C1 = 0.22µF, CIN = COUT = 10µF unless otherwise noted (Note 2).
PARAMETER
CONDITIONS
POR Leakage Current
VPOR = 5V
●
MIN
–1
POR Trip Point (With Respect to VOUT)
VOUT Ramping Negative
●
– 10
TYP
MAX
UNITS
µA
1
– 7.5
POR Trip Point Hysteresis
–5
%
1
IOUT Short-Circuit Current
VOUT = 0V
tON
Soft Start Turn-On Time
POR Delay
After VOUT Above POR Threshold
12
●
The ● denotes specifications which apply over the full operating
temperature range.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
%
40
mA
280
ms
4
140
●
ms
200
Note 2: For VIN ≥ 8V, COUT = 22µF.
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TYPICAL PERFORMANCE CHARACTERISTICS
LTC1515-X
3.3V Efficiency vs Output Current
100
VOUT = 3.3V
TA = 25°C
VIN = 2.7V
VIN = 2V
80
80
EFFICIENCY (%)
VIN = 4.4V
VIN = 2.7V
60
250
VIN = 6V
OUTPUT VOLTAGE RIPPLE (mVP-P)
100
EFFICIENCY (%)
LTC1515-X 3.3V Output Voltage
Ripple vs Input Voltage
LTC1515-X
5V Efficiency vs Output Current
VIN = 6V
40
VIN = 3.3V
60
VIN = 8V
40
20
20
VOUT = 5V
TA = 25°C
0
0.01
0.1
1
10
OUTPUT CURRENT (mA)
0
0.01
100
COUT = 22µF
100
COUT = 47µF
10
1515 G04
6
4
INPUT VOLTAGE (V)
8
10
1515 G03
VOUT = 5V
IOUT = 0mA
3.35
3.30
100
80
25°C
60
85°C
–40°C
40
20
3.20
8
2
120
3.25
0
COUT = 47µF
0
OPERATING CURRENT (µA)
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE RIPPLE (mVP-P)
COUT = 10µF
6
4
INPUT VOLTAGE (V)
50
LTC1515-X Operating Current
vs Input Voltage
VOUT = 3.3V
IOUT = 10mA
COUT = 10µF
TA = 25°C
3.40
150
COUT = 22µF
100
100
3.45
VOUT = 5V
IOUT = 10mA
TA = 25°C
2
COUT = 10µF
LTC1515-X 3.3V Output Voltage
vs Input Voltage
250
0
150
1515 G02
LTC1515-X 5V Output Voltage
Ripple vs Input Voltage
50
200
0
0.1
1
10
OUTPUT CURRENT (mA)
1515 G01
200
VOUT = 3.3V
IOUT = 10mA
TA = 25°C
0
2
6
4
INPUT VOLTAGE (V)
8
10
1515 G05
0
2
6
4
INPUT VOLTAGE (V)
8
10
1515 G06
3
LTC1515 Series
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TYPICAL PERFORMANCE CHARACTERISTICS
100
VOUT = 5V
IOUT = 10mA
TA = 25°C
VOUT = 3.3V
IOUT = 10mA
TA = 25°C
80
60
40
EFFICIENCY (%)
80
EFFICIENCY (%)
EFFICIENCY (%)
100
100
VOUT = 3V
IOUT = 10mA
TA = 25°C
80
20
LTC1515-X
5V Efficiency vs Input Voltage
LTC1515-X
3.3V Efficiency vs Input Voltage
LTC1515-X
3V Efficiency vs Input Voltage
60
40
40
0
2
6
4
INPUT VOLTAGE (V)
8
10
20
60
0
2
6
4
INPUT VOLTAGE (V)
8
20
10
1515 G09
2
4
8
6
INPUT VOLTAGE (V)
10
1515 G08
1515 G07
LTC1515-X Shutdown Supply
Current vs Input Voltage
12
LTC1515-X Step-Down Mode
5V Load Transient Response
LTC1515-X Step-Up Mode
5V Load Transient Response
25
POSITIVE SUPPLY CURRENT (µA)
SHDN = 0V
VOUT
AC COUPLED
100mV/DIV
VOUT
AC COUPLED
100mV/DIV
20
15
10
50mA
IOUT
50mA/DIV
85°C
0mA
IOUT
50mA/DIV
25°C
5
–40°C
VIN = 8V, VOUT = 5V, COUT = 10µF, TA = 25°C
1515 G10
VIN = 3.3V, VOUT = 5V, COUT = 10µF, TA = 25°C
1515 G11
0
0
2
6
4
INPUT VOLTAGE (V)
8
10
1515 G12
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PIN FUNCTIONS
SHDN (Pin 1): Shutdown Input. A logic low on the SHDN
pin puts the part into shutdown mode. A logic high (VSHDN
≥ 1.6V) enables the part. At high VIN voltages, the SHDN
pin may still be controlled with 3V logic without causing a
large rise in VIN quiescent current. The SHDN pin may not
float; connect to VIN if unused.
POR (Pin 2): Open-Drain Power-On Reset Output. This pin
will pull low upon initial power-up, during shutdown or
until VOUT has been within 6.5% of its regulated value for
more than 200ms typ.
5/3 (LTC1515-X) (Pin 3): Output Voltage Select. A logic
high on the 5/3 pin will force VOUT to regulate to 5V. A logic
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low will force VOUT to 3V (LTC1515-3/5) or 3.3V (LTC15153.3/5). As with the SHDN pin, the 5/3 pin may be driven with
3V logic over the entire VIN range. The 5/3 pin may not float.
FB (LTC1515) (Pin 3): Feedback Input. The voltage on this
pin is compared to the internal reference voltage (1.232V)
to keep the output in regulation. An external resistor divider
is required between VOUT and FB to adjust the output
voltage. Total divider resistance should not exceed 2M.
GND (Pin 4): Ground. Should be tied to a ground plane for
best performance.
C1– (Pin 5): Charge Pump Flying Capacitor, Negative
Terminal.
LTC1515 Series
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PIN FUNCTIONS
C1+ (Pin 6): Charge Pump Flying Capacitor, Positive
Terminal.
VIN (Pin 7): Charge Pump Input Voltage. May be between
2V and 10V. VIN should be bypassed with a ≥ 10µF low
ESR capacitor as close as possible to the pin for best
performance.
VOUT (Pin 8): Regulated Output Voltage. Pin selectable to
either 3V/5V, 3.3V/5V or adjustable using an external
resistor divider (LTC1515). VOUT should be bypassed with
a ≥ 10µF low ESR capacitor as close as possible to the pin
for best performance.
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SI PLIFIED BLOCK DIGRAM
C1–
VIN
C1+
STEP-UP/STEP-DOWN
CHARGE PUMP
VOUT
(LTC1515-X)
SHDN
(LTC1515-X)
–
650kHz
OSCILLATOR
EN
+
POR
FB
(LTC1515)
–
EN
RESET
COUNTER
VOS
+
5/3
(LTC1515-X)
1.232V
VREF
GND
LTC1515 • BD
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APPLICATIONS INFORMATION
Regulator Operation
The regulator section of the LTC1515, LTC1515-3/5 and
LTC1515-3.3/5 consists of a charge pump, reference,
comparator and some logic. The divided down output
voltage is compared to the internal reference voltage.
When the divided output drops below the reference voltage, the charge pump is enabled, which boosts the output
back into regulation. Hysteresis in the comparator forces
the regulator to burst on and off and causes approximately
100mV of peak-to-peak ripple to appear at the output. By
enabling the charge pump only when needed, the parts
achieve high efficiencies with low output load currents.
Each part’s charge pump has a unique architecture that
allows the input voltage to be either stepped up or stepped
down to produce a regulated output. Internal circuitry
senses the VIN to VOUT differential voltage and controls the
charge pump operating mode. In addition, the effective
output impedance of the charge pump is internally
adjusted to prevent large inrush currents and allow for a
wide input voltage range. When the input voltage is lower
than the output voltage, the charge pump operates as a
step-up voltage doubler. When the input voltage is greater
than the output, the charge pump operates as a step-down
gated switch.
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LTC1515 Series
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APPLICATIONS INFORMATION
Output Voltage Selection
ROUT
The output voltage of the LTC1515 is selected using an
external resistor divider (see Figure 1). The output voltage
is determined using the following formula:
VOUT = (1.232V)[1 + (R1/R2)]
The total resistance of R1 and R2 should not exceed 2M,
otherwise excess ripple may appear at VOUT.
1
R1
2
3
SHDN
VOUT
POR
VIN
LTC1515
8
+
2VIN
FB
C1+
6
GND
C1–
5
VOUT
IOUT
COUT
–
LT1515 • F02
Figure 2. Step-Up Mode Equivalent Circuit
40
30
IOUT = 20mA
IOUT = 50mA
20
10
0
1
7
2
3
4
5
INPUT VOLTAGE (V)
LT1515 • F03
Figure 3. Step-Up Mode ROUT vs Input Voltage
R2
4
LTC1515 • F01
Figure 1. LTC1515 Output Voltage Selection
Maximum VOUT and IOUT Calculations for the LTC1515
The maximum output voltage and current available with
the LTC1515 can be calculated based on the effective
output resistance of the charge pump and the open circuit
output voltage. In step-up mode, the open circuit output
voltage is approximately 2VIN (see Figure 2). In step-down
mode, the open circuit output voltage equals VIN. The
relationship between ROUT and VIN in step-up mode is shown
in Figure 3.
The following formulas can be used to find the maximum
output voltage that may be programmed using the LTC1515
for a given minimum input voltage and output current
load.
Step-Up Mode: Max VOUT = (2)(Min VIN) – (IOUT)(ROUT)
Step-Down Mode: Max VOUT = (Min VIN) – (IOUT)(ROUT)
When VIN – (IOUT)(ROUT) is less than the programmed
VOUT, the part will automatically switch from step-down
mode to step-up mode. In both step-up mode and step-
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+
–
OUTPUT RESISTANCE (Ω)
The LTC1515-X versions have internal resistor networks
which set the output voltage. The 5/3 pin controls an
internal switch that shorts out a portion of the resistor
network to change the output voltage. A logic high on this
pin produces a 5V output and a low produces either a 3V
output or a 3.3V output.
down mode, ROUT is internally adjusted to ensure that the
maximum output current rating can be met.
Capacitor Selection
For best performance, low ESR capacitors are recommended for both CIN and COUT to reduce noise and ripple.
The CIN and COUT capacitors should be either ceramic or
tantalum and should be 10µF or greater. If the input source
impedance is very low (< 0.5Ω) CIN may not be needed.
Increasing the size of COUT to 22µF or greater will reduce
output voltage ripple — particularly with high VIN voltages
(8V or greater). A ceramic capacitor is recommended for
the flying capacitor C1 with a value of 0.1µF or 0.22µF.
Smaller values may be used in low output current
applications.
Output Ripple
Normal LTC1515 series operation produces voltage ripple
on the VOUT pin. Output voltage ripple is required for the
parts to regulate. Low frequency ripple exists due to the
hysteresis in the sense comparator and propagation delays in the charge pump enable/disable circuits. High
frequency ripple is also present mainly from the ESR
LTC1515 Series
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APPLICATIONS INFORMATION
(equivalent series resistance) in the output capacitor.
Typical output ripple (VIN < 8V) under maximum load is
100mV peak-to-peak with a low ESR, 10µF output capacitor. For applications requiring VIN to exceed 8V, a 22µF or
larger COUT capacitor is recommended to maintain maximum ripple in the 100mV range.
The magnitude of the ripple voltage depends on several
factors. High input voltages increase the output ripple
since more charge is delivered to COUT per charging cycle.
A large C1 flying capacitor (> 0.22µF) also increases ripple
in step-up mode for the same reason. Large output
current load and/or a small output capacitor (<10µF)
results in higher ripple due to higher output voltage dV/dt.
High ESR capacitors (ESR > 0.5Ω) on the output pin cause
high frequency voltage spikes on VOUT with every clock
cycle.
There are several ways to reduce the output voltage ripple.
A large COUT capacitor (22µF or greater) will reduce both
the low and high frequency ripple due to the lower COUT
charging and discharging dV/dt and the lower ESR typically found with higher value (larger case size) capacitors.
A low ESR (<0.5Ω) ceramic output capacitor will minimize the high frequency ripple, but will not reduce the low
frequency ripple unless a high capacitance value is chosen. A reasonable compromise is to use a 10µF to 22µF
tantalum capacitor in parallel with a 1µF to 3.3µF ceramic
capacitor on VOUT to reduce both the low and high
frequency ripple. An RC or LC filter may also be used to
reduce high frequency voltage spikes (see Figure 4).
LTC1515/
LTC1515-X
VOUT
8
+
VOUT
1µF
CERAMIC
15µF
TANTALUM
LTC1515/
LTC1515-X
VOUT
+
10µF
TANTALUM
Internal soft start circuitry controls the rate at which VOUT
may be charged from 0V to its final regulated value. The
typical start-up time from VOUT = 0V to 5V is 4ms. This
corresponds to an effective VOUT charging current of only
12.5mA for a 10µF output capacitor (27.5mA for 22µF,
etc.). Note that any output current load present during
start-up will add directly to the charging currents mentioned above. The soft start circuitry limits start-up current both at initial power-up and when coming out of
shutdown.
As the VIN (or boosted VIN) to VOUT voltage differential
grows, the effective output impedance of the charge pump
is automatically increased by internal voltage sensing
circuitry. This feature minimizes the current spikes pulled
from VIN whenever the charge pump is enabled and helps
to reduce both input and output ripple.
Power-On Reset
The POR pin is an open-drain output that pulls low when
the output voltage is out of regulation. When the VOUT
rises to within 6.5% of regulation, an internal timer is
started which releases POR after 200ms (typ). In shutdown, the POR output is pulled low. In normal operation,
an external pull-up resistor is generally used between the
POR pin and VOUT.
Protection Features
2Ω
8
ing out of shutdown mode. Whenever large VIN (or boosted
VIN) to VOUT voltage differentials are present, most charge
pumps will pull large current spikes from the input supply.
Only the effective charge pump output impedance limits
the current while the charge pump is enabled. This may
disrupt input supply regulation, especially if the input
supply is a low power DC/DC converter or linear regulator.
The LTC1515 family minimizes inrush currents both at
start-up and under high VIN to VOUT operation.
+
VOUT
10µF
TANTALUM
LT1515 • F04
Figure 4. Output Ripple Reduction Techniques
Inrush Currents
A common problem with switched capacitor regulators is
inrush current—particularly during power-up and com-
All of the parts contain thermal shutdown and shortcircuit protection features. The parts will shut down when
the junction temperature reaches approximately 150°C
and will resume operation once the junction temperature
has dropped back to approximately 140°C. The parts will
limit output current to 12mA (typ) when a short circuit
condition (VOUT < 100mV) exists. The parts can survive an
indefinite short to GND.
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.
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LTC1515 Series
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TYPICAL APPLICATIONS
Low Power, Low Noise Step-Up/Step-Down 5V Supply with Reset
1.4M
470k
ON OFF
1
2
RESET
3
4
402k
VOUT
SHDN
POR
LTC1515
FB
GND
VIN
5.5V
8
7
C1+
6
C1–
5
+
VIN = 3V TO 10V
+
2Ω
22µF
10µF
0.22µF
+
8
IN
LT1121-5
1
OUT
GND
Programmable 3V/5V GSM SIM Card Power Supply
10µF
+
10µF
3
1
ON OFF
NC
5V 3V
SHDN
VOUT
8
VOUT = 5V
IOUT = 20mA
VRIPPLE < 1mVP-P
LTC1515 • TA03
VOUT = 3V OR 5V
IOUT = 15mA
2
7
POR
VIN
LTC1515-3/5
6
5/3
C1+
4
5
C1–
GND
+
3
+
10µF
Li-Ion
10µF
0.1µF
LTC1515 • TA04
Positive and Negative Supply
1
ON OFF
NC
VIN
SHDN
VOUT
2
VOUT = 5V
IOUT = 15mA, 2.7V ≤ VIN ≤ 4.4V
IOUT = 50mA, 3.3V ≤ VIN ≤ 4.4V
8
7
POR
VIN
LTC1515-3/5
6
5/3
C1+
4
5
GND
C1–
+
3
0.22µF
+
10µF
10µF
470Ω
8.2k
Q2
Q1
* CENTRAL SEMICONDUCTOR
CMPSH-35 DUAL SCHOTTKY
** OPTIONAL CIRCUITRY FOR MAINTAINING
–VOUT WITH LOW VOUT LOADS
Q1, Q2: 2N3904
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PACKAGE DESCRIPTION
2.4k
0.22µF
**
*
+
0.053 – 0.069
(1.346 – 1.752)
0°– 8° TYP
0.016 – 0.050
0.406 – 1.270
LTC1515 • TA05
Dimensions in inches (millimeters) unless otherwise noted.
0.189 – 0.197*
(4.801 – 5.004)
(LTC DWG # 05-08-1610)
0.008 – 0.010
(0.203 – 0.254)
VOUT = –1V TO –3.5V
IOUT = 5mA
10µF
S8 Package
8-Lead Plastic Small Outline (Narrow 0.150)
0.010 – 0.020
× 45°
(0.254 – 0.508)
VIN = 2.7V TO 4.4V
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
8
7
6
5
0.004 – 0.010
(0.101 – 0.254)
0.050
(1.270)
TYP
0.150 – 0.157**
(3.810 – 3.988)
0.228 – 0.244
(5.791 – 6.197)
1
2
3
4
SO8 0996
RELATED PARTS
PART NUMBER
LTC1514 Series
LTC1516
LTC1517-5
LTC1522
LTC1555/LTC1556
LTC660
8
DESCRIPTION
Step-Up/Step-Down Switched Capacitor DC/DC Converters
Micropower, Regulated 5V Charge Pump DC/DC Converter
Micropower, Regulated 5V Charge Pump DC/DC Converter
Micropower, Regulated 5V Charge Pump DC/DC Converter
SIM Power Supply and Level Translators
100mA CMOS Voltage Converter
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417● (408)432-1900
FAX: (408) 434-0507● TELEX: 499-3977 ● www.linear-tech.com
COMMENTS
VIN 2V to 10V, 3.3V and 5V Versions, IOUT to 50mA
IOUT = 20mA (VIN ≥ 2V), IOUT = 50mA (VIN ≥ 3V)
LTC1522 Without Shutdown and Packaged in SOT-23
Available in 8-Pin MSOP, 6µA Quiescent Current, IOUT = 20mA
Step-Up/Step-Down SIM Power Supply and Level Translators
5V to – 5V Conversion with Low Voltage Loss
1515f LT/TP 0298 4K • PRINTED IN USA
 LINEAR TECHNOLOGY CORPORATION 1997