LT1054/LT1054L
Switched-Capacitor Voltage
Converter with Regulator
FEATURES
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DESCRIPTION
The LT
®
1054 is a monolithic, bipolar, switched-capacitor
voltage converter and regulator. The LT1054 provides
higher output current than previously available converters
with significantly lower voltage losses. An adaptive switch
driver scheme optimizes efficiency over a wide range of
output currents. Total voltage loss at 100mA output current
is typically 1.1V. This holds true over the full supply voltage
range of 3.5V to 15V. Quiescent current is typically 2.5mA.
The LT1054 also provides regulation, a feature not previ-
ously available in switched-capacitor voltage converters. By
adding an external resistive divider a regulated output can
be obtained. This output will be regulated against changes
in both input voltage and output current. The LT1054 can
also be shut down by grounding the feedback pin. Supply
current in shutdown is less than 100µA.
The internal oscillator of the LT1054 runs at a nominal
frequency of 25kHz. The oscillator pin can be used to ad-
just the switching frequency or to externally synchronize
the LT1054.
The LT1054 is pin compatible with previous converters
such the LTC1044/LTC7660.
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Output Current: 100mA (LT1054)
125mA (LT1054L)
Reference and Error Amplifier for Regulation
Low Loss: 1.1V at 100mA
Operating Range:3.5V to 15V (LT1054)
3.5V to 7V (LT1054L)
External Shutdown
External Oscillator Synchronization
Can Be Paralleled
Pin Compatible with the LTC
®
1044/LTC7660
Available in SW16 and SO-8 Packages
APPLICATIONS
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Voltage Inverter
Voltage Regulator
Negative Voltage Doubler
Positive Voltage Doubler
L,
LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
BLOCK DIAGRAM
V
REF
6
2.5V
R
DRIVE
V
IN
8
REFERENCE
2
LT1054/LT1054 Voltage Loss
3.5V ≤ V
IN
≤ 15V (LT1054)
3.5V ≤ V
IN
≤ 7V (LT1054L)
C
IN
= C
OUT
= 100µF
INDICATES GUARANTEED
TEST POINT
LT1054
LT1054L
+
1
FEEDBACK/
SHUTDOWN
–
R
7
OSC
Q
OSC
Q
CAP
–
4
C
IN
*
VOLTAGE LOSS (V)
+
CAP
+
2
1
DRIVE
DRIVE
3 GND
T
J
= 125°C
T
J
= 25°C
T
J
= –55°C
0
*EXTERNAL CAPACITORS
+
C
OUT
*
0
25
5 –V
OUT
DRIVE
LT1054 • BD
50
75
100
OUTPUT CURRENT (mA)
125
1054 TA01•
1954lff
1
LT1054/LT1054L
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Supply Voltage (Note 2)
LT1054 .................................................................16V
LT1054L .................................................................7V
Input Voltage
Pin 1 ................................................. 0V
≤
V
PIN1
≤
V
+
Pin 3 (S Package) ............................. 0V
≤
V
PIN3
≤
V
+
Pin 7 .............................................. 0V
≤
V
PIN7
≤
V
REF
Pin 13 (S Package) ...................... 0V
≤
V
PIN13
≤
V
REF
Operating Junction Temperature Range
LT1054C/LT1054LC .............................. 0°C to 100°C
LT1054I............................................. – 40°C to 100°C
LT1054M............................................ –55°C to 125°C
Maximum Junction Temperature (Note 3)
LT1054C/LT1054LC ......................................... 125°C
LT1054I............................................................. 125°C
LT1054M........................................................... 150°C
Storage Temperature Range
J8, N8 and S8 Packages .................... –55°C to 150°C
S Package ......................................... – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
TOP VIEW
FB/SHDN 1
CAP
+
2
GND 3
CAP
–
4
8
7
6
5
V
+
OSC
V
REF
V
OUT
FB/SHDN 1
CAP
+
2
8
7
6
5
V
+
OSC
V
REF
V
OUT
NC 1
NC 2
FB/SHDN 3
CAP
+
4
GND 5
CAP
–
6
NC 7
NC 8
16 NC
15 NC
14 V
+
13 OSC
12 V
REF
11 V
OUT
10 NC
9
NC
GND 3
CAP
–
4
J8 PACKAGE
N8 PACKAGE
8-LEAD PLASTIC DIP 8-LEAD CERAMIC DIP
T
JMAX
= 125°C,
θ
JA
= 130°C/W
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 125°C,
θ
JA
= 120°C/W
SEE REGULATION AND CAPACITOR SELECTION SECTIONS
IN THE APPLICATIONS INFORMATION FOR IMPORTANT
INFORMATION ON THE S8 DEVICE
SW PACKAGE
16-LEAD PLASTIC SO
T
JMAX
= 125°C,
θ
JA
= 150°C/W
ORDER INFORMATION
LEAD FREE FINISH
LT1054CN8#PBF
LT1054IN8#PBF
LT1054MJ8#PBF
LT1054CS8#PBF
LT1054LCS8#PBF
LT1054IS8#PBF
LT1054CSW#PBF
LT1054ISW#PBF
LT1054CJ8#PBF
OBSOLETE PART
TAPE AND REEL
LT1054CN8#TRPBF
LT1054IN8#TRPBF
LT1054MJ8#TRPBF
LT1054CS8#TRPBF
LT1054LCS8#TRPBF
LT1054IS8#TRPBF
LT1054CSW#TRPBF
LT1054ISW#TRPBF
LT1054CJ8#TRPBF
PART MARKING
LT1054CN8
LT1054IN8
LT1054MJ8
1054
1054L
1054I
LT1054CSW
LT1054ISW
LT1054CJ8
PACKAGE DESCRIPTION
8-Lead Plastic DIP
8-Lead Plastic DIP
8-Lead Ceramic DIP
8-Lead Plastic SO
8-Lead Plastic SO
8-Lead Plastic SO
16-Lead Plastic SO
16-Lead Plastic SO
8-Lead Ceramic DIP
TEMPERATURE RANGE
0°C to 100°C
–40°C to 100°C
–55°C to 125°C
0°C to 100°C
0°C to 100°C
–40°C to 100°C
0°C to 100°C
–40°C to 100°C
0°C to 100°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
1054lff
2
LT1054/LT1054L
ELECTRICAL CHARACTERISTICS
PARAMETER
Supply Current
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 7)
CONDITIONS
I
LOAD
= 0mA
LT1054:
V
IN
= 3.5V
V
IN
= 15V
l
l
l
l
l
l
l
l
l
l
l
l
l
MIN
TYP
2.5
3.0
2.5
3.0
MAX
4.0
5.0
4.0
5.0
15
7
UNITS
mA
mA
mA
mA
V
V
V
V
V
Ω
kHz
kHz
V
V
V
mV
mV
mA
µA
LT1054L: V
IN
= 3.5V
V
IN
= 7V
Supply Voltage Range
Voltage Loss (V
IN
– |V
OUT
|)
LT1054
LT1054L
C
IN
= C
OUT
= 100µF Tantalum (Note 4)
I
OUT
= 10mA
I
OUT
= 100mA
I
OUT
= 125mA (LT1054L)
∆I
OUT
= 10mA to 100mA (Note 5)
LT1054: 3.5V ≤ V
IN
≤ 15V
LT1054L: 3.5V ≤ V
IN
≤ 7V
I
REF
= 60µA, T
J
= 25°C
V
IN
= 7V, T
J
= 25°C, R
L
= 500Ω (Note 6)
LT1054: 7V ≤ V
IN
≤ 12V, R
L
= 500Ω (Note 6)
V
IN
= 7V, 100Ω ≤ 500Ω (Note 6)
V
PIN1
= 0V
3.5
3.5
0.35
1.10
1.35
10
15
15
2.35
2.25
–4.70
25
25
2.50
–5.00
5
10
300
100
0.55
1.60
1.75
15
40
35
2.65
2.75
–5.20
25
50
200
Output Resistance
Oscillator Frequency
Reference Voltage
Regulated Voltage
Line Regulation
Load Regulation
Maximum Switch Current
Supply Current in Shutdown
l
l
l
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 absolute maximum supply voltage rating of 16V is for
unregulated circuits using LT1054. For regulation mode circuits using
LT1054 with V
OUT
≤ 15V at Pin 5 (Pin 11 on S package), this rating may be
increased to 20V. The absolute maximum supply voltage for LT1054L is 7V.
Note 3:
The devices are guaranteed by design to be functional up to the
absolute maximum junction temperature.
Note 4:
For voltage loss tests, the device is connected as a voltage inverter,
with pins 1, 6, and 7 (3, 12, and 13 S package) unconnected. The voltage
losses may be higher in other configurations.
Note 5:
Output resistance is defined as the slope of the curve, (∆V
OUT
vs
∆I
OUT
), for output currents of 10mA to 100mA. This represents the linear
portion of the curve. The incremental slope of the curve will be higher at
currents <10mA due to the characteristics of the switch transistors.
Note 6:
All regulation specifications are for a device connected as a
positive-to-negative converter/regulator with R1 = 20k, R2 = 102.5k,
C1 = 0.002µF (C1 = 0.05µF S package) C
IN
= 10µF tantalum, C
OUT
= 100µF
,
tantalum.
Note 7:
The S8 package uses a different die than the H, J8, N8 and S
packages. The S8 device will meet all the existing data sheet parameters.
See Regulation and Capacitor Selection in the Applications Information
section for differences in application requirements.
1954lff
3
LT1054/LT1054L
TYPICAL PERFORMANCE CHARACTERISTICS
Shutdown Threshold
0.6
0.5
0.4
0.3
0.2
0.1
0
– 50 – 25
SUPPLY CURRENT (mA)
V
PIN1
5
Supply Current
I
L
= 0
35
Oscillator Frequency
SHUTDOWN THRESHOLD (V)
4
FREQUENCY (kHz)
3
25
V
IN
= 15V
V
IN
= 3.5V
2
1
0
15
–70 –50 –25 0
25 50 75
TEMPERATURE (°C)
50
25
75
0
TEMPERATURE (°C)
100
125
0
10
5
INPUT VOLTAGE (V)
15
LT1054 • TPC02
100 125
LT1054 • TPC03
LT1054 • TPC01
Supply Current in Shutdown
120
AVERAGE INPUT CURRENT (mA)
100
QUIESCENT CURRENT (µA)
80
60
40
20
0
V
PIN1
= 0V
140
120
Average Input Current
1.4
1.2
VOLTAGE LOSS (V)
1.0
0.8
0.6
0.4
0.2
0
20
60
80
40
OUTPUT CURRENT (mA)
100
0
Output Voltage Loss
I
OUT
= 100mA
100
80
60
40
20
0
I
OUT
= 50mA
I
OUT
= 10mA
INVERTER CONFIGURATION
C
OUT
= 100µF TANTALUM
f
OSC
= 25kHz
0 10 20 30 40 50 60 70 80 90 100
INPUT CAPACITANCE (µF)
LT1054 • TPC06
0
10
5
INPUT VOLTAGE (V)
15
LT1054 • TPC04
LT1050 • TPC05
Output Voltage Loss
INVERTER CONFIGURATION
C
IN
= 10µF TANTALUM
C
OUT
= 100µF TANTALUM
VOLTAGE LOSS (V)
Output Voltage Loss
INVERTER CONFIGURATION
C
IN
= 100µF TANTALUM
C
OUT
= 100µF TANTALUM
2
VOLTAGE LOSS (V)
2
I
OUT
= 100mA
1
I
OUT
= 100mA
1
I
OUT
= 50mA
I
OUT
= 10mA
0
I
OUT
= 50mA
I
OUT
= 10mA
0
1
10
OSCILLATOR FREQUENCY (kHz)
100
1
10
OSCILLATOR FREQUENCY (kHz)
100
LT1054 • TPC07
LT1054 • TPC08
1054lff
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LT1054/LT1054L
TYPICAL PERFORMANCE CHARACTERISTICS
Regulated Output Voltage
–4.7
REFERENCE VOLTAGE CHANGE (mV)
–4.8
–4.9
OUTPUT VOLTAGE (V)
–5.0
–5.1
100
80
60
40
20
0
–20
–40
–60
–80
50
25
0
75
TEMPERATURE (°C)
100
125
Reference Voltage Temperature
Coefficient
V
REF
AT 0 = 2.500V
–11.6
–11.8
–12.0
–12.2
–12.4
–12.6
–50 –25
50
25
0
75
TEMPERATURE (°C)
100
125
–100
–50 –25
LT1054 • TPC09
LT1054 • TPC10
PIN FUNCTIONS
FB/SHDN (Pin 1):
Feedback/Shutdown Pin. This pin has
two functions. Pulling Pin 1 below the shutdown threshold
(≈ 0.45V) puts the device into shutdown. In shutdown the
reference/regulator is turned off and switching stops. The
switches are set such that both C
IN
and C
OUT
are discharged
through the output load. Quiescent current in shutdown
drops to approximately 100µA (see Typical Performance
Characteristics). Any open-collector gate can be used to
put the LT1054 into shutdown. For normal (unregulated)
operation the device will start back up when the external
gate is shut off. In LT1054 circuits that use the regulation
feature, the external resistor divider can provide enough
pull-down to keep the device in shutdown until the output
capacitor (C
OUT
) has fully discharged. For most applica-
tions where the LT1054 would be run intermittently, this
does not present a problem because the discharge time
of the output capacitor will be short compared to the off-
time of the device. In applications where the device has
to start up before the output capacitor (C
OUT
) has fully
discharged, a restart pulse must be applied to Pin 1 of
the LT1054. Using the circuit of Figure 5, the restart signal
can be either a pulse (t
p
> 100µs) or a logic high. Diode
coupling the restart signal into Pin 1 will allow the output
voltage to come up and regulate without overshoot. The
resistor divider R3/R4 in Figure 5 should be chosen to
provide a signal level at pin 1 of 0.7V to 1.1V.
Pin 1 is also the inverting input of the LT1054’s error
amplifier and as such can be used to obtain a regulated
output voltage.
CAP
+
/CAP
–
(Pin 2/Pin 4):
Pin 2, the positive side of the
input capacitor (C
IN
), is alternately driven between V
+
and ground. When driven to V
+
, Pin 2 sources current
from V
+
. When driven to ground Pin 2 sinks current to
ground. Pin 4, the negative side of the input capacitor, is
driven alternately between ground and V
OUT
. When driven
to ground, Pin 4 sinks current to ground. When driven to
V
OUT
Pin 4 sources current from C
OUT
. In all cases current
flow in the switches is unidirectional as should be expected
using bipolar switches.
V
OUT
(Pin 5):
In addition to being the output pin this pin
is also tied to the substrate of the device.
Special care
must be taken in LT1054 circuits to avoid pulling this
pin positive with respect to any of the other pins.
Pulling
Pin 5 positive with respect to Pin 3 (GND) will forward
bias the substrate diode which will prevent the device from
starting. This condition can occur when the output load
driven by the LT1054 is referred to its positive supply (or
to some other positive voltage). Note that most op amps
present just such a load since their supply currents flow
from their V
+
terminals to their V
–
terminals. To prevent
start-up problems with this type of load an external
1954lff
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