LT1054/LT1054L Switched-Capacitor Voltage Converter with Regulator FEATURES
■ ■ ■ ■
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 previously 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 adjust the switching frequency or to externally synchronize the LT1054. The LT1054 is pin compatible with previous converters such the LTC1044/LTC7660.
■ ■ ■ ■ ■
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
VREF 6 2.5V R DRIVE VIN 8 REFERENCE 2
LT1054/LT1054 Voltage Loss
3.5V ≤ VIN ≤ 15V (LT1054) 3.5V ≤ VIN ≤ 7V (LT1054L) CIN = COUT = 100µF INDICATES GUARANTEED TEST POINT LT1054 LT1054L
+
1 FEEDBACK/ SHUTDOWN
–
R 7 OSC
Q OSC Q CAP – 4
CIN*
VOLTAGE LOSS (V)
+
CAP + 2
1
DRIVE
DRIVE 3 GND
TJ = 125°C TJ = 25°C TJ = – 55°C 0
*EXTERNAL CAPACITORS
+
COUT*
0
25
5 –VOUT DRIVE
LT1054 • BD
50 75 100 OUTPUT CURRENT (mA)
125
1054 TA01•
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LT1054/LT1054L ABSOLUTE MAXIMUM RATINGS
(Note 1)
Supply Voltage (Note 2) LT1054 ................................................................. 16V LT1054L ................................................................. 7V Input Voltage Pin 1 ................................................. 0V ≤ VPIN1 ≤ V+ Pin 3 (S Package) ............................. 0V ≤ VPIN3 ≤ V+ Pin 7 .............................................. 0V ≤ VPIN7 ≤ VREF Pin 13 (S Package) ...................... 0V ≤ VPIN13 ≤ VREF 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
+
NC 1 8 7 6 5 V+ OSC VREF VOUT NC 2 FB/SHDN 3 CAP + 4 GND 5 CAP – 6 NC 7 NC 8
16 NC 15 NC 14 V + 13 OSC 12 VREF 11 VOUT 10 NC 9 NC
FB/SHDN 1 8 7 6 5 V+ OSC VREF VOUT CAP + 2
2
GND 3 CAP – 4
GND 3 CAP
–
4
J8 PACKAGE N8 PACKAGE 8-LEAD PLASTIC DIP 8-LEAD CERAMIC DIP TJMAX = 125°C, θJA = 130°C/W
S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 125°C, θJA = 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 TJMAX = 125°C, θJA = 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/
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LT1054/LT1054L ELECTRICAL CHARACTERISTICS
PARAMETER Supply Current
The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. (Note 7)
CONDITIONS ILOAD = 0mA LT1054: VIN = 3.5V VIN = 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: VIN = 3.5V VIN = 7V Supply Voltage Range Voltage Loss (VIN – |VOUT|) LT1054 LT1054L CIN = COUT = 100µF Tantalum (Note 4) IOUT = 10mA IOUT = 100mA IOUT = 125mA (LT1054L) ∆IOUT = 10mA to 100mA (Note 5) LT1054: 3.5V ≤ VIN ≤ 15V LT1054L: 3.5V ≤ VIN ≤ 7V IREF = 60µA, TJ = 25°C VIN = 7V, TJ = 25°C, RL = 500Ω (Note 6) LT1054: 7V ≤ VIN ≤ 12V, RL = 500Ω (Note 6) VIN = 7V, 100Ω ≤ 500Ω (Note 6) VPIN1 = 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 VOUT ≤ 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, (∆VOUT vs ∆IOUT), 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 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 (CIN), 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 VOUT. When driven to ground, Pin 4 sinks current to ground. When driven to VOUT Pin 4 sources current from COUT. In all cases current flow in the switches is unidirectional as should be expected using bipolar switches. VOUT (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
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LT1054/LT1054L PIN FUNCTIONS
transistor must be added as shown in Figure 1. This will prevent VOUT (Pin 5) from being pulled above the ground pin (Pin 3) during start-up. Any small, general purpose transistor such as 2N2222 or 2N2219 can be used. RX should be chosen to provide enough base drive to the external transistor so that it is saturated under nominal output voltage and maximum output current conditions. In some cases an N-channel enhancement mode MOSFET can be used in place of the transistor. RX ≤ OSC (Pin 7): Oscillator Pin. This pin can be used to raise or lower the oscillator frequency or to synchronize the device to an external clock. Internally Pin 7 is connected to the oscillator timing capacitor (Ct ≈ 150pF) which is alternately charged and discharged by current sources of ±7µA so that the duty cycle is ≈50%. The LT1054 oscillator is designed to run in the frequency band where switching losses are minimized. However the frequency can be raised, lowered, or synchronized to an external system clock if necessary. The frequency can be lowered by adding an external capacitor (C1, Figure 2) from Pin 7 to ground. This will increase the charge and discharge times which lowers the oscillator frequency. The frequency can be increased by adding an external capacitor (C2, Figure 2, in the range of 5pF to 20pF) from Pin 2 to Pin 7. This capacitor will couple charge into CT at the switch transitions, which will shorten the charge and discharge time, raising the oscillator frequency. Synchronization can be accomplished by adding an external resistive pull-up from Pin 7 to the reference pin (Pin 6). A 20k pull-up is recommended. An open collector gate or an NPN transistor can then be used to drive the oscillator pin at the external clock frequency as shown in Figure 2. Pulling up Pin 7 to an external voltage is not recommended. For circuits that require both frequency synchronization and regulation, an external reference can be used as the reference point for the top of the R1/R2 divider allowing Pin 6 to be used as a pullup point for Pin 7.
FB/SHDN V + VIN C2
( VOUT )β
IOUT
V+
IL LOAD FB/SHDN V+ RX
+ –
LT1054 • F01
IQ
IOUT
CIN
+
OSC CAP + LT1054 GND VREF CAP – VOUT
COUT
Figure 1
Figure 2
V+ (Pin 8): Input Supply. The LT1054 alternately charges CIN to the input voltage when CIN is switched in parallel with the input supply and then transfers charge to COUT when CIN is switched in parallel with COUT. Switching occurs at the oscillator frequency. During the time that CIN
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6
+
VREF (Pin 6): Reference Output. This pin provides a 2.5V reference point for use in LT1054-based regulator circuits. The temperature coefficient of the reference voltage has been adjusted so that the temperature coefficient of the regulated output voltage is close to zero. This requires the reference output to have a positive temperature coefficient as can be seen in the typical performance curves. This nonzero drift is necessary to offset a drift term inherent in the internal reference divider and comparator network tied to the feedback pin. The overall result of these drift terms is a regulated output which has a slight positive temperature coefficient at output voltages below 5V and a slight negative TC at output voltages above 5V. Reference output current should be limited, for regulator feedback networks, to approximately 60µA. The reference pin will draw ≈100µA when shorted to ground and will not affect the internal reference/regulator, so that this pin can also be used as a pull-up for LT1054 circuits that require synchronization.
+
+
CIN
OSC CAP + LT1054 GND VREF CAP – VOUT COUT
C1
LT1054 • F02
LT1054/LT1054L PIN FUNCTIONS
is charging, the peak supply current will be approximately equal to 2.2 times the output current. During the time that CIN is delivering charge to COUT the supply current drops to approximately 0.2 times the output current. An input supply bypass capacitor will supply part of the peak input current drawn by the LT1054 and average out the current drawn from the supply. A minimum input supply bypass capacitor of 2µF preferably tantalum or some other low ESR , type is recommended. A larger capacitor may be desirable in some cases, for example, when the actual input supply is connected to the LT1054 through long leads, or when the pulse current drawn by the LT1054 might affect other circuitry through supply coupling.
APPLICATIONS INFORMATION
Theory of Operation To understand the theory of operation of the LT1054, a review of a basic switched-capacitor building block is helpful. In Figure 3 when the switch is in the left position, capacitor C1 will charge to voltage V1. The total charge on C1 will be q1 = C1V1. The switch then moves to the right, discharging C1 to voltage V2. After this discharge time the charge on C1 is q2 = C1V2. Note that charge has been transferred from the source V1 to the output V2. The amount of charge transferred is: ∆q = q1 – q2 = C1(V1 – V2) If the switch is cycled f times per second, the charge transfer per unit time (i.e., current) is: I = (f)(∆q) = (f)[C1(V1 – V2)] To obtain an equivalent resistance for the switchedcapacitor network we can rewrite this equation in terms of voltage and impedance equivalence: I= V1– V2 V1– V2 = 1/ fC1 REQUIV
V1 f C1 C2 RL
LT1054 • F03
V2
Figure 3. Switched-Capacitor Building Block
V1 REQUIV C2 RL
LT1054 • F04
V2
REQUIV = 1 fC1
Figure 3. Switched-Capacitor Equivalent Circuit
eventually be dominated by the 1/fC1 term and voltage losses will rise. Note that losses also rise as frequency increases. This is caused by internal switching losses which occur due to some finite charge being lost on each switching cycle. This charge loss per-unit-cycle, when multiplied by the switching frequency, becomes a current loss. At high frequency this loss becomes significant and voltage losses again rise. The oscillator of the LT1054 is designed to run in the frequency band where voltage losses are at a minimum. Regulation The error amplifier of the LT1054 servos the drive to the PNP switch to control the voltage across the input capacitor (CIN) which in turn will determine the output voltage. Using the reference and error amplifier of the LT1054, an external resistive divider is all that is needed to set the regulated output voltage. Figure 5 shows the basic regulator configuration and the formula for calculating the appropriate resistor values. R1 should be chosen to
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A new variable REQUIV is defined such that REQUIV = 1/fC1. Thus the equivalent circuit for the switched-capacitor network is as shown in Figure 4. The LT1054 has the same switching action as the basic switched-capacitor building block. Even though this simplification doesn’t include finite switch on-resistance and output voltage ripple, it provides an intuitive feel for how the device works. These simplified circuits explain voltage loss as a function of frequency (see Typical Performance Characteristics). As frequency is decreased, the output impedance will
7
LT1054/LT1054L APPLICATIONS INFORMATION
R3 FB/SHDN V + R4 CIN + 10µF TANTALUM OSC CAP + LT1054 GND VREF CAP – VOUT VOUT COUT 100µF TANTALUM
LT1054 • F05
VIN
2.2µF
R1 R2 C1
FOR EXAMPLE: TO GET VOUT = – 5V REFERRED TO THE GROUND PIN OF THE LT1054, CHOOSE R1 = 20k, THEN R2 = 20k
|–5V| + 1 = 102.6k* 2.5V – 40mV 2 *CHOOSE THE CLOSEST 1% VALUE
)
)
Figure 5
be 20k or greater because the reference output current is limited to ≈100µA. R2 should be chosen to be in the range of 100k to 300k. For optimum results the ratio of CIN/COUT is recommended to be 1/10. C1, required for good load regulation at light load currents, should be 0.002µF for all output voltages. A new die layout was required to fit into the physical dimensions of the S8 package. Although the new die of the LT1054CS8 will meet all the specifications of the existing LT1054 data sheet, subtle differences in the layout of the new die require consideration in some application circuits. In regulating mode circuits using the 1054CS8 the nominal values of the capacitors, CIN and COUT, must be approximately equal for proper operation at elevated junction temperatures. This is different from the earlier part. Mismatches within normal production tolerances for the capacitors are acceptable. Making the nominal capacitor values equal will ensure proper operation at elevated junction temperatures at the cost of a small degradation in the transient response of regulator circuits. For unregulated circuits the values of CIN and COUT are normally equal for all packages. For S8 applications assistance in unusual applications circuits, please consult the factory. It can be seen from the circuit block diagram that the maximum regulated output voltage is limited by the supply voltage. For the basic configuration, |VOUT| referred to the
8
+
|VOUT| |VOUT| R2 = +1 ≈ +1 1.21V VREF R1 – 40mV 2 WHERE VREF = 2.5V NOMINAL
)
RESTART SHUTDOWN
)) )
ground pin of the LT1054 must be less than the total of the supply voltage minus the voltage loss due to the switches. The voltage loss versus output current due to the switches can be found in Typical Performance Characteristics. Other configurations such as the negative doubler can provide higher output voltages at reduced output currents (see Typical Applications). Capacitor Selection For unregulated circuits the nominal values of CIN and COUT should be equal. For regulated circuits see the section on Regulation. While the exact values of CIN and COUT are noncritical, good quality, low ESR capacitors such as solid tantalum are necessary to minimize voltage losses at high currents. For CIN the effect of the ESR of the capacitor will be multiplied by four due to the fact that switch currents are approximately two times higher than output current and losses will occur on both the charge and discharge cycle. This means that using a capacitor with 1Ω of ESR for CIN will have the same effect as increasing the output impedance of the LT1054 by 4Ω. This represents a significant increase in the voltage losses. For COUT the affect of ESR is less dramatic. COUT is alternately charged and discharged at a current approximately equal to the output current and the ESR of the capacitor will cause a step function to occur in the output ripple at the switch transitions. This step function will degrade the output regulation for changes in output load current and should be avoided. Realizing that large value tantalum capacitors can be expensive, a technique that can be used is to parallel a smaller tantalum capacitor with a large aluminum electrolytic capacitor to gain both low ESR and reasonable cost. Where physical size is a concern some of the newer chip type surface mount tantalum capacitors can be used. These capacitors are normally rated at working voltages in the 10V to 20V range and exhibit very low ESR (in the range of 0.1Ω). Output Ripple The peak-to-peak output ripple is determined by the value of the output capacitor and the output current. Peak-topeak output ripple may be approximated by the formula: dV = IOUT 2fCOUT
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LT1054/LT1054L APPLICATIONS INFORMATION
where dV = peak-to-peak ripple and f = oscillator frequency. For output capacitors with significant ESR a second term must be added to account for the voltage step at the switch transitions. This step is approximately equal to: (2IOUT)(ESR of COUT) Power Dissipation The power dissipation of any LT1054 circuit must be limited such that the junction temperature of the device does not exceed the maximum junction temperature ratings. The total power dissipation must be calculated from two components, the power loss due to voltage drops in the switches and the power loss due to drive current losses. The total power dissipated by the LT1054 can be calculated from: P ≈ (VIN – |VOUT|)(IOUT) + (VIN)(IOUT)(0.2) where both VIN and VOUT are referred to the ground pin (Pin 3) of the LT1054. For LT1054 regulator circuits, the power dissipation will be equivalent to that of a linear regulator. Due to the limited power handling capability of the LT1054 packages, the user will have to limit output current requirements or take steps to dissipate some power external to the LT1054 for large input/output differentials. This can be accomplished by placing a resistor in series with CIN as shown in Figure 6. A portion of the input voltage will then be dropped across this resistor without affecting the output regulation. Because switch current is approximately 2.2 times the output current and the resistor will cause a voltage drop when CIN is both charging and discharging, the resistor should be chosen as: RX = VX/(4.4 IOUT)
VIN RX CIN FB/SHDN V + OSC CAP + LT1054 GND VREF CAP – VOUT VOUT COUT
LT1054 • F06
where: VX ≈ VIN – [(LT1054 Voltage Loss)(1.3) + |VOUT|] and IOUT = maximum required output current. The factor of 1.3 will allow some operating margin for the LT1054. For example: assume a 12V to – 5V converter at 100mA output current. First calculate the power dissipation without an external resistor: P = (12V – | – 5V|)(100mA) + (12V)(100mA)(0.2) P = 700mW + 240mW = 940mW At θJA of 130°C/W for a commercial plastic device this would cause a junction temperature rise of 122°C so that the device would exceed the maximum junction temperature at an ambient temperature of 25°C. Now calculate the power dissipation with an external resistor (RX). First find how much voltage can be dropped across RX. The maximum voltage loss of the LT1054 in the standard regulator configuration at 100mA output current is 1.6V, so: VX = 12V – [(1.6V)(1.3) + | – 5V|] = 4.9V and RX = 4.9V/(4.4)(100mA) = 11Ω This resistor will reduce the power dissipated by the LT1054 by (4.9V)(100mA) = 490mW. The total power dissipated by the LT1054 would then be (940mW – 490mW) = 450mW. The junction temperature rise would now be only 58°C. Although commercial devices are guaranteed to be functional up to a junction temperature of 125°C, the specifications are only guaranteed up to a junction temperature of 100°C, so ideally you should limit the junction temperature to 100°C. For the above example this would mean limiting the ambient temperature to 42°C. Other steps can be taken to allow higher ambient temperatures. The thermal resistance numbers for the LT1054 packages represent worst-case numbers with no heat sinking and still air. Small clip-on type heat sinks can be used to lower the thermal resistance of the LT1054 package. In some systems there may be some available airflow which will help to lower the thermal resistance. Wide PC board traces from the LT1054 leads can also help to remove heat from the device. This is especially true for plastic packages.
+
R1 R2 C1
Figure 6
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LT1054/LT1054L TYPICAL APPLICATIONS
Basic Voltage Inverter
FB/SHDN V +
Basic Voltage Inverter/Regulator
VIN 2µF FB/SHDN V + OSC CAP + LT1054 GND VREF CAP – VOUT VOUT 100µF
LT1054 • TA03
100µF
+
OSC CAP LT1054 GND VREF CAP – VOUT
+
–VOUT 100µF
LT1054 • TAO2
10µF
REFER TO FIGURE 5
Negative Voltage Doubler
FB/SHDN V +
Positive Doubler + –
VOUT VOUT 50mA RX* 1N4001 VIN 1N4001 3.5V TO 15V
100µF
+
VIN 2µF
OSC CAP + LT1054 GND VREF CAP – VOUT
+ –
+
QX* 100µF
100µF
+
10µF FB/SHDN V+
VIN VIN = – 3.5V TO –15V VOUT = 2VIN + (LT1054 VOLTAGE LOSS) + (QX SATURATION VOLTAGE) LT1054 • TAO4 *SEE FIGURE 3
+
VIN = 3.5V TO 15V VOUT ≈ 2VIN – (VL + 2VDIODE) VL = LT1054 VOLTAGE LOSS
OSC CAP + LT1054 GND VREF CAP – VOUT
LT1054 • TAO5
100mA Regulating Negative Doubler
VIN 3.5 TO 15V
+
FB/SHDN V +
2.2µF
FB/SHDN V + VOUT SET R1 40k 0.002µF
HP5082-2810 20k
10µF
+
10µF
+
OSC CAP + LT1054 #1 GND VREF CAP
–
10µF
+
10µF
+
OSC CAP + LT1054 #2 GND VREF CAP – VOUT
1N4002 1N4002
VOUT 10µF
1N4002 1N4002
1N4002
100µF
VIN = 3.5 TO 15V VOUT MAX ≈ – 2VIN + [1054 VOLTAGE LOSS + 2(VDIODE)]
–VOUT IOUT ≅ 100mA MAX
|VOUT| |VOUT| R2 = +1 = + 1 , REFER TO FIGURE 5 1.21V R1 VREF – 40mV 2
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)) )
10
+
R2 500k
10µF
LT1054 • TAO6
+
|VOUT| |VOUT| R2 = +1 = +1 , 1.21V VREF R1 – 40mV 2
)
)) )
+
R1 R2 0.002µF
+
+
VIN
2µF
+
+ + +
+
2µF
PIN 2 LT1054 #1
LT1054/LT1054L TYPICAL APPLICATIONS
Bipolar Supply Doubler
VIN 3.5V TO 15V
++
+VOUT
100µF
+ + +
10µF
–
10µF
FB/SHDN V + OSC CAP + LT1054 GND VREF CAP
–
100µF
VOUT
+ –
1µF
10µF 100µF –VOUT
LT1054 • TAO7
= 1N4001
5V to ± 12V Converter
VIN = 5V
+
5µF VOUT ≈ 12V IOUT = 25mA 1N914 1N914
FB/SHDN V +
+
10µF
+
OSC CAP + LT1054 #1 GND VREF CAP – VOUT 2N2219 100µF
100µF
+ +
10µF
FB/SHDN V + OSC CAP + LT1054 #2 GND VREF CAP – VOUT 20k
10µF
Strain Gauge Bridge Signal Conditioner
10k INPUT TTL OR CMOS LOW FOR ON 10k 2N2907 5V 10k ZERO TRIM
+
40
10µF 5k GAIN TRIM
1
A1 1/2 LT1013
301k 100k 350 10k
200k
FB/SHDN V +
5V
10µF
+
OSC CAP + LT1054 GND VREF CAP – VOUT
3k
2N2222
+
A = 125 FOR 0V TO 3V OUT FROM FULL-SCALE BRIDGE OUTPUT OF 24mV
100µF TANTALUM
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+
3
5
–
–
0.022µF
8
2
100k
5k
6
+
+
1k
5µF
+
TO PIN 4 LT1054 #1 100µF VOUT ≈ –12V IOUT = 25mA
LT1054 • TAO8
+
VIN = 3.5V TO 15V +VOUT ≈ 2VIN – (VL + 2VDIODE) –VOUT ≈ – 2VIN + (VL + 2VDIODE) VL = LT1054 VOLTAGE LOSS
+
1M 7
A2 1/2 LT1013 4
+
LT1054 • TAO9
11
LT1054/LT1054L TYPICAL APPLICATIONS
3.5V to 5V Regulator
VIN 3.5V TO 5.5V
20k
1N914
1
8 LTC1044 7 6 5
1N914 1N914 10µF
FB/SHDN V +
+
R1 20k
1µF 5µF R2 125k R2 125k
+
2 3 4
+
100µF
3k
VOUT = 5V
VIN = 3.5V TO 5.5V VOUT = 5V IOUT(MAX) = 50mA 1N5817
2N2219 1N914
LT1054 • TA10
Regulating 200mA, 12V to – 5V Converter +
5µF 12V
FB/SHDN V + OSC CAP + LT1054 #1 GND VREF CAP – VOUT R1 39.2k R2 200k 200µF VOUT = –5V IOUT = 0mA to 200mA
FB/SHDN V +
HP5082-2810
10 1/2W
10µF
10µF 0.002µF
+
10 1/2W
OSC CAP + LT1054 #2 GND VREF CAP – VOUT
20k
+
REFER TO FIGURE 5
Digitally Programmable Negative Supply
15V
+
5µF 20k 16 LT1004-2.5 2.5V 20k 14
FB/SHDN V +
10µF
+
CAP + OSC LT1054 GND VREF CAP – VOUT
12
+
+
|VOUT| |VOUT| R2 = +1 = +1 , 1.21V R1 VREF – 40mV 2
)
)) )
LT1054 • TA11
11
AD558
DIGITAL INPUT
13
12
LT1054 • TA12
VOUT = – VIN (PROGRAMMED) 100µF
+
CAP –
VOUT
0.002µF
+
+ –
OSC CAP + LT1054 GND VREF
1µF
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LT1054/LT1054L PACKAGE DESCRIPTION
J8 Package 8-Lead CERDIP (Narrow .300 Inch, Hermetic)
(Reference LTC DWG # 05-08-1110)
CORNER LEADS OPTION (4 PLCS) .405 (10.287) MAX 8 7 6 5
.005 (0.127) MIN
.023 – .045 (0.584 – 1.143) HALF LEAD OPTION .045 – .068 (1.143 – 1.650) FULL LEAD OPTION .300 BSC (7.62 BSC)
.025 (0.635) RAD TYP 1 2 3 4
.220 – .310 (5.588 – 7.874)
.200 (5.080) MAX .015 – .060 (0.381 – 1.524)
.008 – .018 (0.203 – 0.457)
0 – 15 .045 – .065 (1.143 – 1.651) .014 – .026 (0.360 – 0.660) .100 (2.54) BSC
NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS
.125 3.175 MIN
J8 0801
N8 Package 8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
.400* (10.160) MAX 8 7 6 5
.300 – .325 (7.620 – 8.255)
.045 – .065 (1.143 – 1.651)
.130 .005 (3.302 0.127)
.255 .015* (6.477 0.381)
.008 – .015 (0.203 – 0.381) 1 2 3 4
.065 (1.651) TYP
INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
NOTE: 1. DIMENSIONS ARE
(
+.035 .325 –.015 8.255 +0.889 –0.381
)
.100 (2.54) BSC
.120 (3.048) .020 MIN (0.508) MIN .018 .003 (0.457 0.076)
N8 1002
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13
LT1054/LT1054L PACKAGE DESCRIPTION
S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.045 ±.005 .050 BSC
.189 – .197 (4.801 – 5.004) NOTE 3 8 7 6 5
.245 MIN
.160 ±.005
.228 – .244 (5.791 – 6.197) .150 – .157 (3.810 – 3.988) NOTE 3
.030 ±.005 TYP RECOMMENDED SOLDER PAD LAYOUT
.010 – .020 × 45° (0.254 – 0.508) .008 – .010 (0.203 – 0.254) .016 – .050 (0.406 – 1.270)
NOTE: 1. DIMENSIONS IN 0°– 8° TYP
1 .053 – .069 (1.346 – 1.752)
2
3
4
.004 – .010 (0.101 – 0.254)
INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
.014 – .019 (0.355 – 0.483) TYP
.050 (1.270) BSC
SO8 0303
SW Package 16-Lead Plastic Small Outline (Wide .300 Inch)
(Reference LTC DWG # 05-08-1620)
.030 .005 TYP N .050 BSC .045 .005 .398 – .413 (10.109 – 10.490) NOTE 4 16 15 14 13 12 11 10 9
N .420 MIN .325 .005 NOTE 3 .394 – .419 (10.007 – 10.643) N/2
1
2
3
N/2
RECOMMENDED SOLDER PAD LAYOUT 1 .291 – .299 (7.391 – 7.595) NOTE 4 .010 – .029 ¥ 45∞ (0.254 – 0.737)
0 – 8 TYP
2
3
4
5
6
7
8
.093 – .104 (2.362 – 2.642)
.037 – .045 (0.940 – 1.143)
.005 (0.127) RAD MIN
.009 – .013 (0.229 – 0.330) NOTE: 1. DIMENSIONS IN
NOTE 3 .016 – .050 (0.406 – 1.270)
.050 (1.270) BSC
INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS. THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS 4. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
.014 – .019 (0.356 – 0.482) TYP
.004 – .012 (0.102 – 0.305)
S16 (WIDE) 0502
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14
LT1054/LT1054L REVISION HISTORY
REV F DATE 12/10 DESCRIPTION The LTC1054MJ8 is now available. Changes reflected throughout the data sheet
(Revision history begins at Rev F)
PAGE NUMBER 1 to 16
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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.
15
LT1054/LT1054L TYPICAL APPLICATIONS
Positive Doubler with Regulation
VIN = 5V 50k 10µF
Negative Doubler with Regulator
VIN 3.5V TO 15V 2µF FB/SHDN V +
1N5817 VOUT 8V 50mA 100µF
FB/SHDN V + OSC CAP LT1054 GND VREF CAP – 10k VOUT
+
+
+
+
1N5817 0.03µF 5.5k
+
10k 5V
10µF
+ +
OSC CAP + LT1054 GND VREF CAP – VOUT 1N4001
2µF
R1, 20k 100µF 1N4001 –VOUT 100µF R2 1M 0.002µF
10µF
0.1µF
LT1054 • TA13
|VOUT| |VOUT| R2 = +1 = + 1 , REFER TO FIGURE 5 1.21V R1 VREF – 40mV 2
)
)) )
THE TYPICAL APPLICATIONS CIRCUITS WERE VERIFIED USING THE STANDARD LT1054. FOR S8 APPLICATIONS ASSISTANCE IN ANY OF THE UNUSUAL APPLICATIONS CIRCUITS PLEASE CONSULT THE FACTORY
RELATED PARTS
PART NUMBER LTC®1144 LTC1514/LTC1515 LT1611 LT1614 LTC1911 LTC3250/LTC3250-1.2/ LTC3250-1.5 LTC3251 LTC3252 DESCRIPTION Switched-Capacitor Wide Input Range Voltage Converter with Shutdown Step-Up/Step-Down Switched-Capacitor DC/DC Converters 150mA Output, 1.4mHz Micropower Inverting Switching Regulator 250mA Output, 600kHz Micropower Inverting Switching Regulator 250mA, 1.5MHz Inductorless Step-Down DC/DC Converter Inductorless Step-Down DC/DC Converter COMMENTS Wide Input Voltage Range: 2V to 18V, ISD < 8µA, SO8 VIN: 2V to 10V, VOUT: 3.3V to 5V, IQ = 60µA, SO8 VIN: 0.9V to 10V, VOUT: ±34V ThinSOT™ VIN: 0.9V to 6V, VOUT: ±30V, IQ = 1mA, MS8, SO8 VIN: 2.7V to 5.5V, VOUT: 1.5V/1.8V, IQ = 180µA, MS8 VIN: 3.1V to 5.5V, VOUT: 1.2V, 1.5V, IQ = 35µA, ThinSOT
500mA Spread Spectrum Inductorless Step-Down DC/DC Converter VIN: 2.7V to 5.5V, VOUT: 0.9V to 1.6V, 1.2V, 1.5V, IQ = 9µA, MS10E Dual 250mA, Spread Spectrum Inductorless Step-Down DC/DC Converter VIN: 2.7V to 5.5V, VOUT: 0.9V to 1.6V, IQ = 50µA, DFN12
16 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
LT 1210 REV F • PRINTED IN USA
www.linear.com
LINEAR TECHNOLOGY CORPORA TION 2010
+
+
2.5k
LT1006 VIN = 3.5V TO 15V VOUT(MAX) ≈ – 2VIN + (VL + 2VDIODE) VL = LT1054 VOLTAGE LOSS
+
–
10k
LT1054 • TA14
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