1
2
3
6
5
4
LM2766
www.ti.com
SNVS071B –MARCH 2000–REVISED MAY 2013
LM2766 Switched Capacitor Voltage Converter
Check for Samples: LM2766
1FEATURES DESCRIPTION
The LM2766 CMOS charge-pump voltage converter
2• Doubles Input Supply Voltage operates as a voltage doubler for an input voltage in
• SOT-23 6-Pin Package the range of +1.8V to +5.5V. Two low cost capacitors
• 20ΩTypical Output Impedance and a diode are used in this circuit to provide up to 20
mA of output current.
• 90% Typical Conversion Efficiency at 20 mA
• 0.1µA Typical Shutdown Current The LM2766 operates at 200 kHz switching
frequency to reduce output resistance and voltage
ripple. With an operating current of only 350 µA
APPLICATIONS (operating efficiency greater than 90% with most
• Cellular Phones loads) and 0.1µA typical shutdown current, the
• Pagers LM2766 provides ideal performance for battery
powered systems. The device is manufactured in a
• PDAs SOT-23 6-pin package.
• Operational Amplifier Power Supplies
• Interface Power Supplies
• Handheld Instruments
Basic Application Circuits
Figure 1. Voltage Doubler
Connection Diagram
Figure 2. DBV Package Top View
Figure 3. Actual Size
1Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
2All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date. Copyright © 2000–2013, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
LM2766
SNVS071B –MARCH 2000–REVISED MAY 2013
www.ti.com
Pin Description
Pin Name Function
1 V+ Power supply positive voltage input.
2 GND Power supply ground input.
3 CAP−Connect this pin to the negative terminal of the charge-pump capacitor.
4 SD Shutdown control pin, tie this pin to V+ in normal operation.
5 VOUT Positive voltage output.
6 CAP+ Connect this pin to the positive terminal of the charge-pump capacitor.
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
Absolute Maximum Ratings(1)(2)
Supply Voltage (V+ to GND, or V+ to VOUT) 5.8V
SD (GND −0.3V) to (V+ + 0.3V)
VOUT Continuous Output Current 40 mA
Output Short-Circuit Duration to GND(3) 1 sec.
Continuous Power Dissipation (TA= 25°C)(4) 600 mW
TJMax(4) 150°C
(1) Absolute maximum ratings indicate limits beyond which damage to the device may occur. Electrical specifications do not apply when
operating the device beyond its rated operating conditions.
(2) If Military/Aerospace specified devices are required, please contact the TI Sales Office/ Distributors for availability and specifications.
(3) VOUT may be shorted to GND for one second without damage. However, shorting VOUT to V+ may damage the device and should be
avoided. Also, for temperatures above 85°C, VOUT must not be shorted to GND or V+, or device may be damaged.
(4) The maximum allowable power dissipation is calculated by using PDMax = (TJMax −TA)/θJA, where TJMax is the maximum junction
temperature, TAis the ambient temperature, and θJA is the junction-to-ambient thermal resistance of the specified package.
Operating Ratings
θJA(1) 210°C/W
Junction Temperature Range −40° to 100°C
Ambient Temperature Range −40° to 85°C
Storage Temperature Range −65°C to 150°C
Lead Temp. (Soldering, 10 seconds) 240°C
Human body model 2kV
ESD Rating(2) Machine model 200V
(1) The maximum allowable power dissipation is calculated by using PDMax = (TJMax −TA)/θJA, where TJMax is the maximum junction
temperature, TAis the ambient temperature, and θJA is the junction-to-ambient thermal resistance of the specified package.
(2) The human body model is a 100pF capacitor discharged through a 1.5kΩresistor into each pin. The machine model is a 200pF
capacitor discharged directly into each pin.
2Submit Documentation Feedback Copyright © 2000–2013, Texas Instruments Incorporated
Product Folder Links: LM2766
LM2766
www.ti.com
SNVS071B –MARCH 2000–REVISED MAY 2013
Electrical Characteristics
Limits in standard typeface are for TJ= 25°C, and limits in boldface type apply over the full operating temperature range.
Unless otherwise specified: V+ = 5V, C1= C2= 1.0 μF.(1)
Symbol Parameter Condition Min Typ Max Units
V+ Supply Voltage 1.8 5.5 V
IQSupply Current No Load 350 950 µA
ISD Shutdown Supply Current 0.1 0.5 µA
TA= 85°C 0.2
VSD Shutdown Pin Input Voltage Shutdown Mode 0.6 V
Normal Operation 2.0
ILOutput Current 2.5V ≤VIN ≤5.5V 20 mA
1.8V ≤VIN < 2.5V 10
ROUT Output Resistance(2) IL= 20 mA 20 55 Ω
fOSC Oscillator Frequency See(3) 220 400 700 kHz
fSW Switching Frequency See(3) 110 200 350 kHz
PEFF Power Efficiency IL= 20 mA to GND 94 %
VOEFF Voltage Conversion Efficiency No Load 99.96 %
(1) In the test circuit, capacitors C1and C2are 1.0 µF, 0.3Ωmaximum ESR capacitors. Capacitors with higher ESR will increase output
resistance, reduce output voltage and efficiency.
(2) Specified output resistance includes internal switch resistance and capacitor ESR. See the details in the application information for
positive voltage doubler.
(3) The output switches operate at one half of the oscillator frequency, fOSC = 2fSW.
Test Circuit
Figure 4. LM2766 Test Circuit
Copyright © 2000–2013, Texas Instruments Incorporated Submit Documentation Feedback 3
Product Folder Links: LM2766
LM2766
SNVS071B –MARCH 2000–REVISED MAY 2013
www.ti.com
Typical Performance Characteristics
(Circuit of Figure 4, VIN = 5V, TA= 25°C unless otherwise specified)
Supply Current vs Output Resistance vs
Supply Voltage Capacitance
Figure 5. Figure 6.
Output Resistance vs Output Resistance vs
Supply Voltage Temperature
Figure 7. Figure 8.
Efficiency
Output Voltage vs vs
Load Current Load Current
Figure 9. Figure 10.
4Submit Documentation Feedback Copyright © 2000–2013, Texas Instruments Incorporated
Product Folder Links: LM2766
LM2766
www.ti.com
SNVS071B –MARCH 2000–REVISED MAY 2013
Typical Performance Characteristics (continued)
(Circuit of Figure 4, VIN = 5V, TA= 25°C unless otherwise specified)
Switching Frequency vs Switching Frequency vs
Supply Voltage Temperature
Figure 11. Figure 12.
Output Ripple vs
Load Current
Figure 13.
Copyright © 2000–2013, Texas Instruments Incorporated Submit Documentation Feedback 5
Product Folder Links: LM2766
LM2766
SNVS071B –MARCH 2000–REVISED MAY 2013
www.ti.com
CIRCUIT DESCRIPTION
The LM2766 contains four large CMOS switches which are switched in a sequence to double the input supply
voltage. Energy transfer and storage are provided by external capacitors. Figure 14 illustrates the voltage
conversion scheme. When S2and S4are closed, C1charges to the supply voltage V+. During this time interval,
switches S1and S3are open. In the next time interval, S2and S4are open; at the same time, S1and S3are
closed, the sum of the input voltage V+ and the voltage across C1gives the 2V+ output voltage when there is no
load. The output voltage drop when a load is added is determined by the parasitic resistance (Rds(on) of the
MOSFET switches and the ESR of the capacitors) and the charge transfer loss between capacitors. Details will
be discussed in the following application information section.
Figure 14. Voltage Doubling Principle
POSITIVE VOLTAGE DOUBLER
The main application of the LM2766 is to double the input voltage. The range of the input supply voltage is 1.8V
to 5.5V.
The output characteristics of this circuit can be approximated by an ideal voltage source in series with a
resistance. The voltage source equals 2V+. The output resistance Rout is a function of the ON resistance of the
internal MOSFET switches, the oscillator frequency, and the capacitance and ESR of C1and C2. Since the
switching current charging and discharging C1is approximately twice as the output current, the effect of the ESR
of the pumping capacitor C1will be multiplied by four in the output resistance. The output capacitor C2is
charging and discharging at a current approximately equal to the output current, therefore, its ESR only counts
once in the output resistance. A good approximation of Rout is:
(1)
where RSW is the sum of the ON resistance of the internal MOSFET switches shown in Figure 14. RSW is typically
8Ωfor the LM2766.
The peak-to-peak output voltage ripple is determined by the oscillator frequency as well as the capacitance and
ESR of the output capacitor C2:
(2)
High capacitance, low ESR capacitors can reduce both the output resistance and the voltage ripple.
The Schottky diode D1is only needed to protect the device from turning-on its own parasitic diode and potentially
latching-up. During start-up, D1will also quickly charge up the output capacitor to VIN minus the diode drop
thereby decreasing the start-up time. Therefore, the Schottky diode D1should have enough current carrying
capability to charge the output capacitor at start-up, as well as a low forward voltage to prevent the internal
parasitic diode from turning-on. A Schottky diode like 1N5817 can be used for most applications. If the input
voltage ramp is less than 10V/ms, a smaller Schottky diode like MBR0520LT1 can be used to reduce the circuit
size.
SHUTDOWN MODE
A shutdown (SD) pin is available to disable the device and reduce the quiescent current to 0.1 µA. In normal
operating mode, the SD pin is connected to V+. The device can be brought into the shutdown mode by applying
to the SD pin a voltage less than 20% of the V+ pin voltage.
6Submit Documentation Feedback Copyright © 2000–2013, Texas Instruments Incorporated
Product Folder Links: LM2766
LM2766
www.ti.com
SNVS071B –MARCH 2000–REVISED MAY 2013
CAPACITOR SELECTION
As discussed in the Positive Voltage Doubler section, the output resistance and ripple voltage are dependent on
the capacitance and ESR values of the external capacitors. The output voltage drop is the load current times the
output resistance, and the power efficiency is
(3)
Where IQ(V+) is the quiescent power loss of the IC device, and IL2Rout is the conversion loss associated with the
switch on-resistance, the two external capacitors and their ESRs.
The selection of capacitors is based on the specifications of the dropout voltage (which equals Iout Rout), the
output voltage ripple, and the converter efficiency. Low ESR capacitors (Table 1) are recommended to maximize
efficiency, reduce the output voltage drop and voltage ripple.
Table 1. Low ESR Capacitor Manufacturers
Manufacturer Phone Website Capacitor Type
Nichicon Corp. (847)-843-7500 www.nichicon.com PL & PF series, through-hole aluminum electrolytic
AVX Corp. (843)-448-9411 www.avxcorp.com TPS series, surface-mount tantalum
Sprague (207)-324-4140 www.vishay.com 593D, 594D, 595D series, surface-mount tantalum
Sanyo (619)-661-6835 www.sanyovideo.com OS-CON series, through-hole aluminum electrolytic
Murata (800)-831-9172 www.murata.com Ceramic chip capacitors
Taiyo Yuden (800)-348-2496 www.t-yuden.com Ceramic chip capacitors
Tokin (408)-432-8020 www.tokin.com Ceramic chip capacitors
Other Applications
PARALLELING DEVICES
Any number of LM2766s can be paralleled to reduce the output resistance. Each device must have its own
pumping capacitor C1, while only one output capacitor Cout is needed as shown in Figure 15. The composite
output resistance is:
(4)
Figure 15. Lowering Output Resistance by Paralleling Devices
Copyright © 2000–2013, Texas Instruments Incorporated Submit Documentation Feedback 7
Product Folder Links: LM2766
LM2766
SNVS071B –MARCH 2000–REVISED MAY 2013
www.ti.com
CASCADING DEVICES
Cascading the LM2766s is an easy way to produce a greater voltage (A two-stage cascade circuit is shown in
Figure 16).
The effective output resistance is equal to the weighted sum of each individual device:
Rout = 1.5Rout_1 + Rout_2 (5)
Note that increasing the number of cascading stages is pracitically limited since it significantly reduces the
efficiency, increases the output resistance and output voltage ripple.
Figure 16. Increasing Output Voltage by Cascading Devices
REGULATING VOUT
It is possible to regulate the output of the LM2766 by use of a low dropout regulator (such as LP2980-5.0). The
whole converter is depicted in Figure 17
A different output voltage is possible by use of LP2980-3.3, LP2980-3.0, or LP2980-adj.
Note that the following conditions must be satisfied simultaneously for worst case design:
2Vin_min >Vout_min +Vdrop_max (LP2980) + Iout_max × Rout_max (LM2766) (6)
2Vin_max < Vout_max +Vdrop_min (LP2980) + Iout_min × Rout_min (LM2766) (7)
Figure 17. Generate a Regulated +5V from +3V Input Voltage
8Submit Documentation Feedback Copyright © 2000–2013, Texas Instruments Incorporated
Product Folder Links: LM2766
LM2766
www.ti.com
SNVS071B –MARCH 2000–REVISED MAY 2013
REVISION HISTORY
Changes from Revision A (May 2013) to Revision B Page
• Changed layout of National Data Sheet to TI format ............................................................................................................ 8
Copyright © 2000–2013, Texas Instruments Incorporated Submit Documentation Feedback 9
Product Folder Links: LM2766
PACKAGE OPTION ADDENDUM
www.ti.com 1-Nov-2013
Addendum-Page 1
PACKAGING INFORMATION
Orderable Device Status
(1)
Package Type Package
Drawing Pins Package
Qty Eco Plan
(2)
Lead/Ball Finish
(6)
MSL Peak Temp
(3)
Op Temp (°C) Device Marking
(4/5)
Samples
LM2766M6 NRND SOT-23 DBV 6 1000 TBD Call TI Call TI -40 to 85 S16B
LM2766M6/NOPB ACTIVE SOT-23 DBV 6 1000 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 S16B
LM2766M6X/NOPB ACTIVE SOT-23 DBV 6 3000 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 S16B
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
(6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish
value exceeds the maximum column width.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
PACKAGE OPTION ADDENDUM
www.ti.com 1-Nov-2013
Addendum-Page 2
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0
(mm) B0
(mm) K0
(mm) P1
(mm) W
(mm) Pin1
Quadrant
LM2766M6 SOT-23 DBV 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3
LM2766M6/NOPB SOT-23 DBV 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3
LM2766M6X/NOPB SOT-23 DBV 6 3000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3
PACKAGE MATERIALS INFORMATION
www.ti.com 23-Sep-2013
Pack Materials-Page 1
*All dimensions are nominal
Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
LM2766M6 SOT-23 DBV 6 1000 210.0 185.0 35.0
LM2766M6/NOPB SOT-23 DBV 6 1000 210.0 185.0 35.0
LM2766M6X/NOPB SOT-23 DBV 6 3000 210.0 185.0 35.0
PACKAGE MATERIALS INFORMATION
www.ti.com 23-Sep-2013
Pack Materials-Page 2
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other
changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest
issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and
complete. All semiconductor products (also referred to herein as “components”) are sold subject to TI’s terms and conditions of sale
supplied at the time of order acknowledgment.
TI warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in TI’s terms
and conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessary
to support this warranty. Except where mandated by applicable law, testing of all parameters of each component is not necessarily
performed.
TI assumes no liability for applications assistance or the design of Buyers’ products. Buyers are responsible for their products and
applications using TI components. To minimize the risks associated with Buyers’ products and applications, Buyers should provide
adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or
other intellectual property right relating to any combination, machine, or process in which TI components or services are used. Information
published by TI regarding third-party products or services does not constitute a license to use such products or services or a warranty or
endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the
third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of significant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alteration
and is accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such altered
documentation. Information of third parties may be subject to additional restrictions.
Resale of TI components or services with statements different from or beyond the parameters stated by TI for that component or service
voids all express and any implied warranties for the associated TI component or service and is an unfair and deceptive business practice.
TI is not responsible or liable for any such statements.
Buyer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory and safety-related requirements
concerning its products, and any use of TI components in its applications, notwithstanding any applications-related information or support
that may be provided by TI. Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which
anticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might cause
harm and take appropriate remedial actions. Buyer will fully indemnify TI and its representatives against any damages arising out of the use
of any TI components in safety-critical applications.
In some cases, TI components may be promoted specifically to facilitate safety-related applications. With such components, TI’s goal is to
help enable customers to design and create their own end-product solutions that meet applicable functional safety standards and
requirements. Nonetheless, such components are subject to these terms.
No TI components are authorized for use in FDA Class III (or similar life-critical medical equipment) unless authorized officers of the parties
have executed a special agreement specifically governing such use.
Only those TI components which TI has specifically designated as military grade or “enhanced plastic” are designed and intended for use in
military/aerospace applications or environments. Buyer acknowledges and agrees that any military or aerospace use of TI components
which have not been so designated is solely at the Buyer's risk, and that Buyer is solely responsible for compliance with all legal and
regulatory requirements in connection with such use.
TI has specifically designated certain components as meeting ISO/TS16949 requirements, mainly for automotive use. In any case of use of
non-designated products, TI will not be responsible for any failure to meet ISO/TS16949.
Products Applications
Audio www.ti.com/audio Automotive and Transportation www.ti.com/automotive
Amplifiers amplifier.ti.com Communications and Telecom www.ti.com/communications
Data Converters dataconverter.ti.com Computers and Peripherals www.ti.com/computers
DLP® Products www.dlp.com Consumer Electronics www.ti.com/consumer-apps
DSP dsp.ti.com Energy and Lighting www.ti.com/energy
Clocks and Timers www.ti.com/clocks Industrial www.ti.com/industrial
Interface interface.ti.com Medical www.ti.com/medical
Logic logic.ti.com Security www.ti.com/security
Power Mgmt power.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense
Microcontrollers microcontroller.ti.com Video and Imaging www.ti.com/video
RFID www.ti-rfid.com
OMAP Applications Processors www.ti.com/omap TI E2E Community e2e.ti.com
Wireless Connectivity www.ti.com/wirelessconnectivity
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2013, Texas Instruments Incorporated
