LTC3261 High Voltage, Low Quiescent Current Inverting Charge Pump Description Features n n n n n n n 4.5V to 32V VIN Range Inverting Charge Pump Generates –VIN 60µA Quiescent Current in Burst Mode® Operation Charge Pump Output Current Up to 100mA 50kHz to 500kHz Programmable Oscillator Frequency Short-Circuit/Thermal Protection Low Profile Thermally Enhanced 12-Pin MSOP Package Applications n n n n Bipolar/Inverting Supplies Industrial/Instrumentation Bias Generators Portable Medical Equipment Portable Instruments The LTC®3261 is a high voltage inverting charge pump that operates over a wide 4.5V to 32V input range and is capable of delivering up to 100mA of output current. The charge pump employs either low quiescent current Burst Mode operation or low noise constant frequency mode. In Burst Mode operation the charge pump VOUT regulates to –0.94 • VIN and the LTC3261 draws only 60µA of quiescent current. In constant frequency mode the charge pump produces an output equal to –VIN and operates at a fixed 500kHz or to a programmed frequency between 50kHz to 500kHz using an external resistor. The LTC3261 is available in a thermally enhanced 12-pin MSOP package. 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. Typical Application 15V to –15V Inverter 1µF VOUT Ripple C+ 15V C– –15V VOUT VIN 10µF 10µF VOUT 10mV/DIV AC-COUPLED MODE = L VOUT 200mV/DIV AC-COUPLED MODE = H VOUT = –14.8V LTC3261 EN MODE RT VOUT = –14.1V GND 100µs/DIV 3261 TA01a VIN = 15V fOSC = 500kHz IOUT = 5mA 3261 TA01 3261fb For more information www.linear.com/3261 1 LTC3261 Absolute Maximum Ratings Pin Configuration (Notes 1, 3) VIN, EN, MODE............................................ –0.3V to 36V VOUT............................................................ –36V to 0.3V RT................................................................. –0.3V to 6V VOUT Short-Circuit Duration.............................. Indefinite Operating Junction Temperature Range (Note 2)................................................... –55°C to 150°C Storage Temperature Range.................. –65°C to 150°C Lead Temperature (Soldering, 10 sec).................... 300°C TOP VIEW NC 1 RT 2 NC 3 VOUT 4 C– 5 NC 6 13 GND 12 11 10 9 8 7 NC MODE EN VIN C+ NC MSE PACKAGE 12-LEAD PLASTIC MSOP TJMAX = 150°C, θJA = 40°C/W EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB Order Information LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3261EMSE#PBF LTC3261EMSE#TRPBF 3261 12-Lead Plastic MSOP –40°C to 125°C LTC3261IMSE#PBF LTC3261IMSE#TRPBF 3261 12-Lead Plastic MSOP –40°C to 125°C LTC3261HMSE#PBF LTC3261HMSE#TRPBF 3261 12-Lead Plastic MSOP –40°C to 150°C LTC3261MPMSE#PBF LTC3261MPMSE#TRPBF 3261 12-Lead Plastic MSOP –55°C to 150°C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. 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/ 3261fb 2 For more information www.linear.com/3261 LTC3261 Electrical Characteristics The l denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = EN = 12V, MODE = 0V, RT = 200kΩ. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Charge Pump VIN Input Voltage Range VUVLO VIN Undervoltage Lockout Threshold VIN Rising VIN Falling IVIN VIN Quiescent Current Shutdown, = EN = 0V MODE = VIN, IVOUT = 0mA MODE = 0V, IVOUT = 0mA VRT RT Regulation Voltage VOUT VOUT Regulation Voltage MODE = 12V MODE = 0V fOSC Oscillator Frequency RT = GND ROUT Charge Pump Output Impedance MODE = 0V, RT = GND ISHORT_CKT Max IVOUT Short-Circuit Current VOUT = GND, RT = GND l l l 4.5 3.4 450 V 4 V V 2 60 3.5 5 120 5.5 l VMODE(H) MODE Threshold Rising VMODE(L) MODE Threshold Falling l IMODE MODE Pin Internal Pull-Down Current VEN(H) EN Threshold Rising l VEN(L) EN Threshold Falling l IEN EN Pin Internal Pull-Down Current 100 0.4 VIN = MODE = 32V V –0.94 • VIN –VIN V V 500 550 VIN = EN = 32V KHz Ω 160 250 1.1 2 mA V 1.0 V 0.7 1.1 0.4 µA µA mA 1.200 32 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 LTC3261 is tested under pulsed load conditions such that TJ ≈ TA. The LTC3261E is guaranteed to meet specifications from 0°C to 85°C junction temperature. Specifications over the –40°C to 125°C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. The LTC3261I is guaranteed over the –40°C to 125°C operating junction temperature range, the LTC3261H is guaranteed over the –40°C to 150°C operating junction temperature range and the LTC3261MP is tested and guaranteed over the full –55°C to 150°C operating junction temperature range. High junction temperatures degrade operating lifetimes; operating lifetime is derated for junction temperatures greater than 125°C. Note that 32 3.8 3.6 µA 2 V 1.0 V 0.7 µA the maximum ambient temperature consistent with these specifications is determined by specific operating conditions in conjunction with board layout, the rated package thermal impedance and other environmental factors. The junction temperature (TJ, in °C) is calculated from the ambient temperature (TA, in °C) and power dissipation (PD, in Watts) according to the formula: TJ = TA + (PD • θJA), where θJA = 40°C/W is the package thermal impedance. Note 3: This IC includes overtemperature protection that is intended to protect the device during momentary overload conditions. Junction temperatures will exceed 150°C when overtemperature protection is active. Continuous operation above the specified maximum operating junction temperature may result in device degradation or failure. 3261fb For more information www.linear.com/3261 3 LTC3261 Typical Performance Characteristics (TA = 25°C, CFLY = 1µF, CIN = COUT = 10µF unless otherwise noted) 600 400 300 RT = 200kΩ 200 100 0 5 10 15 20 25 SUPPLY VOLTAGE (V) 30 500 400 300 200 100 0 35 1 10 100 RT (kΩ) 1000 3261 G01 14 80 VIN = 12V 60 VIN = 5V 40 20 0 6 4 40 35 30 25 20 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 3261 G07 fOSC = 500kHz fOSC = 200kHz fOSC = 50kHz 6 5 4 3 2 1 0 5 10 15 20 25 SUPPLY VOLTAGE (V) 30 0 –50 –25 35 0 25 50 75 100 125 150 TEMPERATURE (°C) 3261 G06 VOUT Short Circuit Current vs Temperature 250 VOUT SHORT CIRCUIT CURRENT (mA) EFFECTIVE OPEN LOOP RESISTANCE (Ω) 45 7 VOUT Short-Circuit Current vs Supply Voltage fOSC = 500kHz 50 VIN = 12V 3261 G05 Effective Open-Loop Resistance vs Temperature 55 25 50 75 100 125 150 TEMPERATURE (°C) 8 8 0 25 50 75 100 125 150 TEMPERATURE (°C) VIN = 32V VIN = 25V VIN = 12V 0 9 10 3261 G04 60 5 3261 G03 2 0 –50 –25 10 Quiescent Current vs Temperature (Constant Frequency Mode) fOSC = 500kHz fOSC = 200kHz fOSC = 50kHz 12 QUIESCENT CURRENT (mA) QUIESCENT CURRENT (µA) 120 VIN = 32V 15 3261 G02 RT = GND 100 VIN = 32V VIN = 12V VIN = 5V 20 Quiescent Current vs Supply Voltage (Constant Frequency Mode) Quiescent Current vs Temperature (Burst Mode Operation) 140 Shutdown Current vs Temperature 0 –50 –25 10000 200 200 VOUT SHORT CIRCUIT CURRENT (mA) 0 25 QUIESCENT CURRENT (mA) 500 Oscillator Frequency vs RT SHUTDOWN CURRENT (µA) RT = GND OSCILLATOR FREQUENCY (kHz) OSCILLATOR FREQUENCY (kHz) 600 Oscillator Frequency vs Supply Voltage fOSC = 500kHz 150 100 fOSC = 200kHz 50 0 0 5 10 15 20 25 SUPPLY VOLTAGE (V) 30 35 3261 G08 VIN = 12V RT = GND 180 160 140 120 100 –50 –25 0 25 50 75 TEMPERATURE (°C) 100 125 3261 G8b 3261fb 4 For more information www.linear.com/3261 LTC3261 Typical Performance Characteristics (TA = 25°C, CFLY = 1µF, CIN = COUT = 10µF unless otherwise noted) Voltage Loss (VIN – |VOUT|) vs Output Current (Constant Frequency Mode) fOSC = 50kHz fOSC = 200kHz fOSC = 500kHz VOLTAGE LOSS (V) 2.5 VIN = 12V 2.0 1.5 1.0 0.5 0.0 0.1 1 10 OUTPUT CURRENT (mA) 80 VOUT 500mV/DIV AC-COUPLED fOSC = 200kHz 70 60 50 –5mA IOUT –50mA fOSC = 500kHz 40 30 20 VIN = 12V fOSC = 500kHz 10 0 100 0 5 10 15 20 25 SUPPLY VOLTAGE (V) VOUT Transient (MODE = Low to High) VIN = 12V fOSC = 500kHz IOUT = –5mA 2ms/DIV 3261 G12 AVERAGE INPUT CURRENT (mA) 100 MODE 30 2ms/DIV 3261 G11 35 3261 G10 3261 G09 VOUT 500mV/DIV AC-COUPLED VOUT Load Transient Burst Mode Operation (MODE = H) 90 EFFECTIVE OPEN LOOP RESISTANCE (Ω) 3.0 Effective Open-Loop Resistance vs Supply Voltage Average Input Current vs Output Current 10 VOUT Ripple MODE = L MODE = H 1 0.1 0.1 VIN = 12V fOSC = 500kHz 1 10 OUTPUT CURRENT (mA) 100 VOUT 10mV/DIV AC-COUPLED MODE = L VOUT 200mV/DIV AC-COUPLED MODE = H 100µs/DIV 3261 G14 VIN = 15V fOSC = 500kHz IOUT = 5mA 3261 G13 3261fb For more information www.linear.com/3261 5 LTC3261 Pin Functions NC (Pins 1, 3, 6, 7,12): No Connect Pins. These pins are not connected to the LTC3261 die. These pins should be left floating or connected to ground. Pins 6 and 7 can also be shorted to adjacent pins. VIN (Pin 9): Input Voltage for the Charge Pump. VIN should be bypassed with a low impedance ceramic capacitor. RT (Pin 2): Input Connection for Programming the Switching Frequency. The RT pin servos to a fixed 1.2V when the EN pin is driven to a logic “high”. A resistor from RT to GND sets the charge pump switching frequency. If the RT pin is tied to GND, the switching frequency defaults to a fixed 500kHz. MODE (Pin 11): Logic Input. The MODE pin determines the charge pump operating mode. A logic “high” on the MODE pin forces the charge pump into Burst Mode operation regulating V OUT to approximately –0.94 • VIN with hysteretic control. A logic “low” on the MODE pin forces the charge pump to operate as an openloop inverter with a constant switching frequency. The switching frequency in both modes is determined by an external resistor from the RT pin to GND. In Burst Mode, this represents the frequency of the burst cycles before the part enters the low quiescent current sleep state. EN (Pin 10): Logic Input. A logic “high” on the EN pin enables the inverting charge pump. VOUT (Pin 4): Charge Pump Output Voltage. In constant frequency mode (MODE = low) this pin is driven to –VIN. In Burst Mode operation, (MODE = high) this pin voltage is regulated to –0.94 • VIN using an internal burst comparator with hysteretic control. C– (Pin 5): Flying Capacitor Negative Connection. GND (Exposed Pad Pin 13): Ground. The exposed package pad is ground and must be soldered to the PC board ground plane for proper functionality and for rated thermal performance. C+ (Pin 8): Flying Capacitor Positive Connection. Block Diagram 8 5 C+ 9 VIN C– S1 S4 11 EN MODE 4 S2 S3 10 VOUT CHARGE PUMP AND INPUT LOGIC 50kHz TO 500kHz OSC 13 RT 2 GND 3261 BD 3261fb 6 For more information www.linear.com/3261 LTC3261 Operation (Refer to the Block Diagram) Shutdown Mode In shutdown mode, all circuitry except the internal bias is turned off. The LTC3261 is in shutdown when a logic low is applied to the enable input (EN). The LTC3261 only draws 2µA (typical) from the VIN supply in shutdown. Constant Frequency Operation The LTC3261 provides low noise constant frequency operation when a logic low is applied to the MODE pin. The charge pump and oscillator circuit are enabled using the EN pin. At the beginning of a clock cycle, switches S1 and S2 are closed. The external flying capacitor across the C+ and C– pins is charged to the VIN supply. In the second phase of the clock cycle, switches S1 and S2 are opened, while switches S3 and S4 are closed. In this configuration the C+ side of the flying capacitor is grounded and charge is delivered through the C– pin to VOUT. In steady state the VOUT pin regulates at –VIN less any voltage drop due to the load current on VOUT. The charge transfer frequency can be adjusted between 50kHz and 500kHz using an external resistor on the RT pin. At slower frequencies the effective open-loop output resistance (ROL) of the charge pump is larger and it is able to provide smaller average output current. Figure 1 can be used to determine a suitable value of RT to achieve a required oscillator frequency. If the RT pin is grounded, the part operates at a constant frequency of 500kHz. Burst Mode Operation The LTC3261 provides low power Burst Mode operation when a logic high is applied to the MODE pin. In Burst Mode operation, the charge pump charges the VOUT pin to –0.94 • VIN (typical). The part then shuts down the internal oscillator to reduce switching losses and goes into a low current state. This state is referred to as the sleep state in which the IC consumes only about 60µA. When the output voltage droops enough to overcome the burst comparator hysteresis, the part wakes up and commences charge pump cycles until output voltage exceeds –0.94 • VIN (typical). This mode provides lower operating current at the cost of higher output ripple and is ideal for light load operation. The frequency of charging cycles is set by the external resistor on the RT pin. The charge pump has a lower ROL at higher frequencies. For Burst Mode operation it is recommended that the RT pin be tied to GND. This minimizes the charge pump ROL, quickly charges the output up to the burst threshold and optimizes the duration of the low current sleep state. 600 OSCILLATOR FREQUENCY (kHz) The LTC3261 is a high voltage inverting charge pump. It supports a wide input power supply range from 4.5V to 32V. 500 400 300 200 100 0 1 10 100 RT (kΩ) 1000 10000 3261 F01 Figure 1. Oscillator Frequency vs RT Soft-Start The LTC3261 has built in soft-start circuitry to prevent excessive current flow during start-up. The soft-start is achieved by internal circuitry that slowly ramps the amount of current available at the output storage capacitor. The soft-start circuitry is reset in the event of a commanded shutdown or thermal shutdown. Short-Circuit/Thermal Protection The LTC3261 has built-in short-circuit current limit as well as overtemperature protection. During a short-circuit condition, the part automatically limits its output current to approximately 160mA. If the junction temperature exceeds approximately 175°C the thermal shutdown circuitry disables current delivery to the output. Once the junction temperature drops back to approximately 165°C current delivery to the output is resumed. When thermal protection is active the junction temperature is beyond the specified operating range. Thermal protection is intended for momentary overload conditions outside normal operation. Continuous operation above the specified maximum operating junction temperature may impair device reliability. 3261fb For more information www.linear.com/3261 7 LTC3261 Applications Information Effective Open-Loop Output Resistance The effective open-loop output resistance (ROL) of a charge pump is a very important parameter which determines the strength of the charge pump. The value of this parameter depends on many factors such as the oscillator frequency (fOSC), value of the flying capacitor (CFLY), the nonoverlap time, the internal switch resistances (RS) and the ESR of the external capacitors. Typical ROL values as a function of temperature are shown in Figure 2 EFFECTIVE OPEN LOOP RESISTANCE (Ω) 60 55 VIN = 32V VIN = 25V VIN = 12V fOSC = 500kHz 50 45 40 35 30 IOUT 1 • – tON COUT fOSC where fOSC is the oscillator frequency tON is the on-time of the oscillator (1µs) typical and COUT is the value of the output capacitor. Just as the value of COUT controls the amount of output ripple, the value of CIN controls the amount of ripple present at the input (VIN) pin. The amount of bypass capacitance required at the input depends on the source impedance driving VIN. For best results it is recommended that VIN be bypassed with at least 2µF of low ESR capacitance. A high ESR capacitor such as tantalum or aluminum will have higher input noise than a low ESR ceramic capacitor. Therefore, a ceramic capacitor is recommended as the main bypass capacitance with a tantalum or aluminum capacitor used in parallel if desired. Flying Capacitor Selection 25 20 –50 –25 VRIPPLE(P-P) ≈ 0 25 50 75 100 125 150 TEMPERATURE (°C) 3261 F02 Figure 2. Typical ROL vs Temperature Input/Output Capacitor Selection The style and value of capacitors used with the LTC3261 determine several important parameters such as regulator control loop stability, output ripple, charge pump strength and minimum turn-on time. To reduce noise and ripple, it is recommended that low ESR ceramic capacitors be used for the charge pump output. The charge pump output capacitor should retain at least 2µF of capacitance over operating temperature and bias voltage. Tantalum and aluminum capacitors can be used in parallel with a ceramic capacitor to increase the total capacitance but should not be used alone because of their high ESR. In constant frequency mode, the value of COUT directly controls the amount of output ripple for a given load current. Increasing the size of COUT will reduce the output ripple at the expense of higher minimum turn-on time. The peak-to-peak output ripple at the VOUT pin is approximately given by the expression: The flying capacitor controls the strength of the charge pump. A 1µF or greater ceramic capacitor is suggested for the flying capacitor for applications requiring the full rated output current of the charge pump. For very light load applications, the flying capacitor may be reduced to save space or cost. For example, a 0.2µF capacitor might be sufficient for load currents up to 20mA. A smaller flying capacitor leads to a larger effective openloop resistance (ROL) and thus limits the maximum load current that can be delivered by the charge pump. Ceramic Capacitors Ceramic capacitors of different materials lose their capacitance with higher temperature and voltage at different rates. For example, a capacitor made of X5R or 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 range. Z5U and Y5V capacitors may also have a poor voltage coefficient causing them to lose 60% or more of their capacitance when the rated voltage is applied. Therefore when comparing different capacitors, it is often more appropriate to compare the amount of achievable capacitance for a given case size rather than discussing the specified capacitance value. The capacitor manufacture’s data sheet 3261fb 8 For more information www.linear.com/3261 LTC3261 Applications Information should be consulted to ensure the desired capacitance at all temperatures and voltages. Table 1 is a list of ceramic capacitor manufacturers and their websites. Table 1 AVX www.avxcorp.com Kemet www.kemet.com Murata www.murata.com Taiyo Yuden www.t-yuden.com Vishay www.vishay.com TDK www.component.tdk.com Layout Considerations Due to high switching frequency and high transient currents produced by LTC3261, careful board layout is necessary for optimum performance. A true ground plane and short connections to all the external capacitors will improve performance and ensure proper regulation under all conditions. Figure 3 shows an example layout for the LTC3261. The power dissipated in the LTC3261 is: PD = (VIN – |VOUT|) • (IOUT) where IOUT denotes output current at the VOUT pin. The derating curve in Figure 4 assumes a maximum thermal resistance, θJA, of 40°C/W for the package. This can be achieved with a four layer PCB that includes 2oz Cu traces and six vias from the exposed pad of the LTC3261 to the ground plane. It is recommended that the LTC3261 be operated in the region corresponding to TJ ≤ 150°C for continuous operation as shown in Figure 4. Operation beyond 150°C should be avoided as it may degrade part performance and liftetime. At high temperatures, typically around 175°C, the part is placed in thermal shutdown and the output is disabled. When the part cools back down to a low enough temperature, typically around 165°C, the output is re-enabled and the part resumes normal operation. The flying capacitor nodes C+ and C– switch large currents at a high frequency. These nodes should not be routed close to sensitive pins such as the RT pin . GND CFLY Thermal Management Derating Power at High Temperatures To prevent an overtemperature condition in high power applications, Figure 4 should be used to determine the maximum combination of ambient temperature and power dissipation. The power dissipated in the LTC3261 should always fall under the line shown for a given ambient temperature. VIN VOUT EN MODE RT GND 3261 F03 Figure 3. Recommended Layout 6 MAXIMUM POWER DISSIPATION (W) At high input voltages and maximum output current, there can be substantial power dissipation in the LTC3261. If the junction temperature increases above approximately 175°C, the thermal shutdown circuitry will automatically deactivate the output. To reduce the maximum junction temperature, a good thermal connection to the PC board ground plane is recommended. Connecting the exposed pad of the package to a ground plane under the device on two layers of the PC board can reduce the thermal resistance of the package and PC board considerably. θJA = 40°C/W 5 4 3 2 RECOMMENDED OPERATION 1 0 –50 –25 TJ = 150°C 0 25 50 75 100 125 150 175 AMBIENT TEMPERATURE (°C) 3261 F04 Figure 4. Maximum Power Dissipation vs Ambient Temperature 3261fb For more information www.linear.com/3261 9 LTC3261 Typical Applications High Input Divide by 2 Voltage Divider C2 1µF 50V 9V TO 32V C1 4.7µF 50V VIN C+ EN C– VOUT LTC3261 MODE RT GND 3261 TA04 VIN/2 C3 4.7µF 25V NOTE: MINIMUM LOAD OF 120µA IS REQUIRED TO ASSURE START-UP Inverting Charge Pump with Bipolar Doubler D1 1N4148 4.5V TO 32V C1 4.7µF 50V C+ VIN EN LTC3261 C– D4 1N4148 D3 1N4148 GND VOUT 3261 TA06 ~ 2VIN C5 4.7µF 100V C2 1µF 50V C3 1µF 50V C4 1µF 50V MODE RT D2 1N4148 ~ –2VIN C6 4.7µF 100V –VIN C7 4.7µF 50V NOTE: I2VIN • 2 + I–2VIN • 2 + IOUT < = 100mA 3261fb 10 For more information www.linear.com/3261 LTC3261 Typical Applications High Voltage to Inverted Low Voltage Charge Pump 4.5V TO 32V C1 4.7µF 50V D1 MBR0540 VIN VOUT VOUT C4 4.7µF 50V EN C+ C2 1µF 50V V –V – |I | •R VOUT – IN f OUT OL –Vf 2 LTC3261 D2 MBR0540 C3 1µF 50V D3 MBR0540 C– MODE GND RT 3261 TA07 3261fb For more information www.linear.com/3261 11 LTC3261 Package Description Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. MSE Package 12-Lead Plastic MSOP, Exposed Die Pad (Reference LTC DWG # 05-08-1666 Rev F) BOTTOM VIEW OF EXPOSED PAD OPTION 2.845 ± 0.102 (.112 ± .004) 5.23 (.206) MIN 2.845 ± 0.102 (.112 ± .004) 0.889 ± 0.127 (.035 ± .005) 6 1 1.651 ± 0.102 (.065 ± .004) 1.651 ± 0.102 3.20 – 3.45 (.065 ± .004) (.126 – .136) 12 0.65 0.42 ± 0.038 (.0256) (.0165 ± .0015) BSC TYP RECOMMENDED SOLDER PAD LAYOUT 0.254 (.010) 0.35 REF 4.039 ± 0.102 (.159 ± .004) (NOTE 3) 0.12 REF DETAIL “B” CORNER TAIL IS PART OF DETAIL “B” THE LEADFRAME FEATURE. FOR REFERENCE ONLY 7 NO MEASUREMENT PURPOSE 0.406 ± 0.076 (.016 ± .003) REF 12 11 10 9 8 7 DETAIL “A” 0° – 6° TYP 3.00 ± 0.102 (.118 ± .004) (NOTE 4) 4.90 ± 0.152 (.193 ± .006) GAUGE PLANE 0.53 ± 0.152 (.021 ± .006) DETAIL “A” 1.10 (.043) MAX 0.18 (.007) SEATING PLANE 0.22 – 0.38 (.009 – .015) TYP 1 2 3 4 5 6 0.650 (.0256) BSC NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX 6. EXPOSED PAD DIMENSION DOES INCLUDE MOLD FLASH. MOLD FLASH ON E-PAD SHALL NOT EXCEED 0.254mm (.010") PER SIDE. 0.86 (.034) REF 0.1016 ± 0.0508 (.004 ± .002) MSOP (MSE12) 0911 REV F 3261fb 12 For more information www.linear.com/3261 LTC3261 Revision History REV DATE DESCRIPTION A 9/12 Changed the Operating Junction Temperature to –55°C to 150°C in the Absolute Maximum section 2 Added LTC3261HMSE and LTC3261MPMSE to Order Information table 2 Added the word junction to the heading for Electric Characteristics 3 Added LTC3261H and LTC3261MP guarantees into Note 2 following LTC3261I sentence 3 Deleted Thermal Shutdown curve from Figure 4 9 Changed two paragraphs with respect to operation at 150°C and thermal shutdown 9 Updated Related Parts list 14 Corrected pin number on MODE pin in Pin Functions page 6 B 1/13 PAGE NUMBER 3261fb 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 its circuits as described herein will not infringe on existing patent rights. Forofmore information www.linear.com/3261 13 LTC3261 Typical Application 24V to –24V Inverter C2 1µF 8 5 + C– C 9 24V VOUT VIN C1 10µF 4 LTC3261 10 11 –24V C3 10µF EN MODE RT 2 GND 13 3261 TA03 Related Parts PART NUMBER DESCRIPTION COMMENTS LT1054/LT1054L Switched-Capacitor Voltage Converters with Regulator VIN: 3.5V to 15V/7V, IOUT = 100mA/125mA, N8, S08, SO16 Packages LTC1144 Switched-Capacitor Wide Input Range Voltage Converter with Shutdown Wide Input Voltage Range: 2V to 18V, ISD < 8µA, SO8 Package LTC1514/LTC1515 Step-Up/Step-Down Switched-Capacitor DC/DC Converters VIN: 2V to 10V, VOUT: 3.3V to 5V, IQ = 60µA, SO8 Package LT®1611 150mA Output, 1.4MHz Micropower Inverting Switching Regulator VIN: 0.9V to 10V, VOUT = ±34V, ThinSOT™ Package LT1614 250mA Output, 600kHz Micropower Inverting Switching Regulator VIN: 0.9V to 6V, VOUT = ±30V, IQ = 1mA, MS8, SO8 Packages LTC1911 250mA, 1.5MHz Inductorless Step-Down DC/DC Converter VIN: 2.7V to 5.5V, VOUT = 1.5V/1.8V, IQ = 180µA, MS8 Package LTC3250/LTC3250-1.2/ Inductorless Step-Down DC/DC Converters LTC3250-1.5 VIN: 3.1V to 5.5V, VOUT = 1.2V, 1.5V, IQ = 35µA, ThinSOT Package LTC3251 500mA Spread Spectrum Inductorless Step-Down DC/DC VIN: 2.7V to 5.5V, VOUT: 0.9V to 1.6V, 1.2V, 1.5V, IQ = 9µA, MS10E Package Converter LTC3252 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 Package LTC3260 Low Noise Dual Supply Inverting Charge Pump VIN: 4.5V to 32V, VOUT = –VIN, IOUT = 100mA, FOSC = 50kHz to 500kHz, VLDO+ = 1.2V to 32V, ILDO+ = 50mA, VLDO– = –1.2V to –32V, ILDO– = 50mA, DE14 and MSE16 Packages 3261fb 14 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 For more information www.linear.com/3261 ● ● (408) 432-1900 FAX: (408) 434-0507 www.linear.com/3261 LT 0113 REV B • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 2012