LTC1983-3/LTC1983-5 100mA Regulated Charge-Pump Inverters in ThinSOT U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO Fixed Output Voltages: –3V, –5V or Low Noise VIN to –VIN Inverted Output ±4% Output Voltage Accuracy Low Quiesient Current: 25µA 100mA Output Current Capability 3V to 5.5V Operating Voltage Range (LTC1983-3) 2.3V to 5.5V Operating Voltage Range (LTC1983-5) Internal 900kHz Oscillator “Zero Current” Shutdown Short-Circuit and Over-Temperature Protected Low Profile (1mm) ThinSOTTM Package U APPLICATIO S ■ ■ ■ –3V Generation in Single-Supply Systems Portable Equipment LCD Bias Supplies GaAs FET Bias Supplies The LTC1983-3/LTC1983-5 have many useful features for portable applications including very low quiescent current (25µA typical) and a zero current shutdown mode programmed through the SHDN pin. The LTC1983-3/LTC1983-5 are over-temperature and short-circuit protected. The parts are available in a 6-pin low profile (1mm) ThinSOT package. , LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. U ■ The LTC®1983-3 and LTC1983-5 are inverting charge pump DC/DC converters that produce negative regulated outputs. The parts require only three tiny external capacitors and can provide up to 100mA of output current. The devices can operate in open loop mode (creating a –VIN supply) or regulated output mode depending on the input supply voltage and the output current. TYPICAL APPLICATIO –3V at 100mA DC/DC Converter OFF ON –3.1 GND C– C+ –3.2 COUT 10µF LTC1983-3 SHDN –3.3 VOUT = –3V IOUT = UP TO 100mA VOUT VIN VOUT (V) VIN 3V TO 5.5V CIN 10µF VOUT vs IOUT 1983-3 TA01 VIN = 5V –3.0 –2.9 VIN = 3.3V CFLY 1µF –2.8 CFLY: TAIYO YUDEN LMK212BJ105 CIN, COUT: TAIYO YUDEN JMK316BJ106ML –2.7 0 20 40 60 IOUT (mA) 80 100 1983 TA02 sn1983 1983fs 1 LTC1983-3/LTC1983-5 U W W W ABSOLUTE AXI U RATI GS U W U PACKAGE/ORDER I FOR ATIO (Note 1) VIN to GND ................................................... –0.3V to 6V SHDN Voltage .............................................. –0.3V to 6V VOUT to GND (LTC1983-3) .................. 0.2V to VOUT Max VOUT to GND (LTC1983-5) .................. 0.2V to VOUT Max IOUT Max ............................................................. 125mA Output Short-Circuit Duration .......................... Indefinite Operating Temperature Range (Note 2) ...–40°C to 85°C Storage Temperature Range ................. – 65°C to 125°C Lead Temperature (Soldering, 10 sec).................. 300°C ORDER PART NUMBER TOP VIEW VCC 1 6 SHDN VOUT 2 5 GND C+ 3 LTC1983ES6-3 LTC1983ES6-5 4 C– S6 PART MARKING S6 PACKAGE 6-LEAD PLASTIC SOT-23 TJMAX = 125°C, θJA = 256°C/W LTPC LTYB Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 5V, CFLY = 1µF, COUT = 10µF unless otherwise noted. PARAMETER CONDITIONS MIN VIN Operating Voltage (Regulated Output Mode) (LTC1983-3) VIN Min Startup Voltage ● 3.0 2.3 TYP MAX UNITS 5.5 V V VOUT (LTC1983-3) VIN ≥ 3.3V, IOUT ≤ 25mA VIN ≥ 5V, IOUT ≤ 100mA ● ● –2.88 –2.88 –3 –3 –3.12 –3.12 V V VOUT (LTC1983-5) VIN ≥ 5V, VIN –5V ≥ IOUT • ROUT ● – 4.8 –5 – 5.2 V VIN Operating Current VIN ≤ 5.5V, IOUT = 0µA, SHDN = VIN ● 25 60 VIN Operating Current (Open-Loop Mode) (LTC1983-5) VIN = 3.3V VIN = 4.75V VIN Shutdown Current SHDN = 0V, VIN ≤ 5.5V Output Ripple 3.3 ≤ VIN ≤ 5.5 60 mVP-P Open-Loop Output Impedance (LTC1983-3): ROUT VIN = 3.3V, VOUT = –3V 11 Ω Open-Loop Output Impedance (LTC1983-5): ROUT VIN = 3.3V, IOUT ≈ 50mA VIN = 5V, IOUT ≈ 60mA 11 8.5 Ω Ω Oscillator Frequency (Non-Burst Mode® Operation) 900 kHz ● SHDN Input Low ● Burst Mode is a registered trademark of Linear Technology Corporation. Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. VSHDN = 5.5V 0.1 ● SHDN Input High SHDN Input Current µA 2.5 4 ● mA mA µA 1 1.1 V 2.2 0.3 V 4 µA Note 2: The LTC1983E-3/LTC1983E-5 are guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the – 40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. sn1983 1983fs 2 LTC1983-3/LTC1983-5 U W TYPICAL PERFOR A CE CHARACTERISTICS 90 30 12.5 80 60 40 10.5 10.0 30 9.5 20 9.0 10 0 20 VIN = 3.3V VIN = 5V 5 3.35 1983 G03 –3VOUT vs IOUT Over Temperature (VIN = 5V) –3VOUT vs IOUT Over Temperature –2.1 3.3 VIN = 5V VIN = 3.3V –2.3 3.2 120°C –2.5 VOUT (V) 50 VOUT (–V) 3.1 VIN = 5V –2.7 80°C –2.9 0.1 1 10 100 80°C –3.5 0 20 IOUT (mA) 80 60 100 40 OUTPUT CURRENT (mA) 1983 GO4 2.7 120 0 20 40 60 80 100 OUTPUT CURRENT (mA) Open-Loop Input Current vs VIN (LTC1983-5) Burst Mode Current vs Temperature (LTC1983-3) 4.5 VIN = 5V 50 TA = 25°C 4.7 120 1983 G06 1983 G05 Open-Loop Current vs Temperature (LTC1983-5) VIN = 5V 45 4.0 40 4.5 3.5 4.1 35 IIN (µA) IIN (mA) 4.3 3.0 30 25 2.5 3.9 20 2.0 3.7 3.5 –40 40°C 2.8 –3.3 0 0.01 –40°C 0°C 3.0 2.9 –40°C, 0°C, 40°C –3.1 25 IIN (mA) 100 80 60 40 IOUT (mA) 1983 TA02 75 4.9 20 VIN (V) Efficiency vs IOUT EFFICIENCY (%) 0 5.35 4.35 1983 G01 VOUT = –3V TA = 25°C 15 10 8.0 2.35 100 80 60 40 IOUT (mA) ROUT 20 8.5 TA = 25°C 0 ROUT (Ω) ROUT (Ω) 11.0 50 100 VIN = 2.3V 25 11.5 VIN = 3.3V VIN = 2.3V TA = 25°C IOUT = 25mA TA = 25°C 12.0 VIN = 5V 70 EFFICIENCY (%) Output Impedance vs IOUT (LTC1983-5) Output Impedance vs Input Voltage Efficiency vs IOUT (LTC1983-5) 60 10 TEMPERATURE (°C) 110 1983 G07 1.5 15 2.3 2.8 3.3 3.3 VIN (V) 4.3 4.8 10 –40 10 60 110 TEMPERATURE (°C) 1983 G09 1983 G08 sn1983 1983fs 3 LTC1983-3/LTC1983-5 U W TYPICAL PERFOR A CE CHARACTERISTICS Burst Mode Input Current vs VIN (LTC1983-3) SHDN Pin Threshold Voltage vs Temperature 1.0 18 30.5 16 30.0 14 29.5 IOUT = 10mA 0.8 VIN = 3V 12 29.0 28.5 0.9 VTHRESHOLD (V) TA = 25°C ROUT (Ω) INPUT CURRENT (µA) 31.0 ROUT vs Temperature (IOUT = 10mA) 10 VIN = 5V 8 0.7 0.6 0.5 0.4 28.0 6 27.5 4 0.2 27.0 2 0.1 26.5 3.1 3.6 4.6 4.1 VIN (V) 5.1 0.3 0 –50 5.5 0 50 100 TEMPERATURE (°C) 1983 G10 3.0 1200 2.5 1000 ROUT (Ω) ISHDN 1400 2.0 1.5 0.5 200 150 150 VOUT Start-Up into 100mA Resistive Load VIN = 5V TA = 25°C VOUT 1V 600 400 100 TEMPERATURE (°C) 50 100 TEMPERATURE (°C) 800 1.0 50 0 1983 G12 ROUT vs CFLY (VIN = 5V) 3.5 0 0 –50 1983 G11 SHDN Pin Input Current vs Temperature 0 –50 150 VIN 5V 50µs/DIV 0 0.01 0.1 1983 G15 1 CFLY (µF) 1983 G14 1983 G13 VOUT Load Step Reponse from IOUT = 0 to IOUT = 100mA VOUT Ripple at 30mA Load VOUT Ripple at 100mA Load VOUT 20mV VOUT 20mV VOUT 20mV IOUT 100mA 1µs/DIV 1983 G16 2.5µs/DIV 1983 G17 100µs/DIV 1983 G18 sn1983 1983fs 4 LTC1983-3/LTC1983-5 U U U PI FU CTIO S VIN (Pin 1): Charge Pump Input Voltage. May be between 2.3V and 5.5V. VIN should be bypassed with a ≥4.7µF low ESR capacitor as close as possible to the pin for best performance. VOUT (Pin 2): Regulated Output Voltage for the IC. VOUT should be bypassed with a ≥4.7µF low ESR capacitor as close as possible to the pin for best performance. C + (Pin 3): Charge Pump Flying Capacitor Positive Terminal. This node is switched between VIN and GND (It is connected to VCC during shutdown). C – (Pin 4): Charge Pump Flying Capacitor Negative Terminal. This node is switched between GND and VOUT (It is connected to GND during shutdown). GND (Pin 5): Signal and Power Ground for the 6-Pin SOT-23 package. This pin should be tied to a ground plane for best performance. SHDN (Pin 6): Shutdown. Grounding this pin shuts down the IC. Tie to VIN to enable. This pin should not be pulled above the VIN voltage or below GND. W BLOCK DIAGRA LTC1983-X VIN C+ CFLY 1µF C– CIN 10µF S1A S2A CLOCK1 SHDN CONTROL LOGIC S1B VREF + CLOCK2 S2B CHARGE PUMP COUT 10µF – VOUT COMP1 1µA 1983 BD sn1983 1983fs 5 LTC1983-3/LTC1983-5 U OPERATIO (Refer to Block Diagram) The LTC1983-3/LTC1983-5 use a switched capacitor charge pump to invert a positive input voltage to a regulated –3V ±4% (LTC1983-3) or –5 ±4% (LTC1983-5) output voltage. Regulation is achieved by sensing the output voltage through an internal resistor divider and enabling the charge pump when the output voltage droops above the upper trip point of COMP1. When the charge pump is enabled, a 2-phase, nonoverlapping clock controls the charge pump switches. Clock 1 closes the S1 switches which enables the flying capacitor to charge up to the VIN voltage. Clock 2 closes the S2 switches that invert the VIN voltage and connect the bottom plate of CFLY to the output capacitor at VOUT. This sequence of charging and discharging continues at a free-running frequency of 900kHz (typ) until the output voltage has been pumped down to the lower trip point of COMP1 and the charge pump is disabled. When the charge pump is disabled, the LTC1983 draws only 25µA (typ) from VIN which provides high efficiency at low load conditions. In shutdown mode, all circuitry is turned off and the part draws less than 1µA from the VIN supply. VOUT is also disconnected from VIN and CFLY. The SHDN pin has a threshold of approximately 0.7V. The part enters shutdown when a low is applied to the SHDN pin . The SHDN pin should not be floated; it must be driven with a logic high or low. Open-Loop Operation The LTC1983-3/LTC1983-5 inverting charge pumps regulate at –3V/–5V respectively, unless the input voltage is too low or the output current is too high. The equations for output voltage regulation are as follows: VIN –5.06V > IOUT • ROUT (LTC1983-5) VIN –3.06V > IOUT • ROUT (LTC1983-3) If this condition is not met, then the part will run in open loop mode and act as a low output impedance inverter for which the output voltage will be: VOUT = –[VIN –(IOUT • ROUT)] For all ROUT values, check the corresponding curves in the Typical Performance Characteristics section (Note: CFLY = 1µF for all ROUT curves). The ROUT value will be different for different flying caps, as shown in the following equation: 1 ROUT = ROUT (curve ) – 1.11Ω + fOSC • C FLY Short-Circuit/Thermal Protection During short-circuit conditions, the LTC1983 will draw several hundred milliamps from VIN causing a rise in the junction temperature. On-chip thermal shutdown circuitry disables the charge pump once the junction temperature exceeds ≈155°C, and reenables the charge pump once the junction temperature falls back to ≈145°C. The LTC1983 will cycle in and out of thermal shutdown indefinitely without latchup or damage until the VOUT short is removed. Capacitor Selection For best performance, it is recommended that low ESR capacitors be used for both CIN and COUT to reduce noise and ripple. The CIN and COUT capacitors should be either ceramic or tantalum and should be 4.7µF or greater. Aluminum electrolytic are not recommended because of their high equivalent series resistance (ESR). If the source impedance is very low, CIN may not be needed. Increasing the size of COUT to 10µF or greater will reduce output voltage ripple. The flying capacitor and COUT should also have low equivalent series inductance (ESL). The board layout is critical as well for inductance for the same reason (the suggested board layout should be used). A ceramic capacitor is recommended for the flying capacitor with a value in the range of 0.1µF to 4.7µF. Note that a large value flying cap (>1µF) will increase output ripple unless COUT is also increased. For very low load applications, C1 may be reduced to 0.01µF to 0.047µF. This will reduce output ripple at the expense of efficiency and maximum output current. sn1983 1983fs 6 LTC1983-3/LTC1983-5 U OPERATIO (Refer to Block Diagram) There are many aspects of the capacitors that must be taken into account. First, the temperature stability of the dielectric is a main concern. For ceramic capacitors, a three character code specifies the temperature stability (e.g. X7R, Y5V, etc.). The first two characters represent the temperature range that the capacitor is specified and the third represents the absolute tolerance that the capacitor is specified to over that temperature range. The ceramic capacitor used for the flying and output capacitors should be X5R or better. Second, the voltage coefficient of capacitance for the capacitor must be checked and the actual value usually needs to be derated for the operating voltage (the actual value has to be larger than the value needed to take into account the loss of capacitance due to voltage bias across the capacitor). Third, the frequency characteristics need to be taken into account because capacitance goes down as the frequency of oscillation goes up. Typically, the manufacturers have capacitance vs frequency curves for their products. This curve must be referenced to be sure the capacitance will not be too small for the application. Finally, the capacitor ESR and ESL must be low for reasons mentioned in the following section. Output Ripple Normal LTC1983 operation produces voltage ripple on the VOUT pin. Output voltage ripple is required for the LTC1983 to regulate. Low frequency ripple exists due to the hysteresis in the sense comparator and propagation delays in the charge pump enable/disable circuits. High frequency ripple is also present mainly due to ESR of the output capacitor. Typical output ripple under maximum load is 60mVP-P with a low ESR 10µF output capacitor. The magnitude of the ripple voltage depends on several factors. High input voltage to negative output voltage differentials [(VIN + VOUT) >1V] increase the output ripple since more charge is delivered to COUT per clock cycle. A large flying capacitor (>1µF) also increases ripple for the same reason. Large output current load and/or a small output capacitor (<10µF) results in higher ripple due to higher output voltage dV/dt. High ESR capacitors (ESR > 0.1Ω) on the output pin cause high frequency voltage spikes on VOUT with every clock cycle. There are several ways to reduce the output voltage ripple. A larger COUT capacitor (22µF or greater) will reduce both the low and high frequency ripple due to the lower COUT charging and discharging dV/dt and the lower ESR typically found with higher value (larger case size) capacitors. A low ESR ceramic output capacitor will minimize the high frequency ripple, but will not reduce the low frequency ripple unless a high capacitance value is chosen. A reasonable compromise is to use a 10µF to 22µF tantalum capacitor in parallel with a 1µF to 4.7µF ceramic capacitor on VOUT to reduce both the low and high frequency ripple. However, the best solution is to use 10µF to 22µF, X5R ceramic capacitors which are available in 1206 package sizes. An RC filter may also be used to reduce high frequency voltage spikes (see Figure 1). In low load or high VIN applications, smaller values for CFLY may be used to reduce output ripple. A smaller flying capacitor (0.01µF to 0.047µF) delivers less charge per clock cycle to the output capacitor resulting in lower output ripple. However, the smaller value flying caps also reduce the maximum IOUT capability as well as efficiency. LTC1983-X 3.9Ω VOUT 10µF TANTALUM VOUT 10µF TANTALUM 15µF TANTALUM VOUT 1µF CERAMIC LTC1983-X VOUT 1983 F01 Figure 1. Output Ripple Reduction Techniques sn1983 1983fs 7 LTC1983-3/LTC1983-5 U OPERATIO (Refer to Block Diagram) Inrush Currents During normal operation, VIN will experience current transients in the several hundred milliamp range whenever the charge pump is enabled. During start-up, these inrush currents may approach 1 to 2 amps. For this reason, it is important to minimize the source resistance between the input supply and the VIN pin. Too much source resistance may result in regulation problems or even prevent startup. One way that this can be avoided (especially when the source impedance can’t be lowered due to system constraints) is to use a large VIN capacitor with low ESR right at the VIN pin. If ceramic capacitors are used, you may need to add 1µF to 10µF tantalum capacitor in parallel to limit input voltage transients. Input voltage transients will occur if VIN is applied via a switch or a plug. One example of this situation is in USB applications. Ultralow Quiescent Current Regulated Supply The LTC1983 contains an internal resistor divider (refer to the Block Diagram) that draws only 1µA (typ for the 3V version) from VOUT during normal operation. During shutdown, the resistor divider is disconnected from the output and the part draws only leakage current from the output. During no-load conditions, applying a 1Hz to 100Hz, 2% to 5% duty cycle signal to the SHDN pin ensures that the circuit of Figure 2 comes out of shutdown frequently enough to maintain regulation even under low-load conditions. Since the part spends nearly all of its time in shutdown, the no-load quiescent current is essentially zero. However, the part will still be in operation during the time the SHDN pin is high, so the current will not be zero and can be calculated using the following equations to determine the approximate maximum current: IIN(MAX) = [(Time out of shutdown) • (Burst Mode operation quiescent current) + (Normal operating IIN) • (Time output is being charged before the LTC1983 enters Burst Mode operation)]/(Period of SHDN signal). This number will be highly dependent on the amount of board leakage current and how many devices are connected to VOUT (each will draw some leakage current) and must be calculated and verified for each different board design. VIN 3.3V TO 5.5V CIN 10µF TANTALUM LTC1983-3 VIN SHDN GND C+ VOUT FROM MPU SHDN –3V ± 4% C– COUT 10µF CERAMIC CFLY 1µF CERAMIC SHDN PIN WAVEFORMS: LOW IQ MODE (IOUT ≤ 100µA) VOUT LOAD ENABLE MODE (IOUT = 100µA TO 100mA) (1Hz TO 100Hz, 2% TO 5% DUTY CYCLE) 1983 F02 Figure 2. Ultralow Quiescent Current Regulated Supply The LTC1983 must be out of shutdown for a minimum duration of 200µs to allow enough time to sense the output and keep it in regulation. A 1Hz, 2% duty cycle signal will keep VOUT in regulation under no-load conditions. Even though the term no-load is used, there will always be board leakage current and leakage current drawn by anything connected to VOUT. This is why it is necessary to wake the part up every once in a while to verify regulation. As the VOUT load current increases, the frequency with which the part is taken out of shutdown must also be increased to prevent VOUT from drooping below the – 2.88V (for the 3V version) during the OFF phase (see Figure 3). A 100Hz, 2% duty cycle signal on the SHDN pin ensures proper regulation with load currents as high as 100µA. When load current greater than 100µA is needed, the SHDN pin must be forced high as in normal operation. Each time the LTC1983 comes out of shutdown, the part delivers a minimum of one clock cycle worth of charge to the output. Under high VIN (>4V) and/or low IOUT (<10µA) conditions, this behavior may cause a net excess of charge to be delivered to the output capacitor if a high frequency signal is used on the SHDN pin (e.g., 50Hz to 100Hz). Under such conditions, VOUT will slowly drift positive and may even go out of regulation. To avoid this potential sn1983 1983fs 8 LTC1983-3/LTC1983-5 U OPERATIO (Refer to Block Diagram) 1000 MAXIMUM SHDN OFF TIME (ms) problem in the low IQ mode, it is necessary to switch the part in and out of shutdown at the minimum allowable frequency (refer to Figure 3) for a given output load. General Layout Considerations Due to the high switching frequency and high transient currents produced by the LTC1983, careful board layout is a must. A clean board layout using a ground plane and short connections to all capacitors will improve performance and ensure proper regulation under all conditions (refer to Figures 4a and 4b). You will not get advertised performance with careless layout. SHDN ON PULSE WIDTH = 200µs COUT = 10µF 100 10 1 1 10 100 OUTPUT CURRENT (µA) 1000 1983 F03b Figure 3 VIN: 2.3V TO 5.5V VOUT 1 VIN 2 VOUT 3 C+ SHDN 6 GND 5 C– 4 CIN CFLY COUT 1983 F04a Figure 4a. Recommended Component Placement for a Single Layer Board TOP LAYER 1 VIN VOUT 2 VOUT 3 C+ BOTTOM LAYER SHDN 6 CIN GND 5 C– 4 COUT CFLY 1983 F04b Figure 4b. Recommended Component Placement for a Double Layer Board sn1983 1983fs 9 LTC1983-3/LTC1983-5 U TYPICAL APPLICATIO S 2.5V to –2.5V DC/DC Converter VIN 2.5V VIN 4.7µF CERAMIC LTC1983-5 SHDN OFF ON VOUT –2.5V VOUT 1µF CERAMIC GND C– C+ 1983 TA03 0.47µF CERAMIC 100mA Inverting DC/DC Converter VIN 2.5V TO 5.5V OFF ON VIN 10µF CERAMIC LTC1983-5 SHDN C+ VOUT –VIN VOUT 10µF GND C– 1983 TA04 1µF CERAMIC sn1983 1983fs 10 LTC1983-3/LTC1983-5 U PACKAGE DESCRIPTIO S6 Package 6-Lead Plastic SOT-23 (Reference LTC DWG # 05-08-1636) 2.90 BSC (NOTE 4) 0.754 0.854 ± 0.127 2.80 BSC 3.254 1.50 – 1.75 (NOTE 4) PIN ONE ID 0.95 BSC 1.9 BSC RECOMMENDED SOLDER PAD LAYOUT 0.30 – 0.45 TYP 6 PLCS (NOTE 3) 0.95 BSC 0.80 – 0.90 0.20 BSC 0.01 – 0.10 1.00 MAX DATUM ‘A’ 0.30 – 0.50 REF 0.09 – 0.20 (NOTE 3) 1.90 BSC S6 TSOT-23 0801 NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. JEDEC PACKAGE REFERENCE IS MO-193 sn1983 1983fs 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. 11 LTC1983-3/LTC1983-5 U TYPICAL APPLICATIO Combined Unregulated Doubler and Regulated Inverter VIN CIN 10µF CERAMIC OFF ON VIN VOUT VOUT COUT1 10µF CERAMIC LTC1983-3/ LTC1983-5 SHDN GND C+ C– CFLY 1µF CERAMIC D1 CBOOST 1µF D2 VBOOST = 2VIN –2(VD) COUT2 10µF CERAMIC VBOOST 1983 TA05 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC1261 Switched-Capacitor Regulated Voltage Inverter Selectable Fixed Output Voltages LTC1261L Switched-Capacitor Regulated Voltage Inverter Adjustable and Fixed Output Voltages, Up to 20mA IOUT, MSOP LTC1429 Clock-Synchronized Switched-Capacitor Voltage Inverter Synchronizable Up to 2MHz System Clock LTC1514/LTC1515 Step-Up/Step-Down Switched-Capacitor DC/DC Converters VIN 2V to 10V, Adjustable or Fixed VOUT, IOUT to 50mA LTC1516 Micropower Regulated 5V Charge Pump DC/DC Converter IOUT = 20mA (VIN ≥ 2V), IOUT = 50mA (VIN ≥ 3V) LTC1522 Micropower Regulated 5V Charge Pump DC/DC Converter IOUT = 10mA (VIN ≥ 2.7V), IOUT = 20mA (VIN ≥ 3V) LTC1550L/LTC1551L Low Noise, Switched-Capacitor Regulated Voltage Inverters 900kHz Charge Pump, 1mVP-P Ripple LT1611 1.4MHz Inverting Mode Switching Regulator –5V at 150mA from a 5V Input, 5-Lead ThinSOT LT1617/LT1617-1 Micropower, Switched-Capacitor Voltage Inverter VIN 1.2V/1V to 15V; 350mA/100mA Current Limit LTC1682/-3.3/-5 Doubler Charge Pumps with Low Noise LDO MS8 and SO-8 Packages, IOUT = 80mA, Output Noise = 60µVRMS LTC1751/-3.3/-5 Doubler Charge Pumps VOUT =5V at 100mA; VOUT =3.3V at 80mA; ADJ; MSOP Packages LTC1754/-3.3/-5 Doubler Charge Pumps with Shutdown ThinSOT Package; IQ = 13µA; IOUT = 50mA LTC1928-5 Doubler Charge Pump with Low Noise LDO ThinSOT Output Noise = 60µVRMS; VOUT = 5V; VIN = 2.7V to 4V LTC3200 Constant Frequency Doubler Charge Pump Low Noise, 5V Output or Adjustable sn1983 1983fs 12 Linear Technology Corporation LT/TP 0302 2K • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2002