CAT660

CAT660 100 mA CMOS Charge Pump Inverter/Doubler Description The CAT660 is a charge−pump voltage converter. It will invert a 1.5 V to 5.5 V input to a −1.5 V to −5.5 V output. Only two external capacitors are needed. With a guaranteed 100 mA output current capability, the CAT660 can replace a switching regulator and its inductor. Lower EMI is achieved due to the absence of an inductor. In addition, the CAT660 can double a voltage supplied from a battery or power supply. Inputs from 2.5 V to 5.5 V will yield a doubled, 5 V to 11 V output voltage. A Frequency Control pin (BOOST/FC) is provided to select either a high (80 kHz) or low (10 kHz) internal oscillator frequency, thus allowing quiescent current vs. capacitor size trade−offs to be made. The 80 kHz frequency is selected when the FC pin is connected to V+. The operating frequency can also be adjusted with an external capacitor at the OSC pin or by driving OSC with an external clock. Both 8−pin DIP and SOIC packages are available in the industrial temperature range. The CAT660 replaces the MAX660 and the LTC®660. In addition, the CAT660 is pin compatible with the 7660/1044, offering an easy upgrade for applications with 100 mA loads. Features http://onsemi.com SOIC−8 V SUFFIX CASE 751BD PDIP−8 L SUFFIX CASE 646AA PIN CONFIGURATION BOOST/FC CAP+ GND CAP− (Top View) 1 V+ OSC LV OUT • • • • • • • • • • Replaces MAX660 and LTC®660 Converts V+ to V− or V+ to 2V+ Low Output Resistance, 4 W Typical High Power Efficiency Selectable Charge Pump Frequency − 10 kHz or 80 kHz − Optimize Capacitor Size Low Quiescent Current Pin−compatible, High−current Alternative to 7660/1044 Industrial Temperature Range Available in 8−pin SOIC and DIP Packages These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS Compliant Negative Voltage Generator Voltage Doubler Voltage Splitter Low EMI Power Source GaAs FET Biasing Lithium Battery Power Supply Instrumentation LCD Contrast Bias Cellular Phones, Pagers 1 MARKING DIAGRAMS 660ELA 660EVA 660ELA = CAT660ELA 660EVA = CAT660EVA or 660EVA = CAT660EVA−T3 ORDERING INFORMATION Device CAT660ELA CAT660EVA CAT660EVA−T3 Package PDIP−8 (Pb−Free) SOIC−8 (Pb−Free) SOIC−8 (Pb−Free) Shipping 50 / Tube 100 / Tube 3,000 / Tape & Reel Applications • • • • • • • • • © Semiconductor Components Industries, LLC, 2010 May, 2010 − Rev. 24 Publication Order Number: CAT660/D CAT660 Typical Application +VIN 1.5 V to 5.5 V 1 2 C1 + 1 mF to 150 mF 3 4 BOOST/FC CAP+ GND CAP− CAT660 V+ OSC LV OUT 8 7 6 5 C2 Inverted Negative Voltage Output 1 mF to 150 mF 1 mF to 150 mF C1 1 + 2 3 4 BOOST/FC CAP+ GND CAP− CAT660 V+ OSC LV OUT 8 7 6 5 Doubled Positive Voltage C2 Output 1 mF to 150 mF VIN = 2.5 V to 5.5 V Figure 1. Voltage Inverter Table 1. PIN DESCRIPTIONS Figure 2. Positive Voltage Doubler Circuit Configuration Pin Number 1 Name Boost/FC Inverter Mode Frequency Control for the internal oscillator. With an external oscillator BOOST/FC has no effect. Boost/FC Open V+ 2 3 4 5 6 CAP+ GND CAP− OUT LV Oscillator Frequency 10 kHz typical, 5 kHz minimum 80 kHz typical, 40 kHz minimum Same as inverter. Power supply. Positive voltage input. Same as inverter. Power supply ground. LV must be tied to OUT for all input voltages. Doubler Mode Same as inverter. Charge pump capacitor. Positive terminal. Power supply ground. Charge pump capacitor. Negative terminal. Output for negative voltage. Low−Voltage selection pin. When the input voltage is less than 3 V, connect LV to GND. For input voltages above 3 V, LV may be connected to GND or left open. If OSC is driven externally, connect LV to GND. Oscillator control input. An external capacitor can be connected to lower the oscillator frequency. An external oscillator can drive OSC and set the chip operating frequency. The charge−pump frequency is one−half the frequency at OSC. Power supply. Positive voltage input. 7 OSC Same as inverter. Do not overdrive OSC in doubling mode. Standard logic levels will not be suitable. See the applications section for additional information. Positive voltage output. 8 V+ http://onsemi.com 2 CAT660 Table 2. ABSOLUTE MAXIMUM RATINGS Parameters V+ to GND Input Voltage (Pins 1, 6 and 7) BOOST/FC and OSC Input Voltage Output Short−circuit Duration to GND (OUT may be shorted to GND for 1 sec without damage but shorting OUT to V+ should be avoided.) Continuous Power Dissipation (TA = 70°C) Plastic DIP SOIC TDFN Storage Temperature Lead Soldering Temperature (10 sec) Operating Ambient Temperature Range Ratings 6 −0.3 to (V+ + 0.3) The least negative of (Out − 0.3 V) or (V+ − 6 V) to (V+ + 0.3 V) 1 Units V V V sec. 730 500 1 −65 to +160 300 −40 to +85 mW mW W °C °C °C Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. NOTE: TA = Ambient Temperature Table 3. ELECTRICAL CHARACTERISTICS (V+ = 5 V, C1 = C2 = 150 mF, Boost/FC = Open, COSC = 0 pF, inverter mode with test circuit as shown in Figure 3 unless otherwise noted. Temperature is over operating ambient temperature range unless otherwise noted.) Parameter Supply Voltage Symbol VS Conditions Inverter: LV = Open, RL = 1 kW Inverter: LV = GND, RL = 1 kW Doubler: LV = OUT, RL = 1 kW Supply Current IS BOOST/FC = open, LV = Open BOOST/FC = V+, LV = Open Output Current Output Resistance IOUT RO OUT is more negative than −4 V IL = 100 mA, C1 = C2 = 150 mF (Note 2) BOOST/FC = V+ (C1, C2 ESR ≤ 0.5 W) IL = 100 mA, C1 = C2 = 10 mF Oscillator Frequency (Note 3) OSC Input Current Power Efficiency FOSC BOOST/FC = Open BOOST/FC = V+ IOSC PE BOOST/FC = Open BOOST/FC = V+ RL = 1 kW connected between V+ and OUT, TA = 25°C (Doubler) RL = 500 W connected between GND and OUT, TA = 25°C (Inverter) IL = 100 mA to GND, TA = 25°C (Inverter) Voltage Conversion Efficiency VEFF No load, TA = 25°C 99 96 92 5 40 10 80 ±1 ±5 98 96 88 99.9 % mA % 100 4 7 12 kHz Min 3.0 1.5 2.5 0.09 0.3 Typ Max 5.5 5.5 5.5 0.5 3 mA W mA Units V 1. In Figure 3, test circuit capacitors C1 and C2 are 150 mF and have 0.2 W maximum ESR. Higher ESR levels may reduce efficiency and output voltage. 2. The output resistance is a combination of the internal switch resistance and the external capacitor ESR. For maximum voltage and efficiency keep external capacitor ESR under 0.2 W. 3. FOSC is tested with COSC = 100 pF to minimize test fixture loading. The test is correlated back to COSC = 0 pF to simulate the capacitance at OSC when the device is inserted into a test socket without an external COSC. http://onsemi.com 3 CAT660 Voltage Inverter CAT660 V+ 1 2 + C1 150 mF 3 4 BOOST/FC CAP+ GND CAP− V+ OSC LV OUT 8 7 6 5 C2 150 mF IS V+ 5V External Oscillator COSC RL IL VOUT + Figure 3. Test Circuit (Typical characteristic curves are generated using the test circuit in Figure 3. Inverter test conditions are: V+ = 5 V, LV = GND, BOOST/FC = Open and TA = 25°C unless otherwise indicated. Note that the charge−pump frequency is one−half the oscillator frequency.) 150 120 90 No Load 60 30 0 120 100 INPUT CURRENT (mA) 80 60 40 20 0 −50 VIN = 5 V TYPICAL OPERATING CHARACTERISTICS INPUT CURRENT (A) VIN = 3 V VIN = 2 V 1 2 3 4 5 6 −25 0 25 50 75 100 125 INPUT VOLTAGE (V) TEMPERATURE (°C) Figure 4. Supply Current vs. Input Voltage 10 OUTPUT RESISTANCE (W) 8 6 100 W Load 4 2 0 OUTPUT RESISTANCE (W) 8 7 6 5 4 3 2 −50 Figure 5. Supply Current vs. Temperature (No Load) VIN = 2 V VIN = 3 V VIN = 5 V 1 2 3 4 5 6 −25 0 25 50 75 100 125 INPUT VOLTAGE (V) TEMPERATURE (°C) Figure 6. Output Resistance vs. Input Voltage Figure 7. Output Resistance vs. Temperature (50 W Load) http://onsemi.com 4 CAT660 TYPICAL OPERATING CHARACTERISTICS 5.0 INV. OUTPUT VOLTAGE (V) 4.8 4.6 4.4 4.2 4.0 1.0 0.8 0.6 0.4 0.2 0 OUTPUT VOLTAGE (V) V+ = 3 V V+ = 5 V 0 20 40 60 80 100 0 20 40 60 80 100 LOAD CURRENT (mA) LOAD CURRENT (mA) Figure 8. Inverted Output Voltage vs. Load, V+ = 5 V 20 18 16 FREQUENCY (kHz) 14 12 10 8 6 4 2 0 BOOST = OPEN 2 3 4 SUPPLY VOLTAGE (V) 5 6 0 2 LV = OPEN LV = GND FREQUENCY (kHz) 150 200 Figure 9. Output Voltage Drop vs. Load Current 100 LV = GND LV = OPEN 50 BOOST = +V 3 4 SUPPLY VOLTAGE (V) 5 6 Figure 10. Oscillator Frequency vs. Supply Voltage 10,000 No Load INPUT CURRENT (mA) 1,000 V+ = 5 V Figure 11. Oscillator Frequency vs. Supply Voltage 100 10 1 10 100 1,000 OSCILLATOR FREQUENCY (kHz) Figure 12. Supply Current vs. Oscillator Frequency http://onsemi.com 5 CAT660 Application Information Circuit Description and Operating Theory The CAT660 switches capacitors to invert or double an input voltage. Figure 13 shows a simple switch capacitor circuit. In position 1 capacitor C1 is charged to voltage V1. The total charge on C1 is Q1 = C1V1. When the switch moves to position 2, the input capacitor C1 is discharged to voltage V2. After discharge, the charge on C1 is Q2 = C1V2. The charge transferred is: DQ + Q1 * Q2 + C1 (V1 * V2) If the switch is cycled “F” times per second, the current (charge transfer per unit time) is: I+F DQ + F C1 (V1 * V2) Rearranging in terms of impedance: I+ (V1 * V2) + V1 * V2 REQ (1 FC1) The 1/FC1 term can be modeled as an equivalent impedance REQ. A simple equivalent circuit is shown in Figure 14. This circuit does not include the switch resistance V1 C2 V2 nor does it include output voltage ripple. It does allow one to understand the switch−capacitor topology and make prudent engineering tradeoffs. For example, power conversion efficiency is set by the output impedance, which consists of REQ and switch resistance. As switching frequency is decreased, REQ, the 1/FC1 term, will dominate the output impedance, causing higher voltage losses and decreased efficiency. As the frequency is increased quiescent current increases. At high frequency this current becomes significant and the power efficiency degrades. The oscillator is designed to operate where voltage losses are a minimum. With external 150 mF capacitors, the internal switch resistances and the Equivalent Series Resistance (ESR) of the external capacitors determine the effective output impedance. A block diagram of the CAT660 is shown in Figure 15. The CAT660 is a replacement for the MAX660 and the LTC660. REQ V1 V2 C1 RL REQ + 1 FC1 C2 RL Figure 13. Switched−Capacitor Building Block Figure 14. Switched−Capacitor Equivalent Circuit http://onsemi.com 6 CAT660 Oscillator Frequency Control The switching frequency can be raised, lowered or driven from an external source. Figure 16 shows a functional diagram of the oscillator circuit. The CAT660 oscillator has four control modes: Table 4. BOOST/FC Pin Connection Open BOOST/FC = V+ Open or BOOST/FC = V+ Open OSC Pin Connection Open Open External Capacitor External Clock Nominal Oscillator Frequency 10 kHz 80 kHz − Frequency of external clock If BOOST/FC and OSC are left floating (Open), the nominal oscillator frequency is 10 kHz. The pump frequency is one−half the oscillator frequency. V+ (8) By connecting the BOOST/FC pin to V+, the charge and discharge currents are increased, and the frequency is increased by approximately 8 times. Increasing the frequency will decrease the output impedance and ripple currents. This can be an advantage at high load currents. Increasing the frequency raises quiescent current but allows smaller capacitance values for C1 and C2. If pin 7, OSC, is loaded with an external capacitor the frequency is lowered. By using the BOOST/FC pin and an external capacitor at OSC, the operating frequency can be set. Note that the frequency appearing at CAP+ or CAP− is one−half that of the oscillator. Driving the CAT660 from an external frequency source can be easily achieved by driving Pin 7 and leaving the BOOST pin open, as shown in Figure 16. The output current from Pin 7 is small, typically 1 mA to 8 mA, so a CMOS can drive the OSC pin. For 5 V applications, a TTL logic gate can be used if an external 100 kΩ pull−up resistor is used as shown in Figure 17. SW1 BOOST/FC 8x (1) OSC OSC (7) f B2 f CAP+ (2) + C1 SW2 CAP− (4) VOUT (5) C2 + LV (6) CLOSED WHEN V+ > 3.0 V GND (3) (N) = Pin Number Figure 15. CAT660 Block Diagram http://onsemi.com 7 CAT660 Capacitor Selection Low ESR capacitors are necessary to minimize voltage losses, especially at high load currents. The exact values of C1 and C2 are not critical but low ESR capacitors are necessary. The ESR of capacitor C1, the pump capacitor, can have a pronounced effect on the output. C1 currents are approximately twice the output current and losses occur on both the charge and discharge cycle. The ESR effects are thus multiplied by four. A 0.5 Ω ESR for C1 will have the same effect as a 2 Ω increase in CAT660 output impedance. Table 5. VRIPPLE vs. FOSC VRIPPLE (mV) 87 28 V+ I IOUT (mA) 100 100 Output voltage ripple is determined by the value of C2 and the load current. C2 is charged and discharged at a current roughly equal to the load current. The internal switching frequency is one−half the oscillator frequency. VRIPPLE + IOUT (FOSC C2) ) IOUT ESRC2 For example, with a 10 kHz oscillator frequency (5 kHz switching frequency), a 150 mF C2 capacitor with an ESR of 0.2 Ω and a 100 mA load peak−to−peak ripple voltage is 87 mV. FOSC (kHz) 10 80 C2 (mF) 150 150 C2 ESR (W) 0.2 0.2 7.0 I BOOST/FC (1) REQUIRED FOR TTL LOGIC CAT660 NC OSC (7) ~18 pF + C1 1 8 V+ BOOST/FC 2 7 CAP+ OSC 3 6 GND LV 4 5 CAP− OUT + 100 k V+ OSC INPUT −V+ C2 LV (6) 7.0 I I Figure 16. Oscillator Figure 17. External Clocking http://onsemi.com 8 CAT660 Capacitor Suppliers The following manufacturers supply low−ESR capacitors: Table 6. CAPACITOR SUPPLIERS Manufacturer AVX/Kyocera Vishay/Sprague Sanyo Nichicon Capacitor Type TPS/TPS3 595 MV−AX, UGX F55 HC/HD Phone 843−448−9411 402−563−6866 619−661−6835 847−843−7500 WEB www.avxcorp.com www.vishay.com www.sanyo.com www.nichicon−us.com Email avx@avxcorp.com − Svcsales@sanyo.com − Comments Tantalum Aluminum Aluminum Tantalum Aluminum Capacitor manufacturers continually introduce new series and offer different package styles. It is recommended that before a design is finalized capacitor manufacturers should be surveyed for their latest product offerings. Controlling Loss in CAT660 Applications There are three primary sources of voltage loss: 1. Output resistance: VLOSSW = ILOAD x ROUT, where ROUT is the CAT660 output resistance and ILOAD is the load current. 2. Charge pump (C1) capacitor ESR: VLOSSC1 ≈ 4 x ESRC1 x ILOAD, where ESRC1 is the ESR of capacitor C1. 3. Output or reservoir (C2) capacitor ESR: VLOSSC2 = ESRC2 x ILOAD, where ESRC2 is the ESR of capacitor C2. Increasing the value of C2 and/or decreasing its ESR will reduce noise and ripple. The effective output impedance of a CAT660 circuit is approximately: Rcircuit [ Rout 660 ) (4 ESRC1) ) ESRC2 http://onsemi.com 9 CAT660 Typical Applications Voltage Inversion Positive−to−Negative The CAT660 easily provides a negative supply voltage from a positive supply in the system. Figure 18 shows a typical circuit. The LV pin may be left floating for positive input voltages at or above 3.3 V. CAT660 NC + C1 1 2 3 4 BOOST/FC CAP+ GND CAP− V+ OSC LV OUT 8 7 6 5 C2 VOUT = −VIN VIN 1.5 V to 5.5 V + Figure 18. Voltage Inverter Positive Voltage Doubler The voltage doubler circuit shown in Figure 19 gives VOUT = 2 x VIN for input voltages from 2.5 V to 5.5 V. 1N5817* CAT660 1 2 C1 150 mF + 3 4 BOOST/FC CAP+ GND CAP− V+ OSC LV OUT 8 7 6 5 + VOUT = 2VIN C2 150 mF VIN 2.5 V to 5.5 V *SCHOTTKY DIODE IS FOR START−UP ONLY Figure 19. Voltage Doubler http://onsemi.com 10 CAT660 Precision Voltage Divider A precision voltage divider is shown in Figure 20. With very light load currents under 100 nA, the voltage at pin 2 will be within 0.002% of V+/2. Output voltage accuracy decreases with increasing load. CAT660 1 2 + C1 150 mF 3 4 BOOST/FC CAP+ GND CAP− V+ OSC LV OUT 8 7 6 5 V+ 3 V to 11 V V ) ± 0.002% 2 IL ≤ 100 nA + C2 150 mF Figure 20. Precision Voltage Divider (Load 3 100 nA) Battery Voltage Splitter Positive and negative voltages that track each other can be obtained from a battery. Figure 21 shows how a 9 V battery can provide symmetrical positive and negative voltages equal to one−half the battery voltage. CAT660 BATTERY 9V 3 V ≤ VBAT ≤ 11 V VBAT + 1 2 3 4 BOOST/FC CAP+ GND CAP− V+ OSC LV OUT 8 7 6 5 V * BAT (−4.5 V) 2 C2 150 mF V ) BAT (4.5 V) 2 C1 150 mF + Figure 21. Battery Splitter http://onsemi.com 11 CAT660 Cascade Operation for Higher Negative Voltages The CAT660 can be cascaded as shown in Figure 22 to generate more negative voltage levels. The output resistance is approximately the sum of the individual CAT660 output resistance. VOUT = −N x VIN, where N represents the number of cascaded devices. +VIN 8 2 + C1 3 4 CAT660 “1” 5 + C1 2 3 4 CAT660 “N” 5 + C2 VOUT = −NVIN 8 + C2 Figure 22. Cascading to Increase Output Voltage Parallel Operation Paralleling CAT660 devices will lower output resistance. As shown in Figure 23, each device requires its own pump capacitor, C2, but the output reservoir capacitor is shared with all devices. The value of C2 should be increased by a factor of N, where N is the number of devices. The output impedance of the combined CAT660’s is: R OUT (Of “N” CAT660 s) + R OUT (Of the CAT660) N (Number of devices) +VIN 8 2 + C1 3 4 CAT660 “1” 5 + C1 2 3 4 CAT660 “N” 5 8 + C2 Figure 23. Paralleling Devices Reduce Output Resistance http://onsemi.com 12 CAT660 PACKAGE DIMENSIONS SOIC 8, 150 mils CASE 751BD−01 ISSUE O SYMBOL A A1 b c E1 E D E E1 e h L PIN # 1 IDENTIFICATION TOP VIEW 0.25 0.40 MIN 1.35 0.10 0.33 0.19 4.80 5.80 3.80 1.27 BSC 0.50 1.27 NOM MAX 1.75 0.25 0.51 0.25 5.00 6.20 4.00 θ 0º 8º D h A1 A θ c e SIDE VIEW b L END VIEW Notes: (1) All dimensions are in millimeters. Angles in degrees. (2) Complies with JEDEC MS-012. http://onsemi.com 13 CAT660 PACKAGE DIMENSIONS PDIP−8, 300 mils CASE 646AA−01 ISSUE A SYMBOL A A1 A2 b E1 b2 c D E E1 e eB PIN # 1 IDENTIFICATION D L 7.87 2.92 3.30 0.38 2.92 0.36 1.14 0.20 9.02 7.62 6.10 3.30 0.46 1.52 0.25 9.27 7.87 6.35 2.54 BSC 10.92 3.80 4.95 0.56 1.78 0.36 10.16 8.25 7.11 MIN NOM MAX 5.33 TOP VIEW E A A2 A1 b2 L c e SIDE VIEW Notes: (1) All dimensions are in millimeters. (2) Complies with JEDEC MS-001. b eB END VIEW http://onsemi.com 14 CAT660 Example of Ordering Information (Note 6) Prefix CAT Device # 660 Suffix EVA T3 Company ID (Optional) Product Number 660 Package ELA: PDIP EVA: SOIC Tape & Reel (Note 7) T: Tape & Reel 3: 3,000 / Reel 4. 5. 6. 7. All packages are RoHS−compliant (Lead−free, Halogen−free). The standard lead finish is Matte−Tin. The device used in the above example is a CAT660EVA−T3 (SOIC, Tape & Reel, 3,000/Reel). For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D. ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. 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American Technical Support: 800−282−9855 Toll Free USA/Canada Europe, Middle East and Africa Technical Support: Phone: 421 33 790 2910 Japan Customer Focus Center Phone: 81−3−5773−3850 ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative http://onsemi.com 15 CAT660/D