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ICL7660MAX1044CMOS电源电压变换器

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ICL7660MAX1044CMOS电源电压变换器 _______________General Description The MAX1044 and ICL7660 are monolithic, CMOS switched-capacitor voltage converters that invert, dou- ble, divide, or multiply a positive input voltage. They are pin compatible with the industry-standard ICL7660 and LTC1044. ...

ICL7660MAX1044CMOS电源电压变换器
_______________General Description The MAX1044 and ICL7660 are monolithic, CMOS switched-capacitor voltage converters that invert, dou- ble, divide, or multiply a positive input voltage. They are pin compatible with the industry-standard ICL7660 and LTC1044. Operation is guaranteed from 1.5V to 10V with no external diode over the full temperature range. They deliver 10mA with a 0.5V output drop. The MAX1044 has a BOOST pin that raises the oscillator frequency above the audio band and reduces external capacitor size requirements. The MAX1044/ICL7660 combine low quiescent current and high efficiency. Oscillator control circuitry and four power MOSFET switches are included on-chip. Applications include generating a -5V supply from a +5V logic supply to power analog circuitry. For applica- tions requiring more power, the MAX660 delivers up to 100mA with a voltage drop of less than 0.65V. ________________________Applications -5V Supply from +5V Logic Supply Personal Communications Equipment Portable Telephones Op-Amp Power Supplies EIA/TIA-232E and EIA/TIA-562 Power Supplies Data-Acquisition Systems Hand-Held Instruments Panel Meters ____________________________Features ' Miniature µMAX Package ' 1.5V to 10.0V Operating Supply Voltage Range ' 98% Typical Power-Conversion Efficiency ' Invert, Double, Divide, or Multiply Input Voltages ' BOOST Pin Increases Switching Frequencies (MAX1044) ' No-Load Supply Current: 200µA Max at 5V ' No External Diode Required for Higher-Voltage Operation ______________Ordering Information Ordering Information continued at end of data sheet. * Contact factory for dice specifications. M A X 1 0 4 4 /IC L 7 6 6 0 Switched-Capacitor Voltage Converters ________________________________________________________________ Maxim Integrated Products 1 Call toll free 1-800-998-8800 for free samples or literature. 19-4667; Rev 1; 7/94 MAX1044 ICL7660 4 3 2 1 CAP- GND CAP+ (N.C.) BOOST 5 6 7 8 VOUT LV OSC V+ TOP VIEW ( ) ARE FOR ICL7660 DIP/SO/µMAX TO-99 ICL7660 N.C. CAP+ GND CAP- VOUT LV OSC V+ AND CASE 1 2 3 4 5 6 7 8 _________________Pin Configurations NEGATIVE VOLTAGE CONVERTER CAP+ CAP- V+ VOUT GND INPUT SUPPLY VOLTAGE NEGATIVE OUTPUT VOLTAGE MAX1044 ICL7660 __________Typical Operating Circuit Dice* 8 SO 8 Plastic DIP PIN-PACKAGETEMP. RANGE 0°C to +70°C 0°C to +70°C 0°C to +70°CMAX1044C/D MAX1044CSA MAX1044CPA PART 8 Plastic DIP-40°C to +85°CMAX1044EPA M A X 1 0 4 4 /I C L 7 6 6 0 Switched-Capacitor Voltage Converters 2 _______________________________________________________________________________________ ABSOLUTE MAXIMUM RATINGS ELECTRICAL CHARACTERISTICS (Circuit of Figure 1, V+ = 5.0V, LV pin = 0V, BOOST pin = open, ILOAD = 0mA, TA = TMIN to TMAX, unless otherwise noted.) Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Note 1: The Maxim ICL7660 and MAX1044 can operate without an external output diode over the full temperature and voltage ranges. The Maxim ICL7660 can also be used with an external output diode in series with pin 5 (cathode at VOUT) when replacing the Intersil ICL7660. Tests are performed without diode in circuit. Note 2: fOSC is tested with COSC = 100pF to minimize the effects of test fixture capacitance loading. The 1pF frequency is correlat- ed to this 100pF test point, and is intended to simulate pin 7’s capacitance when the device is plugged into a test socket with no external capacitor. For this test, the LV pin is connected to GND for comparison to the original manufacturer’s device, which automatically connects this pin to GND for (V+ > 3V). Supply Voltage (V+ to GND, or GND to VOUT)....................10.5V Input Voltage on Pins 1, 6, and 7 .........-0.3V ≤ VIN ≤ (V+ + 0.3V) LV Input Current ..................................................................20µA Output Short-Circuit Duration (V+ ≤ 5.5V)..................Continuous Continuous Power Dissipation (TA = +70°C) Plastic DIP (derate 9.09mW/°C above +70°C) ............727mW SO (derate 5.88mW/°C above +70°C).........................471mW µMAX (derate 4.1mW/°C above +70°C) ......................330mW CERDIP (derate 8.00mW/°C above +70°C).................640mW TO-99 (derate 6.67mW/°C above +70°C)....................533mW Operating Temperature Ranges MAX1044C_ _ /ICL7660C_ _ ..............................0°C to +70°C MAX1044E_ _ /ICL7660E_ _ ............................-40°C to +85°C MAX1044M_ _ /ICL7660M_ _ ........................-55°C to +125°C Storage Temperature Range ............................-65°C to + 150°C Lead Temperature (soldering, 10sec) .............................+300°C kHz TA = 0°C to +70°C TA = +25°C TA = -55°C to +125°C VOSC = 0V or V+, LV open RL = 5kΩ, TA = +25°C, fOSC 5kHz, LV open TA = -40°C to +85°C RL = 10kΩ, LV open RL = 10kΩ, LV to GND fOSC = 2.7kHz (ICL7660), fOSC = 1kHz (MAX1044), V+ = 2V, IL = 3mA, LV to GND 30 200RL = ∞, pins 1 and 7 no connection, LV open µA 10 Supply Current 20 Pin 1 = 0V Pin 1 = V+ 3Oscillator Sink or Source Current %95 98Power Efficiency COSC = 1pF, LV to GND (Note 2) 400 1 Ω 325 Output Resistance IL = 20mA, fOSC = 5kHz, LV open 200 TA = 0°C to +70°C TA = -40°C to +85°C 200 UNITSMAX1044MIN TYP MAXPARAMETER 325 TA = +25°C 130 325 130 150 200 V 1.5 10 Supply Voltage Range (Note 1) 65 100 5 Oscillator Frequency 100 V+ = 2V V+ = 5V MΩ1.0 Oscillator Impedance 80 175 95 98 400 300 250 225 ICL7660 MIN TYP MAX 300 140 250 120 150 250 3.0 10.0 1.5 3.5 55 100 10 100 1.0 TA = -55°C to +125°C RL = ∞, pins 1 and 7 = V+ = 3V TA = +25°C TA = +25°C TA = 0°C to +70°C TA = -40°C to +85°C TA = -55°C to +125°C V+ = 5V V+ = 2V RL = ∞, TA = +25°C, LV open 99.0 99.9 %97.0 99.9Voltage Conversion Efficiency µA kΩ CONDITIONS 80 90 100 30 101 EFFICIENCY vs. OSCILLATOR FREQUENCY 70 M AX 10 44 -F ig 7 OSCILLATOR FREQUENCY (Hz) EF FI CI EN CY (% ) 104 50 40 102 103 6x105 60 105 C1 , C 2 = 10 0µ F C1 , C 2 = 10 µF C1 , C 2 = 1µ F EXTERNAL HCMOS OSCILLATOR 10,000 100,000 0.1 1 OSCILLATOR FREQUENCY vs. EXTERNAL CAPACITANCE 1000 M AX 10 44 -F ig 8 COSC (pF) OS CI LL AT OR F RE QU EN CY (H z) 1000 10 1 10 100 100,000 100 10,000 ICL7660 and MAX1044 with BOOST = OPEN MAX1044 with BOOST -V+ 100 1 OSCILLATOR FREQUENCY vs. SUPPLY VOLTAGE M AX 10 44 -F ig 9 SUPPLY VOLTAGE (V) OS CI LL AT OR F RE QU EN CY (H z) 4 10,000 1000 2 3 6 7 8 9 10 100,000 5 FROM TOP TO BOTTOM AT 5V MAX1044, BOOST = V+, LV = GND MAX1044, BOOST = V+, LV = OPEN ICL7660, LV = GND ICL7660, LV = OPEN MAX1044, BOOST = OPEN, LV = GND MAX1044, BOOST = OPEN, LV = OPEN 0 0 1 2 3 4 5 6 7 8 9 10 OUTPUT VOLTAGE and OUTPUT RIPPLE vs. LOAD CURRENT -0.5 -2.0 M AX 10 44 -F ig 1 LOAD CURRENT (mA) OU TP UT V OL TA GE (V ) OU TP UT R IP PL E (m Vp -p ) -1.5 -1.0 0 250 200 150 100 50 400 350 300 OUTPUT VOLTAGE V+ = 2V LV = GND OUTPUT RIPPLE A: MAX1044 with BOOST = V+ B: ICL7660 C: MAX1044 with BOOST = OPEN A B C 0 0 5 10 15 20 25 30 35 40 OUTPUT VOLTAGE and OUTPUT RIPPLE vs. LOAD CURRENT -0.5 -2.0 -2.5 -3.0 -3.5 -4.0 -4.5 -5.0 M AX 10 44 -F ig 2 LOAD CURRENT (mA) OU TP UT V OL TA GE (V ) OU TP UT R IP PL E (m Vp -p ) -1.5 -1.0 0 720 640 560 480 400 320 240 160 80 800 OUTPUT VOLTAGE OUTPUT RIPPLE V+ = 5V LV = OPEN A A B C B C A: MAX1044 with BOOST = V+ B: ICL7660 C: MAX1044 with BOOST = OPEN 0 0 5 10 15 20 25 30 35 40 OUTPUT VOLTAGE and OUTPUT RIPPLE vs. LOAD CURRENT -1 -4 -5 -6 -7 -8 -9 -10 M AX 10 44 -F ig 3 LOAD CURRENT (mA) OU TP UT V OL TA GE (V ) OU TP UT R IP PL E (m Vp -p ) -3 -2 0 700 630 560 490 420 350 280 210 140 70 V+ = 10V LV = OPEN OUTPUT RIPPLE A B A: MAX1044 with BOOST = V+ B: ICL7660 C: MAX1044 with BOOST = OPEN C B C A OUTPUT VOLTAGE 0 0 1 2 3 4 5 6 7 8 9 10 EFFICIENCY and SUPPLY CURRENT vs. LOAD CURRENT 10 40 50 60 70 80 90 100 M AX 10 44 -F ig 4 LOAD CURRENT (mA) EF FI CI EN CY (% ) SU PP LY C UR RE NT (m A) 30 20 0 7 8 9 10 6 5 4 3 2 1 SUPPLY CURRENT EFFICIENCY V+ = 2V LV = GND 0 0 5 10 15 20 25 30 35 40 EFFICIENCY and SUPPLY CURRENT vs. LOAD CURRENT 10 40 50 60 70 80 90 100 M AX 10 44 -F ig 5 LOAD CURRENT (mA) EF FI CI EN CY (% ) SU PP LY C UR RE NT (m A) 30 20 0 35 40 45 50 30 25 20 15 10 5 V+ = 5V LV = OPEN EFFICIENCY A: MAX1044 with BOOST = V+ B: ICL7660 C: MAX1044 with BOOST = OPEN SUPPLY CURRENT B C A 0 0 5 10 15 20 25 30 35 40 EFFICIENCY and SUPPLY CURRENT vs. LOAD CURRENT 10 40 50 60 70 80 90 100 M AX 10 44 -F ig 6 LOAD CURRENT (mA) EF FI CI EN CY (% ) SU PP LY C UR RE NT (m A) 30 20 0 35 40 45 50 30 25 20 15 10 5V+ = 10V LV = OPEN A: MAX1044 with BOOST = V+ B: ICL7660 C: MAX1044 with BOOST = OPEN SUPPLY CURRENT B, C EFFICIENCY A M A X 1 0 4 4 /IC L 7 6 6 0 Switched-Capacitor Voltage Converters _______________________________________________________________________________________ 3 __________________________________________Typical Operating Characteristics (V+ = 5V; CBYPASS = 0.1µF; C1 = C2 = 10µF; LV = open; OSC = open; TA = +25°C; unless otherwise noted.) 0.1 1 2 3 4 5 6 7 8 9 10 QUIESCENT CURRENT vs. SUPPLY VOLTAGE M AX 10 44 -F ig 1 2 SUPPLY VOLTAGE (V) QU IE SC EN T CU RR EN T (µ A) 10 1 100 1000 2000 A B D C A: MAX1044, BOOST = V+, LV = GND B: MAX1044, BOOST = V+, LV = OPEN C: ICL7660 and MAX1044 with BOOST = OPEN, LV = GND; ABOVE 5V, MAX1044 ONLY D: ICL7660 and MAX1044 with BOOST = OPEN, LV = OPEN 0 101 102 103 104 105 OUTPUT RESISTANCE vs. OSCILLATOR FREQUENCY M AX 10 44 -F ig 1 4 FREQUENCY (Hz) RE SI ST AN CE (Ω ) 200 100 300 400 500 600 700 800 900 1000 C1 , C 2 = 10 0µ F C1 , C 2 = 1µ F C1 , C 2 = 10 µF EXTERNAL HCMOS OSCILLATOR 0 -50 -25 0 25 50 75 100 125 QUIESCENT CURRENT vs. TEMPERATURE M AX 10 44 -F ig 1 3 TEMPERATURE (°C) QU IE SC EN T CU RR EN T (µ A) 200 100 300 400 500 ICL7660, MAX1044 with BOOST = OPEN MAX1044 with BOOST = V+ 0 1 2 3 4 5 6 7 8 9 10 OUTPUT RESISTANCE vs. SUPPLY VOLTAGE M AX 10 44 -F ig 1 5 SUPPLY VOLTAGE (V) OU TP UT R ES IS TA NC E (Ω ) 40 20 60 80 100 120 140 160 180 200 20 -60 -40 -20 0 20 40 60 80 100 120 140 OUTPUT RESISTANCE vs. TEMPERATURE M AX 10 44 -F ig 1 6 TEMPERATURE (°C) OU TP UT R ES IS TA NC E (Ω ) 40 30 50 60 70 80 ICL7660, MAX1044 with BOOST = OPEN MAX1044 with BOOST = V+ M A X 1 0 4 4 /I C L 7 6 6 0 Switched-Capacitor Voltage Converters 4 _______________________________________________________________________________________ ____________________________Typical Operating Characteristics (continued) (V+ = 5V; CBYPASS = 0.1µF; C1 = C2 = 10µF; LV = open; OSC = open; TA = +25°C; unless otherwise noted.) 0 -50 OSCILLATOR FREQUENCY vs. TEMPERATURE M AX 10 44 -F ig 1 0 TEMPERATURE (°C) OS CI LL AT OR F RE QU EN CY (k Hz ) 25 40 20 -25 0 75 100 125 60 80 100 50 A: MAX1044 with BOOST = V+ B: ICL7600 C: MAX1044 with BOOST = OPEN B A C 1 100 101 102 103 104 105 5x105 QUIESCENT CURRENT vs. OSCILLATOR FREQUENCY M AX 10 44 -F ig 1 1 OSCILLATOR FREQUENCY (Hz) QU IE SC EN T CU RR EN T (µ A) 100 10 1000 10,000 USING EXTERNAL HCMOS OSCILLATOR USING EXTERNAL CAPACITOR _______________Detailed Description The MAX1044/ICL7660 are charge-pump voltage con- verters. They work by first accumulating charge in a bucket capacitor and then transfer it into a reservoir capacitor. The ideal voltage inverter circuit in Figure 2 illustrates this operation. During the first half of each cycle, switches S1 & S3 close and switches S2 & S4 open, which connects the bucket capacitor C1 across V+ and charges C1. During the second half of each cycle, switches S2 & S4 close and switches S1 & S3 open, which connects the positive terminal of C1 to ground and shifts the nega- tive terminal to VOUT. This connects C1 in parallel with the reservoir capacitor C2. If the voltage across C2 is smaller than the voltage across C1, then charge flows from C1 to C2 until the voltages across them are equal. During successive cycles, C1 will continue pouring charge into C2 until the voltage across C2 reaches - (V+). In an actual voltage inverter, the output is less than - (V+) since the switches S1–S4 have resistance and the load drains charge from C2. Additional qualities of the MAX1044/ICL7660 can be understood by using a switched-capacitor circuit model. Switching the bucket capacitor, C1, between the input and output of the circuit synthesizes a resis- tance (Figures 3a and 3b.) When the switch in Figure 3a is in the left position, capacitor C1 charges to V+. When the switch moves to the right position, C1 is discharged to VOUT. The charge transferred per cycle is: ∆Q = C1(V+ - VOUT). If the switch is cycled at frequency f, then the resulting M A X 1 0 4 4 /IC L 7 6 6 0 Switched-Capacitor Voltage Converters _______________________________________________________________________________________ 5 MAX1044 ICL7660 BOOST CAP+ GND CBYPASS = 0.1µF V+ RL CAP- V+ OSC C1 10µF LV VOUT C2 10µF COSC EXTERNAL OSCILLATOR VOUT _____________________________________________________________ Pin Description NAME FUNCTION BOOST (MAX1044) Frequency Boost. Connecting BOOST to V+ increases the oscillator frequency by a factor of six. When the oscillator is driven externally, BOOST has no effect and should be left open. PIN 1 N.C. (ICL7660) No Connection 3 GND Ground. For most applications, the positive terminal of the reservoir capacitor is connected to this pin. 2 CAP+ Connection to positive terminal of Charge-Pump Capacitor 6 LV Low-Voltage Operation. Connect to ground for supply voltages below 3.5V. ICL7660: Leave open for supply voltages above 5V. 5 VOUT Negative Voltage Output. For most applications, the negative terminal of the reservoir capacitor is connected to this pin. 4 CAP- Connection to negative terminal of Charge-Pump Capacitor 7 OSC Oscillator Control Input. Connecting an external capacitor reduces the oscillator frequency. Minimize stray capacitance at this pin. 8 V+ Power-Supply Positive Voltage Input. (1.5V to 10V). V+ is also the substrate connection. Figure 1. Maxim MAX1044/ICL7660 Test Circuit M A X 1 0 4 4 /I C L 7 6 6 0 current is: I = f x ∆Q = f x C1(V+ - VOUT). Rewriting thisequation in Ohm’s law form defines an equivalent resis- tance synthesized by the switched-capacitor circuit where: where f is one-half the oscillator frequency. This resis- tance is a major component of the output impedance of switched-capacitor circuits like the MAX1044/ICL7660. As shown in Figure 4, the MAX1044/ICL7660 contain MOSFET switches, the necessary transistor drive cir- cuitry, and a timing oscillator. ________________Design Information The MAX1044/ICL7660 are designed to provide a simple, compact, low-cost solution where negative or doubled supply voltages are needed for a few low- power components. Figure 5 shows the basic negative voltage converter circuit. For many applications, only two external capacitors are needed. The type of capacitor used is not critical. Proper Use of the Low-Voltage (LV) Pin Figure 4 shows an internal voltage regulator inside the MAX1044/ICL7660. Use the LV pin to bypass this regulator, in order to improve low-voltage performance I (V+ - V ) 1 / (f x C1) R 1 f x C1 OUT EQUIV = = and Switched-Capacitor Voltage Converters 6 _______________________________________________________________________________________ S1 V+ S2 S3 S4 C1 C2 VOUT = -(V+) Figure 2. Ideal Voltage Inverter V+ C1 f C2 RLOAD VOUT Figure 3a. Switched Capacitor Model REQUIV = REQUIV VOUT RLOAD 1 V+ f × C1 C2 Figure 3b. Equivalent Circuit 1M BOOST pin 1 OSC pin 7 LV pin 6 GND pin 3 CAP- pin 4 S2S1 S4S3 CAP+ pin 2 V+ pin 8 VOUT pin 5 ÷ 2 Q OS CI LL AT OR IN TE RN AL RE GU LA TO R Q Figure 4. MAX1044 and ICL7660 Functional Diagram and allow operation down to 1.5V. For low-voltage operation and compatibility with the industry-standard LTC1044 and ICL7660, the LV pin should be connect- ed to ground for supply voltages below 3.5V and left open for supply voltages above 3.5V. The MAX1044’s LV pin can be grounded for all operat- ing conditions. The advantage is improved low-voltage performance and increased oscillator frequency. The disadvantage is increased quiescent current and reduced efficiency at higher supply voltages. For Maxim’s ICL7660, the LV pin must be left open for supply voltages above 5V. When operating at low supply voltages with LV open, connections to the LV, BOOST, and OSC pins should be short or shielded to prevent EMI from causing oscillator jitter. Oscillator Frequency Considerations For normal operation, leave the BOOST and OSC pins of the MAX1044/ICL7660 open and use the nominal oscillator frequency. Increasing the frequency reduces audio interference, output resistance, voltage ripple, and required capacitor sizes. Decreasing frequency reduces quiescent current and improves efficiency. Oscillator Frequency Specifications The MAX1044/ICL7660 do not have a precise oscillator frequency. Only minimum values of 1kHz and 5kHz for the MAX1044 and a typical value of 10kHz for the ICL7660 are specified. If a specific oscillator frequency is required, use an external oscillator to drive the OSC pin. Increasing Oscillator Frequency Using the BOOST Pin For the MAX1044, connecting the BOOST pin to the V+ pin raises the oscillator frequency by a factor of about 6. Figure 6 shows this connection. Higher frequency oper- ation lowers output impedance, reduces output ripple, allows the use of smaller capacitors, and shifts switch- ing noise out of the audio band. When the oscillator is driven externally, BOOST has no effect and should be left open. The BOOST pin should also be left open for normal operation. Reducing the Oscillator Frequency Using COSC An external capacitor can be connected to the OSC pin to lower the oscillator frequency (Figure 6). Lower frequency operation improves efficiency at low load currents by reducing the IC’s quiescent supply current. It also increases output ripple and output impedance. This can be offset by using larger values for C1 and C2. Connections to the OSC pin should be short to prevent stray capacitance from reducing the oscillator frequency. Overdriving the OSC Pin with an External Oscillator Driving OSC with an external oscillator is useful when the frequency must be synchronized, or when higher frequencies are required to reduce audio interference. The MAX1044/ICL7660 can be driven up to 400kHz. The pump and output ripple frequencies are one-half the external clock frequency. Driving the MAX1044/ICL7660 at a higher frequency increases the ripple frequency and allows the use of smaller capacitors. It also increases the quiescent current. The OSC input threshold is V+ - 2.5V when V+ ‡ 5V, and is V+ / 2 for V+ < 5V. If the external clock does not swing all the way to V+, use a 10kΩ pull-up resistor (Figure 7). Output Voltage Considerations The MAX1044/ICL7660 o
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