MEMORY存储芯片ICL7660ESA中文规格书 - 图文

MAX1044/ICL7660

Switched-Capacitor Voltage Converters

General Description

The MAX1044 and ICL7660 are monolithic, CMOS switched-capacitor voltage converters that invert, double, 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 applications 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

Typical Operating Circuit

INPUTCAP+V+SUPPLYVOLTAGEMAX1044ICL7660CAP-VNEGATIVEOUTOUTPUTVOLTAGEGNDNEGATIVE VOLTAGE CONVERTERFeatures

●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 appears at end of data sheet.

Pin Configurations

TOP VIEW+(N.C.) BOOST18V+CAP+2MAX1044ICL76607OSCGND36LVCAP-45VOUTDIP/SO/μMAXV+ AND CASEN.C.8OSC17CAP+2ICL76606LVGND35VOUT4( ) ARE FOR ICL7660CAP-TO-99MAX1044/ICL7660Switched-Capacitor Voltage Converters

Absolute Maximum Ratings

Supply Voltage (V+ to GND, or GND to VOUT)..................10.5VInput Voltage on Pins 1, 6, and 7 .......-0.3V ≤ VIN ≤ (V+ + 0.3V)LV Input Current ..................................................................20μAOutput Short-Circuit Duration (V+ ≤ 5.5V) ................ContinuousContinuous Power Dissipation (TA = +70°C)

Plastic DIP (derate 9.09mW/°C above +70°C) ............727mWSO (derate 5.88mW/°C above +70°C) ........................471mWμMAX (derate 4.1mW/°C above +70°C) .....................330mW

CERDIP (derate 8.00mW/°C above +70°C) ................640mWTO-99 (derate 6.67mW/°C above +70°C) ...................533mWOperating Temperature Ranges

MAX1044C_ _ /ICL7660C_ _ .............................0°C to +70°CMAX1044E_ _ /ICL7660E_ _ .........................-40°C to +85°CMAX1044M_ _ /ICL7660M_ _ ......................-55°C to +125°CStorage Temperature Range ...........................-65°C to + 150°CLead Temperature (soldering, 10sec) .............................+300°C

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.

Electrical Characteristics

(Circuit of Figure 1, V+ = 5.0V, LV pin = 0V, BOOST pin = open, ILOAD = 0mA, TA = TMIN to TMAX, unless otherwise noted.)

PARAMETERRL = ∞, pins 1 and 7 no connection, LV openCONDITIONSTA = +25°CTA = 0°C to +70°CTA = -40°C to +85°CTA = -55°C to +125°C103.01.5TA = +25°CTA = 0°C to +70°CTA = -40°C to +85°CTA = -55°C to +125°CfOSC = 2.7kHz (ICL7660), fOSC = 1kHz (MAX1044), TA = 0°C to +70°CV+ = 2V, IL = 3mA, TA = -40°C to +85°CLV to GNDTA = -55°C to +125°COscillator FrequencyPower EfficiencyVoltage Conversion EfficiencyOscillator Sink or Source CurrentOscillator ImpedanceCOSC = 1pF, LV to GND (Note 2)V+ = 5VV+ = 2V519597.09899.93201.01001.01009599.09899.9TA = +25°C6510100130130150325325325400101.55510.03.5100120140150250300300400kHz%%μAM?k??VMAX1044MINTYP30MAX200200200200MINICL7660TYP80MAX175225250250μAUNITSSupply CurrentRL = ∞, pins 1 and 7 = V+ = 3VSupply Voltage Range (Note 1)RL = 10kΩ, LV openRL = 10kΩ, LV to GNDIL = 20mA, fOSC = 5kHz, LV openOutput ResistanceRL = 5kΩ, TA = +25°C, fOSC 5kHz, LV openRL = ∞, TA = +25°C, LV openVOSC = 0V or V+, LV openTA = +25°CPin 1 = 0VPin 1 = V+V+ = 2VV+ = 5VNote 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

correlated 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).

MAX1044/ICL7660Switched-Capacitor Voltage Converters

Pin Description

PIN

NAMEBOOST (MAX1044)N.C.(ICL7660)CAP+GNDCAP-VOUTLVOSCV+

FUNCTION

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.No Connection

Connection to positive terminal of Charge-Pump Capacitor

Ground. For most applications, the positive terminal of the reservoir capacitor is connected to this pin.Connection to negative terminal of Charge-Pump Capacitor

Negative Voltage Output. For most applications, the negative terminal of the reservoir capacitor is connected to this pin.

Low-Voltage Operation. Connect to ground for supply voltages below 3.5V. ICL7660: Leave open for supply voltages above 5V.

Oscillator Control Input. Connecting an external capacitor reduces the oscillator frequency. Minimize stray capacitance at this pin.

Power-Supply Positive Voltage Input. (1.5V to 10V). V+ is also the substrate connection.

1

2345678

V+BOOSTV+CBYPASS= 0.1μFEXTERNALOSCILLATOROSCCOSCGNDLVRLCAP+C110μFMAX1044ICL7660terminal of C1 to ground and shifts the negative 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 resistance (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: ΔQ = C1(V+ - VOUT). If the switch is cycled at frequency f, then the resulting current is: I = f x ΔQ = f x C1(V+ - VOUT). Rewriting this equation in Ohm’s law form defines an equivalent resistance synthesized by the switched-capacitor circuit where:

I=

?VOUT)1/(fxC1)and

1

REQUIV=

fxC1

CAP-VOUTC210μFVOUT(V+

MAX1044/ICL7660S1S2V+C1S3S4C2VOUT = -(V+)Figure 2. Ideal Voltage Inverter

fV+VOUTC1C2RLOADFigure 3a. Switched Capacitor Model

REQUIVV+VOUTREQUIV = 1f x C1C2RLOADFigure 3b. Equivalent Circuit

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.

Switched-Capacitor Voltage Converters

V+pin 8CAP+S1pin 2S21MBOOST Rpin 1OTQALL 2 IOSCCQSpin 7OS3S4 RVLAONTpin 5OUTLVARLEUGNDCAP-pin 6TNGEIRpin 3pin 4Figure 4. MAX1044 and ICL7660 Functional Diagram

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 com-ponents. 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 and allow operation down to 1.5V. For low-voltage opera-tion and compatibility with the industry-standard LTC1044 and ICL7660, the LV pin should be connected 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.

MAX1044/ICL7660Switched-Capacitor Voltage Converters