COMS Voltage Converters ICL7660 CMOS Voltage Converters The ICL7660 are monolithic CMOS power supply circuits which offer unique performance advantages over previously available devices. The ICL7660 performs supply voltage conversions from positive to negative for an input range of +1.5V to +10.0V resulting in complementary output voltages of -1.5V to -10.0V. Only 2 noncritical external capacitors are needed for the charge pump and charge reservoir functions. The ICL7660 can also be connected to function as voltage doublers and will generate output voltages up to +18.6V with a +10V input. Contained on the chip are a series DC supply regulator, RC oscillator, voltage level translator, and four output power MOS switches. A unique logic element senses the most negative voltage in the device and ensures that the output N-Channel switch source-substrate junctions are not forward biased. This assures latchup free operation. The oscillator, when unloaded, oscillates at a nominal frequency of 10kHz for an input supply voltage of 5.0V. This frequency can be lowered by the addition of an external capacitor to the “OSC” terminal, or the oscillator may be overdriven by an external clock. The “LV” terminal may be tied to GROUND to bypass the internal series regulator and improve low voltage (LV) operation. At medium to high voltages (+3.5V to +10.0V), the LV pin is left floating to prevent device latchup. Pinouts Features x Simple Conversion of +5V Logic Supply to ±5V Supplies x Simple Voltage Multiplication (VOUT = (-) nVIN) x Typical Open Circuit Voltage Conversion Efficiency 99.9% x Typical Power Efficiency 98% x Wide Operating Voltage Range SOP8 DIP 8 TOP VIEW - ICL7660 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5V to 10.0V x Easy to Use - Requires Only 2 External Non-Critical Passive Components Applications x On Board Negative Supply for Dynamic RAMs x Localized ȝProcessor (8080 Type) Negative Supplies x Inexpensive Negative Supplies x Data Acquisition Systems Pin Description Name NC CAP+ GND CAPVOUT LV OSC V+ Pin# 1 2 3 4 5 6 7 8 Function “+” Capacitor Plate Ground “-” Capacitor Plate Output Voltage Low Supply Voltage Oscillator Supply Voltage Order Information Part No. Temp. Range (ć) Package ICL7660CSA 0 to 70 SOP8 ICL7660CPA 0 to 70 DIP8 1 WWW.HN-ELEC.COM COMS Voltage Converters ICL7660 Absolute Maximum Ratings Supply Voltage ICL7660 . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +10.5V LV and OSC Input Voltage . . . . . . -0.3V to (V+ +0.3V) for V+ < 5.5V (V+ -5.5V) to (V+ +0.3V) for V+ > 5.5V Current into LV . . . . . . . . . . . . . . . . . . . . . . . . . . 20ȝA for V+ > 3.5V Temperature Range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C Thermal Resistance, șJA (°C/W). . . . . . . . . . . . . . . . . . . . . . . . . . . .150 Maximum Storage Temperature Range. . . . . . . . . . . . -65°C to 150°C Electrical Characteristics ( V+ = 5V, TA = 25°C, COSC = 0, unless otherwise specified) PARAMETER Supply Current Supply Voltage Range - Lo SYMBOL I+ VL+ Supply Voltage Range - Hi VL+ Output Source Resistans ROUT Oscillator Frequency Power Efficiency Voltage Conversion Efficiency Oscillator Frequency fOSC PEF VOUT EF ZOSC TEST CONDITIONS RL= MIN TA MAX, RL = 10kȍ, LV to GND MIN TA MAX, RL = 10kȍ, LV to Open IOUT = 20mA, TA = 25°C IOUT = 20mA, 0°C TA 70°C V+ = 2V, IOUT = 3mA, LV to GND, 0°C TA 70°C MIN 1.5 TYP 170 - MAX 500 3.5 UNITS PA V 3.0 - 10.0 V - 55 - 100 120 300 RL = 5k RL= 95 97 10 98 99.9 - kHz % % V+ = 2V V+ = 5V - 1.0 100 - M k 2 WWW.HN-ELEC.COM COMS Voltage Converters ICL7660 Functional Block Diagram TYPICAL APPLICATION CIRCUITS ICL7660 FIGURE 1. SIMPLE NEGATIVE CONVERTER ICL7660 ICL7660 FIGURE 2. PARALLELING DEVICES ICL7660 ICL7660 FIGURE 3. CASCADING DEVICES FOR INCREASED OUTPUT VOLTAGE 3 WWW.HN-ELEC.COM COMS Voltage Converters ICL7660 ICL7660 FIGURE 4. LOWERING OSCILLATOR FREQUENCY ICL7660 FIGURE 5. COMBINED NEGATIVE VOLTAGE CONVERTER AND POSITIVE DOUBLER ICL7660 FIGURE 6. POSITIVE VOLT DOUBLER ICL7660 FIGURE 7. SPLITTING A SUPPLY IN HALF 4 WWW.HN-ELEC.COM