MAX864 19-0478 Rev 0 3/96 Dual-Output Charge Pump with Shutdown General Description Features The MAX864 CMOS, charge-pump, DC-DC voltage Requires Only Four Capacitors converter produces a positive and a negative output from a single positive input, and requires only four Dual Outputs (Positive and Negative) capacitors. The charge pump first doubles the input Low Input Voltages: +1.75V to +6.0V voltage, then inverts the doubled voltage. The input voltage ranges from +1.75V to +6.0V. 1A Logic-Controlled Shutdown The internal oscillator can be pin-programmed from Selectable Frequencies Allow Optimization 7kHz to 185kHz, allowing the quiescent current, capac- itor size, and switching frequency to be optimized. The of Capacitor Size and Supply Current 55 output impedance permits useful output currents up to 20mA. The MAX864 also has a 1A logic-con- trolled shutdown. The MAX864 comes in a 16-pin QSOP package that uses the same board area as a standard 8-pin SOIC. For more space-sensitive applications, the MAX865 is available in an 8-pin MAX package, which uses half Ordering Information the board area of the MAX864. PART TEMP. RANGE PIN-PACKAGE Applications MAX864C/D 0C to +70C Dice* Low-Voltage GaAsFET Bias in Wireless Handsets MAX864EEE -40C to +85C 16 QSOP VCO and GaAsFET Supply * Contact factory for dice specifications. Split Supply from 2 to 4 Ni Cells or 1 Li+ Cell Low-Cost Split Supply for Low-Voltage Data-Acquisition Systems Split Supply for Analog Circuitry LCD Panels Typical Operating Circuit Pin Configuration V IN +2V IN V+ IN TOP VIEW (+1.75V TO +6.0V) C1+ C1- 1 C1+ 16 C2+ 2 15 V+ MAX864 C1- GND 3 N.C. 14 C2- 4 MAX864 13 N.C. C2+ V- 5 12 IN -2V V- IN SHDN 6 11 GND C2- FC1 7 10 N.C. FC0 FC1 SHDN GND FC0 8 9 N.C. V V V IN IN IN QSOP Maxim Integrated Products 1 For free samples & the latest literature: Dual-Output Charge Pump with Shutdown ABSOLUTE MAXIMUM RATINGS V+ to GND..............................................................-0.3V to +12V Operating Temperature Range SHDN, FC0, FC1 to GND .............................-0.3V to (V+ + 0.3V) MAX864EEE......................................................-40C to +85C IN to GND..............................................................-0.3V to +6.2V Continuous Power Dissipation (T = +70C) A V- to GND ...............................................................+0.3V to -12V QSOP (derate 8.70mW/C above +70C).....................696mW V- Output Current .............................................................100mA Storage Temperature Range ............................ -65C to +160C V- Short Circuit to GND .................................................Indefinite Lead Temperature (soldering, 10sec) .............................+300C 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 (Note 1) (V = 5V, SHDN = V , circuit of Figure 1, T = T to T , unless otherwise noted. Typical values are at T = +25C.) IN IN A MIN MAX A PARAMETER SYMBOL MIN TYP MAX UNITS SUPPLY T = +25C 1.75 1.25 A Minimum Start-Up Voltage R = 10k V LOAD T = T to T 2.00 A MIN MAX Maximum Supply Voltage R = 10k 6.0 V LOAD FC1 = FC0 = GND, f = 7kHz 0.6 1.0 FC1 = GND, FC0 = IN, f = 33kHz 2.4 3.65 Supply Current mA FC1 = IN, FC0 = GND, f = 100kHz 711 FC1 = FC0 = IN, f = 185kHz 12 18 Shutdown Current FC1 = FC0 = IN or GND, SHDN = GND 0.1 1 A FC1 = FC0 = GND 57 10 FC1 = GND, FC0 = IN 24 33 48 Oscillator Frequency kHz FC1 = IN, FC0 = GND 70 100 140 FC1 = FC0 = IN 130 185 260 INPUTS AND OUTPUTS Logic Input Low Voltage SHDN, FC0, FC1 2.2 1.0 V Logic Input High Voltage SHDN, FC0, FC1 3.5 2.8 V Logic Input Bias Current SHDN, FC0 = FC1 = GND or IN -1 1 A V+ to IN Shutdown Resistance I = 10mA 22 100 V+ V- to GND Shutdown ResistanceI = 10mA 650 V- T = +25C 55 75 A I = 10mA, I = 0mA V+ V- T = T to T 100 A MIN MAX Output Resistance (Note 1) T = +25C 34 50 A V+ = 10V, I = 10mA (forced) V- T = T to T 60 A MIN MAX V+, R = 95 99 L Voltage Conversion Efficiency % V-, R = L 95 99 Note 1: Measured using the capacitor values in Table 1. Capacitor ESR contributes approximately 10% of the output impedance ESR + 1 / (pump frequency x capacitance) . 2 MAX864