CAT661 High Frequency 100 mA CMOS Charge Pump, Inverter/Doubler Description The CAT661 is a chargepump voltage converter. It can invert a CAT661 Typical Application +V IN Doubled 1.5 V to 5.5 V Positive 1 8 1 8 Voltage BOOST/FC BOOST/FC V+ V+ 1 F to Output 2 7 C2 2 7 100 F Inverted CAP+ OSC + CAP+ OSC 1 F to Negative C1 + CAT661 C1 CAT661 6 3 6 3 100 F Voltage LV GND LV GND Output V = 2.5 V 1 F to 5 4 5 4 IN CAP CAP OUT OUT to 5.5 V 100 F 1 F to C2 100 F Figure 1. Voltage Inverter Figure 2. Positive Voltage Doubler Table 1. PIN DESCRIPTIONS Circuit Configuration Pin Number Name Inverter Mode Doubler Mode 1 Boost/FC Frequency Control for the internal oscillator. With an external Same as inverter. oscillator BOOST/FC has no effect. Boost/FC Oscillator Frequency Oscillator Frequency Open 25 kHz typical, 10 kHz minimum 40 kHz typical V+ 135 kHz typical, 80 kHz minimum 135 kHz typical, 40 kHz minimum 2 CAP+ Charge Pump Capacitor. Positive terminal. Same as inverter. 3 GND Power Supply Ground. Power supply. Positive voltage input. 4 CAP Charge pump capacitor. Negative terminal. Same as inverter. 5 OUT Output for negative voltage. Power supply ground. 6 LV Low Voltage selection pin. When the input voltage is less LV must be tied to OUT for all input than 3 V, connect LV to GND. For input voltages above 3 V, voltages. LV may be connected to GND or left open. If OSC is driven externally, connect LV to GND. 7 OSC Oscillator control input. An external capacitor can be connec- Same as inverter. Do not overdrive OSC ted to lower the oscillator frequency. An external oscillator in doubling mode. Standard logic levels can drive OSC and set the chip operating frequency. The will not be suitable. See the applications chargepump frequency is onehalf the frequency at OSC. section for additional information. 8 V+ Power supply. Positive voltage input. Positive voltage output.