MAX1697

19-1499; Rev 3; 12/08 MAX1697 60mA, SOT23 Inverting Charge Pump with Shutdown General Description The MAX1697 ultra-small, monolithic, CMOS chargepump voltage inverter accepts an input voltage ranging from +1.25V to +5.5V. This device features an ultra-low 12Ω output resistance, permitting loads of up to 60mA with maximum efficiency. The MAX1697 is available with operating frequencies of 12kHz, 35kHz, 125kHz, or 250kHz, allowing optimization of supply current or external component size. Its small external components and micropower shutdown mode make this device ideal for both battery-powered and board-level voltage conversion applications. Oscillator control circuitry and four power MOSFET switches are included on-chip. Applications include generating a negative supply from a +5V or +3.3V logic supply to power analog circuitry. All versions come in a 6-pin SOT23 package and deliver 60mA. For applications with lower current requirements, the MAX1719/MAX1720/MAX1721 are pin-compatible SOT23 charge pumps that supply up to 25mA. Applications Negative Supply from +5V or +3.3V Logic Supplies Small LCD Panels GaAsFET Bias Supplies Handy-Terminals, PDAs Battery-Operated Equipment Typical Operating Circuit 1μF INPUT 1.5V to 5.5V C1+ IN C1OUT MAX1697U ON SHDN OFF GND NEGATIVE OUTPUT -1 ✕ VIN 60mA 1μF Features ♦ 60mA Output Current ♦ Low 12Ω Output Resistance ♦ 150µA Supply Current (MAX1697R) ♦ Requires Only Two 1µF Capacitors (MAX1697U) ♦ Start-Up Current Limited ♦ +1.25V to...