LM2685 Datasheet | National Semiconductor

Description The LM2685 CMOS charge-pump voltage converter operates as an input voltage doubler, +5V regulator and inverter for an input voltage in the range of +2.85V to +6.5V. Five low cost capacitors are used in this circuit to provide up to 50m A of output current at +5V ( ± 5%), and 15m A at - 5V. The LM2685 operates at a 130 k Hz switching frequency to reduce output resistance and voltage ripple. With an operating current of only 800µA (operating efficiency greater than 80% with most loads) and 6µA typical shutdown current, the LM2685 is ideal for use in battery powered systems. The device is in a small 14-pin TSSOP package. Features n n n n n n n +5V regulated output Inverts V05(+5V) to VNEG(- 5V) Doubles input supply voltage TSSOP-14 package 80% typical conversion efficiency at 25m A Input voltage range of 2.85V to 6.5V Independent shutdown control pins Applications n n n n n Cellular phones Pagers PDAs Handheld instrumentation 3.3V to 5V voltage conversion applications Typical Application and Connection Diagram DS101100-2 14-Pin TSSOP DS101100-1 Ordering Information Order Number LM2685MTC LM2685MTCX Package Type TSSOP-14 TSSOP-14 NSC Package Drawing MTC14 MTC14 Supplied As 94 Units, Rail 2.5k Units, Tape and Reel © 2000 National Semiconductor Corporation DS101100 .national. Pin Description Pin No. 1 2 3 4 5 6 Name VIN GND VNEG VNSW CE SDP Power supply input voltage. Power supply ground. Negative output voltage created by inverting V05. VNEG output connected through a series switch, NSW. Chip enable input. This pin is high for normal operation and low for shutdown. (See Shutdown and Load Disconnect section in the Detailed Device Description division). Positive side shutdown input. This pin is low for normal operation and high for positive side shutdown and VPSW load disconnect. (See Shutdown and Load Disconnect section in the Detailed Device Description division). Negative side shutdown input. This pin is low for normal operation and high for...