LTC1261 Switched Capacitor Regulated Voltage Inverter FEATURES DESCRIPTION n Regulated Negative Voltage from a The LTC 1261 is a switched-capacitor voltage inverter Single Positive Supply designed to provide a regulated negative voltage from n Can Provide Regulated 5V from a 3V Supply a single positive supply. The LTC1261CS operates from n REG Pin Indicates Output is in Regulation a single 3V to 8V supply and provides an adjustable n Low Output Ripple: 5mV Typ output voltage from 1.25V to 8V. An on-chip resistor n Supply Current: 600A Typ string allows the LTC1261CS to be configured for output n Shutdown Mode Drops Supply Current to 5A voltages of 3.5V, 4V, 4.5V or 5V with no external n Up to 15mA Output Current components. The LTC1261CS8 is optimized for applica- n Adjustable or Fixed Output Voltages tions which use a 5V or higher supply or which require n Requires Only Three or Four External Capacitors low output voltages. It requires a single external 0.1F n Available in SO-8 Packages capacitor and provides adjustable and fixed output voltage options in 8-lead SO packages. The LTC1261CS requires one or two external 0.1F capacitors, depending on input APPLICATIONS voltage. Both versions require additional external input and output bypass capacitors. An optional compensation n GaAs FET Bias Generators capacitor at ADJ/COMP can be used to reduce the output n Negative Supply Generators voltage ripple. n Battery-Powered Systems n Single Supply Applications Each version of the LTC1261 will supply up to 12mA output current with guaranteed output regulation of 5%. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. The LTC1261 includes an open-drain REG output which pulls low when the output is within 5% of the set value. Output ripple is typically as low as 5mV. Quiescent current is typically 600A when operating and 5A in shutdown. The LTC1261 is available in a 14-lead narrow body SO package and an 8-lead SO package. TYPICAL APPLICATION 4V Generator with Power Valid Waveforms for 4V Generator with Power Valid 5V 1 8 0V 5V V SHDN CC 10k OUT 2 7 + C1 REG POWER VALID C1 C2 4V LTC1261-4 1F 0.1F 3 6 V = 4V OUT C1 OUT 5V AT 10mA C4 SHDN 4 5 GND COMP + 3.3F 0V C3* 5V 100pF LTC1261 TA01 POWER VALID 0V *OPTIONAL LTC1261 TA02 0.2ms/DIV 1261fb 1 For more information www.linear.com/LTC1261LTC1261 ABSOLUTE MAXIMUM RATINGS (Note 1) Supply Voltage (Note 2) .............................................9V Output Short-Circuit Duration .......................... Indefinite Output Voltage (Note 5) ...............................0.3V to 9V Commercial Temperature Range (Note 7) .... 0C to 70C Total Voltage, V to V (Note 2) ...........................12V Industrial Temperature Range (Note 7) ... 40C to 85C CC OUT Input Voltage Storage Temperature Range ................... 65C to 150C SHDN Pin .....................................0.3V to V + 0.3V Lead Temperature (Soldering, 10 sec) .................. 300C CC REG Pin ................................................. 0.3V to 12V ADJ, R R1, R ..............V 0.3V to V + 0.3V O, ADJ OUT CC PIN CONFIGURATION TOP VIEW TOP VIEW NC 1 14 V CC + C1 2 13 SHDN V 1 8 SHDN CC + C1 3 12 REG C1 2 7 REG + C2 4 11 OUT C1 3 6 OUT C2 5 10 ADJ GND 4 5 ADJ (COMP*) GND 6 9 R ADJ S8 PACKAGE R0 7 8 R1 8-LEAD PLASTIC SO *FOR FIXED VERSIONS S PACKAGE T = 150C, = 150C/W JMAX JA 14-LEAD PLASTIC SO T = 150C, = 110C/W JMAX JA ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC1261CS8 PBF LTC1261CS8 TRPBF 1261 8-Lead Plastic S0 0C to 70C LTC1261IS8 PBF LTC1261IS8 TRPBF 1261 8-Lead Plastic S0 40C to 85C LTC1261CS8-4 PBF LTC1261CS8-4 TRPBF 12614 8-Lead Plastic S0 0C to 70C LTC1261CS8-4.5 PBF LTC1261CS8-4.5 TRPBF 126145 8-Lead Plastic S0 0C to 70C LTC1261CS PBF LTC1261CS TRPBF LTC1261CS 14-Lead Plastic S0 0C to 70C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on nonstandard lead based finish parts. For more information on lead free part marking, go to: