Switched-Capacitor a Voltage Inverter with Shutdown ADM8828/ADM8829 FUNCTIONAL BLOCK DIAGRAMS FEATURES Inverts Input Supply Voltage 99% Voltage Conversion Efficiency OUT 1 6 CAP+ 25 mA Output Current ADM8828 IN 2 5 SHDN TOP VIEW Shutdown Function (Not to Scale) CAP 3 4 GND Requires Only Two Capacitors 1 mF Capacitors 18 V Output Resistance 1 6 OUT CAP+ +1.5 V to +5.5 V Input Range ADM8829 IN 2 5 NC 600 mA Quiescent Current TOP VIEW (Not to Scale) CAP 3 4 GND 20 nA Shutdown Current (ADM8828) NC = NO CONNECT APPLICATIONS Handheld Instruments LCD Panels Cellular Phones PDAs Remote Data Acquisition Op Amp Power Supplies GENERAL DESCRIPTION +1.5V TO +5.5V INPUT The ADM8828/ADM8829 is a charge-pump voltage inverter which may be used to generate a negative supply from a positive CAP+ IN input. Input voltages ranging from +1.5 V to +5.5 V can be + ADM8828/ C1 inverted into a negative 1.5 V to 5.5 V output supply. This 1mF ADM8829 SHUTDOWN inverting scheme is ideal for generating a negative rail in single SHDN CONTROL CAP power-supply systems. Only two small external capacitors are needed for the charge pump. Output currents up to 25 mA with INVERTED OUT GND NEGATIVE greater than 99% efficiency are achievable. OUTPUT C2 + 1mF The ADM8828 also features a low power shutdown (SHDN) pin. This can be used to disable the device and reduce the quies- Figure 1. Typical Circuit Configuration cent current to 20 nA. The ADM8828/ADM8829 is available in a 6-lead SOT-23 package. Rev. B Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. use. Specifications subject to change without notice. No license is granted by Tel: 781.329.4700 19992019 Analog Devices, Inc. All rights reserved. implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. 1 (V = +5 V, C1, C2 = 1 mF, T = T to T unless other- IN A MIN MAX wise noted) ADM8828/ADM8829SPECIFICATIONS Parameter Min Typ Max Units Test Conditions/Comments Input Voltage, IN 1.5 5.5 V R = 10 k L Supply Current 600 1000 A Unloaded Output Current 25 mA Output Resistance 18 28 I = 5 mA L Output Ripple 25 mV p-p I = 5 mA L 130 mV p-p I = 25 mA L Charge-Pump Frequency 50 120 190 kHz 65 kHz V = +2.25 V IN Power Efficiency 90 % R = 200 L 87 % R = 1 k L Voltage Conversion Efficiency 99.5 99.96 % No Load 98 % R = 1 k L 91 % R = 200 L Shutdown Supply Current, I 0.02 2 A SHDN = IN SHDN Shutdown Input Voltage, V 2.0 V SHDN High = Disabled SHDN 0.8 V SHDN Low = Enabled Shutdown Exit Time 175 sI = 5 mA L NOTES 1 C1 and C2 are low ESR (<0.2 ) electrolytic capacitors. High ESR will degrade performance. Specifications subject to change without notice. ABSOLUTE MAXIMUM RATINGS* PIN FUNCTION DESCRIPTIONS (T = +25C unless otherwise noted) A Mnemonic Function Input Voltage (IN to GND) . 0.3 V to +6 V CAP+ Positive Charge-Pump Capacitor Terminal. OUT to GND 6.0 V to +0.3 V OUT, IN Output Current (Continuous) 50 mA GND Power Supply Ground. Output Short Circuit Duration to GND . 10 secs CAP Negative Charge-Pump Capacitor Terminal. Power Dissipation, RT-6 570 mW OUT Output, Negative Voltage. (Derate 8.3 mW/C above +70C) SHDN Shutdown Control Input. This input, when , Thermal Impedance 120C/W JA high, is used to disable the charge pump Operating Temperature Range thereby reducing the power consumption. Industrial (A Version) 40C to +85C IN Positive Power Supply Input. Storage Temperature Range . 65C to +150C Lead Temperature Range (Soldering 10 sec) +300C Vapor Phase (70 sec) +215C PIN CONFIGURATIONS Infrared (15 sec) +220C ESD Rating >3500 V *This is a stress rating only and functional operation of the device at these or any 1 6 OUT CAP+ other conditions above those indicated in the operation section of this specification ADM8828 is not implied. Exposure to absolute maximum rating conditions for extended IN 2 5 SHDN TOP VIEW periods may affect device reliability. (Not to Scale) 3 4 CAP GND 1 6 CAP+ OUT ADM8829 IN 2 5 NC TOP VIEW (Not to Scale) CAP 3 4 GND NC = NO CONNECT 2 REV. B