LTC3265 Low Noise Dual Supply with Boost and Inverting Charge Pumps FEATURES DESCRIPTION n Boost Charge Pump Generates 2 V The LTC 3265 is a low noise dual polarity output power IN P (V Range: 4.5V to 16V) supply including a boost charge pump, an inverting charge IN P n pump and two low noise positive and negative LDO post Inverting Charge Pump Generates V IN N regulators. The boost charge pump powers the positive (V Range: 4.5V to 32V) IN N n LDO post regulator while the inverting charge pump pow- Low Noise Positive LDO Post Regulator Up to 50mA n ers the negative LDO regulator. Each LDO can provide up Low Noise Negative LDO Post Regulator Up to 50mA n to 50mA of output current. The LDO output voltages can 135A Quiescent Current in Burst Mode Operation be adjusted using external resistor dividers. with Both LDO Regulators On n 50kHz to 500kHz Programmable Oscillator Frequency The charge pumps employ low quiescent current n Stable with Ceramic Capacitors BurstMode operation or low noise constant frequency n Short-Circuit/Thermal Protection mode. During Burst Mode operation, the boost charge n + Low Profile 3mm 5mm 18-Lead DFN and Thermally pump regulates its output (V ) to 0.94 2 V while OUT IN P Enhanced 20-Lead TSSOP Packages the inverting charge pump regulates its output (V ) OUT to 0.94 V . In Burst Mode operation the LTC3265 IN N draws only 135A of quiescent current with both LDOs APPLICATIONS on. In constant frequency mode, the boost and inverting n charge pumps produce outputs equal to 2 V and Low Noise Bipolar/Inverting Supplies IN P V respectively and operate at a fixed 500kHz or to n IN N Industrial/Instrumentation Low Noise Bias Generators a programmed value between 50kHz to 500kHz using an external resistor. The LTC3265 is available in low profile L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the 3mm 5mm 0.75mm 18-lead DFN and thermally property of their respective owners. enhanced 20-lead TSSOP packages. TYPICAL APPLICATION Low Noise 15V Outputs from a Single 12V Input LDO Rejection of V Ripple OUT 1F + V OUT 10mV/DIV AC-COUPLED + CBST CBST + V + LDO V V IN N OUT 10mV/DIV 10F AC-COUPLED + V +15V LDO 12V V LDO IN P 10mV/DIV 10F 10F LTC3265 AC-COUPLED 604K + + V EN ADJ OUT + 10mV/DIV EN BYP 52.3k 100nF AC-COUPLED MODE GND 3265 TA01b 1s/DIV 100nF + + CINV BYP V = 12V, V = V IN P IN N OUT 52.3k + 1F V = 15V LDO CINV ADJ V = 15V LDO f = 500kHz 604K OSC + I = 20mA LDO V LDO 15V OUT I = 20mA LDO 10F 10F RT 3265 TA01a 3265fa 1 For more information www.linear.com/LTC3265LTC3265 ABSOLUTE MAXIMUM RATINGS (Notes 1, 3) + V , EN , EN , MODE .............................. 0.3V to 18V BYP ......................................................... 2.5V to 0.3V IN P + V , V .............................................. 0.3V to 36V LDO Short-Circuit Duration ............................ Indefinite OUT IN N + LDO ............................................................16V to 36V Operating Junction Temperature Range V , LDO ............................................... 36V to 0.3V (Note 2) .................................................. 55C to 150C OUT + RT, ADJ ...................................................... 0.3V to 6V Storage Temperature Range .................. 65C to 150C + BYP ......................................................... 0.3V to 2.5V Lead Temperature (Soldering, 10 sec) ADJ ............................................................ 6V to 0.3V FE Only .............................................................300C PIN CONFIGURATION TOP VIEW TOP VIEW + NC 1 20 V OUT + + CBST 1 18 V CBST 2 19 LDO OUT + + + + CBST 2 17 LDO CBST 3 18 ADJ + V 3 16 ADJ + IN P VIN P 4 17 BYP + EN 4 15 BYP EN 5 16 MODE 19 21 BYP 5 14 MODE GND GND + BYP 6 15 EN + ADJ 6 13 EN ADJ 7 14 RT LDO 7 12 RT LDO 8 13 V V 8 11 V IN N OUT IN N + + CINV 9 10 CINV V 9 12 CINV OUT CINV 10 11 NC DHC PACKAGE 18-LEAD (5mm 3mm) PLASTIC DFN FE PACKAGE T = 150C, = 42C/W 20-LEAD PLASTIC TSSOP JMAX JA EXPOSED PAD (PIN 19) IS GND, MUST BE SOLDERED TO PCB T = 150C, = 38C/W JMAX JA EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION (