LT3487 Boost and Inverting Switching Regulator for CCD Bias FEATURES DESCRIPTIO Generates 15V at 45mA, 8V at 90mA from a The LT 3487 dual channel switching regulator generates Li-Ion Cell positive and negative outputs for biasing CCD imagers. Output Disconnect The device delivers up to 8V at 90mA and 15V at 45mA Sequencing: Positive Output Reaches Regulation from a lithium-ion cell, providing bias for many popular Before Negative Channel Begins Switching CCD imagers. The boost regulator incorporates output Internal Schottky Diodes disconnect technology to eliminate the DC current path 2MHz Constant Switching Frequency from V to the output load that is present in standard IN Requires Only One Resistor per Channel to Set boost con gurations. The 2MHz switching frequency Output Voltages allows CCD solutions using tiny, low pro le capacitors V Range: 2.3V to 16V and inductors and generates low noise outputs that are IN Output Voltage Up to 28V easy to lter. Schottky diodes are internal and the output Short-Circuit Robust voltages are set with one resistor per channel, reducing Capacitor Programmable Soft-Start the external component count. Separate V Pin Allows Separate Sources for BAT Intelligent soft-start allows sequential soft-start of the two Power and Control Circuitry channels with a single capacitor. The soft-start is sequenced Available in 10-Lead (3mm 3mm) DFN Package such that the output ramp of the negative channel begins U after the ramp of the positive channel. Internal sequencing APPLICATIO S circuitry also disables the negative channel until the positive channel has reached 87% of its nal value, ensuring that CCD Bias the sum of the two outputs is always positive. TFT LCD Bias OLED Bias The LT3487 is available in a 10-pin 3mm 3mm DFN Rail Generation for Op Amps package. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATIO Conversion Ef ciency 15H10H 80 POS CHANNEL AT CAP 75 2.2F SWN V SWP BAT V IN 70 3V TO 12V V CAP POS CHANNEL IN 65 AT V POS 1F 549k 100nF LT3487 60 NEG CHANNEL DN FBP 47pF 4.7F 55 15H 50 V NEG FBN 8V 324k V POS 45 90mA RUN/SS RUN/SS 15V V POS V = 3.6V IN 45mA 40 GND 22F 100nF 0 20 40 60 80 100 LOAD CURRENT (mA) 3487 TA01a 3487 TA01b 3487f 1 EFFICIENCY (%) U ULT3487 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW V Voltage ............................................................... 16V IN V Voltage ............................................................. 16V BAT CAP 10 V 1 POS SWP, SWN Voltage ................................................... 32V SWP 2 9 FBP 11 CAP, V .................................................................30V V 3 8 RUN/SS BAT POS SWN 4 7 FBN DN Voltage ............................................................. 32V DN 5 6 V IN RUN/SS Voltage ..........................................................8V FBP Voltage ................................................................ 6V DD PACKAGE 10-LEAD (3mm 3mm) PLASTIC DFN FBN Voltage ................................................ 0.2V to 6V = 43C/W, = 3C/W JA JC Maximum Junction Temperature .......................... 125C EXPOSED PAD (PIN 11) IS GND, MUST BE CONNECTED TO PCB Operating Temperature Range ................. 40C to 85C ORDER PART NUMBER DD PART MARKING Storage Temperature Range ................... 65C to 125C LT3487EDD LBXB Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: