ADP1111 Analog Devices, ADP1111 Datasheet
ADP1111
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ADP1111 Summary of contents
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... The fixed outputs are 3 and 12 V; and an adjustable version is also available. The ADP1111 can deliver 100 from input in step-up mode can deliver 200 from input in step-down mode. ...
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... I Tied LIM +25° 3 650 SAT 650 ADP1111 SET REF SET = 300 μA I SINK SET ≤ V ≤ ≤ V ≤ 100 kΩ ...
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... SET pin and its negative input is con- nected to the 1.25 V reference. It can be left open if unused. On the ADP1111 (adjustable) version this pin is con- nected to the comparator input. On the ADP1111-3.3, ADP1111-5 and ADP1111-12, the pin goes directly to the internal application resistor that sets output voltage ...
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... ADP1111–Typical Characteristics 1.4 1.2 1 0.4 0.2 0 0.1 0.2 0.4 0.6 I CURRENT – A SWITCH Figure 2. Saturation Voltage vs. I Step-Up Mode 2.0 1.8 1.6 1.4 1 12V IN 1.0 0.8 0.6 0.4 0.2 0 0.1 0.2 0.4 0.6 I CURRENT – A SWITCH Figure 3. Switch ON Voltage vs. I Step-Down Mode 1400 1200 1000 QUIESCENT CURRENT 800 600 400 200 0 1 INPUT VOLTAGE – V Figure 4 ...
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... Figure 12. Quiescent Current vs. Temperature 250 200 150 100 50 0 – Figure 13. Feedback Bias Current vs. Temperature –5– ADP1111 @ V = 12V I = 0.65A TEMPERATURE – C QUIESCENT CURRENT TEMPERATURE – C BIAS CURRENT 0 ...
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... ADP1111, the output voltage can be higher, lower opposite polarity than the input voltage. To specify an inductor for the ADP1111, the proper values of inductance, saturation current and dc resistance must be determined. This process is not difficult, and specific equations for each circuit configuration are provided in this data sheet ...
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... Replacing ‘t’ in the above equation with the ON time of the ADP1111 (7 μs, typical) will define the peak current for a given inductor value and input voltage. At this point, the inductor energy can be calculated as follows • PEAK L ...
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... INDUCTOR SELECTION–POSITIVE-TO-NEGATIVE CONVERTER The configuration for a positive-to-negative converter using the ADP1111 is shown in Figure 22. As with the step-up converter, all of the output power for the inverting circuit must be supplied by the inductor. The required inductor power is derived from the formula: ...
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... D1 into the load, and the output voltage is driven above the input voltage. The output voltage is fed back to the ADP1111 via resistors R1 and R2. When the voltage at pin FB falls below 1.25 V, SW1 turns “on” again, and the cycle repeats. The output voltage is therefore set by the formula: = 1.25 V • ...
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... IN CE OUT Figure 20. Step-Down Model the input voltage to the ADP1111 varies over a wide range, a • 7μs current limiting resistor at Pin 1 may be required particular circuit requires high peak inductor current with minimum input supply voltage, the peak current may exceed the switch maxi- mum rating and/or saturate the inductor when the supply voltage is at the maximum value. See the “ ...
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... For example, a particular design may require peak switch current of 800 mA with a 2.0 V input exceed 1.6 A. The ADP1111 limits switch current to 1.5 A and thereby protects the switch, but the output ripple will increase. Selecting the proper resistor will limit the switch current to 800 mA, even if V and maximum switch current is shown in Figure 6 ...
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... ON time; however, the ADP1111 will still provide a properly regulated output voltage. PROGRAMMING THE GAIN BLOCK The gain block of the ADP1111 can be used as a low-battery detector, error amplifier or linear post regulator. The gain block consists amp with PNP inputs and an open-collector NPN output. The inverting input is internally connected to the ADP1111’ ...
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... All Surface Mount Step-Up Converter This is the most basic application (along with the basic step- down configuration to follow) of the ADP1111. It takes full advantage of surface mount packaging for all the devices used in the design. The circuit can provide + 100 mA of output current and can be operated off of battery power for use in portable equipment ...
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... Figure 32. Voltage Controlled Positive-to-Negative Converter + –22 V LCD Bias Generator This circuit uses an adjustable-output version of the ADP1111 to generate a +22.5 V reference output that is level-shifted to give an output of – operation from a +5 volt supply is desired, change ohms. The circuit will deliver 7 mA with a 3 volt supply and 40 mA with a 5 volt supply ...
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... V ADP1111ANZ ADP1111ARZ ADJ ADP1111ARZ- ADP1111ARZ-12-REEL 12 V ADP1111ARZ-3.3 3.3 V ADP1111ARZ ADP1111ARZ-5-REEL 5 V ADP1111ARZ-REEL ADJ RoHS Compliant Part. ©1996–2009 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D08365-0-11/09(A) REV. A ...