LT1501 LINER [Linear Technology], LT1501 Datasheet
LT1501
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LT1501 Summary of contents
Page 1
... Two package types are available. The LT1500 comes in a 14-pin SO package, with two options available for fixed output (3.3V or 5V) or adjustable operation. A reduced feature part, the LT1501, comes in the smaller 8-pin SO package with internal frequency compensation also available in adjustable and fixed output voltage versions. ...
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... C, = 100 C/ W JMAX JA ORDER PART NUMBER LT1500CS-3/5 LT1500IS-3 2.3V unless otherwise noted CONDITIONS LT1500/LT1501 All Conditions (Note 6) LT1500-3/5, Select Pin Open All Conditions (Note 6) LT1500-3/5, Select Pin Grounded All Conditions (Note 2.3V to 15V IN (3.3V/5V) TOP VIEW SHDN ...
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... I = 100 20V SW Falling Edge V = 1.2V 100 A LBI SINK I = 2mA SINK V = 1.3V, V 15V LBI LBO V = 3.3V SYNC FB Pin Open Note 4 Current Flows Out of Pin LT1500/LT1501 MIN TYP MAX UNITS 200 280 A 320 0.4 1 2.0 2 ...
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... LT1500/LT1501 ELECTRICAL CHARACTERISTICS The denotes specifications which apply over the full operating temperature range. Note 1: Feedback pin or output is held sightly above the regulated value to force the V node low and switching to stop. C Note 2: See Typical Performance Characteristics for graph of Guaranteed Switch Voltage vs Saturation Voltage. ...
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... LOAD CURRENT (mA) LT1500/01 • TPC15 Maximum Load Current (5V Output) 600 500 400 300 200 100 0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 INPUT VOLTAGE (V) LT1500/01 • TPC09 LT1500/LT1501 Efficiency (12V Output) 100 I = 50mA 90 LOAD 10mA LOAD LOW LOSS INDUCTOR ...
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... LT1500/LT1501 W U TYPICAL PERFORMANCE CHARACTERISTICS Burst Mode Threshold 120 LOAD CURRENT IS 100 REDUCED UNTIL Burst Mode OPERATION STARTS 3.3V OUT OUT 12V OUT INPUT VOLTAGE (V) LT1500/01 • TPC01 Quiescent Input Supply Current 400 ...
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... With most applications, only the external inductor is tied to this pin. GND: This pin carries only low level current in the LT1500, but it carries full switch current in the LT1501. The negative end of the input bypass capacitor should be connected close to this pin and the pin should go directly to the ground plane with the LT1501 ...
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... LT1500/LT1501 W BLOCK DIAGRAM LBO + LBI – 1.24V BIAS SHDN BURST COMPARATOR 1.265V REFERENCE 100k – NEGATIVE ERROR AMP 100k + NFB APPLICATIONS INFORMATION OPERATION (SEE BLOCK DIAGRAM) The LT1500 uses a current mode architecture without the need for an internal oscillator. Switching frequency is determined by the value of the external inductor used ...
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... The regulated output volt- age will fall slightly over a relatively long period of time (remember that load current is very low) until the error amplifier output rises enough to turn off the adaptive bias LT1500/LT1501 9 ...
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... LT1500/LT1501 U U APPLICATIONS INFORMATION mode. Normal operation resumes for one or more switch cycles and the output voltage increases until the error amplifier output falls below threshold, initiating a new adaptive bias shutdown. DESIGN GUIDE Selecting Inductor Value Inductor value is chosen as a compromise between size, switching frequency, efficiency and maximum output cur- rent ...
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... The equivalent circuit of the Select pin function is shown in Figure 2. ) Note that there is a switch in series with the V switch is turned off in shutdown to eliminate shutdown current drawn by the voltage divider. For adjustable parts LT1500/LT1501 M . 118 k – ...
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... There may be additional current drawn by the adjustable LT1500 in shutdown if the divider voltage at the feedback node exceeds 0.6V. See Typical Performance Characteristics. Loop Stability The LT1501 is internally compensated since the device has no spare pin for a compensation point. The LT1500 brings out the V pin to which an external series R C network is connected ...
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... A pull-up current and the external capacitor value determine soft start time typical application a 0.22 F capacitor is sufficient to limit input surges and prevent output overshoot, even with overcompensation on the V pin. Output voltages greater than 6V with very large output LT1500/LT1501 301 ...
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... LT1500/LT1501 U U APPLICATIONS INFORMATION capacitors may require the capacitor to be larger. To ensure proper reset of the soft start capacitor, an external resistor must be connected in parallel with the capacitor. The resistor value should be 470k or more. Calculating Temperature Rise For most applications, temperature rise in the IC will be fairly low and will not be a problem ...
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... DWG # 05-08-1610 0.228 – 0.244 (5.791 – 6.197 0.053 – 0.069 (1.346 – 1.752) 0 – 8 TYP 0.014 – 0.019 (0.355 – 0.483) LT1500/LT1501 0.337 – 0.344* (8.560 – 8.738 0.150 – 0.157** (3.810 – 3.988 0.004 – ...
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... Linear Technology Corporation 16 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 : (408) 434-0507 FAX TELEX IN I SENSE ON(HI) SHDN SW OFF (LO) LBI OUT 5V LT1500-3.3/LT1501-5 470k LBO SYNC SELECT TO SYSTEM SS GND PGND COMP 100k 1nF 0. COMMENTS 1.8V Minimum Input, Drives N-Channel MOSFETs 94% Efficiency, 130 A I ...