Datasheet LTC1258 (Analog Devices) - 7
| Manufacturer | Analog Devices |
| Description | Micropower Low Dropout References |
| Pages / Page | 8 / 7 — APPLICATIONS INFORMATION. Figure 2. Adding a Damping Resistor with Output … |
| File Format / Size | PDF / 137 Kb |
| Document Language | English |
APPLICATIONS INFORMATION. Figure 2. Adding a Damping Resistor with Output Capacitors Greater Than 1μF
Model Line for this Datasheet
- LTC1258CMS8-2.5#PBF LTC1258CMS8-2.5#PBF LTC1258CMS8-2.5#TRPBF LTC1258CMS8-2.5#TRPBF LTC1258CMS8-3#PBF LTC1258CMS8-3#PBF LTC1258CMS8-3#TRPBF LTC1258CMS8-3#TRPBF LTC1258CMS8-4.1#PBF LTC1258CMS8-4.1#PBF LTC1258CMS8-4.1#TRPBF LTC1258CMS8-4.1#TRPBF LTC1258CMS8-5#PBF LTC1258CMS8-5#PBF LTC1258CMS8-5#TRPBF LTC1258CMS8-5#TRPBF LTC1258CS8-2.5#PBF LTC1258CS8-2.5#PBF LTC1258CS8-2.5#TRPBF LTC1258CS8-2.5#TRPBF LTC1258CS8-3#PBF LTC1258CS8-3#PBF LTC1258CS8-3#TRPBF LTC1258CS8-3#TRPBF LTC1258CS8-4.1#PBF LTC1258CS8-4.1#PBF LTC1258CS8-4.1#TRPBF LTC1258CS8-4.1#TRPBF LTC1258CS8-5#PBF LTC1258CS8-5#PBF LTC1258CS8-5#TRPBF LTC1258CS8-5#TRPBF
Text Version of Document
LTC1258 Series
APPLICATIONS INFORMATION
10k LTC1258-5 5.2V 2 1 TO IN OUT 5V 12.6V COUT >1μF 1k GND 0.1μF DAMPING RESISTOR 4 <1k 1258 F02 100 RESISTOR VALUE (Ω)
Figure 2. Adding a Damping Resistor with Output Capacitors Greater Than 1μF
10 1 10 100 1000
Internal P-Channel Pass Transistor
OUTPUT CAPACITOR VALUE (μF) 1258 F03 The LTC1258 series features an internal P-channel MOSFET
Figure 3. Damping Resistance vs Output Capacitor Value
pass transistor. This provides several advantages over PNP-based references waste considerable amounts of similar designs using a PNP bipolar pass transistor. current when the pass transistor is saturated. In addition, These references consume only 4μA of quiescent current the LTC1258 series provides a lower dropout voltage under light and heavy loads as well as in dropout; whereas, (200mV max) than PNP-based references.
PACKAGE DESCRIPTION MS8 Package 8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660 Rev F) 3.00 p 0.102 (.118 p .004) 0.52 (NOTE 3) 8 7 6 5 (.0205) REF 0.889 p 0.127 (.035 p .005) DETAIL “A” 3.00 p 0.102 0.254 4.90 p 0.152 (.118 p .004) (.010) (.193 p .006) 0o – 6o TYP (NOTE 4) GAUGE PLANE 5.23 (.206) 3.20 – 3.45 MIN (.126 – .136) 0.53 p 0.152 1 2 3 4 (.021 p .006) 1.10 0.86 (.043) (.034) DETAIL “A” MAX REF 0.42 p 0.038 0.65 0.18 (.0165 p .0015) (.0256) (.007) TYP BSC SEATING RECOMMENDED SOLDER PAD LAYOUT PLANE 0.22 – 0.38 0.1016 p 0.0508 (.009 – .015) (.004 p .002) TYP 0.65 MSOP (MS8) 0307 REV F (.0256) BSC NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. 2. DRAWING NOT TO SCALE INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. 5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610) .189 – .197 (4.801 – 5.004) .045 p.005 NOTE 3 .050 BSC .010 – .020 s 45o .053 – .069 8 7 6 5 (0.254 – 0.508) (1.346 – 1.752) .004 – .010 .008 – .010 0o– 8o TYP (0.101 – 0.254) (0.203 – 0.254) .245 .150 – .157 MIN .160 p.005 .228 – .244 .016 – .050 (3.810 – 3.988) (5.791 – 6.197) .014 – .019 .050 (0.406 – 1.270) NOTE 3 (0.355 – 0.483) (1.270) NOTE: TYP BSC INCHES 1. DIMENSIONS IN SO8 0303 (MILLIMETERS) .030 p.005 2. DRAWING NOT TO SCALE TYP 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. 1 2 3 4 RECOMMENDED SOLDER PAD LAYOUT MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) 1258sfb Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. 7
APPLICATIONS INFORMATION
10k LTC1258-5 5.2V 2 1 TO IN OUT 5V 12.6V COUT >1μF 1k GND 0.1μF DAMPING RESISTOR 4 <1k 1258 F02 100 RESISTOR VALUE (Ω)
Figure 2. Adding a Damping Resistor with Output Capacitors Greater Than 1μF
10 1 10 100 1000
Internal P-Channel Pass Transistor
OUTPUT CAPACITOR VALUE (μF) 1258 F03 The LTC1258 series features an internal P-channel MOSFET
Figure 3. Damping Resistance vs Output Capacitor Value
pass transistor. This provides several advantages over PNP-based references waste considerable amounts of similar designs using a PNP bipolar pass transistor. current when the pass transistor is saturated. In addition, These references consume only 4μA of quiescent current the LTC1258 series provides a lower dropout voltage under light and heavy loads as well as in dropout; whereas, (200mV max) than PNP-based references.
PACKAGE DESCRIPTION MS8 Package 8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660 Rev F) 3.00 p 0.102 (.118 p .004) 0.52 (NOTE 3) 8 7 6 5 (.0205) REF 0.889 p 0.127 (.035 p .005) DETAIL “A” 3.00 p 0.102 0.254 4.90 p 0.152 (.118 p .004) (.010) (.193 p .006) 0o – 6o TYP (NOTE 4) GAUGE PLANE 5.23 (.206) 3.20 – 3.45 MIN (.126 – .136) 0.53 p 0.152 1 2 3 4 (.021 p .006) 1.10 0.86 (.043) (.034) DETAIL “A” MAX REF 0.42 p 0.038 0.65 0.18 (.0165 p .0015) (.0256) (.007) TYP BSC SEATING RECOMMENDED SOLDER PAD LAYOUT PLANE 0.22 – 0.38 0.1016 p 0.0508 (.009 – .015) (.004 p .002) TYP 0.65 MSOP (MS8) 0307 REV F (.0256) BSC NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. 2. DRAWING NOT TO SCALE INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. 5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610) .189 – .197 (4.801 – 5.004) .045 p.005 NOTE 3 .050 BSC .010 – .020 s 45o .053 – .069 8 7 6 5 (0.254 – 0.508) (1.346 – 1.752) .004 – .010 .008 – .010 0o– 8o TYP (0.101 – 0.254) (0.203 – 0.254) .245 .150 – .157 MIN .160 p.005 .228 – .244 .016 – .050 (3.810 – 3.988) (5.791 – 6.197) .014 – .019 .050 (0.406 – 1.270) NOTE 3 (0.355 – 0.483) (1.270) NOTE: TYP BSC INCHES 1. DIMENSIONS IN SO8 0303 (MILLIMETERS) .030 p.005 2. DRAWING NOT TO SCALE TYP 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. 1 2 3 4 RECOMMENDED SOLDER PAD LAYOUT MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) 1258sfb Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. 7
