LTC1258 Series
7
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.
PACKAGE DESCRIPTION
Internal P-Channel Pass Transistor
The LTC1258 series features an internal P-channel MOSFET
pass transistor. This provides several advantages over
similar designs using a PNP bipolar pass transistor.
These references consume only 4μA of quiescent current
under light and heavy loads as well as in dropout; whereas,
PNP-based references waste considerable amounts of
current when the pass transistor is saturated. In addition,
the LTC1258 series provides a lower dropout voltage
(200mV max) than PNP-based references.
LTC1258-5
OUT
IN
GND
4
2
5.2V
TO
12.6V
1
5V
1258 F02
0.1μF
C
OUT
>1μF
DAMPING RESISTOR
<1k
OUTPUT CAPACITOR VALUE (μF)
1
10
RESISTOR VALUE (Ω)
100
1k
10k
10 100 1000
1258 F03
Figure 2. Adding a Damping Resistor with
Output Capacitors Greater Than 1μF
Figure 3. Damping Resistance vs Output Capacitor Value
APPLICATIONS INFORMATION
MS8 Package
8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660 Rev F)
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
MSOP (MS8) 0307 REV F
0.53 p 0.152
(.021 p .006)
SEATING
PLANE
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
0.18
(.007)
0.254
(.010)
1.10
(.043)
MAX
0.22 – 0.38
(.009 – .015)
TYP
0.1016 p 0.0508
(.004 p .002)
0.86
(.034)
REF
0.65
(.0256)
BSC
0
o – 6o TYP
DETAIL “A”
DETAIL “A”
GAUGE PLANE
12
3
4
4.90
p 0.152
(.193 p .006)
8
7
6
5
3.00 p 0.102
(.118 p .004)
(NOTE 3)
3.00 p 0.102
(.118 p .004)
(NOTE 4)
0.52
(.0205)
REF
5.23
(.206)
MIN
3.20 – 3.45
(.126 – .136)
0.889
p 0.127
(.035 p .005)
RECOMMENDED SOLDER PAD LAYOUT
0.42 p 0.038
(.0165 p .0015)
TYP
0.65
(.0256)
BSC
.016 – .050
(0.406 – 1.270)
.010 – .020
(0.254 – 0.508)
s 45o
0o– 8o TYP
.008 – .010
(0.203 – 0.254)
SO8 0303
.053 – .069
(1.346 – 1.752)
.014 – .019
(0.355 – 0.483)
TYP
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
1
2
3
4
.150 – .157
(3.810 – 3.988)
NOTE 3
8
7
6
5
.189 – .197
(4.801 – 5.004)
NOTE 3
.228 – .244
(5.791 – 6.197)
.245
MIN
.160
p.005
RECOMMENDED SOLDER PAD LAYOUT
.045 p.005
.050 BSC
.030 p.005
TYP
INCHES
(MILLIMETERS)
NOTE:
1. DIMENSIONS IN
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
