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SBVU004 − NOVEMBER 2003
DEM−TO263LDO
DESCRIPTION
The Texas Instruments DEM−TO263LDO demonstration
module (DEM) helps designers evaluate the operation and
performance of Texas Instrument’s low-dropout regulators
(LDOs). This module is compatible with most positive out-
put LDOs offered in the 5-lead TO220 (KC) and TO263
(KTT) packages. (Note that the TO263 package is also
known as DDPAK.)
CIRCUIT
The schematic in Figure 1 illustrates all the possible
connections available on this DEM. Depending on the
LDO being evaluated, different components can be
omitted. Each model may only use some of the
components. The schematics in Figure 2 illustrate the
connections required to evaluate the two most-common
LDO pinouts in the TO220 and TO263 packages.
R1/C1
J2
J1
J3
1
2
1
U1
GND
2
5
4
3
1
2
J4
J5
1
2
1
2
J6
1
2
R4/C4
R5/C5
R6/C6
R2/C2
R3/C3
1
2
NOTE: All resistors shown in this schematic can be used as capacitors;
they must be configured by the user.
Figure 1. Circuit Schematic
COMPONENTS
This DEM is specifically designed to be assembled using
surface-mount devices with footprints ranging from 0603 to
1210. Additional holes have been provided to accommodate
leaded components. When selecting components, refer to
the product datasheet for specific guidelines.
BOARD LAYOUT
This DEM is a two-layer printed circuit board (PCB). The
LDO is grounded through pin 3 to the top ground plane.
The bottom layer of the PCB also provides extra pads
where additional surface-mount components can be
added in parallel to the top-side components. Figure 3
shows the top assembly layer for the PCB.
R5/C5
VIN
J4
J5
J6
1
2
5
U1
GND
4
1
2
3
EN
1
2
J2
FB
J1
VOUT
1
2
GND
1
2
J3
GND
1
2
R2/C2
R1/C1
R3/C3
1
2
(a) Circuit Configuration, Pinout A
R1/C1
VIN
J2
J1
J3
1
2
2
U1
GND
1
4
5
3
EN
1
2
J4
FB
J5
VOUT
1
2
GND
1
2
J6
GND
1
2
R4/C4
R5/C5
R6/C6
1
2
(b) Circuit Configuration, Pinout B
Figure 2. Example Board Configurations for
Evaluating LDOs in the TO220 or TO263
packages.
Figure 3. PCB Layout − Top Assembly
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments
semiconductor products and disclaimers thereto appears at the end of this document.
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