Datasheet
P =(V V ) I- ´
D IN OUT OUT
TLV712xx
SBVS150A –SEPTEMBER 2010–REVISED JANUARY 2011
www.ti.com
DROPOUT VOLTAGE The internal protection circuitry of the TLV712xx has
been designed to protect against overload conditions.
The TLV712xx uses a PMOS pass transistor to
It was not intended to replace proper heatsinking.
achieve low dropout. For the complete output voltage
Continuously running the TLV712xx into thermal
range of 0.7 V to 1.2 V, the device can supply 300
shutdown degrades device reliability.
mA with a rated minimum input voltage of 2.0 V. Note
that the dropout voltage specification is not relevant
POWER DISSIPATION
for the TLV712xx family of devices because the
output voltage range of the device does not exceed
The ability to remove heat from the die is different for
1.2 V and the minimum input voltage for the device is
each package type, presenting different
2.0 V.
considerations in the printed circuit board (PCB)
layout. The PCB area around the device that is free
TRANSIENT RESPONSE of other components moves the heat from the device
to the ambient air.
As with any regulator, increasing the size of the
output capacitor reduces over-/undershoot magnitude Thermal performance data for TLV712xx were
but increases the duration of the transient response. gathered using the TLV700 evaluation module (EVM),
a two-layer board with two ounces of copper per side.
The dimensions and layout for the SOT23-5 package
UNDERVOLTAGE LOCKOUT (UVLO)
EVM are shown in Figure 19 and Figure 20.
The TLV712xx uses an undervoltage lockout circuit to
Corresponding thermal performance data are given in
keep the output shut off until internal circuitry is
Table 1. Note that this board has provision for
operating properly.
soldering not only the SOT23-5 package on the
bottom layer, but also an SC-70 package on the top
THERMAL INFORMATION
layer. The dimensions and layout of the SON-6 (DSE)
package EVM are shown in Figure 21 and Figure 22.
Thermal protection disables the output when the
Corresponding thermal performance data are given in
junction temperature rises to approximately +165°C,
Table 1. Using heavier copper increases the
allowing the device to cool. When the junction
effectiveness in removing heat from the device. The
temperature cools to approximately +145°C, the
addition of plated through-holes to heat-dissipating
output circuitry is again enabled. Depending on power
layers also improves heatsink effectiveness.
dissipation, thermal resistance, and ambient
temperature, the thermal protection circuit may cycle
Power dissipation depends on input voltage and load
on and off. This cycling limits the dissipation of the
conditions. Power dissipation (P
D
) is equal to the
regulator, protecting it from damage as a result of
product of the output current and the voltage drop
overheating.
across the output pass element, as shown in
Equation 2.
Any tendency to activate the thermal protection circuit
indicates excessive power dissipation or an
(2)
inadequate heatsink. For reliable operation, junction
temperature should be limited to +125°C maximum.
PACKAGE MOUNTING
To estimate the margin of safety in a complete design
Solder pad footprint recommendations for the
(including heatsink), increase the ambient
TLV712xx are available from the Texas Instruments
temperature until the thermal protection is triggered;
web site at www.ti.com. The recommended land
use worst-case loads and signal conditions.
pattern for the DBV and DSE packages are shown in
Figure 23 and Figure 24 respectively.
Table 1. EVM Dissipation Ratings
PACKAGE R
qJA
T
A
< +25°C T
A
= +70°C T
A
= +85°C
DBV 200°C/W 500 mW 275 mW 200 mW
DSE 180°C/W 555 mW 305 mW 222 mW
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