TC1301B Microchip Technology, TC1301B Datasheet - Page 17

• Manufacturer Part Number: TC1301B
• Description: Dual LDO
• Manufacturer: Microchip Technology

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6.0
6.1
The TC1301A/B is used for applications that require
the integration of two LDO’s and a microcontroller
RESET.
FIGURE 6-1:
TC1301A/B.
6.1.1
6.2
6.2.1
The internal power dissipation within the TC1301A/B is
a function of input voltage, output voltage, output
current and quiescent current. The following equation
can be used to calculate the internal power dissipation
for each LDO.
© 2005 Microchip Technology Inc.
C
1 µF Ceramic
X5R
C
1 µF Ceramic
X5R
System RESET
System RESET
OUT1
OUT1
System RESET Load = 10 k
Input Voltage Range = 2.7V to 4.2V
2.8V @ 300 mA
2.8V @ 300 mA
C
10 nF Ceramic
bypass
APPLICATION CIRCUITS/
ISSUES
Typical Application
Power Calculations
Package Type = 3X3DFN8
V
APPLICATION INPUT CONDITIONS
POWER DISSIPATION
IN
V
maximum = 4.2V
IN
1
2
3
4
1
2
3
4
typical = 3.6V
V
V
RESET
V
GND
Bypass
RESET
V
GND
Bypass
OUT1
OUT2
OUT1
OUT1
TC1301A
TC1301B
Typical Application Circuit
SHDN2
SHDN2
SHDN1
ON/OFF Control V
= 300 mA maximum
= 150 mA maximum
V
V
ON/OFF Control V
V
OUT2
OUT2
DET
V
V
IN
IN
ON/OFF Control V
8
7
6
5
8
7
6
5
1.8V
@ 150 mA
1.8V
@ 150 mA
C
1 µF Ceramic
X5R
C
1 µF Ceramic
X5R
OUT2
OUT2
OUT2
OUT2
OUT1
C
1 µF
C
1 µF
BATTERY
IN
BATTERY
IN
2.7V
4.2V
2.7V
4.2V
to
to
EQUATION 6-1:
In addition to the LDO pass element power dissipation,
there is power dissipation within the TC1301A/B as a
result of quiescent or ground current. The power
dissipation as a result of the ground current can be
calculated using the following equation. The V
quiescent current and the V
considered. The V
quiescent current, while the V
the voltage detector current.
EQUATION 6-2:
The total power dissipated within the TC1301A/B is the
sum of the power dissipated in both of the LDO’s and
the P(I
the typical I
Operating at a maximum of 4.2V results in a power
dissipation of 0.5 milliWatts. For most applications, this
is small compared to the LDO pass device power
dissipation and can be neglected.
The
temperature specified for the TC1301A/B is 125
estimate the internal junction temperature of the
TC1301A/B, the total internal power dissipation is
multiplied by the thermal resistance from junction to
ambient (R
from junction to ambient for the 3X3DFN8 pin package
is estimated at 41
EQUATION 6-3:
P
V
V
P
V
I
I
T
P
R
T
VIN
VDET
LDO
IN(MAX)
OUT(MIN)
AMAX
I(GND)
IN(MAX)
J(MAX)
TOTAL
P
JA
LDO
GND
maximum
P
T
I GND
J MAX
= Maximum continuous junction
= Total device power dissipation.
= Thermal resistance from junction-to-
= Maximum ambient temperature.
= Total current in ground pin.
= Maximum input voltage.
= Current flowing in the V
= Current in the V
=
= LDO Pass device internal power
= Maximum input voltage
= LDO minimum output voltage
) term. Because of the CMOS construction,
temperature.
ambient.
output current on either LDO output.
RESET loaded.
JA
dissipation
V
GND
) of the device. The thermal resistance
IN MAX
=
=
°
V
C/W.
P
for the TC1301A/B is 116 µA.
continuous
IN MAX
IN
TOTAL
–
current is a result of LDO
TC1301A/B
V
OUT MIN
DET
DET
R
DET
I
VIN
JA
pin with
pin current are both
operating
current is a result of
+
+
IN
T
DS21798B-page 17
I
AMAX
VDET
pin with no
I
OUT MAX
junction
°
IN
C
.
pin
To