OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

TC1223-2.85VCTTR

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P16
TC1223/TC1224
DS21368C-page 4 2002-2012 Microchip Technology Inc.
3.0 DETAILED DESCRIPTION
The TC1223 and TC1224 are precision fixed output
voltage regulators. Unlike bipolar regulators, the
TC1223 and TC1224’s supply current does not
increase with load current. In addition, V
OUT
remains
stable and within regulation over the entire 0mA to
I
OUTMAX
operating load current range, (an important
consideration in RTC and CMOS RAM battery back-up
applications).
Figure 3-1 shows a typical application circuit. The
regulator is enabled any time the shutdown input
(SHDN
) is at or above V
IH
, and shutdown (disabled)
when SHDN
is at or below V
IL
. SHDN may be
controlled by a CMOS logic gate, or I/O port of a micro-
controller. If the SHDN
input is not required, it should be
connected directly to the input supply. While in
shutdown, supply current decreases to 0.05A (typical)
and V
OUT
falls to zero volts.
FIGURE 3-1: TYPICAL APPLICATION
CIRCUIT
3.1 Output Capacitor
A 1F (min) capacitor from V
OUT
to ground is
recommended. The output capacitor should have an
effective series resistance greater than 0.1 and less
than 5.0, and a resonant frequency above 1MHz. A
1F capacitor should be connected from V
IN
to GND if
there is more than 10 inches of wire between the
regulator and the AC filter capacitor, or if a battery is
used as the power source. Aluminum electrolytic or
tantalum capacitor types can be used. (Since many
aluminum electrolytic capacitors freeze at approxi-
mately -30°C, solid tantalums are recommended for
applications operating below -25°C.) When operating
from sources other than batteries, supply-noise
rejection and transient response can be improved by
increasing the value of the input and output capacitors
and employing passive filtering techniques.
TC1223
TC1224
V
OUT
SHDN
GND
NC
1μF
+
V
IN
V
OUT
Shutdown Control
(to CMOS Logic or Tie
to V
IN
if unused)
1μF
+
Battery
+
2002-2012 Microchip Technology Inc. DS21368C-page 5
TC1223/TC1224
4.0 THERMAL CONSIDERATIONS
4.1 Thermal Shutdown
Integrated thermal protection circuitry shuts the
regulator off when die temperature exceeds 160°C.
The regulator remains off until the die temperature
drops to approximately 150°C.
4.2 Power Dissipation
The amount of power the regulator dissipates is
primarily a function of input and output voltage, and
output current. The following equation is used to
calculate worst case actual power dissipation:
EQUATION 4-1:
The maximum allowable power dissipation (Equation
4-2) is a function of the maximum ambient temperature
(T
AMAX
), the maximum allowable die temperature
(T
JMAX
) and the thermal resistance from junction-to-air
(
JA
). The 5-Pin SOT-23A package has a
JA
of
approximately 220°C/Watt.
EQUATION 4-2:
Equation 4-1 can be used in conjunction with Equation
4-2 to ensure regulator thermal operation is within
limits. For example:
Given:
V
INMAX
= 3.0V ±10%
V
OUTMIN
= 2.7V – 2.5%
I
LOADMAX
= 40mA
T
JMAX
= 125°C
T
AMAX
= 55°C
Find: 1. Actual power dissipation
2. Maximum allowable dissipation
Actual power dissipation:
P
D
(V
INMAX
– V
OUTMIN
)I
LOADMAX
= [(3.0 x 1.1) – (2.7 x .975)]40 x 10
–3
= 26.7mW
Maximum allowable power dissipation:
In this example, the TC1223 dissipates a maximum of
26.7mW; below the allowable limit of 318mW. In a
similar manner, Equation 4-1 and Equation 4-2 can be
used to calculate maximum current and/or input
voltage limits.
4.3 Layout Considerations
The primary path of heat conduction out of the package
is via the package leads. Therefore, layouts having a
ground plane, wide traces at the pads, and wide power
supply bus lines combine to lower
JA
and therefore
increase the maximum allowable power dissipation
limit.
P
DMAX
= (T
JMAX
– T
AMAX
)
JA
Where all terms are previously defined.
P
DMAX
= (T
JMAX
– T
AMAX
)
JA
= (125 – 55)
220
= 318mW
TC1223/TC1224
DS21368C-page 6 2002-2012 Microchip Technology Inc.
5.0 TYPICAL CHARACTERISTICS
(Unless Otherwise Specified, All Parts Are Measured At Temperature = 25°C)
Note: The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein are
not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside the warranted range.
0.000
0.002
0.004
0.006
0.008
0.010
0.012
0.014
0.016
0.018
0.020
-40 -20 0 20 50 70 125
DROPOUT VOLTAGE (V)
I
LOAD
= 10mA
C
IN
= 1μF
C
OUT
= 1μF
TEMPERATURE (°C)
Dropout Voltage vs. Temperature
(V
OUT
= 3.3V)
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0.140
0.160
0.180
0.200
-40 -20 0 20 50 70 125
DROPOUT VOLTAGE (V)
I
LOAD
= 100mA
C
IN
= 1μF
C
OUT
= 1μF
TEMPERATURE (°C)
Dropout Voltage vs. Temperature
(V
OUT
= 3.3V)
0
10
20
30
40
50
60
70
80
90
GND CURRENT (
μ
A)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5
I
LOAD
= 100mA
C
IN
= 1μF
C
OUT
= 1μF
Ground Current vs. V
IN
(V
OUT
= 3.3V)
V
IN
(V)
0.000
0.010
0.020
0.030
0.040
0.050
0.060
0.070
0.080
0.090
0.100
-40 -20 0 20 50 70 125
DROPOUT VOLTAGE (V)
I
LOAD
= 50mA
C
IN
= 1μF
C
OUT
= 1μF
TEMPERATURE (°C)
Dropout Voltage vs. Temperature
(V
OUT
= 3.3V)
0
10
20
30
40
50
60
70
80
90
GND CURRENT (
μ
A)
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5
I
LOAD
= 10mA
C
IN
= 1μF
C
OUT
= 1μF
Ground Current vs. V
IN
(V
OUT
= 3.3V)
V
IN
(V)
0
0.5
1
1.5
2
2.5
3
3.5
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7
I
LOAD
= 0
C
IN
= 1μF
C
OUT
= 1μF
V
IN
(V)
V
OUT
(V)
V
OUT
vs.
V
IN
(V
OUT
= 3.3V)
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P16

TC1223-2.85VCTTR

Mfr. #:
Buy TC1223-2.85VCTTR
Manufacturer:
Microchip Technology
Description:
LDO Voltage Regulators 50mA LDO w/Shutdown
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet