
TC1240/TC1240A
DS21516C-page 2
2003 Microchip Technology Inc.
1.0
ELECTRICAL
CHARACTERISTICS
Absolute Maximum Ratings
Input Voltage (V
IN
to GND)
TC1240 ............................................. +4.5V, -0.3V
TC1240A........................................... +5.8V, -0.3V
Output Voltage (V
OUT
to GND)
TC1240 .......................................+9.0V, V
IN
-0.3V
TC1240A................................... +11.6V, V
IN
-0.3V
Current at V
OUT
Pin............................................50 mA
Short-Circuit Duration: V
OUT
to GND.............Indefinite
Thermal Resistance .......................................210°C/W
Power Dissipation (
T
A
= +25
°C)........................600 mW
Operating Temperature Range.............-40°C to +85°C
Storage Temperature (Unbiased).......-65°C to +150°C
Stresses above those listed under “Absolute Maximum
Ratings” may cause permanent damage to the device. These
are stress ratings only and functional operation of the device
at these or any other conditions above those indicated in the
operation sections of the specifications is not implied.
Exposure to Absolute Maximum Rating conditions for
extended periods may affect device reliability.
TC1240 ELECTRICAL SPECIFICATIONS
Electrical Specifications:
Unless otherwise noted, typical values apply at T
A
= +25°C. Minimum and maximum val-
ues apply for T
A
= -40° to +85°C, and V
IN
= +2.8V, C
1
= C
2
= 3.3 μF, SHDN = GND.
Parameters
Sym
Min
Typ
Max
Units
Conditions
Supply Current
Shutdown Supply Current
Minimum Supply Voltage
Maximum Supply Voltage
Oscillator Frequency
Switching Frequency
(Note 1)
Shutdown Input Logic High
Shutdown Input Logic Low
Power Efficiency
Voltage Conversion Efficiency
Output Resistance
(Note 2)
I
DD
I
SHDN
V
MIN
V
MAX
F
OSC
F
SW
V
IH
V
IL
P
EFF
V
EFF
R
OUT
—
—
2.5
—
—
40
1.4
—
86
97.5
—
—
180
0.1
—
—
160
80
—
—
93
99.96
17
—
300
1.0
—
4.0
—
125
—
0.4
—
—
—
30
μA
μA
V
V
kHz
kHz
V
V
%
%
R
LOAD
=
∞
SHDN = V
IN
R
LOAD
= 1.0 k
R
LOAD
= 1.0 k
T
A
= -40°C to +85°C
T
A
= -40°C to +85°C
V
IN
= V
MIN
to V
MAX
V
IN
= V
MIN
to V
MAX
R
LOAD
= 1.0 k
R
LOAD
=
∞
R
LOAD
= 1.0 k
T
A
= -40°C to +85°C
Note 1:
Switching frequency is one-half internal oscillator frequency.
Capacitor contribution is approximately 26% of the output impedance [ESR = 1 / switching frequency x
capacitance].
2: