Datasheet

TC1240/TC1240A
DS21516D-page 2  2001-2012 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 I
DD
— 180 300 µA R
LOAD
= 
Shutdown Supply Current I
SHDN
— 0.1 1.0 µA SHDN = V
IN
Minimum Supply Voltage V
MIN
2.5 — — V R
LOAD
= 1.0 k
Maximum Supply Voltage V
MAX
——4.0VR
LOAD
= 1.0 k
Oscillator Frequency F
OSC
—160—kHzT
A
= -40°C to +85°C
Switching Frequency (Note 1) F
SW
40 80 125 kHz T
A
= -40°C to +85°C
Shutdown Input Logic High V
IH
1.4 — — V V
IN
= V
MIN
to V
MAX
Shutdown Input Logic Low V
IL
——0.4VV
IN
= V
MIN
to V
MAX
Power Efficiency P
EFF
86 93 — % R
LOAD
= 1.0 k
Voltage Conversion Efficiency V
EFF
97.5 99.96 — % R
LOAD
= 
Output Resistance (Note 2) R
OUT
—
—
17
—
—
30
 R
LOAD
= 1.0 k
T
A
= -40°C to +85°C
Note 1: Switching frequency is one-half internal oscillator frequency.
2: Capacitor contribution is approximately 26% of the output impedance [ESR = 1 / switching frequency x
capacitance].