M
Features
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TC1240/TC1240A
General Description
The TC1240/TC1240A is a doubling CMOS charge
pump voltage converter in a small 6-Pin SOT-23A
package. The TC1240 doubles an input voltage that
can range from +2.5V to +4.0V, while the TC1240A
doubles an input voltage that can range from +2.5V to
+5.5V. Conversion efficiency is typically >99%. Internal
oscillator frequency is 160 kHz for both devices. The
TC1240 and TC1240A have an active-high shutdown
that limits the current consumption of the devices to
less than 1 µA.
External component requirement is only two capacitors
for standard voltage doubler applications. All other
circuitry (including control, oscillator and power
MOSFETs) are integrated on-chip. Typical supply cur-
rent is 180 µA for the TC1240 and 550 µA for the
TC1240A. Both devices are available in a 6-Pin SOT-
23A surface mount package.
Positive Doubling Charge Pumps with Shutdown
in a SOT-23 Package
Charge Pumps in 6-Pin SOT-23A Package
>99% Typical Voltage Conversion Efficiency
Voltage Doubling
Input Voltage Range, TC1240: +2.5V to +4.0V,
TC1240A: +2.5V to +5.5V
Low Output Resistance, TC1240: 17Ω (Typical)
TC1240A: 12Ω (Typical)
Only Two External Capacitors Required
Low Supply Current, TC1240: 180 µA (Typical)
TC1240A: 550 µA (Typical)
Power-Saving Shutdown Mode (1 µA Maximum)
Shutdown Input Fully Compatible with 1.8V Logic
Systems
Applications
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Cellular Phones
Pagers
PDAs, Portable Data Loggers
Battery Powered Devices
Handheld Instruments
Typical Application Circuit
Positive Voltage Doubler
+
C+
C-
V
IN
INPUT
Package Type
6-Pin SOT-23A
C+
6
V
OUT
SHDN
5
4
C
1
TC1240
TC1240A
SHDN
OFF
ON
V
OUT
GND
+
C
2
2 x INPUT
TC1240ECH
TC1240AECH
1
V
IN
2
GND
3
C-
NOTE:
6-Pin SOT-23A is equivalent to the
EIAJ (SC-74A)
2003 Microchip Technology Inc.
DS21516C-page 1
TC1240/TC1240A
1.0
ELECTRICAL
CHARACTERISTICS
† 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.
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
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
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)
Note 1:
2:
Sym
I
DD
I
SHDN
V
MIN
V
MAX
F
OSC
F
SW
V
IH
V
IL
P
EFF
V
EFF
R
OUT
Min
—
—
2.5
—
—
40
1.4
—
86
97.5
—
—
Typ
180
0.1
—
—
160
80
—
—
93
99.96
17
—
Max
300
1.0
—
4.0
—
125
—
0.4
—
—
—
30
Units
µA
µA
V
V
kHz
kHz
V
V
%
%
Ω
R
LOAD
=
∞
SHDN = V
IN
R
LOAD
= 1.0 kΩ
R
LOAD
= 1.0 kΩ
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 kΩ
R
LOAD
=
∞
R
LOAD
= 1.0 kΩ
T
A
= -40°C to +85°C
Conditions
Switching frequency is one-half internal oscillator frequency.
Capacitor contribution is approximately 26% of the output impedance [ESR = 1 / switching frequency x
capacitance].
DS21516C-page 2
2003 Microchip Technology Inc.
TC1240/TC1240A
TC1240A ELECTRICAL SPECIFICATIONS
Electrical Specifications:
Unless otherwise noted, typical values apply at T
A
= +25°C. Minimum and maximum
values apply for T
A
= -40° to +85°C, and V
IN
= +5.0V, C
1
= C
2
= 3.3 µF, SHDN = GND.
Parameters
Supply Current
Shutdown Supply Current
Minimum Supply Voltage
Maximum Supply Voltage
Output Current
Sum of the R
DS(ON)
of the
internal MOSFET Switches
Oscillator Frequency
Switching Frequency
(Note 1)
Shutdown Input Logic High
Shutdown Input Logic Low
Power Efficiency
Voltage Conversion Efficiency
Output Resistance
(Note 2)
Note 1:
2:
Sym
I
DD
I
SHDN
V
MIN
V
MAX
I
LOAD
R
SW
F
OSC
F
SW
V
IH
V
IL
P
EFF
V
EFF
R
OUT
Min
—
—
2.5
—
20
—
—
40
1.4
—
86
99
—
—
Typ
550
0.01
—
—
—
4
160
80
—
—
94
99.96
12
—
Max
900
1.0
—
5.5
—
8
—
125
—
0.4
—
—
—
25
Units
µA
µA
V
V
mA
Ω
kHz
kHz
V
V
%
%
Ω
I
LOAD
= 20 mA
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
I
LOAD
= 5 mA
R
LOAD
=
∞
I
LOAD
= 20 µA
T
A
= -40°C to +85°C
R
LOAD
=
∞
SHDN = V
IN
Conditions
Switching frequency is one-half internal oscillator frequency.
Capacitor contribution is approximately 26% of the output impedance [ESR = 1 / switching frequency x
capacitance].
2003 Microchip Technology Inc.
DS21516C-page 3
TC1240/TC1240A
2.0
Note:
TYPICAL PERFORMANCE CURVES
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.
Note:
Unless otherwise indicated, typical values apply at T
A
= +25°C.
700
SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
450
400
350
300
250
200
150
100
50
V
IN
= 2.8V
V
IN
= 4.0V
600
500
400
300
200
100
0
2.00
3.00
4.00
SUPPLY VOLTAGE (V)
5.00
6.00
0
-50
-25
0
25
50
75
TEMPERATURE (°C)
100
125
FIGURE 2-1:
Supply Current vs. Supply
Voltage (No Load).
OUTPUT SOURCE RESISTANCE (Ω)
20
FIGURE 2-4:
Supply Current vs.
Temperature (No Load).
OUTPUT SOURCE RESISTANCE (Ω)
25
20
V
IN
= 2.8V
15
V
IN
= 4.0V
10
5
0
-50
15
10
5
0
2.00
3.00
4.00
SUPPLY VOLTAGE (V)
5.00
6.00
-25
0
25
50
75
TEMPERATURE (°C)
100
125
FIGURE 2-2:
Output Source Resistance
vs. Supply Voltage (with R
LOAD
= 1 kΩ)
1
0.9
0.8
VOLT DROP (V)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
5
10
15 20 25 30 35
LOAD CURRENT (mA)
40
45
50
V
IN
= 2.8V
V
IN
= 4.0V
FIGURE 2-5:
Output Source Resistance
vs. Temperature (with R
LOAD
= 1 kΩ).
100%
90%
POWER EFFICIENCY (%)
80%
70%
60%
50%
40%
30%
20%
10%
0%
0
5
10
15 20 25 30 35
LOAD CURRENT (mA)
40
45
50
V
IN
= 2.5V
V
IN
= 3.5V
V
IN
= 4.5V
FIGURE 2-3:
Load Current.
Output Voltage Drop vs.
FIGURE 2-6:
Current.
Power Efficiency vs. Load
DS21516C-page 4
2003 Microchip Technology Inc.
TC1240/TC1240A
Note:
Unless otherwise indicated, typical values apply at T
A
= +25°C.
100
SWITCHING FREQUENCY (kHz)
80
V
IN
= 2.8V
60
40
20
0
-50
V
IN
= 4.0V
-25
0
25
50
75
TEMPERATURE (°C)
100
125
FIGURE 2-7:
Temperature.
Switching Frequency vs.
2003 Microchip Technology Inc.
DS21516C-page 5
