
2
Inverting Dual (
–
V
IN
,
–
2V
IN
)
Charge Pump Voltage Converters
with Shutdown
TC1235
TC1236
TC1237
TC1235/6/7-1 3/24/00
2001 Microchip Technology Inc. DS21371A
Power Dissipation (T
A
≤
70
°
C) MSOP-10 .............320mW
Storage Temperature (Unbiased) .........
–
65
°
C to +150
°
C
Lead Temperature (Soldering, 10sec) ..................+260
°
C
*This is a stress rating only and functional operation of the device at these
or any other conditions above those indicated in the operational 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)......................... +6.0V,
–
0.3V
Output Voltage (
–
V
IN
,
–
2V
IN
to GND)........
–
12.0V, + 0.3V
Current at
–
V
IN
,
–
2V
IN
Pins ......................................10mA
Short-Circuit Duration
–
V
IN
,
–
2V
IN
to GND ........ Indefinite
Operating Temperature Range ...............
–
40
°
C to +85
°
C
PIN DESCRIPTION
Pin Number
Name
Description
1
2
3
4
5
6
7
8
9
C1
–
C2+
NC
C2
–
–
2V
IN
GND
V
IN
SHDN
C1+
–
V
IN
C1 Commutation Capacitor Negative Terminal.
C2 Commutation Capacitor Positive Terminal.
No Connection.
C2 Commutation Capacitor Negative Terminal.
Doubling Inverting Charge Pump Output (
–
2 x V
IN
).
Ground.
Positive Power Supply Input.
Shutdown Input (Active Low).
C1 Commutation Capacitor Positive Terminal.
Inverting Charge Pump Output (
–
1 x V
IN
).
10
NOTES:
1. Capacitor contribution is approximately 20% of the
output impedance [ESR = 1 / pump frequency x capacitance)].
ELECTRICAL CHARACTERISTICS:
T
A
=
–
40
°
C to +85
°
C, V
IN
= +5V, C1 = 3.3
μ
F, C2 = 1
μ
F (TC1235); C1 = 1
μ
F, C2
= 0.33
μ
F (TC1236); C1 = 0.33
μ
F, C2 = 0.1
μ
F (TC1237), SHDN = V
IN
, unless otherwise noted. Typical values are at T
A
= +25
°
C.
Symbol Parameter
Device
Test Conditions
Min
Typ
Max
Unit
I
DD
Supply Current
TC1235
TC1236
TC1237
SHDN = V
IN
SHDN = V
IN
SHDN = V
IN
SHDN = GND, V
IN
= +5V
R
LOAD
= 1k
for
–
V
IN
output
R
LOAD
= 10k
for
–
2V
IN
output
R
LOAD
= 1k
for
–
V
IN
output
R
LOAD
= 10k
for
–
2V
IN
output
—
—
—
—
1.8
75
200
625
0.1
—
120
360
1500
1
—
μ
A
I
SHDN
V
MIN
Shutdown Supply Current All
Minimum Supply Voltage All
μ
A
V
V
MAX
Maximum Supply Voltage All
—
—
5.5
V
F
OSC
Oscillator Frequency
TC1235
TC1236
TC1237
All
8.4
24.5
65
1.4
12
35
125
—
15.6
45.5
170
—
kHz
V
IH
Shutdown Input
Logic High
Shutdown Input
Logic low
Voltage Conversion
Efficiency (Stage 1)
Voltage Conversion
Efficiency (Stage 2)
Output Resistance
for
–
V
IN
output (Note 1)
Output Resistance
for
–
2V
IN
output (Note 1)
Wake-Up Time
From Shutdown Mode
Stage 1
Wake-Up Time
From Shutdown Mode
Stage 2
V
IN
= V
MIN
to V
MAX
V
V
IL
All
V
IN
= V
MIN
to V
MAX
—
—
0.4
V
V
EFF1
All
R
LOAD
=
∞
for
–
V
IN
output
R
LOAD
=
∞
for
–
2V
IN
output
R
LOAD
=
∞
for
–
V
IN
output
R
LOAD
=
∞
for
–
2V
IN
output
I
LOAD
= 0.5mA to 5mA
No Load at -V
IN
Output
I
LOAD
= 0.1mA to 1mA
No Load at -2V
IN
Output
R
LOAD
= 1k
for -V
IN
Output
R
LOAD
= 10k
for -2V
IN
Output
96
99.5
—
%
V
EFF2
All
94
99
—
%
R
OUT1
All
—
45
80
R
OUT2
All
—
135
420
T
WK1
TC1235
TC1236
TC1237
TC1235
TC1236
TC1237
—
—
—
—
—
—
650
250
100
750
280
120
—
—
—
—
—
μ
sec
T
WK2
R
LOAD
= 1k
for -V
IN
Output
R
LOAD
= 10k
for -2V
IN
Output
μ
sec