Datasheet

1
LTC1044A
12V CMOS
Voltage Converter
D
U
ESCRIPTIO
S
F
EA
T
U
RE
U
S
A
O
PP
L
IC
AT
I
■
1.5V to 12V Operating Supply Voltage Range
■
13V Absolute Maximum Rating
■
200µA Maximum No Load Supply Current at 5V
■
Boost Pin (Pin 1) for Higher Switching Frequency
■
97% Minimum Open Circuit Voltage Conversion
Efficiency
■
95% Minimum Power Conversion Efficiency
■
I
S
= 1.5µA with 5V Supply When OSC Pin = 0V or V
+
■
High Voltage Upgrade to ICL7660/LTC1044
■
Conversion of 10V to ±10V Supplies
■
Conversion of 5V to ±5V Supplies
■
Precise Voltage Division: V
OUT
= V
IN
/2 ±20ppm
■
Voltage Multiplication: V
OUT
= ±nV
IN
■
Supply Splitter: V
OUT
= ±V
S
/2
■
Automotive Applications
■
Battery Systems with 9V Wall Adapters/Chargers
The LTC1044A is a monolithic CMOS switched-capacitor
voltage converter. It plugs in for ICL7660/LTC1044 in
applications where higher input voltage (up to 12V) is
needed. The LTC1044A provides several conversion func-
tions without using inductors. The input voltage can be
inverted (V
OUT
= –V
IN
), doubled (V
OUT
= 2V
IN
), divided
(V
OUT
= V
IN
/2) or multiplied (V
OUT
= ±nV
IN
).
To optimize performance in specific applications, a boost
function is available to raise the internal oscillator fre-
quency by a factor of 7. Smaller external capacitors can be
used in higher frequency operation to save board space.
The internal oscillator can also be disabled to save power.
The supply current drops to 1.5µA at 5V input when the
OSC pin is tied to GND or V
+
.
U
A
O
PP
L
IC
AT
ITY
P
I
CA
L
Generating –10V from 10V Output Voltage vs Load Current, V
+
= 10V
LOAD CURRENT (mA)
0
OUTPUT VOLTAGE (V)
–4
–2
0
40
LTC1044A • TA02
–6
–8
–5
–3
–1
–7
–9
–10
10
20
30
50 60 70 80 90 100
T
A
= 25°C
C1 = C2 = 10µF
SLOPE = 45Ω
1
2
3
4
8
7
6
5

LTC1044A
V
+

OSC
LV
V
OUT
BOOST
CAP
+

GND
CAP
–
+
10µF
+
10µF
10V INPUT
–10V OUTPUT
LTC1044A • TA01