LTC660 Datasheet, PDF (1/12 Pages) Linear Technology – 100mA CMOS Voltage Converter

LTC660
100mA CMOS
Voltage Converter
FEATURES
s _{Simple Conversion of 5V to – 5V Supply}
s _{Output Drive: 100mA}
s _{ROUT: 6.5Ω (0.65V Loss at 100mA)}
s _{BOOST Pin (Pin 1) for Higher Switching Frequency}
s _{Inverting and Doubling Modes}
s _{Minimum Open Circuit Voltage Conversion}
Efficiency: 99%
s _{Typical Power Conversion Efficiency}
with a 100mA Load: 88%
s _{Easy to Use}
U
APPLICATIONS
s _{Conversion of 5V to ±5V Supplies}
s _{Inexpensive Negative Supplies}
s _{Data Acquisition Systems}
s _{High Current Upgrade to LTC1044 or LTC7660}
DESCRIPTION
The LTC^®660 is a monolithic CMOS switched-capacitor
voltage converter. It performs supply voltage conversion
from positive to negative from an input range of 1.5V to
5.5V, resulting in complementary output voltages of
– 1.5V to – 5.5V. It also performs a doubling at an input
voltage range of 2.5V to 5.5V, resulting in a doubled
output voltage of 5V to 11V. Only two external capacitors
are needed for the charge pump and charge reservoir
functions.
The converter has an internal oscillator that can be
overdriven by an external clock or slowed down when
connected to a capacitor. The oscillator runs at a 10kHz
frequency when unloaded. A higher frequency outside the
audio band can also be obtained if the BOOST pin is tied
to V ⁺.
The LTC660 contains an internal oscillator, divide-by-two,
voltage level shifter and four power MOSFETs.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
Generating – 5V from 5V
1 _BOOST
V^{+ 8}
2 _CAP+
OSC ⁷
+
C1
150µF
3
LTC660
GND
LV
6
4 _CAP–
V_OUT ⁵
5V INPUT
–5V
OUTPUT
C2
150µF
660 TA01
Output Voltage vs
Load Current for V⁺ = 5V
–5.0
T_A = 25°C
R_OUT = 6.5Ω
–4.8
–4.6
–4.4
–4.2
–4.0
0
20
40
60
80 100
LOAD CURRENT (mA)
660 TA02
1