CAT661 Datasheet, PDF (1/16 Pages) Catalyst Semiconductor – High Frequency 100mA CMOS Charge Pump, Inverter/Doubler

CAT661
High Frequency 100mA CMOS Charge Pump, Inverter/Doubler
FEATURES
ALOGEN ^FR
LEA _{D F REETM}
I Converts V+ to V- or V+ to 2V+
I Low output resistance, 10Ω max.
I High power efficiency
I Selectable charge pump frequency of 25kHz
or 135kHz; optimize capacitor size.
I Low quiescent current
I Pin-compatible to MAX660, LTC660 with higher
frequency operation
I Available in 8-pin SOIC, DIP and 0.8mm thin
4x4mm TDFN packages
I Lead-free, halogen-free package option
APPLICATIONS
I Negative voltage generator
I Voltage doubler
I Voltage splitter
I Low EMI power source
I GaAs FET biasing
I Lithium battery power supply
I Instrumentation
I LCD contrast bias
I Cellular phones, pagers
DESCRIPTION
The CAT661 is a charge-pump voltage converter. It can
invert a positive input voltage to a negative output. Only
two external capacitors are needed. With a guaranteed
100mA output current capability, the CAT661 can replace
a switching regulator and its inductor. Lower EMI is
achieved due to the absence of an inductor.
In addition, the CAT661 can double a voltage supplied
from a battery or power supply. Inputs from 2.5V to 5.5V
will yield a doubled, 5V to 11V output.
A Frequency Control pin (BOOST/FC) is provided to
select either a high (typically 135kHz) or low (25kHz)
internal oscillator frequency, thus allowing quiescent
current vs. capacitor size trade-offs to be made. The
135kHz frequency is selected when the FC pin is
connected to V+. The operating frequency can also be
adjusted with an external capacitor at the OSC pin or by
driving OSC with an external clock.
Both 8-pin DIP and SO packages are available. The
TDFN package 4x4mm footprint features a 0.8mm
maximum height. For die availability, contact Catalyst
Semiconductor marketing.
The CAT661 can replace the MAX660 and the LTC660
in applications where higher oscillator frequency and
smaller capacitors are needed. In addition, the CAT661
is pin compatible with the 7660/1044, offering an easy
upgrade for applications with 100mA loads.
TYPICAL APPLICATION
+VIN
1.5V to 5.5V
C1
+
1 BOOST/FC
V+ 8
2 CAP+
OSC 7
CAT661
3 GND
LV 6
4 CAP-
OUT 5
VOLTAGE INVERTER
Inverted
Negative
Voltage
Output
C1 ⁺
VIN = 2.5V to 5.5V
1 BOOST/FC
V+ 8
2 CAP+ _CAT661 OSC 7
3 GND
LV 6
4 CAP-
OUT 5
POSITIVE VOLTAGE DOUBLER
Doubled
Positive
Voltage
Output
© 2005 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. 5003, Rev. J