Charge Pump Voltage Converters
FEATURES
•
•
•
•
•
•
Simple Conversion of +5V Logic Supply to ±5V Supplies
Simple Voltage Multiplication (V
OUT
= (-) nV
IN
)
Typical Open Circuit Voltage Conversion Efficiency 99.9%
Typical Power Efficiency 98%
Wide Operating Voltage Range- TJ7660 1.5V to 10.0V
Easy to Use - Requires Only 2 External Non-Critical
Passive Components
• No External Diode Over Full Temp. and Voltage Range
TJ7660
SOP-8 PKG
DIP-8 PKG
APPLICATION
•
•
•
•
On Board Negative Supply for Dynamic RAMs
Localized µProcessor (8080 Type) Negative Supplies
Inexpensive Negative Supplies
Data Acquisition Systems
< Pin Configuration
ORDERING INFORMATION
Device
TJ7660D
TJ7660N
Package
SOP-8
D I P-8
DESCRIPTION
The HTC TJ7660 is a monolithic CMOS power supply circuit which offers unique performance
advantages over previously available devices.
The TJ7660 performs supply voltage conversions from positive to negative for an input range
of +1.5V to +10.0V resulting in complementary output voltages of -1.5V to -10.0V. Only 2
noncritical external capacitors are needed for the charge pump and charge reservoir functions.
The TJ7660 can also be connected to function as voltage doublers and will generate output
voltages up to +18.6V with a +10V input. Contained on the chip are a series DC supply
regulator, RC oscillator, voltage level translator, and four output power MOS switches.
A unique logic element senses the most negative voltage in the device and ensures that the
output N-Channel switch source-substrate junctions are not forward biased. This assures
latchup free operation.
The oscillator, when unloaded, oscillates at a nominal frequency of 10kHz for an input supply
voltage of 5.0V.
This frequency can be lowered by the addition of an external capacitor to the “OSC” terminal,
or the oscillator may be overdriven by an external clock.
The “LV” terminal may be tied to GROUND to bypass the internal series regulator and improve
( )
(
)
Jan. 2007-Rev 1.0
1
HTC