Fairchild Semiconductor FAN5660 Datasheet
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FAN5660
Monolithic Inductorless CMOS DC/DC Converter
Features
• Inverts, Doubles or Splits Input Supply Voltage
• 90% Typ Conversion Efficiency at 100mA load current
• 0.5V Typ Loss at 100mA Load
• Low 160µA Operating Current
•5. 0Ω Typ Output Resistance for C1 = C2 = 100µF
• Selectable Oscillator Frequency: 5kHz/50kHz
• 8-pin SOIC package.
Applications
Laptop Computers
•
•
Medical Instruments
•
Interface Power Supplies
Hand-Held Instruments
•
•
Operational-Amplifier Power Supplies
Simplified Block Diagram
General Description
The FAN5660 is a monolithic charge-pump which can
invert, double or split a +1.5V to +5.5V input voltage.
Using only two identical low-cost capacitors, the charge
pump replaces switching regulators, thus eliminating
inductors and their associated cost, size, and EMI. The
device has a greater than 90% efficiency over most of its load
current range and a typical operating current of only 160µA.
The FAN5660 is ideal for both battery-powered and boardlevel voltage conversion applications.
In order to enable the user optimize capacitor size and
quiescent current, the FAN5660 is offered with a frequency
control (FC) pin which selects either 5kHz or 50kHz
operation.
The Oscillator frequency can also be driven with an external
clock. The FAN5660 is available in 8-pin small-outline
packages.
VSS
V+
SYNC
CAP+ CAP–
CONTROL
OSCILLATOR
VSH
LV
FC
REV. 1.0.2 3/28/02
FAN5660
Pin Configuration
Typical Applications
FC
CAP+
+
C1
VSS
CAP-
SYNC
V+
LV
VSH
RL
C1 = C2 = 1 to 470µF
FC
CAP+
VSS
CAP-
IN
V
V
OUT
+
= –V
C2
1
2
8
7
V+
SYNC
FAN5660
3
4
6
LV
5
VSH
SOIC
V
FC
+
IN
+VIN
C1
CAP+
VSS
CAP-
V+
SYNC
LV
VSH
C1 = C2 = 1 to 470µF
+
C2
OUT
= 2V
IN
Figure 1. Inverter, Test Circuit Figure 2. Doubler
IN
V
V
OUT
= –VIN/2
FC
+
+
C2
CAP+
C1
FAN5660
VSS
CAP-
V+
SYNC
LV
VSH
C1 = C2 = 1 to 470µF
Figure 3. Splitter
2
REV. 1.0.2 3/28/02
Pin Definition
FAN5660
Pin
Number
Pin
Name
Inverter Splitter Doubler
1 FC Frequency Control for Internal
Oscillator, FC open, f
typ; FC = V+, f
OSC
= 50kHz typ.
OSC
= 5kHz
Pin Function Description
Same as Inverter Same as Inverter
FC has no effect when SYNC pin is
driven externally
2 CAP+ Charge-Pump Capacitor, Positive
Same as Inverter Same as Inverter
Terminal
3 VSS Power-Supply Ground Input Power-Supply
Positive Voltage
4 CAP- Charge-Pump Capacitor,
Same as Inverter Same as Inverter
Negative Terminal
5 VSH Output, Negative Voltage Power-Supply
Ground Input
6 LV Low-Voltage Operation Input.
Tie LV to VSS when input voltage is
LV must be left open for all
input voltages
less than 2V.
Above 2V, LV must be left open.
7 SYNC Oscillator Control Input.
An external Oscillator may be
connected to overdrive SYNC via a
Same as inverter, however,
do not use SYNC in
voltage-splitting mode.
2 to 5 nF capacitor.
Output
Power-Supply
Positive Voltage
Input
Power-Supply
Ground Input
LV must be left open for
all input voltages
Same as inverter,
however, do not use
SYNC in voltagedoubling mode.
SYNC shall not be connected to a
low impedance DC voltage
8 V+ Power-Supply Positive Voltage
Input
Positive Voltage Input Positive Voltage Output
REV. 1.0.2 3/28/02
3
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