National Semiconductor LM2662, LM2663 Technical data
LM2662/LM2663
Switched Capacitor Voltage Converter
LM2662/LM2663 Switched Capacitor Voltage Converter
January 1999
General Description
The LM2662/LM2663 CMOS charge-pump voltage converter inverts a positive voltage in the range of 1.5V to 5.5V
to the corresponding negative voltage. The LM2662/LM2663
uses two low cost capacitors to provide 200 mA of output
current without the cost, size, and EMI related to inductor
based converters. With an operating current of only 300 µA
and operating efficiency greater than 90% at most loads, the
LM2662/LM2663 provides ideal performance for battery
powered systems. The LM2662/LM2663 may also be used
as a positive voltage doubler.
The oscillator frequency can be lowered by adding an external capacitor to the OSC pin. Also, the OSC pin may be used
to drive the LM2662/LM2663 with an external clock. For
LM2662, a frequency control (FC) pin selects the oscillator
frequency of 20 kHz or 150 kHz. For LM2663, an external
shutdown (SD) pin replaces the FC pin. The SD pin can be
used to disable the device and reduce the quiescent current
to 10 µA. The oscillator frequency for LM2663 is 150 kHz.
Basic Application Circuits
Voltage Inverter Positive Voltage Doubler
Features
n Inverts or doubles input supply voltage
n Narrow SO-8 Package
n 3.5Ω typical output resistance
n 86% typical conversion efficiency at 200 mA
n (LM2662) selectable oscillator
frequency: 20 kHz/150 kHz
n (LM2663) low current shutdown mode
Applications
n Laptop computers
n Cellular phones
n Medical instruments
n Operational amplifier power supplies
n Interface power supplies
n Handheld instruments
10000301
10000302
Splitting VINin Half
10000303
© 2004 National Semiconductor Corporation DS100003 www.national.com
Absolute Maximum Ratings (Note 1)
Power Dissipation (TA= 25˚C) (Note 3) 735
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (V+ to GND, or GND to OUT) 6V
LM2662/LM2663
LV (OUT − 0.3V) to (GND + 3V)
FC, OSC, SD The least negative of (OUT − 0.3V)
or (V+ − 6V) to (V+ + 0.3V)
V+ and OUT Continuous Output Current 250 mA
Output Short-Circuit Duration to GND (Note
Max (Note 3) 150˚C
T
J
θ
(Note 3) 170˚C/W
JA
Operating Junction
Temperature
Range −40˚C to +85˚C
Storage Temperature Range −65˚C to +150˚C
Lead Temperature (Soldering, 10 seconds) 300˚C
ESD Rating 2 kV
2) 1 sec.
Electrical Characteristics
Limits in standard typeface are for TJ= 25˚C, and limits in boldface type apply over the full operating temperature range. Unless otherwise specified: V+ = 5V, FC = Open, C
Symbol Parameter Condition Min Typ Max Units
V+ Supply Voltage R
I
Q
I
SD
Supply Current No Load FC = V+ (LM2662)
Shutdown Supply Current
= 1k Inverter, LV = Open 3.5 5.5
L
(LM2663)
V
SD
Shutdown Pin Input Voltage Shutdown Mode 2.0 (Note 5)
(LM2663) Normal Operation 0.3
I
R
f
f
I
L
OUT
OSC
SW
OSC
Output Current 200 mA
Output Resistance (Note 6) IL= 200 mA 3.5 7 Ω
Oscillator Frequency (Note 7) OSC = Open FC = Open 7 20
Switching Frequency (Note 8) OSC = Open FC = Open 3.5 10
OSC Input Current FC = Open
FC=V+
P
EFF
V
OEFF
Note 1: Absolute maximum ratings indicate limits beyond which damage to the device may occur. Electrical specifications do not apply when operating the device
beyond its rated operating conditions.
Note 2: OUT may be shorted to GND for one second without damage. However, shorting OUT to V+ may damage the device and should be avoided. Also, for
temperatures above 85˚C, OUT must not be shorted to GND or V+, or device may be damaged.
Note 3: The maximum allowable power dissipation is calculated by using P
ambient temperature, and θ
Note 4: In the test circuit, capacitors C
output voltage and efficiency.
Note 5: In doubling mode, when V
Note 6: Specified output resistance includes internal switch resistance and capacitor ESR.
Note 7: For LM2663, the oscillator frequency is 150 kHz.
Note 8: The output switches operate at one half of the oscillator frequency, f
Power Efficiency RL(500) between V+and OUT 90 96 %
I
= 200 mA to GND 86
L
Voltage Conversion Efficiency No Load 99 99.96 %
is the junction-to-ambient thermal resistance of the specified package.
JA
and C2are 47 µF, 0.2Ω maximum ESR capacitors. Capacitors with higher ESR will increase output resistance, reduce
1
>
5V, minimum input high for shutdown equals V
out
= 47 µF.(Note 4)
1=C2
Inverter, LV = GND 1.5 5.5 V
Doubler, LV = OUT 2.5 5.5
1.3 4
FC = Open 0.3 0.8
10 µA
FC=V+ 55 150
FC=V+ 27.5 75
±
2
±
10
DMax
OSC
=(T
=2fSW.
JMax−TA
−3V.
out
)/θJA, where T
is the maximum junction temperature, TAis the
JMax
mW
mALV = Open SD = Ground (LM2663)
V
kHz
kHz
µA
www.national.com 2
Test Circuits
10000304
FIGURE 1. LM2662 and LM2663 Test Circuits
Typical Performance Characteristics
(Circuit of Figure 1)
LM2662/LM2663
10000305
Supply Current vs
Supply Voltage
Output Source
Resistance vs Supply
Voltage
10000337
Supply Current vs
Oscillator Frequency
10000338
Output Source
Resistance vs
Temperature
10000339
10000340
www.national.com3
Typical Performance Characteristics (Circuit of Figure 1) (Continued)
Output Source
Resistance vs
Temperature
LM2662/LM2663
Efficiency vs Load
Current
Output Voltage Drop
vs Load Current
Output Voltage vs
Oscillator Frequency
10000341
10000343
10000342
Efficiency vs
Oscillator Frequency
10000344
Oscillator Frequency
vs External
Capacitance
10000345
www.national.com 4
10000346
Loading...