NSC LM2662M, LM2662MX Datasheet
LM2662/LM2663
Switched Capacitor Voltage Converter
General Description
The LM2662/LM2663 CMOS charge-pump voltage converter inverts a positive voltage in the range of 1.5V to 5.5V
to thecorresponding 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.
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
Basic Application Circuits
Voltage Inverter
DS100003-1
Positive Voltage Doubler
DS100003-2
Splitting VINin Half
DS100003-3
January 1999
LM2662/LM2663 Switched Capacitor Voltage Converter
© 1999 National Semiconductor Corporation DS100003 www.national.com
Absolute Maximum Ratings (Note 1)
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
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 2) 1 sec.
Power Dissipation (T
A
= 25˚C) (Note 3) 735 mW
T
J
Max (Note 3) 150˚C
θ
JA
(Note 3) 170˚C/W
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
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
1=C2
= 47 µF.(Note 4)
Symbol Parameter Condition Min Typ Max Units
V+ Supply Voltage R
L
= 1k Inverter, LV = Open 3.5 5.5
Inverter, LV = GND 1.5 5.5 V
Doubler, LV = OUT 2.5 5.5
I
Q
Supply Current No Load FC = V+ (LM2662)
1.3 4
mALV = Open SD = Ground (LM2663)
FC = Open 0.3 0.8
I
SD
Shutdown Supply Current
10 µA
(LM2663)
V
SD
Shutdown Pin Input Voltage Shutdown Mode 2.0 (Note 5)
V
(LM2663) Normal Operation 0.3
I
L
Output Current 200 mA
R
OUT
Output Resistance (Note 6) IL= 200 mA 3.5 7 Ω
f
OSC
Oscillator Frequency (Note 7) OSC = Open FC = Open 7 20
kHz
FC=V+ 55 150
f
SW
Switching Frequency (Note 8) OSC = Open FC = Open 3.5 10
kHz
FC=V+ 27.5 75
I
OSC
OSC Input Current FC = Open
±
2
µA
FC=V+
±
10
P
EFF
Power Efficiency RL(500) between V+and OUT 90 96
%
I
L
= 200 mA to GND 86
V
OEFF
Voltage Conversion Efficiency No Load 99 99.96
%
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
DMax
=(T
JMax−TA
)/θJA, where T
JMax
is the maximum junction temperature, TAis the
ambient temperature, and θ
JA
is the junction-to-ambient thermal resistance of the specified package.
Note 4: In the test circuit, capacitors C
1
and C2are 47 µF, 0.2Ω maximum ESR capacitors. Capacitors with higherESRwillincreaseoutputresistance,reduceoutput
voltage and efficiency.
Note 5: In doubling mode, when V
out
>
5V, minimum input high for shutdown equals V
out
−3V.
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
OSC
=
2f
SW
.
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Test Circuits
Typical Performance Characteristics
(Circuit of
Figure 1
)
DS100003-4
DS100003-5
FIGURE 1. LM2662 and LM2663 Test Circuits
Supply Current vs
Supply Voltage
DS100003-37
Supply Current vs
Oscillator Frequency
DS100003-38
Output Source
Resistance vs Supply
Voltage
DS100003-39
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Typical Performance Characteristics (Circuit of
Figure 1
) (Continued)
Output Source
Resistance vs
Temperature
DS100003-40
Output Source
Resistance vs
Temperature
DS100003-41
Efficiency vs Load
Current
DS100003-42
Output Voltage Drop
vs Load Current
DS100003-43
Efficiency vs
Oscillator Frequency
DS100003-44
Output Voltage vs
Oscillator Frequency
DS100003-45
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