AIC AIC1660CN

AIC1660
Switched-Capacitor Voltage Converter
n FEATURES
l
n DESCRIPTION
Lowest Output Impedance (Typical 35Ω
at
VIN=5V).
capacitor voltage converter. Designed to be an
l
Improved Direct Replacement for 7660.
l
1.5V to 6V Operation.
l
No External Diode Required.
l
Simple Conversion of +5V to -5V.
l
Low Quiescent Current (Typical 36µA at VIN=5V).
l
High Power Efficiency (Typical 98%)
l
Boost Pin for Higher Switching Frequency.
l
Improved SCR Latchup Protection.
improved direct replacement for the popular 7660
and LTC1044, the main function of the AIC1660 is
to convert a positive input voltage in the range of
1.5V to 6V to the corresponding negative output
voltage in the range of -1.5V to -6V. The input
voltage can also be doubled (V OUT = 2V IN ),
divided (VOUT = VIN /2 ), or multiplied (V OUT =
±nV IN ), as shown in application examples.
n APPLICATIONS
The chip contains a series DC power supply
regulator, oscillator, control circuitry and four
l
RS-232 Power Supplies.
l
Handheld Instruments.
l
Data Acquisition Systems.
l
Supply Splitter, VOUT= ±VIN /2.
l
Operational Amplifier Supplies.
l
Panel Meter.
output power MOS switches. The frequency of
oscillator can be lowered by the addition of an
external capacitor to the OSC pin, or the oscillator
may be over-driven by an external clock.
The boost function is available to raise the
n TYPICAL APPLICATION CIRCUIT
1
2
+
larger than 3V to improve power dissipation.
7
3
6
4
5
specific applications. The “LV” terminal may be
≤3V) operation, or be left floating for input voltage
8
AIC1660
oscillator frequency to optimize performance in
tied to GND to improve low input voltage (V IN
VIN (1.5V to 6V)
10µF
C1
The AIC1660 is a monolithic CMOS switched
Required for
VIN ≤3V
The AIC1660 provides performance superior to
previous
designs
by
combining
low
output
impedance, low quiescent current with high
VOUT=-VIN
+
10µF
C2
efficiency, and by eliminating diode drop voltage
losses. The only required external components
are two low cost electrolytic capacitors.
Negative Voltage Converter
Analog Integrations Corporation
4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC
DS-1660T-P4
TEL: 886-3-5772500
Oct. 4, 01
FAX: 886-3-5772510
www.analog.com.tw
1
AIC1660
n ORDERING INFORMATION
AIC1660 CX
ORDER NUMBER
PIN CONFIGURATION
TOP VIEW
PACKAGE TYPE
N: PLASTIC DIP
S: SMALL OUTLINE
AIC1660CN
(PLASTIC DIP)
BOOST
8 VIN
1
7 OSC
CAP+ 2
AIC1660CS
(PLASTIC SO)
GND 3
6 LV
CAP- 4
5 VOUT
n ABSOLUTE MAXIMUM RATINGS
Supply Voltage .............… … … … … … ............… … … … … … … … ....................................................... 6.0V
Input Voltage on Pin 1, 6 and 7 ...… … … … … ..........................… … … … … … … ............. -0.3V ~VIN + 0.3V
Operating Temperature Range ........… … … … ................… … … … … … .… … .......… … ........... -40°C~+85°C
Storage Temperature Range..........… … … … ...................… … … … … … … … ........................
-65°C~150°C
n TEST CIRCUIT
10µF
+
C1
IS
VIN 8
1
BOOST
2
CAP+
3
AIC1660
LV
GND
4
CAP-
VIN
IL
OSC 7
COSC
External
Oscillator
RL
6
VOUT 5
VOUT
C2
10µF
+
2
AIC1660
n
ELECTRICAL CHARACTERISTICS (VIN=5.0V, TA=25°C, OSC=free running,
unless otherwise specified.)
PARAMETER
TEST CONDITIONS
SYMBOL
Supply Current
RL = ∞
IS
Minimum Supply Voltage
RL = ∞
VINL
Maximum Supply Voltage
RL = ∞
VINH
Output Resistance
IL =20mA,
ROUT
MIN
TYP
MAX
UNIT
36
70
µA
1.5
V
35
6
V
70
Ω
FOSC =10KHz
Oscillator Frequency
FOSC
Pin 1 Floating or GND
10
Pin 1=VIN
50
Power Efficiency
RL= 5K, FOSC =10KHz
Voltage Conversion Efficiency
RL = ∞
KHz
PEFF
96
98
%
VOUTEFF
98
99.9
%
TYPICAL PERFORMANCE CHARACTERISTICS (TA=25°C)
100
Power Efficiency (%)
50
Supply Current (µA)
n
COSC =0
40
30
20
10
90
80
70
60
0
1
2
3
4
5
6
Supply Voltage (V)
Fig. 1 Supply Current vs. Supply Voltage
50
0
10
20
30
40
50
60
70
80
Load Current (mA)
Fig. 2 Power Efficiency vs. Load Current
3
AIC1660
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
2
Output Voltage (V)
Output Voltage (V)
-5
-4
-3
1
0
-1
-2
-2
-10
0
10
20
30
40
50
60
70
0
80
Oscillation Frequency, FOSC (KHz)
Oscillation Frequency, FOSC (KHz)
60
50
40
BOOST MODE
30
20
10
5 1
2
3
4
5
6
2
4
6
8
10
12
14
16
Load Current (mA)
Fig. 4 Power Efficiency vs. Load Current (VIN=2V)
Load Current (mA)
Fig. 3 Output Voltage vs. Load Current
35
30
PIN 1=VIN
25
20
15
10
PIN 1=OPEN
5
0
10
100
1000
10000
Supply Voltage, VIN (V)
External Capacitor (Pin 7 to GND), COSC (pF)
Fig. 5 Oscillator Frequency vs. Supply Voltage
Fig. 6 Oscillator Frequency vs Value of C OSC
450
400
Output Resistance ROUT (Ω)
n
C1=C2=100µF
C1=C2=10µF
C1=C2=1µF
300
200
100
0
0.1
1
10
100
Oscillation Frequency, FOSC (KHz)
Fig. 7
Output Resistance vs. Oscillation Frequency
4
AIC1660
n BLOCK DIAGRAM
VIN
BOOST
Oscillator
÷2
OSC
Voltage
Level
Converter
CAP+
LV
VOUT
CAPSubstrate
Logic
Network
Voltage
Regulator
GND
n PIN DESCRIPTIONS
PIN 1: BOOST- The frequency of oscillator will
be 5 times if boost pin is
connected to VIN.
PIN 6: LV
- If VIN is below 3V, LV should be
tied to GND. For VIN larger than
3V, LV can be floating.
PIN 2: CAP+ - To be connected to the positive
side of the flying capacitor.
PIN 7: OSC
- The frequency of oscillator can
be lowered by the addition of an
external capacitor to the OSC
pin, or the oscillator may be
over-driven by an external clock.
PIN 8: VIN
- Input supply.
PIN 3: GND
- Ground
PIN 4: CAP-
- To be connected to the negative
side of flying capacitor.
PIN 5: VOUT - Negative output voltage, typically
connected to a 10µF capacitor.
5
AIC1660
n APPLICATION EXAMPLES
VIN (1.5V to 6V)
10µF
C1
1
8
2
7
AIC1660
+
3
6
4
5
VOUT =-VIN
+
Fig. 8
Fig. 8 shows a typical connection, which will
provide a negative supply from an available
positive supply without the need of any external
diodes. The LV pin should be connect to ground
for VIN≤3V, or may be “floated“ for VIN >3V
Required for
VIN≤3V
10µF
C2
Negative Voltage Converter
1N4148
VIN (1.5V to 6V)
IOUT
R1
220Ω
C1
10µF
+
1
2
8
VOUT=2VIN
+ (3V to 12V)
C2
10µF
7
AIC1660
3
6
4
5
Fig. 9
Fig. 9 shows a method of voltage doubling.
Voltage doubling is achieved by simply
rearranging the connection of the two external
capacitors. An external 470KΩ resistor is
required to ensure the oscillator will start.
R2 470K
Voltage Doubling
(3 to 12V)
VI N
10µF
VOUT =VIN/2 ± 0.002%
T MIN≤T A≤T MAX
IL <100nA
Fig. 10
+
C1
+
1
8
2
7
AIC1660
3
6
4
5
C2
10 µF
An ultra precision voltage divider is shown in Fig.
10. To achieve the 0.002% accuracy as indicated,
the load current should be kept below 100nA.
However, with a slight loss in accuracy, the load
current can be increased.
Required for VI N≤3V
Ultra Precision Voltage Divider
6
AIC1660
n APPLICATION EXAMPLES (Continued)
VBAT
(6V)
+
1
8
2
7
3
6
4
5
+
C1
10µF
VOUT= VBAT/2 (3.0V)
A common need in many systems is to obtain (+)
and ( - ) supplies from a single battery or power
supply system. Where current requirements are
Required for VBAT≤3V low, the circuit shown in Fig. 11 is a simple
VOUT= -VBAT/2(-3V)
solution.
AIC1660
C2
10µ F
+
Output
Common
Fig. 11
Battery Splitter
n PHYSICAL DIMENSIONS
8 LEAD PLASTIC SO (unit: mm)
D
H
E
e
SYMBOL
MIN
MAX
A
1.35
1.75
A1
0.10
0.25
B
0.33
0.51
C
0.19
0.25
D
4.80
5.00
E
3.80
4.00
e
1.27(TYP)
A
C
A1
l
B
H
5.80
6.20
L
0.40
1.27
L
7
AIC1660
l
8 LEAD PLASTIC DIP (unit: mm)
D
E1
E
A2
A1
C
L
eB
b
e
SYMBOL
MIN
MAX
A1
0.381
—
A2
2.92
4.96
b
0.35
0.56
C
0.20
0.36
D
9.01
10.16
E
7.62
8.26
E1
6.09
7.12
e
2.54 (TYP)
eB
—
10.92
L
2.92
3.81
8