Transcript
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
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Improved Direct Replacement for 7660.
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1.5V to 6V Operation.
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No External Diode Required.
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Simple Conversion of +5V to -5V.
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Low Quiescent Current (Typical 36µA at VIN=5V).
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High Power Efficiency (Typical 98%)
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Boost Pin for Higher Switching Frequency.
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Improved SCR Latchup Protection.
to convert a positive input voltage in the range of 1.5V to 6V to the corresponding negative output
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Handheld Instruments.
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Data Acquisition Systems.
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Supply Splitter, VOUT= ±VIN /2.
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Operational Amplifier Supplies.
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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
V IN (1.5V to 6V)
3 4
divided (VOUT = VIN /2 ), or multiplied (V OUT = ±nV IN ), as shown in application examples.
n TYPICAL APPLICATION CIRCUIT
+
voltage can also be doubled (V OUT = 2V IN ),
regulator, oscillator, control circuitry and four
RS-232 Power Supplies.
2
voltage in the range of -1.5V to -6V. The input
The chip contains a series DC power supply
l
1
improved direct replacement for the popular 7660 and LTC1044, the main function of the AIC1660 is
n APPLICATIONS
10µF C1
The AIC1660 is a monolithic CMOS switched
BOOST
VIN
CAP+
OSC
7
Required for V IN ≤3V
6
LV
CAP-
5 VOUT
specific applications. The “LV” terminal may be tied to GND to improve low input voltage (VIN ≤3V) operation, or be left floating for input voltage larger than 3V to improve power dissipation.
8
GND
oscillator frequency to optimize performance in
The AIC1660 provides performance superior to previous
designs
by
combining
low
output
impedance, low quiescent current with high V OUT =-VI N
AIC1660
+
10µ F 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 TEL: 886-3-5772500
FAX: 886-3-5772510
www.analog.com.tw
DS-1660T-P5 012102
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AIC1660
n ORDERING INFORMATION AIC1660C XXX
PIN CONFIGURATION PACKING TYPE TR: TAPE & REEL TB: TUBE
DIP-8 SO-8 TOP VIEW
PACKAGE TYPE N: PLASTIC DIP S: SMALL OUTLINE
BOOST
Example: AIC1660CSTR à in SO-8 Package & Tape & Reel Packing Type (CN is not available in TR packing type.)
1
8
VIN
CAP+ 2
7
OSC
3
6
LV
CAP- 4
5
VOUT
GND
n ABSOLUTE MAXIMUM RATINGS Supply Voltage (VIN to GND, or GND to VOUT) ......… … … … … … … … ............................................. 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 1 BOOST 2 10µF
+
C1
VIN
IS
8
VIN
7 CAP+
IL
OSC 6
3 GND
LV
4 CAP-
VOUT 5
COSC
External Oscillator RL
VOUT C2 10µF
+
2
AIC1660
n
ELECTRICAL CHARACTERISTICS (VIN=5.0V, TA=25°C, OSC=OPEN, 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
η
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
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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
Oscillator Frequency, FOSC (KHz)
Oscillator Frequency, FOSC (KHz)
60
BOOST=VIN
50
40
30
20
BOOST=OPEN
10 5 1
2
3
4
5
6
4
6
8
10
12
14
16
35 30
PIN 1=VIN 25 20 15 10
PIN 1=OPEN 5 0 10
Supply Voltage, VIN (V)
2
Load Current (mA) Fig. 4 Output Voltage vs. Load Current (VIN=2V)
Load Current (mA) Fig. 3 Output Voltage vs. Load Current
100
1000
10000
External Capacitor (Pin 7 to GND), COSC (pF) Fig. 6 Oscillator Frequency vs. Value of C OSC
Fig. 5 Oscillator Frequency vs. Supply Voltage
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
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AIC1660
n BLOCK DIAGRAM 6 VIN 1 BOOST 7
Oscillator
÷2
OSC
Voltage Level Converter
2
CAP+
6 5
LV
4
VOUT CAP-
Substrate Logic Network
Voltage Regulator
3 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.
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AIC1660
n APPLICATION EXAMPLES 1 BOOST 2
1 0µF C1
+
VIN
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.
7 CAP+
OSC
3 GND
LV 6
4 CAP-
VOUT 5
AIC1660
Fig. 8
VIN (1.5V to 6V)
8
Required for V IN ≤ 3V VOUT = -VIN 10µF C2
+
Negative Voltage Converter
8
2
VIN 3
3
Fig. 9 shows the idealized negative voltage
C1
converter.
C2 5 4
VOUT =-VIN
7
Fig. 9
1 2 3 4
Idealized Negative Voltage Converter
BOOS
VIN 8
CAP+
OSC 7
GND
LV 6
CAP-
VOUT 5
U1
AIC1660
Fig. 10
VIN D1 1N4148
Fig. 10 shows a method of voltage doubling. VOUT=2V IN -2V D . To reduce the voltage drops
D2 +
1N4148 + C1 10µ F
VOUT
across diodes, use Schottky diodes.
C2 10µF
Voltage Doubling
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AIC1660
n APPLICATION EXAMPLES (Continued) (3 to 12V)
1 0µF
+ C1
1 BOOST
VIN 8
2 CAP+
OSC 7
3 GND
LV 6
4 CAP-
VOUT 5
VIN
An ultra precision voltage divider is shown in Fig. Required for V IN≤3V
the load current should be kept below 100nA. However, with a slight loss in accuracy, the load current can be increased.
AIC1660
VOUT +
11. To achieve the 0.002% accuracy as indicated,
C2 1 0µF
V OUT =VIN/2 ± 0.002% T MIN≤T A≤TMAX IL<100nA
Fig. 11
V BAT (6V)
Ultra Precision Voltage Divider
+ + C1 10 µF
1 BOOST
VIN 8
2 CAP+
OSC 7
3 GND
LV 6
4 CAP-
VOUT 5
V OUT = V BAT/2 (3.0V)
A common need in many systems is to obtain (+) and ( - ) supplies from a single
Required for VBAT≤3V V OUT = -V BAT/2(-3V)
battery or power supply system. Where current requirements are low, the circuit shown in Fig. 12 is a simple solution.
AIC1660
C2 1 0µF + Output Common
Fig. 12
Battery Splitter
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AIC1660
n PHYSICAL DIMENSIONS l
8 LEAD PLASTIC SO (unit: mm) D
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
H E
e
e
A
A1
C
B
l
1.27(TYP)
H
5.80
6.20
L
0.40
1.27
L
8 LEAD PLASTIC DIP (unit: mm) D
E1
E
A2 A1 C
L
eB b
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
e
8
