Document
AIC1660
Switched-Capacitor Voltage Converter
n FEATURES
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n DESCRIPTION
at The AIC1660 is a monolithic CMOS switched capacitor voltage converter. Designed to be an 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. The chip contains a series DC power supply regulator, oscillator, control circuitry and four 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 oscillator frequency to optimize performance in specific applications. The “LV” terminal may be tied to GND to improve low input voltage (V IN ≤3V) operation, or be left floating for input voltage larger than 3V to improve power dissipation.
Required for VIN ≤3V VOUT=-VIN + 10µF C2
Lowest Output Impedance (Typical 35Ω VIN=5V). Improved Direct Replacement for 7660. 1.5V to 6V Operation. No External Diode Required. Simple Conversion of +5V to -5V.
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Low Quiescent Current (Typical 36µA at VIN=5V). High Power Efficiency (Typical 98%) Boost Pin for Higher Switching Frequency. Improved SCR Latchup Protection.
n APPLICATIONS
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RS-232 Power Supplies. Handheld Instruments. Data Acquisition Systems. Supply Splitter, VOUT= ±VIN /2. Operational Amplifier Supplies. Panel Meter.
n TYPICAL APPLICATION CIRCUIT
VIN (1.5V to 6V) 1 2 10µF C1 + 3 4 AIC1660 8 7 6 5
The AIC1660 provides performance superior to previous designs by combining low output impedance, low quiescent current with high 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 DS-1660T-P4 Oct. 4, 01
4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC TEL: 886-3-5772500 FAX: 886-3-5772510
www.analog.com.tw
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AIC1660
n ORDERING INFORMATION
AIC1660 CX
PACKAGE TYPE N: PLASTIC DIP S: SMALL OUTLINE
ORDER NUMBER AIC1660CN (PLASTIC DIP) AIC1660CS (PLASTIC SO)
PIN CONFIGURATION
TOP VIEW BOOST 1 8 VIN 7 OSC 6 LV 5 VOUT
CAP+ 2 GND 3 CAP- 4
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
1 2 10µF + C1 3 4 BOOST CAP+ VIN 8 OSC 7 COSC 6 IS VIN IL External Oscillator RL
AIC1660 LV GND CAP-
VOUT 5 C2 10µF +
VOUT
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AIC1660
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ELECTRICAL CHARACTERISTICS (VIN=5.0V, TA=25° C, OSC=free running,
unless otherwise specified.) PARAMETER Supply Current Minimum Supply Voltage Maximum Supply Voltage Output Resistance TEST CONDITIONS RL = ∞ RL = ∞ RL = ∞ IL =20mA, FOSC =10KHz Oscillator Frequency COSC =0 Pin 1 Floating or GND Pin 1=VIN Power Efficiency Voltage Conversion Efficiency RL= 5K, FOSC =10KHz RL = ∞ PEFF VOUTEFF 96 98 FOSC 10 50 98 99.9 % % KHz SYMBOL IS VINL VINH ROUT 35 1.5 6 70 MIN TYP 36 MAX 70 UNIT µA V V Ω
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TYPICAL PERFORMANCE CHARACTERISTICS (TA=25° C)
100
50
Supply Current (µA)
40
30
Power Efficiency (%)
1 2 3 4 5 6
90
80
20
70
10
60
0
50 0 10 20 30 40 50 60 70 80
Supply Voltage (V) Fig. 1 Supply Current vs. Supply Voltage
Load Current (mA)
Fig. 2 Power Efficiency vs. Load Current
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AIC1660
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TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
-5
2
Output Voltage (V)
Output Voltage (V)
1
-4
0
-3
-1
-2
-2
-10 0 10 20 30 40 50 60 70 80
0
2
4
6
8
10
12
14
16
Load Current (mA) Fig. 3 Output Voltage vs. Load Current
Load Current (mA) Fig. 4 Power Efficiency vs. Load Current (VIN=2V)
60
Oscillation Frequency, FOSC (KHz)
35 30
Oscillation Frequency, FOSC (KHz)
PIN 1=VIN
25 20 15 10
50
40
BOOST MODE
30
20
PIN 1=OPEN
5 0 10 100 1000
10 5 1 2 3 4 5 6
Supply Voltage, VIN (V)
Fig. 5 Oscillator Frequency vs. Supply Voltage
External Capacitor (Pin 7 to GND), COSC (pF)
10000
Fig. 6 Oscillator Frequency vs Value of C OSC
450
Output Resistance ROUT (Ω )
400
C1=C2=100µ F 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
VIN BOOST OSC Voltage Level Converter
Oscillator
¡Ò 2
CAP+
LV
VOUT CAPVoltage Regulator Substrate Logic Network
GND
n PIN DESCRIPTIONS
PIN 1: BOOST- The freq.