AMS682 ADMOS | Alldatasheet

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Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140 Advanced AMS682 Monolithic INVERTING VOLTAGE DOUBLER Systems FEATURES APPLICATIONS

  • • 99.9% Voltage Conversion Efficiency •• Portable Handheld Instrumentation
  • • 92% Power Conversion Efficiency •• Cellular Phones
  • • Wide Input Voltage Range +2.4V to 5.5V •• Panel Meters
  • • 185 µµA Supply Current •• -10V from +5V logic Supply
  • • Available in SO-8 and PDIP Packages •• -6V from a Single 3V Lithium Cell
  • • Only 3 external Capacitors Required •• LCD Display Bias Generator
  • • Operational Amplifiers Power Supplies GENERAL DESCRIPTION The AMS682 is a CMOS charge pump converter that provides an inverted doubled output from a single positive supply. Requiring only three external capacitors for full circuit implementation the device has an on -board 12kHz (typical) oscillator which provides the clock. Low output source impedance (typically 140 Ω ), provides output current up to 10mA. The AMS682 features low quiescent current and high efficiency, making it the ideal choice for a wide variety of applications that require a negative voltage derived from a single positive supply. The compact size and minimum external parts count of the AMS682 makes it useful in many medium current, dual voltage analog power supplies. The AMS682E is operational in the full industrial temperature range of -40 °C to 85 °C while AMS682C is operating over a 0 °C to 70 °C temperature range. The AMS682E/AMS682C are available in surface mount 8-Pin SOIC (SO-8) and 8-Pin Plastic DIP (PDIP) packages. ORDERING INFORMATION: PACKAGE TYPE OPERATING

8 LEAD SOIC 8 LEAD PDIP TEMPERATURE RANGE

AMS682ES AMS682EP -40 to 85 ° C AMS682CS AMS682CP 0 to 70 ° C TYPICAL OPERATING CIRCUIT PIN CONFIGURATIONS V IN V OUT GND All Caps = 3.3 µF V OUT = -(2 X V IN ) +2.4V < V IN < +5.5V C 2 C 1 C OUT V IN V OUT GND C 1 C 2 C 1 C 2 ON/OFF 8-LEAD DIP/ 8-LEAD SOIC AMS682 ON/OFF C + V IN GNDV OUT C - C + C -

Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140 AMS682 ABSOLUTE MAXIMUM RATINGS V IN +5.8V Operating Temperature Range V IN ΔV/ ΔT 1V/ µsec AMS682E -40 °C to 85 °C V OUT -11.6V AMS682C 0 °C to 70 °C V OUT Short Circuit Duration Continuous Storage temperature -85 °C to +150 °C Power Dissipation (T A 70 °C) Soldering information Plastic DIP 730mW Lead Temperature (Soldering 10sec) +300 °C SOIC 470mW

ELECTRICAL CHARACTERISTICS

Electrical Characteristics at V IN =+5V and T A = +25°C test circuit figure 1, unless otherwise specified. Parameter Conditions AMS682 Min Typ Max Units Supply Voltage Range V IN R L =2k Ω 2.4  5.5 V Supply Current IIN R L = ∞ R L = ∞ 185 300 400 µA V OUT Source Resistance Source Resistance R OUT I - L = 10mA I - L =10mA I - L = 5mA , V IN = 2.8V 140 170 180 230 320 Ω Oscillator Frequency F OSC  12  kHz Power Efficiency P EFF R L = 2k Ω 90 92  % Voltage Conversion Efficiency V OUT E FF V OUT R L = ∞ 99 99.9  % PIN DESCRIPTION PIN NO 8-PIN DIP/SOIC SYMBOL DESCRIPTION

1 C 1

  • Input. Capacitor C 1 negative terminal.

2 C 2

+ Input. Capacitor C 2 positive terminal.

3 C 2

  • Input. Capacitor C 2 negative terminal 4 V OUT Output. Negative output voltage (-2V IN ) 5 GND Input. Device ground. 6 V IN Input. Power supply voltage.

7 C 1

+ Input. Capacitor C 1 positive terminal. 8 ON/OFF ON/OFF Oscilator. V IN (+5V) V - OUT GND All Caps = 3.3 µF

  • V- OUT C 1 V IN ON/OFF GND 7 8 C OUT R L C 2 C 1

Figure 1. AMS682 Test Circuit

Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140 AMS682 DETAILED DESCRIPTION Phase 1 V SS charge storage- before this phase of the clock cycle, capacitor C 1 is already charged to +5V. C 1 + is then switched to ground and the charge in C 1 - is transferred to C 2 - . Since C 2 + is at +5V, the voltage potential across capacitor C 2 is now -10V. C 3 C1 C2 SW2 -5V SW4 SW3 SW1 V IN =+5V V OUT Figure 2. Charge Pump - Phase 1 Figure 3. Charge Pump - Phase 2 maximum supply voltage will potentially damage the chip. over the entire operating temperature range.

  • The charge pump switches have virtually no offset and are extremely low on resistance.
  • Minimal power is consumed by the drive circuitry.
  • The Impedances of the reservoir and pump capacitors are negligible. For the AMS682, efficiency is as shown below: Voltage Efficiency = V OUT / (-2V IN ) V OUT = -2V IN + V DROP V DROP = (I OUT ) (R OUT ) Power Loss = I OUT (V DR OP ) There will be a substantial voltage difference between V OUT and IN if the impedances of the pump capacitors C 1 and C 2 are high with respect to their respective output loads. If the values of the reservoir capacitor C 3 are larger the output ripple will be reduced. The efficiency will be improved if both pump and reservoir capacitors have larger values. ( See “Capacitor Selection” in Application Section.)

APPLICATIONS

Negative Doubling Converter The AMS682 is most commonly used as a charge pump voltage converter which provides a negative output of two times a positive input voltage (Fig.4) GND V IN6 V - OUT + C 1 C 2 GND V IN V- OUT C 3 22 µF 22 µF 22 µF C 1 C 2 ON/OFF 8 Figure 4. Inverting Voltage Doubler

Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140 AMS682 TYPICAL PERFORMANCE CHARACTERISTICS (F OSC = 12kHz) V IN = 5V V IN = 5V I OUT = 10mA NO LOAD V IN = 5V C3 = 10 µF -7.5 -8.0 -8.5 -9.0 -9.5 -10.0 -10.5 0 5 10 15 240 220 180 160 140 120 1 2 3 4 5 6 V OUT vs. Load Current Output Resistance vs. V IN 200 OUTPUT RESISTANCE ( Ω) V OUT (V) V IN (V)LOAD CURRENT 200 180 160 140 120 100 -50 0 50 100 1 2 3 4 65 300 250 200 150 100 SUPPLY CURRENT ( µA) V IN (V) OUTPUT SOURCE RESISTANCE ( Ω ) Output Source Resistance vs. Temperature TEMPERATURE (°C) 200 150 100 0 5 10 15 20 OUTPUT CURRENT (mA) Output Ripple vs. Output Current OUTPUT RIPPLE (mV PK-PK) Supply Current vs. V IN C1-C3 = 3.3 µF C3 = 100 µF

Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140 AMS682 PACKAGE DIMENSIONS inches (millimeters) unless otherwise noted.

8 LEAD SOIC PLASTIC PACKAGE (S)

8 LEAD PLASTIC DIP PACKAGE (P)

0°-8° TYP 0.010-0.020 (0.254-0.508) S (SO-8 ) AMS DRW# 042293 x 45° 0.016-0.050 (0.406-1.270) 0.008-0.010 (0.203-0.254) 0.004-0.010 (0.101-0.254) 0.014-0.019 (0.355-0.483) 0.053-0.069 (1.346-1.752) 0.050 (1.270) TYP 0.150-0.157** (3.810-3.988) 0.228-0.244 (5.791-6.197) 0.189-0.197* (4.801-5.004) *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 1 2 3 4 8 7 6 5 0.045-0.065 (1.143-1.651) 0.255±0.015* (6.477±0.381) 0.400* (10.160) MAX 1 2 3 4 8 7 6 5 0.130±0.005 (3.302±0.127) 0.018±0.003 (0.457±0.076) 0.100±0.010 -0.381 0.325 +0.025 -0.015 0.009-0.015 (0.229-0.381) 0.300-0.325 (7.620-8.255) 0.065 (1.651) TYP 0.005 (0.127) MIN 0.125 (3.175) MIN 0.015 (0.380) MIN *DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTUSIONS. MOLD FLASH OR PROTUSIONS SHALL NOT EXCEED 0.010" (0.254mm) P (8L PDIP ) AMS DRW# 042294