MC7660N

MC7660 MC7660 Charge Pump DC-DC Voltage Converter Features MC7660 is a charge pump dc-to-dc voltage converter using AL-gate CMOS technology and optimization design. It converters a +4V to +10V input to a corresponding -4V to -10V output using only two external capacitors, eliminating inductors and their associated cost, size and EMI. The on-board oscillator operates at a nominal frequency of 10KHz. Operation below 10 KHz (for lower supply current applications) is possible by connecting an external capacitor from OSC to ground. • Converts +5V Logic supply to + 5V； • Wide input voltage range: 4V~10V ； • Efficient voltage conversion: 99.9%； • Good power efficiency: 98%； • Low power supply: 40uA @5V input； • Easy to use: only two external capacitors required； • Compatible with RS232 negative powersupply standard； • High ESD protection: up to 3kV； • No Dx diode needed for high voltage operation； • Package : SOP8, DIP8。 Applications • LCD Display Module； • Specially designed LCD display module； • Instrument product。 ORDERING INFORMATION DEVICE Package Type MARKING Packing Packing Qty MC7660N DIP8 MC7660 TUBE 2000/box MC7660M/TR SOP8 MC7660 REEL 2500/reel http://www.hgsemi.com.cn 1 2020 MAR MC7660 Pin Configuration MC7660 Pin Assigment PIN Number SOP8 1 2 3 4 5 6 7 8 DIP8 1 2 3 4 5 6 7 8 PIN NAME NC CAP+ GND CAP Vout Low Voltage OSC V+ FUNCTION No connection Connecting external capacitor(+) pin Ground pin Connecting external capacitor(-) pin Voltage output pin Low voltage selection pin Connecting oscillation capacitor pin Power supply pin Block Diagram MC7660 http://www.hgsemi.com.cn 2 2020 MAR MC7660 Absolute Maximum Ratings PARAMETER Input voltage LV PIN input voltage OSC PIN input voltage LV PIN input voltage Output Short Duration (Vsupply ≤5.5V) ContinuousTotal SOP8 Power Dissipation（TA DIP8 ≤75℃） Operating Ambient Temperature Storage Temperature Soldering temperature and time SYMBAL VIN VLX VOSC ILV RATINGS +10.5V -0.3～(V++0.3)（if V+5.5V） 20（if V+>3.5V） UNITS V V µA ∞ Pd 470 mW Pd 730 mW TOpr -40~+85 ℃ Tstg -65~+150 ℃ Tsolder 260℃, 10s Electrical Characteristics(V+=5V,COSC=0) Symbol Item Conditions Min Typ Max Unit I+ V+H + VL Supply Current Supply Voltage, High Supply Voltage, Low RL=∞ LV Open LV to GND IOUT=20mA TA=25℃ IOUT=5mA V+=3V TA=25℃ Pin 7 open RL=5kΩ RL=∞ — 4.0 2.5 40 — — 100 10 3.5 µA V V ROUT FOSC PEFF VOUTEFF Output Resistance Oscillator Frequency Power Efficiency Voltage Conversion Efficiency — 95 98 70 Ω 120 Ω 10 98 99.9 — — — kHz % % Test Circuits MC7660 http://www.hgsemi.com.cn 3 2020 MAR MC7660 Type Characteristics Operation MC7660 together with two external capacitors C1 、C2 complement a voltage Inverter. Capacitor C1 is charged to a voltage V+, for the first half cycle when switches S1 and S3 are closed ( while switches S2 and S4 are open during this half cycle); During the second half cycle of operation, switches S2 and S4 are + closed, with S1 and S3 open, thereby shifting capacitor C2 negatively to -V . The voltage regulator portion of the chip is an integral part of the anti-latch-up circuitry. Its inherent voltage drop can degrade operation at low voltages. To improve low-voltage operation, the LV pin should be connected to GND, disabling the regulator. For supply voltages greater than 3.5V, the LV terminal must be left open to ensure latch-up-proof operation. http://www.hgsemi.com.cn 4 2020 MAR MC7660 Theoretical Power Efficiency Considerations In theory, a capacitive charge pump can approach 100% efficiency if certain conditions are met: 1、 The drive circuitry consumes no power. 2、 The output switches have extremely low ON resistance and no offset when operation. 3、 The impedances of the pump and reservoir capacitors are negligible at the pump frequency. Notes: 1、Supply voltage should not exceed maximum rating; 2、Do not connect LV terminal to GND for supply voltages greater than 3.5V; + 3、Do not short circuit the output to V supply for voltages above 5.5V for extended periods; 4、Polarized capacitors should be connected as the figure above. Typical Application MC7660 MC7660 MC7660 MC7660 may be paralleled to reduce output Above figure is the basic application circuit to resistance (see the above figure) provide a negative supply from -4.0V~ -10V while a positive supply from +4.0V ~ +10V is Rout=Rout(of MC7660 )/n(number of devices) + available. When V =+5V, the output resistance is about 70Ω; The output voltage is –4V while the load current is 10mA. MC7660 MC7660 MC7660 MC7660 MC7660 may be cascaded as shown above to MC7660 may be cascaded as shown above to produce larger negative output voltage (-10V). produce larger negative output voltage (-15V). However, The output resistance is approximately two However, The output resistance is approximately two of a single chip resistance. of a single chip resistance. http://www.hgsemi.com.cn 5 2020 MAR MC7660 MC7660 MC7660 To increase the conversion efficiency, the oscillator frequency may be lowered by connecting a capacitor from pin 7 and pin 8 as shown above. This reduces the switching losses. However, lowering the oscillator frequency will cause an undesirable increase in the impedance of the pump MC7660 may be applied to achieve positive voltage multiplication using the circuit shown in the above figure and reservoir capacitors. So, the values of C1 and C2 should be increased by the same factor that the MC7660 MC7660 In Since the switches that allow the charge pumping above figure, C1、C3 are the pump and reservoir capacitors respectively for the operation are bi-directional, the charge transfer generation of the negative voltage; C2、C4 are can be performed backwards as easily as the pump and reservoir capacitors respectively forwards. for the multiplied positive voltage. When +5V transforming –5V to +5V. The only problem hear is supply is provided, +9V and -5V can be that the internal clock and switch-drive section will generated. not operate until some positive voltage has been In the above figure, MC7660 generated. An initial inefficient pump, as show in left figure, could be used to start this circuit up, after which it will bypass the other (D1 and D2 in left figure would never turn on),or else the diode and resistor show dotted in above figure can used to “force” the internal regulator on. http://www.hgsemi.com.cn 6 2020 MAR MC7660 MC7660 In some applications due to noise, it may be desirable to increase the oscillator frequency. This can be achieved by overdriving the oscillator from an external clock as shown in the above figure. The external clock output should connect a 1k Ω resistor to prevent device latch-up. Besides, the pump frequency will be half of the clock frequency because of the internal circuit http://www.hgsemi.com.cn 7 2020 MAR MC7660 PACKAGE SOP8  

    Dimensions In Millimeters Symbol
Min
Max
Symbol
Min
Max
A 1.225 1.570 D 
  A1   Q  B
   a 
  C    b   C1  
 DIP8
   
 
    
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 2020 MAR MC7660 Important statement: Huaguan Semiconductor Co,Ltd. reserves the right to change the products and services provided without notice. Customers should obtain the latest relevant information before ordering, and verify the timeliness and accuracy of this information. Customers are responsible for complying with safety standards and taking safety measures when using our products for system design and machine manufacturing to avoid potential risks that may result in personal injury or property damage. Our products are not licensed for applications in life support, military, aerospace, etc., so we do not bear the consequences of the application of these products in these fields. Our documentation is only permitted to be copied without any tampering with the content, so we do not accept any responsibility or liability for the altered documents. http://www.hgsemi.com.cn 9 2020 MAR