HT7660 CMOS Switched-Capacitor Voltage Converter Features · No external diode required · Simple conversion of VDD to -VDD · Cascade connection (two devices are connected, · Typically with no load voltage conversion, 99.9% effi- VOUT= -2 VDD) ciency · Boost pin for higher switching frequency · Typical power efficiency is 98% · Easy to use · Wide operating voltage range: 3V to 12V · 8-pin DIP/SOP package - Requires only two external capacitors Applications · RS-232 power supply · Operation amplifier supply · On board negative supply for dynamic RAMS · Data acquisition systems · Supply voltage splitter, VO= ± VDD/2 · Positive voltage doubler General Description an RC oscillator can be lowered by adding an external capacitor between VDD and the OSC pin, or an external clock can be connected to the OSC pin to replace the original oscillator. The LV terminal may be tied to VSS to disable the voltage regulator. By doing this, low voltage operation can be improved. HT7660 is a monolithic CMOS switched-capacitor voltage converter. HT7660 is designed to complete a voltage conversion from positive to negative. The only required external components are two low cost electrolytic capacitors. HT7660 includes a voltage regulator, an RC oscillator and four output power MOS switches. The frequency of Block Diagram VDD OSC BOOST RC Oscillator CAP+ Voltage Level Shifter CAP VOUT LV Voltage Regulator Logic Network VSS Rev. 1.10 1 January 21, 2003 HT7660 Pin Assignment B O O C A V C A S T P + S S P 1 8 2 7 3 6 4 5 V D D O S C L V V O U T H T 7 6 6 0 8 D IP -A /S O P -A Pin Description Pin No. Pin Name I/O Internal Connection Description 1 BOOST I CMOS Pull-low 2 CAP+ O CMOS 3 VSS ¾ ¾ 4 CAP- O NMOS This pin is connected to the negative terminal of Capacitor C1 for a charge pump 5 VOUT O NMOS This pin is connected to the negative terminal of Capacitor C2 for charge reservoir. Output voltage pass through this pin 6 LV I ¾ Floating this pin enables the voltage regulator. Connect this pin to VSS (Ground) to bypass voltage regulator and improve low voltage operation 7 OSC I/O Transmission Gate External clock input pin. This pin can be connected with an external capacitor to reduce switching frequency 8 VDD ¾ Positive power supply ¾ Higher switching frequency selection input This pin is connected to the positive terminal of Capacitor C1 for a charge pump Negative power supply, ground Absolute Maximum Ratings Supply Voltage ...........................VSS-0.3V to VSS+13V Operating Temperature...........................-40°C to 85°C Storage Temperature ............................-50°C to 125°C Note: These are stress ratings only. Stresses exceeding the range specified under ²Absolute Maximum Ratings² may cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability. Electrical Characteristics Symbol VDD Parameter Operating Voltage ISTB Standby Current fOSC System Frequency ROUT Output Source Resistance VCON-EFF Voltage Conversion Efficiency PEFF Power Efficiency Rev. 1.10 Ta=25°C Test Conditions VDD Conditions ¾ ¾ 3V 5V No load 3V ¾ 5V Min. Typ. Max. Unit V 3 ¾ 12 ¾ 26 100 ¾ 80 160 2.5 4 ¾ 5 10 ¾ 3V IOUT=10mA ¾ 97 150 5V IOUT=20mA ¾ 60 100 99 ¾ ¾ 99 99.9 ¾ 96 ¾ ¾ 96 98 ¾ 3V 5V 3V 5V No load RL=5kW 2 mA kHz W % % January 21, 2003 HT7660 Functional Description For high voltage operation, the LV pin is left floating to enable the voltage regulator. This can reduce the current consumption of the RC oscillator, and thus get a fixed switching frequency fOSC with high voltage range. For low voltage operation, the LV pin is connected to VSS to bypass the voltage regulator of which inherent voltage drop can degrade the operation at low voltages. HT7660 needs only two external polarized electrolytic capacitors to complete a negative voltage converter. HT7660 has four MOS power switches: S1, S2, S3 and S4. For the first half cycle, when S2 and S4 are open, Capacitor C1 is charged to a voltage VDD through S1 and S3. During the second half cycle, when S1 and S3 are open, the charge on Capacitor C1 is shifted to Capacitor C2 through S2 and S4. Thereby, the voltage across Capacitor C2 is VDD. Because the positive terminal of C2 is connected to VSS, we get a -VDD voltage at VOUT pin. V S 1 D D A capacitor may be connected between VDD and pin OSC to lower the switching fOSC, and an external clock may be added to replace the built-in RC oscillator. S 2 C A P + C 1 V V S S S S C 2 S 4 S 3 V C A P - O U T = - V D D The operating mode of HT7660 Application Circuits Simple Negative Voltage Converter V V D D 1 2 B O O S T 8 V D D C A P + 6 L V 1 0 m F 4 3 C A P - D D 5 V O U T V V S S O U T = -V D D 1 0 m F H T 7 6 6 0 Simple Voltage Multiplier V 2 V D D C A P + D D 8 2 1 0 m F 4 3 C A P V S S V O U T V D D C A P + 8 1 0 m F 5 4 3 H T 7 6 6 0 C A P - V O U T 5 V O U T = - 2 V D D 1 0 m F V S S H T 7 6 6 0 1 0 m F Rev. 1.10 3 January 21, 2003 HT7660 External Switching Frequency V 2 8 V D D C A P + V 4 C A P - 3 C M O S G a te 5 V O U T V S S D D 1 k W 7 O S C 1 0 m F D D V O U T 1 0 m F H T 7 6 6 0 Lower Switching Frequency V 2 V D D C A P + 4 3 N o te : C C A P - O S C 5 V O U T V S S C 7 O S C 1 0 m F D D 8 V O U T 1 0 m F O S C H T 7 6 6 0 is te n s o f p ic o fa r a d Positive Voltage Doubler V 2 3 8 V D D C A P + D D D 1 V S S D 2 5 V O U T O U T = 2 V D D - 2 V D 1 0 m F 1 0 m F H T 7 6 6 0 N o te : V V is fo r w a r d v o lta g e d r o p o f d io d e D 1 a n d D 2 D Voltage Splitter V R 4 7 m F L 1 V R O U T = V D D - 2 V 2 E E L 2 V D D C A P + L V 4 7 m F 4 3 C A P - V O U T 8 6 5 V S S 4 7 m F H T 7 6 6 0 V Rev. 1.10 D D 4 E E January 21, 2003 HT7660 Combined Negative Voltage Converter and Positive Voltage Doubler V 2 8 V D D C A P + D D V D 1 1 0 m F 4 3 C A P - O U T = 2 V D D 1 0 m F D 2 V Rev. 1.10 D D V S S 1 0 m F D = - V 5 V O U T H T 7 6 6 0 N o te : V O U T - 2 V D 1 0 m F is fo r w a r d v o lta g e d r o p o f d io d e D 1 a n d D 2 5 January 21, 2003 HT7660 Package Information 8-pin DIP (300mil) Outline Dimensions A 8 B 5 4 1 H C D a G E I F Symbol A Rev. 1.10 Dimensions in mil Min. Nom. Max. 355 ¾ 375 B 240 ¾ 260 C 125 ¾ 135 D 125 ¾ 145 E 16 ¾ 20 F 50 ¾ 70 G ¾ 100 ¾ H 295 ¾ 315 I 335 ¾ 375 a 0° ¾ 15° 1 January 21, 2003 HT7660 8-pin SOP (150mil) Outline Dimensions 5 8 A B 4 1 C C ' G H D E Symbol Rev. 1.10 a F Dimensions in mil Min. Nom. Max. A 228 ¾ 244 B 149 ¾ 157 C 14 ¾ 20 C¢ 189 ¾ 197 D 53 ¾ 69 E ¾ 50 ¾ F 4 ¾ 10 G 22 ¾ 28 H 4 ¾ 12 a 0° ¾ 10° 2 January 21, 2003 HT7660 Product Tape and Reel Specfications Reel Dimensions D T 2 A C B T 1 SOP 8N Symbol Description Dimensions in mm A Reel Outer Diameter 330±1.0 B Reel Inner Diameter 62±1.5 C Spindle Hole Diameter 13.0+0.5 -0.2 D Key Slit Width 2.0±0.15 T1 Space Between Flange 12.8+0.3 -0.2 T2 Reel Thickness 18.2±0.2 Rev. 1.10 3 January 21, 2003 HT7660 Carrier Tape Dimensions P 0 D P 1 t E F W C D 1 B 0 P K 0 A 0 SOP 8N Symbol Description Dimensions in mm W Carrier Tape Width 12.0+0.3 -0.1 P Cavity Pitch 8.0±0.1 E Perforation Position 1.75±0.1 F Cavity to Perforation (Width Direction) 5.5±0.1 D Perforation Diameter 1.55±0.1 D1 Cavity Hole Diameter 1.5+0.25 P0 Perforation Pitch 4.0±0.1 P1 Cavity to Perforation (Length Direction) 2.0±0.1 A0 Cavity Length 6.4±0.1 B0 Cavity Width 5.20±0.1 K0 Cavity Depth 2.1±0.1 t Carrier Tape Thickness 0.3±0.05 C Cover Tape Width Rev. 1.10 9.3 4 January 21, 2003 HT7660 Holtek Semiconductor Inc. (Headquarters) No.3, Creation Rd. II, Science Park, Hsinchu, Taiwan Tel: 886-3-563-1999 Fax: 886-3-563-1189 http://www.holtek.com.tw Holtek Semiconductor Inc. (Taipei Sales Office) 4F-2, No. 3-2, YuanQu St., Nankang Software Park, Taipei 115, Taiwan Tel: 886-2-2655-7070 Fax: 886-2-2655-7373 Fax: 886-2-2655-7383 (International sales hotline) Holtek Semiconductor Inc. (Shanghai Sales Office) 7th Floor, Building 2, No.889, Yi Shan Rd., Shanghai, China 200233 Tel: 021-6485-5560 Fax: 021-6485-0313 http://www.holtek.com.cn Holtek Semiconductor Inc. (Shenzhen Sales Office) 5/F, Unit A, Productivity Building, Cross of Science M 3rd Road and Gaoxin M 2nd Road, Science Park, Nanshan District, Shenzhen, China 518057 Tel: 0755-8616-9908, 8616-9308 Fax: 0755-8616-9533 Holtek Semiconductor Inc. (Beijing Sales Office) Suite 1721, Jinyu Tower, A129 West Xuan Wu Men Street, Xicheng District, Beijing, China 100031 Tel: 010-6641-0030, 6641-7751, 6641-7752 Fax: 010-6641-0125 Holtek Semiconductor Inc. (Chengdu Sales Office) 709, Building 3, Champagne Plaza, No.97 Dongda Street, Chengdu, Sichuan, China 610016 Tel: 028-6653-6590 Fax: 028-6653-6591 Holmate Semiconductor, Inc. (North America Sales Office) 46729 Fremont Blvd., Fremont, CA 94538 Tel: 510-252-9880 Fax: 510-252-9885 http://www.holmate.com Copyright Ó 2003 by HOLTEK SEMICONDUCTOR INC. The information appearing in this Data Sheet is believed to be accurate at the time of publication. However, Holtek assumes no responsibility arising from the use of the specifications described. The applications mentioned herein are used solely for the purpose of illustration and Holtek makes no warranty or representation that such applications will be suitable without further modification, nor recommends the use of its products for application that may present a risk to human life due to malfunction or otherwise. Holtek¢s products are not authorized for use as critical components in life support devices or systems. Holtek reserves the right to alter its products without prior notification. For the most up-to-date information, please visit our web site at http://www.holtek.com.tw. Rev. 1.10 5 January 21, 2003