Datasheet

ManualsBrandsMicrochip ManualsDC / DC ControllersDC/DC Converter -3 ... 18V 40mA PDIP

 2001-2012 Microchip Technology Inc. DS21468B-page 1

TC7662A

Features

• Wide Operating Range

- 3V to 18V

• Increased Output Current (40mA)

• Pin Compatible with ICL7662/SI7661/TC7660/

LTC1044

• No External Diodes Required

• Low Output Impedance @ I

= 20mA

-40 Typ.

• No Low-Voltage Terminal Required

• CMOS Construction

• Available in 8-Pin PDIP and 8-Pin CERDIP

Packages

Applications

• Laptop Computers

•Disk Drives

• Process Instrumentation

• P-based Controllers

Device Selection Table

Package Type

General Description

The TC7662A is a pin-compatible upgrade to the

industry standard TC7660 charge pump voltage

converter. It converts a +3V to +18V input to a

corresponding -3V to -18V output using only two low-

cost capacitors, eliminating inductors and their

associated cost, size and EMI. In addition to a wider

power supply input range (3V to 18V versus 1.5V to

10V for the TC7660), the TC7662A can source output

currents as high as 40mA. The on-board oscillator

operates at a nominal frequency of 12kHz. Operation

below 12kHz (for lower supply current applications) is

also possible by connecting an external capacitor from

OSC to ground.

The TC7662A directly is recommended for designs

requiring greater output current and/or lower input/

output voltage drop. It is available in 8-pin PDIP and

CERDIP packages in commercial and extended

temperature ranges.

Part

Number

Package

Operating

Temp.

Range

TC7662ACPA 8-Pin PDIP 0°C to +70°C

TC7662AEPA 8-Pin PDIP -40°C to +85°C

TC7662AIJA 8-Pin CERDIP -25°C to +85°C

TC7662AMJA 8-Pin CERDIP -55°C to +125°C

TC7662A

GND

–

OUT

OSC

8-Pin PDIP

8-Pin CERDIP

Charge Pump DC-to-DC Converter

Summary of content (16 pages)

PAGE 1
TC7662A Charge Pump DC-to-DC Converter Package Type Features • Wide Operating Range - 3V to 18V • Increased Output Current (40mA) • Pin Compatible with ICL7662/SI7661/TC7660/ LTC1044 • No External Diodes Required • Low Output Impedance @ IL = 20mA - 40 Typ. • No Low-Voltage Terminal Required • CMOS Construction • Available in 8-Pin PDIP and 8-Pin CERDIP Packages Applications • • • • Laptop Computers Disk Drives Process Instrumentation P-based Controllers Device Selection Table Operating Temp.
PAGE 2
TC7662A Functional Block Diagram 8 VDD I OSC TC7662A 7 Q + – F/F C Q Comparator with Hysteresis Level Shift P SW1 2 Level Shift N SW4 CAP + + CP EXT GND 3 VREF + Level Shift OUT 4 Level Shift CR EXT N SW2 CAP – RL N SW3 5 VOUT DS21468B-page 2  2001-2012 Microchip Technology Inc.
PAGE 3
TC7662A 1.0 ELECTRICAL CHARACTERISTICS Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions above those indicated in the operation sections of the specifications is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. Absolute Maximum Ratings* Supply Voltage VDD to GND.............................
PAGE 4
TC7662A 2.0 PIN DESCRIPTIONS The descriptions of the pins are listed in Table 2-1. TABLE 2-1: PIN FUNCTION TABLE Pin No. (8-Pin PDIP, CERDIP) Symbol 1 NC 2 C+ 3 GND 4 C- 5 VOUT Output voltage. 6 NC No connection. 7 OSC Oscillator control input. Bypass with an external capacitor to slow the oscillator. 8 VDD Power supply positive voltage input. DS21468B-page 4 Description No connection. Charge pump capacitor positive terminal. Ground terminal.
PAGE 5
TC7662A 3.0 DETAILED DESCRIPTION 3.1 The TC7662A is a capacitive charge pump (sometimes called a switched-capacitor circuit), where four MOSFET switches control the charge and discharge of a capacitor. The functional block diagram shows how the switching action works. SW1 and SW2 are turned on simultaneously, charging CP to the supply voltage, VDD.
PAGE 6
TC7662A 4.0 TYPICAL APPLICATIONS 4.1 Simple Negative Voltage Converter Combining the four RSWX terms as RSW, we see that: RO  2 x RSW + The majority of applications will undoubtedly utilize the TC7662A for generation of negative supply voltages. Figure 4-1 shows typical connections to provide a negative supply where a positive supply of +3V to +18V is available.
PAGE 7
TC7662A 4.2 Output Ripple 4.3 ESR also affects the ripple voltage seen at the output. The total ripple is determined by 2 voltages, A and B, as shown in Figure 4-2. Segment A is the voltage drop across the ESR of CR at the instant it goes from being charged by CP (current flowing into CR) to being discharged through the load (current flowing out of CR). The magnitude of this current change is 2 x IOUT, hence the total drop is 2 x IOUT x ESRCR volts.
PAGE 8
TC7662A 4.5 Changing the TC7662A Oscillator Frequency It is possible to increase the conversion efficiency of 4.7 Combined Negative Voltage Conversion and Positive Supply Multiplication the TC7662A at low load levels by lowering the oscillator frequency. This reduces the switching losses, and is shown in Figure 4-5.
PAGE 9
TC7662A 5.0 TYPICAL CHARACTERISTICS Note: The graphs and tables provided following this note are a statistical summary based on a limited number of samples and are provided for informational purposes only. The performance characteristics listed herein are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified operating range (e.g., outside specified power supply range) and therefore outside the warranted range.
PAGE 10
TC7662A 6.0 PACKAGING INFORMATION 6.1 Package Marking Information Package marking data not available at this time. 6.2 Package Dimensions Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging 8-Pin Plastic DIP PIN 1 .260 (6.60) .240 (6.10) .045 (1.14) .030 (0.76) .070 (1.78) .040 (1.02) .310 (7.87) .290 (7.37) .400 (10.16) .348 (8.84) .200 (5.08) .140 (3.56) .040 (1.02) .020 (0.51) .150 (3.81) .115 (2.92) .
PAGE 11
TC7662A Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging 8-Pin CDIP (Narrow) .110 (2.79) .090 (2.29) PIN 1 .300 (7.62) .230 (5.84) .020 (0.51) MIN. .055 (1.40) MAX. .320 (8.13) .290 (7.37) .400 (10.16) .370 (9.40) .040 (1.02) .020 (0.51) .200 (5.08) .160 (4.06) .150 (3.81) MIN. .200 (5.08) .125 (3.18) .015 (0.38) .008 (0.20) 3° MIN. .400 (10.16) .320 (8.13) .065 (1.65) .020 (0.51) .045 (1.14) .016 (0.
PAGE 12
TC7662A 7.0 REVISION HISTORY Revision B (December 2012) Added a note to each package outline drawing. DS21468B-page 12  2001-2012 Microchip Technology Inc.
PAGE 13
TC7662A Sales and Support Data Sheets Products supported by a preliminary Data Sheet may have an errata sheet describing minor operational differences and recommended workarounds. To determine if an errata sheet exists for a particular device, please contact one of the following: 1. 2. Your local Microchip sales office The Microchip Worldwide Site (www.microchip.com) Please specify which device, revision of silicon and Data Sheet (include Literature #) you are using.
PAGE 14
TC7662A NOTES: DS21468B-page14  2001-2012 Microchip Technology Inc.
PAGE 15
Note the following details of the code protection feature on Microchip devices: • Microchip products meet the specification contained in their particular Microchip Data Sheet. • Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. • There are dishonest and possibly illegal methods used to breach the code protection feature.
PAGE 16
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