TCM828 TCM829. Switched Capacitor Voltage Converters FEATURES GENERAL DESCRIPTION APPLICATIONS ORDERING INFORMATION

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1 Switched Capacitor FEATURES Charge Pump in -Pin SOT-A Package >9% Voltage Conversion Efficiency Voltage Inversion and/or Doubling Low µa () Quiescent Current Operates from +.V to +.V Up to ma Output Current Only Two External Capacitors Required APPLICATIONS LCD Panel Bias Cellular Phones Pagers PDAs, Portable Dataloggers Battery-Powered Devices GENERAL DESCRIPTION The /89 are CMOS charge-pump voltage converters in ultra-small -Pin SOT-A packages. They invert and/or double an input voltage which can range from +.V to +.V. Conversion efficiency is typically >9%. Switching frequency is khz for the and khz for the. External component requirement is only two capacitors (.µf nominal) for standard voltage inverter applications. With a few additional components a positive doubler can also be built. All other circuitry, including control, oscillator, power MOSFETs are integrated on-chip. Supply current is µa () and µa (). The and are available in a -Pin SOT-A surface mount package. PIN CONFIGURATION *-Pin SOT-A ORDERING INFORMATION Part No. Package Temp. Range OUT C + ECT -Pin SOT-A C to +8 C ECT -Pin SOT-A C to +8 C NOTE: -Pin SOT-A is equivalent to EIAJ SC-7A. ECT ECT C GND NOTE: *-Pin SOT-A is equivalent to EIAJ SC-7A TYPICAL OPERATING CIRCUIT Voltage Inverter C + INPUT C GND OUT V OUTPUT Microchip Technology Inc. DS88A /89- //

2 ABSOLUTE MAXIMUM RATINGS* Input Voltage ( to GND) V,.V Output Voltage (OUT to GND)... 6.V, +.V Current at OUT Pin...mA Short-Circuit Duration OUT to GND... Indefinite Operating Temperature Range... C to +8 C Power Dissipation (T A 7 C) -Pin SOT-A...mW Storage Temperature (Unbiased)... 6 C to + C Lead Temperature (Soldering, sec)... + C *This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS: T A = C to +8 C, = +V, = = µf (), = =.µf (), unless otherwise noted. Typical values are at T A = + C. Symbol Parameter Device Test Conditions Min Typ Max Unit I DD Supply Current T A = + C 9 µa 6 V + Minimum Supply R LOAD = kω: T A = C to +8 C. V Voltage V + Maximum Supply R LOAD = kω. V Voltage F OSC Oscillator Frequency T A = + C 8..6 khz.. P EFF Power Efficiency I LOAD = ma, T A = + C 96 % V EFF Voltage Conversion R LOAD = % Efficiency R OUT Output Resistance I OUT = ma, T A = C Ω T A = C to +8 C 6 NOTE:. Capacitor contribution is approximately % of the output impedance [ESR = / pump frequency x capacitance)]. ELECTRICAL CHARACTERISTICS: T A = C to +8 C, = +V, = = µf (), = =.µf () unless otherwise noted. Typical values are at T A = + C. (Note ) Symbol Parameter Device Test Conditions Min Typ Max Unit I DD Supply Current µa V + Supply Voltage Range R LOAD = kω.. V F OSC Oscillator Frequency 6 khz 9. R OUT Output Resistance I OUT = ma 6 Ω NOTE:. All C to +8 C specifications above are guaranteed by design. PIN DESCRIPTION Pin No. (-Pin SOT-A) Symbol Description OUT Inverting charge pump output. Positive power supply input. C Commutation capacitor negative terminal. GND Ground. + C Commutation capacitor positive terminal. /89- // Microchip Technology Inc. DS88A

3 DETAILED DESCRIPTION The /89 charge pump converters invert the voltage applied to the pin. Conversion consists of a twophase operation (Figure ). During the first phase, switches S and S are open and S and S are closed. During this time, charges to the voltage on and load current is supplied from. During the second phase, S and S are closed, and S and S are open. This action connects across, restoring charge to. IN S S S S /89 = ( ) () Losses that occur during charge transfer (from the commutation capacitor to the output capacitor) when a voltage difference between the two capacitors exists. Most of the conversion losses are due to factors (), () and () above. These losses are given by Equation. P LOSS (,, ) = I OUT x R OUT I OUT x [ +8R SWITCH + ESR + ESR ] (f OSC ) Equation. The /(f OSC )() term in Equation is the effective output resistance of an ideal switched capacitor circuit (Figures a, b). The losses in the circuit due to factor () above are also shown in Equation. The output voltage ripple is given by Equation. P LOSS () = [ (.)()( ) + (.)()(V RIPPLE V RIPPLE )] x f OSC Figure. Ideal Switched Capacitor Charge Pump APPLICATIONS INFORMATION Output Voltage Considerations V RIPPLE = Equation. I OUT +(IOUT )(ESR ) (f OSC )() The /89 perform voltage conversion but do not provide regulation. The output voltage will droop in a linear manner with respect to load current. The value of this equivalent output resistance is approximately Ω nominal at + C and = +V. is approximately V at light loads, and droops according to the equation below: V + f Equation. R L V DROOP = I OUT x R OUT = ( V DROOP ) Charge Pump Efficiency The overall power efficiency of the charge pump is affected by four factors: () Losses from power consumed by the internal oscillator, switch drive, etc. (which vary with input voltage, temperature and oscillator frequency). () I R losses due to the on-resistance of the MOSFET switches on-board the charge pump. () Charge pump capacitor losses due to effective series resistance (ESR). Microchip Technology Inc. DS88A Figure a. Ideal Switched Capacitor Model R EQUIV V + R EQUIV = f x R L Figure b. Equivalent Output Resistance /89- //

4 Capacitor Selection In order to maintain the lowest output resistance and output ripple voltage, it is recommended that low ESR capacitors be used. Additionally, larger values of will lower the output resistance and larger values of will reduce output ripple. (See Equation (b)). Table shows various values of and the corresponding output resistance + C. It assumes a.ω ESR and Ω R SW. Table shows the output voltage ripple for various values of. The V RIPPLE values assume ma output load current and.ω ESR. Table. Output Resistance vs. (ESR =.Ω) (µf) R OUT (Ω) R OUT (Ω) Table. Output Voltage Ripple vs. (ESR =.Ω) I OUT ma (µf) V RIPPLE (mv) V RIPPLE (mv) Input Supply Bypassing The input should be capacitively bypassed to reduce AC impedance and minimize noise effects due to the switching internal to the device. The recommended capacitor depends on the configuration of the /89. If the device is loaded from OUT to GND it is recommended that a large value capacitor (at least equal to ) be connected from the input to GND. If the device is loaded from IN to OUT a small (.µf) capacitor from IN to OUT is sufficient. Voltage Inverter The most common application for charge pump devices is the inverter (Figure ). This application uses two external capacitors and (plus a power supply bypass capacitor, if necessary). The output is equal to V IN plus any voltage drops due to loading. Refer to Table and Table for capacitor selection. *µf () Cascading Devices Two or more /89 s can be cascaded to increase output voltage (Figure ). If the output is lightly loaded, it will be close to ( x ) but will droop at least by R OUT of the first device multiplied by the I Q of the second. It can be seen that the output resistance rises rapidly for multiple cascaded devices. For large negative voltage requirements see the TC68 or TCM68 data sheets. Paralleling Devices OUT + IN C.µF* GND Figure. Test Circuit + "" To reduce the value of R OUT, multiple /89s can be connected in parallel (Figure ). The output resistance will be reduced by a factor of N where N is the number of /89 s. Each device will require it s own pump capacitor (), but all devices may share one reservoir capacitor (). However, to preserve ripple performance the value of should be scaled according to the number of paralleled /89 s. "n" = n Figure. Cascading s or s to Increase Output Voltage.µF* Voltage Inverter.µF* R L /89- // Microchip Technology Inc. DS88A

5 "" Voltage Doubler/Inverter R OUT = R OF SINGLE DEVICE OUT NUMBER OF DEVICES + Figure. Paralleling s or s to Reduce Output Resistance Another common application of the /89 is shown in Figure 6. This circuit performs two functions in combination. and form the standard inverter circuit described above. C and C plus the two diodes form the voltage doubler circuit. and C are the pump capacitors and and C are the reservoir capacitors. Because both sub-circuits rely on the same switches if either output is loaded, both will droop toward GND. Make sure that the total current drawn from both the outputs does not total more than ma. "n" = V IN Diode Protection for Heavy Loads When heavy loads require the OUT pin to sink large currents being delivered by a positive source, diode protection may be needed. The OUT pin should not be allowed to be pulled above ground. This is accomplished by connecting a Schottky diode (N87) as shown in Figure 7. Layout Considerations GND OUT Figure 7. High V Load Current As with any switching power supply circuit good layout practice is recommended. Mount components as close together as possible to minimize stray inductance and capacitance. Also use a large ground plane to minimize noise leakage into other circuitry. + D, D = N8 D = C D C = ( ) (V FD ) (V FD ) Figure 6. Combined Doubler and Inverter Microchip Technology Inc. DS88A /89- //

6 TYPICAL CHARACTERISTICS Circuit of Figure, = +V, = = C, T A = + C, unless otherwise noted. OUTPUT RESISTANCE (Ω) 7 6 Output Resistance vs. Supply Voltage OUTPUT RESISTANCE (Ω) Output Resistance vs. Temperature =.V =.V =.V OUTPUT CURRENT (ma) Output Current vs. Capacitance =.7V, =.V =.V, =.V =.9V, =.V. SUPPLY VOLTAGE (V) C C C 8 C TEMPERATURE ( C) CAPACITANCE (µf) OUTPUT CURRENT (ma) Output Current vs. Capacitance =.7V, V =.V =.V, V =.V =.9V, =.V CAPACITANCE (µf) OUTPUT VOLTAGE RIPPLE (mvp-p) Output Voltage Ripple vs. Capacitance Output Voltage Ripple vs. Capacitance =.7V, =.V =.V, =.V =.9V, =.V CAPACITANCE (µf) OUTPUT VOLTAGE RIPPLE (mvp-p) =.7V, =.V =.V, =.V =.9V, =.V CAPACITANCE (µf) SUPPLY CURRENT (µa) 8 6 Supply Current vs. Supply Voltage..... SUPPLY VOLTAGE (V) PUMP FREQUENCY (khz) Pump Frequency vs. Temperature Pump Frequency vs. Temperature =.V =.V 8 6 =.V =.V =.V =.V C C 8 C C C C 8 C TEMPERATURE ( C) TEMPERATURE ( C) PUMP FREQUENCY (khz) /89- // 6 Microchip Technology Inc. DS88A

7 TYPICAL CHARACTERISTICS (Cont.) Circuit of Figure, = +V, = = C, T A = + C, unless otherwise noted. Output Voltage vs. Output Current Efficiency vs. Output Current OUTPUT VOLTAGE (V) =.V =.V =.V EFFICIENCY (%) 8 6 =.V =.V =.V 6 OUTPUT CURRENT (ma) OUTPUT CURRENT (ma) MARKING -PIN SOT-A Part Numbers and Part Marking & = part number code + temperature range (two-digit code). /89 ECT ECT Code CA CB ex: ECT = C A represents year and quarter code represents lot ID number Microchip Technology Inc. DS88A 7 /89- //

8 TAPING FORM Component Taping Orientation for -Pin SOT-A (EIAJ SC-7A) Devices PIN User Direction of Feed User Direction of Feed Device Marking Device Marking W PIN Standard Reel Component Orientation TR Suffix Device (Mark Right Side Up) P Reverse Reel Component Orientation RT Suffix Device (Mark Upside Down) Carrier Tape, Number of Components Per Reel and Reel Size Package Carrier Width (W) Pitch (P) Part Per Full Reel Reel Size -Pin SOT-A 8 mm mm 7 in PACKAGE DIMENSIONS -Pin SOT-A (EIAJ SC-7A).7 (.9) REF.. (.).98 (.).7 (.8).9 (.). (.). (.) PIN.7 (.9) REF.. (.).6 (.7).7 (.). (.9).6 (.). (.) MAX.. (.). (.9). (.6). (.) Dimensions: inches (mm) /89- // 8 Microchip Technology Inc. DS88A

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TC1225 TC1226 TC1227. Inverting Dual ( V IN, 2V IN ) Charge Pump Voltage Converters FEATURES GENERAL DESCRIPTION TYPICAL APPLICATIONS

TC1225 TC1226 TC1227. Inverting Dual ( V IN, 2V IN ) Charge Pump Voltage Converters FEATURES GENERAL DESCRIPTION TYPICAL APPLICATIONS Inverting Dual (, 2 ) FEATURES Small 8-Pin MSOP Package Operates from 1.8V to 5.5V Up to 5mA Output Current at Pin Up to 1mA Output Current at 2 Pin and 2 Outputs Available Low Supply Current... 120µA