REG711 REG 711 www.ti.com 50mA SWITCHED-CAP DC/DC CONVERTER FEATURES DESCRIPTION ● WIDE INPUT RANGE: 1.8V TO 5.5V 5V VERSION: 2.7V TO 5.5V The REG711 is a switched capacitor voltage converter, which produces a regulated, low ripple output voltage from an unregulated input voltage. A wide input supply voltage of 1.8V to 5.5V makes the REG711 ideal for a variety of battery sources, such as single cell Li-Ion, or two and three cell Nickel or Alkaline based chemistries. The input voltage may vary above and below the output voltage and the output will remain in regulation. It works equally well for step up or down without the need for an inductor, providing low EMI DC/DC conversion. The high switching frequency allows the use of small surface-mount capacitors, saving board space and reducing cost. The REG711 is thermally protected and current limited, protecting the load and the regulator during fault conditions. Typical ground pin current (quiescent current) is 1mA at full load, 60µA with no load, and less than 1µA in shutdown mode. This regulator comes in a thin MSOP-8 package with a component height of less than 1.1mm. ● AUTOMATIC STEP-UP/STEP-DOWN OPERATION ● LOW INPUT CURRENT RIPPLE ● LOW OUTPUT VOLTAGE RIPPLE ● MINIMUM NUMBER OF EXTERNAL COMPONENTS—NO INDUCTORS ● 1MHz INTERNAL OSCILLATOR ALLOWS SMALL CAPACITORS ● “SHUTDOWN” MODE ● THERMAL AND CURRENT LIMIT PROTECTION ● FIVE OUTPUT VOLTAGES AVAILABLE: 5.0V, 3.3V, 3.0V, 2.7V, 2.5V ● THIN, SMALL PACKAGE: MSOP-8 APPLICATIONS CPUMP ● SMART CARD READERS ENABLE ● CELLULAR PHONES ● SIM CARD SUPPLIES + ● PORTABLE COMMUNICATION DEVICES REG711 R COUT CIN ● PERSONAL DIGITAL ASSISTANTS + ● MODEMS PGND GND LED ● NOTEBOOK AND PALM-TOP COMPUTERS ● ELECTRONIC GAMES ● HANDHELD METERS ● PCMCIA CARDS ● CARD BUSES ● LCD DISPLAYS Copyright © 2000, Texas Instruments Incorporated SBVS027A Printed in U.S.A. February, 2001 SPECIFICATIONS Boldface limits apply over the specified temperature range, TA = –40°C to +85°C At TA = +25°C, VIN = VOUT/2 + 0.75V, IOUT = 5mA, CIN = COUT = 2.2µF, CPUMP = 0.22µF, VENABLE = 1.3V, unless otherwise noted(1). REG711EA PARAMETER INPUT VOLTAGE Guaranteed Startup REG711-5.0 All Other Models OUTPUT VOLTAGE REG711-5.0 CONDITIONS MIN See conditions under “output voltage” with a resistive load not lower than typical VOUT/IOUT. 2.7 1.8 IOUT IOUT IOUT IOUT IOUT IOUT IOUT IOUT IOUT IOUT REG711-3.3 REG711-3.0 REG711-2.7 REG711-2.5 ≤ ≤ ≤ ≤ ≤ ≤ ≤ ≤ ≤ ≤ 15mA, 50mA, 15mA, 50mA, 15mA, 50mA, 15mA, 50mA, 15mA, 50mA, 2.7V 3.0V 1.8V 2.2V 1.8V 2.2V 1.8V 2.0V 1.8V 2.0V < < < < < < < < < < VIN VIN VIN VIN VIN VIN VIN VIN VIN VIN < < < < < < < < < < 5.5V 5.5V 5.5V 5.5V 5.5V 5.5V 5.5V 5.5V 5.5V 5.5V OUTPUT CURRENT Nominal Short Circuit(2) MAX UNITS 5.5 5.5 V V 4.75 5.0 5.25 V 3.14 3.3 3.46 V 2.85 3.0 3.15 V 2.57 2.7 2.83 V 2.38 2.5 2.62 V 50 NOTE(3) OSCILLATOR FREQUENCY EFFICIENCY(4) RIPPLE VOLTAGE(1) 80 mA mA 1.0 MHz IOUT = 15mA, VIN = 2.7V, REG711-5.0 90 % IOUT = 50mA 40 mVp-p VIN = 1.8 to 5.5V ENABLE CONTROL Logic High Input Voltage Logic Low Input Voltage Logic High Input Current Logic Low Input Current 1.3 –0.2 THERMAL SHUTDOWN Shutdown temperature Shutdown recovery VIN 0.4 100 100 IOUT = 0mA VIN = 1.8 to 5.5V, Enable = 0V 60 0.01 –40 –55 –65 TA TA TA MSOP-8 150 V V nA nA °C °C 160 140 SUPPLY CURRENT (quiescent current) In Shutdown Mode TEMPERATURE RANGE Specification Operating Storage Thermal Resistance, θJA TYP 100 2 µA µA +85 +125 +150 °C °C °C °C/W NOTES: (1) Effective series resistance (ESR) of capacitors is < 0.1Ω. (2) The supply circuit is twice the output short-circuit current. (3) The converter regulates by enabling and disabling periods of switching cycles. The switching frequency is the oscillator frequency during an active period. (4) See efficiency curves for other VIN/VOUT configurations. 2 REG711 SBVS027A PIN CONFIGURATION SIMPLIFIED BLOCK DIAGRAM Top View MSOP CPUMP 0.22µF 7 6 3 VIN REG711 CIN 2.2µF NC 1 8 VOUT Enable 2 7 CPUMP+ VIN 3 6 CPUMP– GND 4 5 PGND 8 VOUT COUT 2.2µF Control & Enable 2 Thermal 5 PGND 4 GND Simplified Block Diagram ELECTROSTATIC DISCHARGE SENSITIVITY ABSOLUTE MAXIMUM RATINGS(1) Supply Voltage ................................................................... –0.3V to +5.5V Enable Input ........................................................................... –0.3V to VIN Output Short-Circuit Duration ...................................................... Indefinite Operating Temperature Range ....................................... –55°C to +125°C Storage Temperature Range .......................................... –65°C to +150°C Junction Temperature ..................................................... –55°C to +150°C Lead Temperature (soldering, 3s) ................................................. +240°C This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. NOTE: (1) Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. PACKAGE/ORDERING INFORMATION PACKAGE PACKAGE DRAWING NUMBER SPECIFIED TEMPERATURE RANGE PACKAGE MARKING(1) ORDERING NUMBER(2) TRANSPORT MEDIA 5.0V MSOP-8 337 –40°C to +85°C C11B " " " " " " " " " " REG711EA-5 REG711EA-5/250 REG711EA-5/2K5 Rails Tape and Reel Tape and Reel 3.3V MSOP-8 337 –40°C to +85°C C11C " " " " " " " " " " REG711EA-3.3 REG711EA-3.3/250 REG711EA-3.3/2K5 Rails Tape and Reel Tape and Reel 3.0V MSOP-8 337 –40°C to +85°C C11D " " " " " " " " " " REG711EA-3 REG711EA-3/250 REG711EA-3/2K5 Rails Tape and Reel Tape and Reel 2.7V MSOP-8 337 –40°C to +85°C C11F " " " " " " " " " " REG711EA-2.7 REG711EA-2.7/250 REG711EA-2.7/2K5 Rails Tape and Reel Tape and Reel 2.5V MSOP-8 337 –40°C to +85°C C11G " " " " " REG711EA-2.5 REG711EA-2.5/250 Rails Tape and Reel OUTPUT VOLTAGE 5V Output REG711EA-5 " " PRODUCT 3.3V Output REG711EA-3.3 " " 3V Output REG711EA-3.0 " " 2.7V Output REG711EA-2.7 " " 2.5V Output REG711EA-2.5 " NOTE: (1) Voltage will be marked on reel. (2) Models with a slash (/) are available only in Tape and Reel in the quantities indicated (e.g., /2K5 indicates 2500 devices per reel). Ordering 2500 pieces of “REG711EA-5/2K5” will get a single 2500-piece Tape and Reel. REG711 SBVS027A 3 TYPICAL PERFORMANCE CURVES At TA = +25°C, VIN = VOUT/2 + 0.75V, IOUT = 5mA, CIN = COUT = 2.2µF, CPUMP = 0.22µF, unless otherwise noted. EFFICIENCY vs LOAD CURRENT REG711 - 5.0V EFFICIENCY vs VIN 90 100 VIN = 2.7V IOUT = 15mA REG711-5.0 80 VIN = 3.0V Efficiency (%) Efficiency (%) 80 60 REG711-2.5 70 60 50 REG711-3.3 40 VIN = VOUT 40 REG711-2.7 REG711-3.0 30 20 1.5 2 2.5 3 3.5 4 4.5 5 0.1 5.5 1 EFFICIENCY vs LOAD CURRENT REG711 - 3.3V EFFICIENCY vs LOAD CURRENT REG711 - 3.0V 90 VIN = 1.8V VIN = 1.8V 80 80 VIN = 2.2V Efficiency (%) 70 60 50 70 VIN = 2.2V 60 50 VIN = VOUT VIN = VOUT 40 40 30 30 0.1 1 10 100 0.1 1 10 Load Current (mA) EFFICIENCY vs LOAD CURRENT REG711 - 2.7V EFFICIENCY vs LOAD CURRENT REG711 - 2.5V 90 80 80 VIN = 1.8V 70 Efficiency (%) Efficiency (%) 100 Load Current (mA) 90 VIN = 2.0V 60 50 VIN = 1.8V 70 60 VIN = 2.0V 50 VIN = VOUT VIN = VOUT 40 40 30 30 0.1 1 10 Load Current (mA) 4 100 Load Current (mA) 90 Efficiency (%) 10 VIN (V) 100 0.1 1 10 100 Load Current (mA) REG711 SBVS027A TYPICAL PERFORMANCE CURVES (Cont.) At TA = +25°C, VIN = VOUT/2 + 0.75V, IOUT = 5mA, CIN = COUT = 2.2µF, CPUMP = 0.22µF, unless otherwise noted. OUTPUT RIPPLE VOLTAGE SHORT-CIRCUIT LOAD CURRENT vs VIN 250 COUT = 2.2µF 225 Load Current (mA) 200 20mV/div 175 150 REG711-3.0 IOUT = 15mA VIN = 2.4V 125 100 COUT = 10µF 75 20mV/div 50 25 BW = 20MHz 0 1.5 2 2.5 3 3.5 4 4.5 5 2.5µs/div 5.5 VIN (V) MAXIMUM LOAD CURRENT vs INPUT VOLTAGE TA ≤ 85°C OUTPUT RIPPLE VOLTAGE vs VIN 60 60 50 50 REG711-3.0 COUT = 2.2µF Ripple (mVp-p) Maximum Load Current (mA) REG711-5.0 COUT = 2.2µF 40 REG711-2.5 REG711-5.0 TA ≤ 80°C REG711-2.7 30 REG711-5.0 20 40 REG711-2.5 COUT = 2.2µF 30 REG711-5.0 20 REG711-3.0 REG711-3.3 REG711-2.5 REG711-3.0 COUT = 10µF COUT = 10µF 10 10 COUT = 10µF 0 0 1.5 2 2.5 3 3.5 4 4.5 5 5.5 1.5 6 2 2.5 3 3.5 4 4.5 5 5.5 5 5.5 VIN (V) VIN (V) OUTPUT RIPPLE VOLTAGE vs VIN INPUT CURRENT AT TURN-ON 60 REG711-3.3V VIN = 3.0V IOUT = 50mA REG711-3.3 COUT = 2.2µF 50 IIN 100mA/div VOUT Ripple (mVp-p) REG711-2.7 COUT = 2.2µF 40 30 20 REG711-3.3 REG711-2.7 COUT = 10µF COUT = 10µF 10 2V/div BW = 20MHz 0 50µs/div 1.5 2 2.5 3 3.5 4 4.5 VIN (V) REG711 SBVS027A 5 TYPICAL PERFORMANCE CURVES (Cont.) At TA = +25°C, VIN = VOUT/2 + 0.75V, IOUT = 5mA, CIN = COUT = 2.2µF, CPUMP = 0.22µF, unless otherwise noted. SUPPLY CURRENT vs TEMPERATURE (No Load) LOAD TRANSIENT RESPONSE 100 IOUT = 0 Supply Current (µA) 80 50mA/div ILOAD 60 VOUT 40 20 20mV/div 0 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 10µs/div Temperature (°C) SUPPPLY CURRENT vs TEMPERATURE (Not Enabled) LINE TRANSIENT RESPONSE 20 REG711-3.3 ILOAD = 50mA 18 Supply Current (nA) 16 4.5V 3.5V 2V/div 14 12 Buck Mode VIN Boost Mode 10 8 VOUT 50mV/div 6 4 2 BW = 20MHz 0 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 50µs/div Temperature (°C) OUTPUT VOLTAGE VS TEMPERATURE OUTPUT VOLTAGE DRIFT HISTOGRAM 0.2 30 25 Percentage of Units (%) Output Votage Change (%) 0.1 0.0 –0.1 –0.2 –0.3 –0.4 15 10 5 –0.5 –0.6 0 –40 –20 0 20 40 60 80 Junction Temperature (°C) 6 20 100 120 140 –140 –120 –100 –80 –60 –40 –20 0 20 40 60 VOUT Drift (ppm/°C) REG711 SBVS027A THEORY OF OPERATION The REG711 regulated charge pump provides a regulated output voltage for input voltages ranging from less than the output to greater than the output. This is accomplished by automatic mode switching within the device. When the input voltage is greater than the required output, the unit functions as a variable pulse-width switch-mode regulator. This operation is shown in Figure 1. Transistors Q1 and Q3 are held off, Q4 is on, and Q2 is switched as needed to maintain a regulated output voltage. VIN Q1 Q2 OFF SWITCHED A conversion clock of 50% duty cycle is generated. During the first half cycle the FET switches are configured as shown in Figure 2A, and CPUMP charges to VIN. During the second half cycle the FET switches are configured as shown in Figure 2B, and the voltage on CPUMP is added to VIN. The output voltage is regulated by skipping clock cycles as necessary. PEAK CURRENT REDUCTION In normal operation, the charging of the pump and output capacitors usually leads to relatively high peak input currents which can be much higher than that of the average load current. The regulator incorporates circuitry to limit the input peak current, lowering the total EMI production of the device and lowering output voltage ripple and input current ripple. Input capacitor (CIN) supplies most of the charge required by input current peaks. CPUMP Q4 Q3 CIN OFF PROTECTION ON The regulator has thermal shutdown circuitry that protects it from damage caused by overload conditions. The thermal protection circuitry disables the output when the junction temperature reaches approximately 160°C, allowing the device to cool. When the junction temperature cools to approximately 140°C, the output circuitry is automatically reenabled. Continuously running the regulator into thermal shutdown can degrade reliability. The regulator also provides current limit to protect itself and the load. VOUT COUT Step-Down (Buck) Mode FIGURE 1. Simplified Schematic of the REG711 Operating in the Step-Down Mode. When the input voltage is less than the required output voltage, the device switched to a step-up or boost mode of operation, as shown in Figure 2. VIN SHUTDOWN MODE A control pin on the regulator can be used to place the device into an energy-saving shutdown mode. In this mode, the output is disconnected from the input as long as VIN is greater than or equal to minimum VIN and the input quiescent current is reduced to 2µA maximum. VIN Q1 Q2 OFF Q1 Q2 ON ON OFF CPUMP – + Q4 Q3 CIN CPUMP – + ON Q4 Q3 OFF CIN OFF ON VOUT VOUT COUT (A) Step-Up (Boost) Mode COUT (B) FIGURE 2. Simplified Schematic of the REG711 Operating in the Step-Up or Boost Mode. REG711 SBVS027A 7 CAPACITOR SELECTION The approximate efficiency is given by: For minimum output voltage ripple, the output capacitor COUT should be a ceramic, surface-mount type. Tantalum capacitors generally have a higher Effective Series Resistance (ESR) and may contribute to higher output voltage ripple. Leaded capacitors also increase ripple due to the higher inductance of the package itself. To achieve best operation with low input voltage and high load current, the input and pump capacitors (CIN, CPUMP respectively) should also be surface-mount ceramic types. In all cases, X7R or X5R dielectric are recommended. See the Typical Operating Circuit shown in Figure 3 for component values. Efficiency (%) = VOUT/(2 • VIN) •100 (step-up operating mode) or VOUT • 100/VIN (step-down operating mode) Table II lists the approximate values of the input voltage at which the device changes internal operating mode. CPUMP 0.22µF PRODUCT OPERATING MODE CHANGES AT VIN OF REG711-2.5 REG711-2.7 REG711-3.0 REG711-3.3 REG711-5.0 > 3.2V > 3.4V > 3.7V > 4.0V Step-up only TABLE II. ENABLE 2 7 6 8 3 VIN CIN 2.2µF REG711 PGND 5 See efficiency curves in the Typical Performance Curves section for various loads and input voltages. VOUT COUT 2.2µF LAYOUT 4 GND FIGURE 3. Typical Operating Circuit. With light loads or higher input voltage, a smaller 0.1µF pump capacitor (CPUMP) and smaller 1µF input and output capacitors (CIN and COUT, respectively) can be used. To minimize output voltage ripple, increase the output capacitor, COUT, to 10µF or larger. The capacitors listed in Table I have been used with the REG711. This is only a representative list of those parts that are compatible, and not the results of a complete survey of an industry-wide offering. Large ripple currents flow in the VIN, PGND and VOUT traces. To minimize both input and output ripple, keep the capacitors as close as possible to the regulator using short, direct circuit traces. A suggested PCB routing is shown in Figure 4. The trace lengths from the input and output capacitors have been kept as short as possible. A star ground system has been implemented, with pin 5 as the center of the star. No ground plane is provided in other layers, as this will provide capacitive coupling for noise spikes. EFFICIENCY The efficiency of the charge pump regulator varies with the output voltage version, the applied input voltage, the load current, and the internal operation mode of the device. MANUFACTURER Kemet Panasonic Taiyo Yuden NOTE: All Capacitors 1206 Size FIGURE 4. Suggested PCB Design for Minimum Ripple. PART NUMBER VALUE TOLERANCE DIELECTRIC MATERIAL C1206C255K8RAC C1206C224K8RAC ECJ3YB1A225K ECJ3VB1C224K LMK325BJ106KN EMK316BJ225KL TKM316BJ224KF 2.2µF 0.22µF 2.2µF 0.22µF 10µF 2.2µF 0.22µF ±10% ±10% ±10% ±10% ±10% ±10% ±10% X7R X7R X7R X7R X5R X7R X7R PACKAGE SIZE RATED WORKING VOLTAGE 1206 1206 1206 1206 1210 1206 1206 10V 10V 10V 16V 10V 16V 25V TABLE I. Capacitors That Have Been Successfully Used With The REG711. 8 REG711 SBVS027A IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgment, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. 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