OPA567 OP A56 7 SBOS287A – JUNE 2005 – REVISED SEPTEMBER 2005 Rail-to-Rail I/O, 2A POWER AMPLIFIER FEATURES DESCRIPTION ● ● ● ● ● HIGH OUTPUT CURRENT: 2A OUTPUT SWINGS TO: 150mV of Rails with IO = 2A THERMAL PROTECTION ADJUSTABLE CURRENT LIMIT TWO FLAGS: Current Limit and Temperature Warning The OPA567 is a low-cost, high-current, operational amplifier designed for driving a wide variety of loads while operating on low-voltage supplies. It operates from either single or dual supplies for design flexibility and has rail-to-rail swing on the input and output. Output swing is within 300mV of the supply rails, with output current of 2A. Smaller loads allow an output swing closer to the rails. ● LOW SUPPLY VOLTAGE OPERATION: 2.7V to 5.5V ● SHUTDOWN FUNCTION WITH OUTPUT DISABLE ● SMALL POWER PACKAGE The OPA567 is unity gain stable, easy to use, and free from the phase inversion problems found in some power amplifiers. High performance is maintained at voltage swings near the output rails. APPLICATIONS The OPA567 provides an accurate user-selected current limit set with an external resistor, or digitally adjusted via a Digital-to-Analog Converter (DAC). ● ● ● ● ● ● THERMOELECTRIC COOLER DRIVER LASER DIODE PUMP DRIVER VALVE, ACTUATOR DRIVER SYNCHRO, SERVO DRIVER TRANSDUCER EXCITATION GENERAL LINEAR POWER BOOSTER FOR OP AMPS V+ TFLAG 10 8 Enable IFLAG (1) 11 OPA567 RELATED PRODUCTS 7 2, 3 OPA567 +IN Two flags are provided. The current limit flag, IFLAG, warns of current limit conditions. TFLAG is a thermal flag that warns of thermal overstress. The TFLAG pin can be connected to the Enable pin to provide a thermal shutdown solution. The OPA567 is available in a tiny 5mm x 5mm Quad Flatpack No-lead (QFN) package and features an exposed thermal pad that enhances thermal and electrical characteristics. It is small and easy to heat sink. The OPA567 is specified for operation over the industrial temperature range, –40°C to +85°C. 1, 12 –IN The output of the OPA567 can be independently disabled using the Enable pin. This feature saves power and protects the load. VO 6 9 4, 5 V– NOTE: (1) Connect for thermal protection. RSET FEATURES PRODUCT Same features as the OPA567, plus current monitor output and paralleling ability in SO-20 PowerPAD™ package. OPA569 ISET Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. PowerPAD is a trademark of Texas Instruments. All other trademarks are the property of their respective owners. Copyright © 2005, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. www.ti.com ABSOLUTE MAXIMUM RATINGS(1) Supply Voltage ................................................................................. +7.5V Output Current ............................................................... See SOA Curves Signal Input Terminals (pins 8 and 9): Voltage(2) ............................................... (V–) – 0.5V to (V+) + 0.5V Current(2) ................................................................................ ±10mA Output Short-Circuit(3) ........ Continuous when thermal protection enabled Enable Pin (pin 11) ........................................ (V–) – 0.5V to (V–) + 7.5V Current Limit Set, ILIMIT Pin (pin 6) ................ (V–) – 0.5V to (V+) + 0.5V Operating Temperature .................................................. –55°C to +125°C Storage Temperature ..................................................... –65°C to +150°C Junction Temperature .................................................................... +150°C ESD Rating: Human Body Model ................................................................... 3kV Charged Device Model .......................................................... 1500V ELECTROSTATIC DISCHARGE SENSITIVITY 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. 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. NOTES: (1) Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not implied. (2) Input terminals are diode-clamped to the power-supply rails. Input signals that can swing more than 0.5V beyond the supply rails should be current limited to 10mA or less. (3) Short-circuit to ground. For the most current package and ordering information, see the Package Option Addendum located at the end of this data sheet. PIN CONFIGURATION PIN DESCRIPTIONS 3 V– 4 VO 2 TFLAG 10 9 +IN 8 –IN 7 IFLAG PIN # NAME 1, 12 V+ Positive Power-Supply Voltage 2, 3 VO Output 4, 5 V– Negative Power-Supply Voltage 6 ISET Current Limit Set Pin(1) 7 IFLAG Current Limit Flag—Indicates when part is in current limit (active LOW). DESCRIPTION 8 –IN Inverting Input 9 +IN Noninverting Input 10 TFLAG 11 ENABLE 6 2 ISET VO Metal heat sink (located on bottom) 5 1 V– V+ QFN 11 12 V+ Enable Top View PACKAGE/ORDERING INFORMATION Thermal Flag—Indicates thermal stress (active LOW). Enabled HIGH, shut down LOW. NOTE: (1) This pin limits the output current. The limited value, ILIMIT, is 9800(ISET), where ISET is the current flowing through the ISET pin. This current is programmed by the resistor RSET connected to V–. OPA567 www.ti.com SBOS287A ELECTRICAL CHARACTERISTICS: VS = +2.7V to +5.5V Boldface limits apply over the specified temperature range, TA = –40°C to +85°C. At TCASE = +25°C, RL = 1kΩ, and connected to VS /2, unless otherwise noted. OPA567 PARAMETER OFFSET VOLTAGE Input Offset Voltage vs Temperature vs Power Supply INPUT BIAS CURRENT Input Bias Current vs Temperature Input Offset Current NOISE Input Voltage Noise Density, f = 1kHz f = 0.1Hz to 10Hz Current Noise Density, f = 1kHz INPUT VOLTAGE RANGE Common-Mode Voltage Range Common-Mode Rejection Ratio CONDITION VOS dVOS /dT PSRR MIN IO = 0V, VS = +5V TA = –40°C to +85°C VS = +2.7V to +5.5V, VCM = (V–) +0.55V IOS in FREQUENCY RESPONSE Gain Bandwidth Product Slew Rate Full-Power Bandwidth(1) Settling Time: ±0.1% Total Harmonic Distortion + Noise(2) OUTPUT Voltage Output Swing from Rail Maximum Continuous Current Output: dc (4) Capacitive Load Drive (5) Closed-Loop Output Impedance(6) AOL GBW SR Linear Operation VS = +5V, –0.1V < VCM < 3.2V VS = +5V, –0.1V < VCM < 5.1V (V–) – 0.1 80 60 0.2V < VO < 4.8V, RL = 1kΩ, VS = +5V 0.3V < VO < 4.7V, RL = 1.15Ω, VS = +5V 100 G = +1, VO = 4.0V Step G = –1, VO = 4.0V Step THD+N VO CLOAD RO RL = 1kΩ, AOL > 100dB IO = ±2A, VS = +5V, AOL > 80dB (3) (V–) + 0.2 (V–) + 0.3 ENABLE/SHUTDOWN INPUT Enable Pin Bias Current HIGH (Output enabled) LOW (Output disabled) Output Disable Time Output Enable Time Externally Adjustable ILIMIT = 1A ILIMIT = 1A VSD VSD ±0.5 ±2 12 60 mV µV/°C µV/V ±1 (doubles every 10°C) ±2 ±10 pA ±10 pA VSD = 0V Pin Open or Forced HIGH Pin Forced LOW RL = 1Ω RL = 1Ω nV/√Hz µVPP fA/√Hz 100 80 (V+) + 0.1 V dB dB 1013 || 4.5 1013 || 9 Ω || pF Ω || pF 126 90 dB dB 1.2 1.2 See Typical Characteristics 5 See Typical Characteristics MHz V/µs (VS) ± 0.02 (VS) ± 0.2 µs (V+) – 0.2 (V+) – 0.3 2.4 V V A See Typical Characteristics 0.1 0.44 45 12M || 570 Ω Ω Ω Ω || pF ±0.2 to ±2.2 ILIMIT = ISET • 9800 RSET = 9800 (1.18V/ILIMIT) ±3 ±10 ±3 ±15 (V–) + 1.05 (V–) + 1.18 (V–) + 1.3 A A Ω % % V 0.2 µA V V µs µs G = 1, dc G = 1, f = 10kHz G = 1, f = 1.2MHz Output Disabled Output Impedance CURRENT LIMIT (ISET Pin) Output Current Limit (7) Current Limit Equation(8) RSET Equation Current Limit Tolerance (8), Positive Negative VSET Tolerance (9) UNITS 12 8 0.6 en INPUT IMPEDANCE Differential Common-Mode OPEN-LOOP GAIN Open-Loop Voltage Gain MAX ±1.3 IB VCM CMRR TYP (V–) + 2.5 (V–) + 0.8 0.5 15 NOTES: (1) See typical characteristic, Maximum Output Voltage vs Frequency. (2) See typical characteristic, Total Harmonic Distortion + Noise vs Frequency. (3) Swing to the rail is measured in final test. Under those conditions, the AOL is derived from characterization. (4) See Safe Operating Area (SOA) plots. (5) See typical characteristic, Overshoot vs Load Capacitance. (6) See the Typical Characteristics section. Higher frequency output impedance can affect frequency stability. (7) External current limit setting resistor is required; see Figure 1. (8) ILIMIT is the value of the desired current limit and is equal to 9800(ISET), where ISET is the current through the ISET pin. ILIMIT tolerance is proportional to the ratio of ILIMIT/ISET. Errors from this parameter can be calibrated out—see the Applications Information section. (9) VSET is a voltage reference that equals the difference between the voltage of the ISET pin and V–, and is referenced to the negative rail. Errors from this parameter can be calibrated out—see the Applications Information section. OPA567 SBOS287A www.ti.com 3 ELECTRICAL CHARACTERISTICS: VS = +2.7V to +5.5V (Cont.) Boldface limits apply over the specified temperature range, TA = –40°C to +85°C. At TCASE = +25°C, RL = 1kΩ, and connected to VS /2, unless otherwise noted. OPA567 PARAMETER CONDITION MIN THERMAL FLAG PIN (TFLAG) Junction Temperature: TJ Alarm (thermal status pin Low) Return to normal operation (Thermal Flag pin High) Thermal Flag Pin Voltage During normal operation During thermal overstress TFLAG pin sourcing 25µA TFLAG pin sinking 25µA (V+) – 0.8V CURRENT LIMIT FLAG PIN (IFLAG) Current Limit Flag Pin Voltage During normal operation During current limit IFLAG pin sourcing 25µA IFLAG pin sinking 25µA (V+) – 0.8V POWER SUPPLY Specified Voltage Range Operating Voltage Range Quiescent Current(10) IQ IO = 0, ILIMIT = 200mA, VS = 5V IO = 0, ILIMIT = 2A, VS = 5V IO = 0, VSD = 0.8V, VS = 5V Junction Temperature Junction Temperature θJC θJA MAX UNITS °C °C +147 +130 V+ V– (V–) + 0.8 V V V+ V– (V–) + 0.8 V V +2.7 +2.5 VS Quiescent Current in Shutdown Mode TEMPERATURE RANGE Specified Range Operating Range Storage Range Thermal Resistance: Junction-to-Case Junction-to-Ambient Thermal overstress Normal operation TYP +3.4 +9 +0.01 –40 –55 –65 6 38 +5.5 +5.5 +6 +11 V V mA mA mA +85 +125 +150 °C °C °C °C/W °C/W NOTES: (10) Quiescent current is a function of the current limit setting. See Adjustable Current Limit and Current Limit Flag Pin in the Applications Information section. 4 OPA567 www.ti.com SBOS287A TYPICAL CHARACTERISTICS At TA = +25°C, VS = +5V, unless otherwise noted. POWER-SUPPLY AND COMMON-MODE REJECTION RATIO vs FREQUENCY 0 160 –20 140 –40 120 –60 100 –80 80 –100 60 –120 40 –140 20 –160 0 –180 CMRR 100 0.1 1 10 100 1k 10k 100k 1M 80 60 40 0 1 10M 10 100 1k Frequency (Hz) OUTPUT SWING TO POSITIVE RAIL vs SUPPLY VOLTAGE OUTPUT SWING TO NEGATIVE RAIL vs SUPPLY VOLTAGE 300 250 250 Swing to Rail (mV) IOUT = 2A 150 IOUT = 1A 100 IOUT = 200mA 50 100k IOUT = –2A 200 150 IOUT = –1A 100 50 IOUT = –200mA 0 0 2.7 3.0 3.5 4.0 4.5 5.0 5.5 2.7 3.0 3.5 4.0 4.5 5.0 Supply Voltage (V) Supply Voltage (V) OUTPUT SWING TO POSITIVE RAIL vs TEMPERATURE OUTPUT SWING TO NEGATIVE RAIL vs TEMPERATURE 300 5.5 300 250 250 IO = 2A IO = 2A Swing to Rail (mV) Swing to Rail (mV) 10k Frequency (Hz) 300 200 PSRR 20 –200 –20 Swing to Rail (mV) 120 PSRR and CMRR (dB) 180 Phase (°) AOL (dB) OPEN-LOOP GAIN AND PHASE vs FREQUENCY 200 150 IO = 1A 100 150 IO = 1A 100 VS = 5V, IO = 200mA VS = 2.7V, IO = 200mA 50 200 50 VS = 5V, IO = 200mA 0 VS = 2.7V, IO = 200mA 0 –55 –35 –15 5 25 45 65 85 –55 Temperature (°C) –15 5 25 45 65 85 Temperature (°C) OPA567 SBOS287A –35 www.ti.com 5 TYPICAL CHARACTERISTICS (Cont.) At TA = +25°C, VS = +5V, unless otherwise noted. INPUT VOLTAGE NOISE SPECTRAL DENSITY vs FREQUENCY 0.1Hz TO 10Hz INPUT VOLTAGE NOISE Input Voltage Noise (nV√Hz) 1000 1µV/div 100 10 1 10 100 1k 10k 1s/div 100k Frequency (Hz) TOTAL HARMONIC DISTORTION+NOISE vs FREQUENCY MAXIMUM OUTPUT VOLTAGE vs FREQUENCY 10 6 VS = 5V RL = 1kΩ 1 4 RL = 1Ω 3 RL = 1kΩ RL = 2Ω THD+N (%) Output Voltage (VPP) 5 0.1 RL = 8Ω 2 0.01 VS = 2.7V 1 RL = 1kΩ RL = 1Ω 0.001 0 100 1k 10k 100k 20 1M 100 1k 10k 20k Frequency (Hz) Frequency (Hz) QUIESCENT CURRENT vs TEMPERATURE QUIESCENT CURRENT vs SUPPLY VOLTAGE 10 10 8 Quiescent Current (mA) Quiescent Current (mA) Current Limit = 2A Current Limit = 1A 6 Current Limit = 200mA 4 2 IQ (ILIMIT = 2A) 6 4 IQ (ILIMIT = 200mA) 2 0 0 2.7 3.0 3.5 4.0 4.5 5.0 –55 5.5 –35 –15 5 25 45 65 85 105 125 Temperature (°C) Supply Voltage (V) 6 8 OPA567 www.ti.com SBOS287A TYPICAL CHARACTERISTICS (Cont.) At TA = +25°C, VS = +5V, unless otherwise noted. SHUTDOWN CURRENT vs TEMPERATURE 12 10 10 Shutdown Current (µA) Shutdown Current (µA) SHUTDOWN CURRENT vs SUPPLY VOLTAGE 12 8 ILIMIT = 200mA, 1A, and 2A 6 4 2 8 6 4 2 0 0 2.7 3.0 3.5 4.0 4.5 5.0 5.5 –55 –35 –15 5 Supply Voltage (V) 105 125 10000 8 1000 Input Bias Current (pA) Quiescent Current (mA) 85 INPUT BIAS CURRENT vs TEMPERATURE QUIESCENT CURRENT vs CURRENT LIMIT SETTING 10 6 4 2 100 10 1 0.1 0.01 0 0 0.5 1.0 1.5 2.0 2.5 –55 –35 –15 5 Current Limit Setting (A) 1.8 1.8 1.6 1.6 1.4 1.4 Slew Rate (V/µs) 2.0 SR– 1.0 0.8 SR+ 0.6 45 65 85 105 125 SLEW RATE vs TEMPERATURE 2.0 1.2 25 Temperature (°C) SLEW RATE vs LOAD RESISTANCE Slew Rate (V/µs) 25 45 65 Temperature (°C) 1.2 1.0 0.8 0.6 0.4 0.4 0.2 0.2 0 SR+ SR– 0 1 10 100 1000 Load Resistance (Ω) –35 –15 5 25 45 65 85 105 125 Temperature (°C) OPA567 SBOS287A –55 www.ti.com 7 TYPICAL CHARACTERISTICS (Cont.) At TA = +25°C, VS = +5V, unless otherwise noted. VOLTAGE ON ISET PIN vs SUPPLY VOLTAGE VOLTAGE ON ISET PIN vs TEMPERATURE 1.25 1.20 Current Limit = 200mA 1.20 [VSET – (V–)] [VSET – (V–)] (V) 1.19 1.18 Current Limit = 1A 1.15 Current Limit = 2A 1.10 1.17 1.05 1.16 –55 –35 –15 5 25 45 65 85 105 2.7 125 3.0 3.5 4.0 4.5 5.0 5.5 Supply Voltage (V) Temperature (°C) OFFSET VOLTAGE PRODUCTION DISTRIBUTION OFFSET VOLTAGE DRIFT PRODUCTION DISTRIBUTION –10 –9 –8 –7 –6 –5 –4 –3 –2 –1 0 1 2 3 4 5 6 7 8 9 10 VOS (mV) Drift (µV/°C) SMALL-SIGNAL STEP RESPONSE (G = +1, RL = 1kΩ) LARGE-SIGNAL STEP RESPONSE (G = +1, RL = 1kΩ) 1V/div 50mV/div –2.0 –1.8 –1.6 –1.4 –1.2 –1.0 –0.8 –0.6 –0.4 –0.2 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Population Population Typical Production Distribution of Packaged Units. 10µs/div 8 20µs/div OPA567 www.ti.com SBOS287A TYPICAL CHARACTERISTICS (Cont.) At TA = +25°C, VS = +5V, unless otherwise noted. LARGE-SIGNAL STEP RESPONSE (G = +1, RL = 10Ω) 1V/div 50mV/div SMALL-SIGNAL STEP RESPONSE (G = +1, RL = 10Ω) 20µs/div SMALL-SIGNAL STEP RESPONSE (G = +1, RL = 1Ω) LARGE-SIGNAL STEP RESPONSE (G = +1, RL = 1Ω) 1V/div 50mV/div 10µs/div 20µs/div 20µs/div ENABLE (10Ω Load) ENABLE (1Ω Load) 2V/div 2V/div Enable/Disable 0.8 to 2.5V Above Negative Supply Output Driven to +2V 1V/div 1V/div Output Driven to +2V 10µs/div 4µs/div OPA567 SBOS287A Enable/Disable 0.8 to 2.5V Above Negative Supply www.ti.com 9 TYPICAL CHARACTERISTICS (Cont.) At TA = +25°C, VS = +5V, unless otherwise noted. DISABLE (1Ω Load) 2V/div 2V/div DISABLE (10Ω Load) Enable/Disable 0.8 to 2.5V Above Negative Supply Output Driven to +2V 1V/div 200ns/div POWER ON (1Ω Load) POWER OFF (1Ω Load) 5V/div 200ns/div Supply 5V to 0V 1V/div Supply 0V to 5V Output Driven to +2V Output Driven to +2V 1ms/div IN AND OUT OF CURRENT LIMIT TRANSIENT (RL = 0.75Ω, Current Limit = 2A) IN AND OUT OF CURRENT LIMIT TRANSIENT (RL = 7.5Ω, Current Limit = 200mA) VOUT (2V/div) 1ms/div Current Limit Flag (5V/div) Current Limit Flag (5V/div) VOUT (2V/div) 1V/div 5V/div 1V/div Output Driven to +2V 200µs/div 200µs/div 10 Enable/Disable 0.8 to 2.5V Above Negative Supply OPA567 www.ti.com SBOS287A TYPICAL CHARACTERISTICS (Cont.) At TA = +25°C, VS = +5V, unless otherwise noted. NO PHASE INVERSION WITH INPUTS LARGER THAN SUPPLY VOLTAGE (G = +1, RL = 10Ω) OVERLOAD RECOVERY (G = +1) 1V/div 1V/div VIN VOUT VOUT VIN 40µs/div 1ms/div CURRENT LIMIT ERROR vs TEMPERATURE CURRENT LIMIT ERROR vs SUPPLY VOLTAGE 15 15 10 Current Limit Error (%) Current Limit Error (%) 10 ILIMIT – 5 0 ILIMIT+ –5 5 0 ILIMIT+ –10 –10 –15 –15 2.7 3.0 3.5 4.0 4.5 5.0 –55 5.5 –35 –15 5 25 45 65 Supply Voltage (V) Temperature (°C) CURRENT LIMIT ERROR vs OUTPUT CURRENT OVERSHOOT vs LOAD CAPACITANCE (G = +1, RL = 1kΩ) 85 50 15 10 40 ILIMIT – 5 Overshoot (%) Current Limit Error (%) ILIMIT – –5 0 ILIMIT+ –5 30 20 10 –10 –15 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 10 2.0 Output Current (A) 1k 10k Load Capacitance (pF) OPA567 SBOS287A 100 www.ti.com 11 TYPICAL CHARACTERISTICS (Cont.) At TA = +25°C, VS = +5V, unless otherwise noted. CLOSED-LOOP OUTPUT IMPEDANCE vs FREQUENCY 100 Output Impedance (Ω) G=1 10 1 0.1 10k 12 100k Frequency (Hz) 1M 2M OPA567 www.ti.com SBOS287A APPLICATIONS INFORMATION R1 R2 BASIC CONFIGURATION V+ Figure 1 shows the OPA567 connected as a basic noninverting amplifier. However, the OPA567 can be used in virtually any op amp configuration. A current limit setting resistor (RSET, in Figure 1) is essential to the OPA567 operation, and cannot be omitted. 47µF 0.1µF 1, 12 8 2, 3 Power-supply terminals should be bypassed with low series impedance capacitors. Using larger tantalum and smaller ceramic type capacitors in parallel is recommended. Powersupply wiring should have low series impedance. OPA567 VIN 9 4, 5 47µF 11 0.1µF The OPA567 operates with excellent performance from a single (+2.7V to +5.5V) supply or from dual supplies. Power supply voltages do not need to be equal as long as the total voltage remains below 5.5V. Parameters that vary significantly with operating voltage are shown in the Typical Characteristics section. Setting the current limit RSET (Ω) ILIMIT (A) 23.2k 11.5k 7.68k 5.76k 0.5 1.0 1.5 2.0 47µF NOTES: (1) RSET sets the current limit value from 0.2A to 2.2A. RSET can be a potentiometer to easily adjust current limit and calibrate out errors at the current limit node. (2) Enable—pull Low to disable output. ADJUSTABLE CURRENT LIMIT AND CURRENT LIMIT FLAG PIN The OPA567 provides over-current protection to the load through its accurate, user-adjustable current limit (pin 6). The current limit value, ILIMIT, can be set from 0.2A to 2.2A by controlling the current to the ISET pin. The current limit, ILIMIT, will be 9800 • ISET, where ISET is the current through the ISET pin. Setting the current limit requires no special power resistors. The output current does not flow through this pin. ISET RSET(1) Enable(2) POWER SUPPLIES VO 6 V– FIGURE 1. Basic Connections. the ISET pin and V–, the negative supply, according to the formula: ILIMIT = 9800 • (1.18V/RSET) Alternatively, the output current limit can be set by applying a voltage source in series with a resistance using the equation: As illustrated in Figure 2, the simplest method of setting the current limit is to connect a resistor or potentiometer between ILIMIT = 9800 • [(1.18V – VADJUST)/RSET] The voltage source must be referenced to V–. 8 8 2, 3 2, 3 1.18V 9 6 ISET 4, 5 1.18V 9 ILIMIT = 9800 (1.18V/RSET) 6 ISET RSET 4, 5 ILIMIT = 9800 (1.18V – VADJUST) RSET VADJUST(1) RPOT V– V– (a) Resistor or Potentiometer Method (b) Resistor/Voltage Source Method Putting a set resistor in series with the potentiometer will prevent potential short-circuit on pin. NOTE: (1) This voltage source must be able to sink the current from the ISET pin, which is ILIMIT/9800. FIGURE 2. Setting the Current Limit—Resistor Method. OPA567 SBOS287A www.ti.com 13 Current Limit Accuracy ENABLE PIN—OUTPUT DISABLE Internally separate circuits monitor the positive and negative current limits. Each circuit output is compared to a single internal reference that is set by the user with an external resistor or a resistor/voltage source combination. The OPA567 employs a patented circuit technique to achieve an accurate and stable current limit throughout the full output range. The initial accuracy of the current limit is typically within 3%; however, because of internal matching limitations, the error can be as much as 15%. The variation of the current limit with factors such as output current level, output voltage, and temperature is shown in the Typical Characteristics section. The Enable pin can disable the OPA567 within microseconds. When disabled, the amplifier draws less than 10µA and its output enters a high-impedance state that allows multiplexing. It is important to note that when the amplifier is disabled, the Thermal Flag pin (TFLAG) circuitry continues to operate. This feature allows use of the TFLAG pin output to implement thermal protection strategies. For more details, please see the section on thermal protection. When the accuracy of one current limit (sourcing or sinking) is more important than the other, it is possible to set its accuracy to better than 1% by adjusting the external resistor or the applied voltage. The accuracy of the other current limit will still be affected by internal matching. Current Limit Flag Pin The OPA567 features an IFLAG pin (pin 7) that can be monitored to determine when the part is in current limit. The output signal of the IFLAG pin is compatible to standard logic in single-supply applications. The output signal is a CMOS logic gate that switches from V+ to V– to indicate that the amplifier is in current limit. The IFLAG pin can source and sink up to 25µA. Additional parasitic capacitance between pins 6 and 7 can cause instability at the edge of the current limit. Avoid routing these traces in parallel close to each other. Quiescent Current Dependence on the Current Limit Setting The OPA567 is a low-power amplifier, with a typical 3.4mA quiescent current (with the current limit configured for 200mA). The quiescent current varies with the current limit setting— it increases 0.5mA for each additional 200mA increase in the current limit, as shown in Figure 3. The OPA567 Enable pin has an internal pull-up circuit, so it does not have to be connected to the positive supply for normal operation. To disable the amplifier, the Enable pin must be connected to no more than (V–) + 0.8V. To enable the amplifier, either allow the Enable pin to float or connect it to at least (V–) + 2.5V. The Enable pin is referenced to the negative supply (V–). Therefore, shutdown operation is slightly different in singlesupply and dual-supply applications. In single-supply operation, V– typically equals common ground; thus, the enable/disable logic signal and the OPA567 Enable pin are referenced to the same potential. In this configuration, the logic level and the OPA567 Enable pin can simply be tied together. Disabling the OPA567 occurs for voltage levels of less than 0.8V. The OPA567 is enabled at logic levels greater than 2.5V. In dual-supply operation, the logic level is referenced to a logic ground. However, the OPA567 Enable pin is still referenced to V–. To disable the OPA567, the voltage level of the logic signal needs to be level-shifted. This level-shifting can be done using an optocoupler, as shown in Figure 4. Examples of output behavior during disabled and enabled conditions with various load impedances are shown in the typical characteristics section. Please note that this behavior is a function of board layout, load impedances, and bypass strategies. For sensitive loads, the use of a low-pass filter or other protection strategy is recommended. QUIESCENT CURRENT vs CURRENT LIMIT SETTING V+ 10 (a) +5V (b) HCT or TTL In Quiescent Current (mA) 1, 12 8 8 9 6 OPA567 11 (1) 2, 3 VO Enable 4, 5 4 2 4N38 Optocoupler 0 0 0.5 1 1.5 2 V– 2.5 Current Limit Setting (A) (a) HCT or TTL In FIGURE 3. Quiescent Current vs Current Limit Setting. 14 (b) NOTE: (1) Optional—may be required to limit leakage current of optocoupler at high temperatures. FIGURE 4. OPA567 Shutdown Configuration for Dual Supplies. OPA567 www.ti.com SBOS287A ENSURING MICROCONTROLLER COMPATIBILITY +V Not all microcontrollers output the same logic state after power-up or reset. 8051-type microcontrollers, for example, output logic High levels on their ports while other models power up with logic Low levels after reset. 1, 12 –In In configuration (a) shown in Figure 4, the enable/disable signal is applied on the cathode side of the photodiode within the optocoupler. A logic High level causes the OPA567 to be enabled, and a logic Low level disables the OPA567. In configuration (b) of Figure 4, with the logic signal applied on the anode side, a high level disables the OPA567 and a low level enables the op amp. OPA567 +In 2, 3 VO 9 6 ISET 4, 5 Output Protection Diode RSET RAIL-TO-RAIL OUTPUT RANGE –V The OPA567 has a class AB output stage with common source transistors that are used to achieve rail-to-rail output swing. It was designed to be able to swing closer to the rail than other existing linear amplifiers, even with high output current levels. A quick way to estimate the output swing with various output current requirements is by using the equation: VSWING [typical] = 0.1 • IO Plots of the Output Swing vs Output Current, Supply Voltage, and Temperature are provided in the Typical Characteristics section. RAIL-TO-RAIL INPUT RANGE The input common-mode voltage range of the OPA567 extends 100mV beyond the supply rails. This is achieved by a complementary input stage with an N-channel input differential pair in parallel with a P-channel differential pair. The N-channel input pair is active for input voltages close to the positive rail while the P-channel input pair is active for input voltages close to the negative rail. The transition point is typically at (V+) – 1.3V, and there is a small transition region around the switching point where both transistors are on. It is important to note that the two input pairs can have offsets of different signs and magnitudes. Therefore, as the transition point is crossed, the offset of the amplifier changes. This offset shift accounts for the reduced common-mode rejection ratio over the full input common-mode range. OUTPUT PROTECTION Reactive and EMF-generating loads can return load current to the amplifier, causing the output voltage to exceed the power-supply voltage. This damaging condition can be avoided with clamp diodes from the output terminal to the power supplies, as shown in Figure 5. Schottky rectifier diodes with a 3A or greater continuous rating are recommended. FIGURE 5. Output Protection Diode. THERMAL FLAG PIN The OPA567 has thermal sensing circuitry that provides a warning signal when the die temperature exceeds safe limits. Unless the TFLAG pin is connected to the Enable pin, when this flag is triggered, the part continues to operate even though the junction temperature exceeds 150°C. This default operation allows maximum usable operation in very harsh conditions but degrades reliability. The TFLAG pin can be used to provide for orderly system shutdown before failure occurs. It can be also used to evaluate the thermal environment to determine need for and appropriate design of a shutdown mechanism. The thermal flag output signal is from a CMOS logic gate that switches from V+ to V– to indicate that the amplifier is in thermal limit. This flag output pin can source and sink up to 25µA. The TFLAG pin is HIGH during normal operation. Power dissipated in the amplifier will cause the junction temperature to rise. When the junction temperature exceeds 150°C, the TFLAG pin will go Low, and remain Low until the amplifier has cooled to 130°C. Despite this hysteresis, with a method of orderly shutdown, the TFLAG pin can cycle on and off, depending on load and signal conditions. This limits the dissipation of the amplifier but may have an undesirable effect on the load. It is possible to connect the TFLAG pin directly to the Enable pin for automatic shutdown protection. When both thermal shutdown and the amplifier enable/disable functions are desired, the externally generated control signal and the TFLAG pin outputs should be combined with an AND gate; see Figure 6. The temperature protection was designed to protect against overload conditions. It was not intended to replace proper heatsinking. Continuously running the OPA567 in and out of thermal shutdown will degrade reliability. OPA567 SBOS287A Output Protection Diode 8 www.ti.com 15 SAFE OPERATING AREA (TA = 25°C) On 10 AND Output Current (A) Disable TFLAG Pin Enable Pin 10 8 9 11 OPA567 2, 3 Thermal pad soldered to 2 oz. copper pad, with 500lfm airflow. 1 Thermal pad soldered to 2 oz. copper pad, without forced air. 0.1 0 FIGURE 6. Enable/Shutdown Control Using TFLAG Pin and External Control Signal. 1 2 3 4 5 6 VS – VOUT (V) FIGURE 7. Safe Operating Area at Room Temperature. Any tendency to activate the thermal protection circuit indicates excessive power dissipation or an inadequate heat sink. For reliable, long term, continuous operation, the junction temperature should be limited to 125°C maximum. To estimate the margin of safety in a complete design (including heat sink), increase the ambient temperature until the thermal protection is triggered. Use worst-case loading and signal conditions. For good, long-term reliability, thermal protection should trigger more than 25°C above the maximum expected ambient conditions of your application. This produces a junction temperature of 125°C at the maximum expected ambient condition. Fast transients of large output current swings (for example, switching quickly from sourcing 2A to sinking 2A) may cause a glitch on the TFLAG pin. When switching large currents is expected, the use of extra bypass between the supplies or a low-pass filter on the TFLAG pin is recommended. POWER DISSIPATION AND SAFE OPERATING AREA Power dissipation depends on power supply, signal, and load conditions. It is dominated by the power dissipation of the output transistors. For DC signals, power dissipation is equal to the product of output current, IOUT and the output voltage across the conducting output transistor (VS – VOUT). Dissipation with AC signals is lower. Application Bulletin SBOA022 explains how to calculate or measure power dissipation with unusual signals and loads and can be found at the TI web site (www.ti.com). Output short-circuits are particularly demanding for the amplifier because the full supply voltage is seen across the conducting transistor. It is very important to note that the temperature protection will not shut the part down in overtemperature conditions, unless the TFLAG pin is connected to the Enable pin; see the section on Thermal Flag. Figure 7 shows the safe operating area at room temperature with various heatsinking efforts. Note that the safe output current decreases as (VS – VOUT) increases. Figure 8 shows the safe operating area at various temperatures with the metal heatsink being soldered to a 2oz copper pad. 16 SAFE OPERATING AREA Thermal Pad Soldered, Various TA 10 Output Current (A) TA = –40°C TA = 0°C 1 TA = +85°C TA = +25°C 0.1 0 1 2 3 4 5 6 VS – VOUT (V) FIGURE 8. Safe Operating Area at Various Ambient Temperatures. Metal heat sink soldered to a 2oz copper pad. The power that can be safely dissipated in the package is related to the ambient temperature and the heatsink design. The QFN package was specifically designed to provide excellent power dissipation, but board layout greatly influences the heat dissipation of the package. Refer to the QFN Package section for further details. The OPA567 has a junction-to-ambient thermal resistance (θJA) value of 38°C/W when soldered to a 2oz copper plane. This value can be further decreased by the addition of forced air. See Figure 9 for the junction-to-ambient thermal resistance of the QFN-12 package. Junction temperature should be kept below 125°C for reliable operation. The junction temperature can be calculated by: TJ = TA + PDθJA where θJA = θJC + θCA TJ = Junction Temperature (°C) TA = Ambient Temperature (°C) PD = Power Dissipated (W) θJA = Junction-to-Ambient Thermal Resistance θJC = Junction-to-Case Thermal Resistance θCA = Case-to-Air Thermal Resistance OPA567 www.ti.com SBOS287A θJA The part is soldered to a 2 oz copper pad under the exposed pad. 38 Soldered to copper pad with forced airflow (150lfm). 36 Soldered to copper pad with forced airflow (250lfm). 35 Soldered to copper pad with forced airflow (500lfm). 34 THERMAL RESISTANCE vs NUMBER OF THERMAL VIAS 100 Thermal Resistance, θJA (°C/W) HEATSINKING METHOD FIGURE 9. Junction-to-Ambient Thermal Resistance with Various Heatsinking Efforts. The Maximum Power Dissipation vs Temperature for the heatsinking methods referenced in Figure 9 is shown in Figure 10. 90 80 70 60 50 40 30 20 10 0 0 1 2 3 4 5 6 Number of Thermal Vias FIGURE 11. Thermal Resistance vs Number of Thermal Vias. MAXIMUM POWER DISSIPATION IN PACKAGE vs TEMPERATURE FEEDBACK CAPACITOR IMPROVES RESPONSE 6 TJ = 150°C Power Dissipated (W) For optimum settling time and stability with higher impedance feedback networks (RF > 50kΩ), it may be necessary to add a feedback capacitor across the feedback resistor, RF, as shown in Figure 12. This capacitor compensates for the zero created by the feedback network impedance and the input capacitance of the OPA567 (and any parasitic layout capacitance). The effect becomes more significant with higher impedance networks. Thermal pad soldered to 2oz. copper pad, with 500lfm airlow. 5 4 3 Thermal pad soldered to 2oz. copper pad, without forced air. 2 The size of the capacitor needed is estimated using the equation: 1 RIN • CIN = RF • CF 0 –75 –50 –25 0 25 50 75 100 125 where CIN is the sum of the input capacitance of the OPA567 plus the parasitic layout capacitance. Temperature (°C) FIGURE 10. Maximum Power Dissipation vs Temperature. CF To appropriately determine required heatsink area, required power dissipation should be calculated and the relationship between power dissipation and thermal resistance should be considered to minimize shutdown conditions and allow for proper long-term operation (junction temperature of 125°C). Once the heatsink area has been selected, worst-case load conditions should be tested to ensure proper thermal protection. RIN RF VIN V+ 1, 12 8 CIN 2, 3 RIN • CIN = RF • CF For applications with limited board size, refer to Figure 11 for the approximate thermal resistance relative to the number of thermal vias. The QFN-12 package is well suited for continuous power levels, as shown in Figure 10. Higher power levels may be achieved in applications with a low on/off duty cycle. VOUT OPA567 9 CL CIN 4, 5 V– Where CIN is equal to the OPA567 input capacitance (approximately 9pF) plus any parasitic layout capacitance. FIGURE 12. Feedback Capacitor for Use with Higher Impedance Networks. OPA567 SBOS287A www.ti.com 17 QFN THERMALLY ENHANCED PACKAGE The OPA567 uses the QFN-12 package, a thermallyenhanced package designed to eliminate the use of bulky heat sinks and slugs traditionally used in thermal packages. This package can be easily mounted using standard printed circuit board (PCB) assembly techniques. See QFN/SON PCB Attachment Application Note (SLUA271) located at www.ti.com. The thermal resistance junction-to-ambient (RθJA) of the QFN package depends on the PCB layout. Using thermal vias and wide PCB traces improve thermal resistance. The thermal pad must be soldered to the PCB. The thermal pad should either be left floating or connected to V–. LAYOUT GUIDELINES The OPA567 is a power amplifier that requires proper layout for best performance. An example layout is appended to the end of this datasheet. Refinements to this layout may be required based on assembly process requirements. power- supply leads. The wire length should be less than 8 inches. Proper power-supply bypassing with low ESR capacitors is essential to achieve good performance. A parallel combination of 100nF ceramic and 47µF tantalum bypass capacitors will provide low impedance over a wide frequency range. Bypass capacitors should be placed as close as practical to the power-supply pins of the OPA567. PCB traces conducting high currents, such as from output to load or from the power-supply connector to the power-supply pins of the OPA567 should be kept as wide and short as possible. This practice will keep inductance low and resistive losses to a minimum. The nine holes in the landing pattern for the OPA567 are for the thermal vias that connect the thermal pad of the OPA567 to the heatsink area on the PCB. All traces conducting high currents are very wide for lowest inductance and minimal resistive losses. Keep power-supply leads as short as possible. This practice will keep inductance low and resistive losses at a minimum. A minimum of 18 gauge wire thickness is recommended for 18 OPA567 www.ti.com SBOS287A APPLICATION CIRCUITS R2 4.99kΩ fO = 10kHz 0.0033µF +1V 0V R1 49.9kΩ 0mA –100mA 1, 12 8 VIN 9 OPA567 (1) R3 49.9kΩ 2, 3 VO 6 RSET RSHUNT 1Ω 4, 5 IO 0V –2.5V Luxeon Star-0 High-Power LED –5V 4.99kΩ Feedback for Constant Current, 1V Input per 100mA Output as Shown. NOTE: (1) Bypass as recommended. FIGURE 13. Grounded Anode LED Driver. 1kΩ 1kΩ 5V 5V 1, 12 1, 12 (1) 8 VIN 9 OPA567 6 8 TEC 2, 3 2, 3 ISET + 4, 5 RSET VTEC (1) OPA567 ISET 3 – Heat/Cool 9 VSET 4, 5 RSET VTEC = 2 (VIN – VSET) NOTE: (1) Bypass as recommended. FIGURE 14. Bridge-Tied Load Driver. NOTE: Total Supply Must be < 5.5V Cooling/Heating. +3.3V 1, 12 (1) 8 VIN 9 IL 2, 3 OPA567 6 ISET 4, 5 TEC RSET –1.2V NOTE: (1) Bypass as recommended. FIGURE 15. Single Power Amplifier Driving Bidirectional Current through a TEC using Asymmetrical Bipolar Power Supplies. OPA567 SBOS287A www.ti.com 19 20 OPA567 www.ti.com SBOS287A OPA567 SBOS287A www.ti.com 21 PACKAGE OPTION ADDENDUM www.ti.com 28-Oct-2005 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty OPA567AIRHGR ACTIVE QFN RHG 12 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR OPA567AIRHGRG4 ACTIVE QFN RHG 12 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR OPA567AIRHGT ACTIVE QFN RHG 12 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR OPA567AIRHGTG4 ACTIVE QFN RHG 12 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR Lead/Ball Finish MSL Peak Temp (3) (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS) or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 1 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Applications Amplifiers amplifier.ti.com Audio www.ti.com/audio Data Converters dataconverter.ti.com Automotive www.ti.com/automotive DSP dsp.ti.com Broadband www.ti.com/broadband Interface interface.ti.com Digital Control www.ti.com/digitalcontrol Logic logic.ti.com Military www.ti.com/military Power Mgmt power.ti.com Optical Networking www.ti.com/opticalnetwork Microcontrollers microcontroller.ti.com Security www.ti.com/security Telephony www.ti.com/telephony Video & Imaging www.ti.com/video Wireless www.ti.com/wireless Mailing Address: Texas Instruments Post Office Box 655303 Dallas, Texas 75265 Copyright 2005, Texas Instruments Incorporated