PowerAmp Design. PowerAmp Design PAD39 POWER OPERATIONAL AMPLIFIER

Transcription

1 PowerAmp Design POWE OPEATIONAL AMPLIFIE KEY FEATUES HIGH VOLTAGE 00 VOLTS HIGH CUENT 0 AMPS 25 WATT DISSIPATION CAPABILITY HIGH SLEW ATE- 0V/µS FOU WIE CUENT LIMIT OPTIONAL BOOST VOLTAGE INPUTS APPLICATIONS LINEA AND OTAY MOTO DIVE YOKE/MAGNETIC FIELD EXCITATION POGAMMABLE POWE SUPPLIES INDUSTIAL (PA) AUDIO DESCIPTION The is a power operational amplifier constructed with surface mount components to provide a cost effective solution for many industrial applications With a footprint only 3.3in 2 the offers outstanding performance that rivals more expensive hybrid component amplifiers or rack-mount amplifiers. User selectable external compensation tailors the amplifier s response to the application requirements. Programmable current limit is builtin. The amplifier circuitry is built on a thermally conductive but electrically insulating substrate. No BeO is used in the. The resulting module is a small, high performance solution for many industrial applications. ev B

2 CICUIT & CONNECTIONS EQUIVALENT CICUIT -ILIM -IN +IN GND NC -VB IQ +ILIM NC NC PINOUT & CONNECTIONS Cc VB GND NC Cc2 NC Cc NC NC NC NC NC +Vs VIEW FOM COMPONENT SIDE C4 + PHASE COMPENSATION TYP. SLEW ATE GAIN Cc 470pF 4V/uS 3 220pF 9V/uS > 5 00pF 5V/uS > 2 47pF 20V/uS -Vs OUT C3 -Vs S C2 + C TO FEEDBACK & LOAD 2

3 POWE OPEATIONAL AMPLIFIE ABSOLUTE MAXIMUM ATINGS SPECIFICATIONS ABSOLUTE MAXIMUM ATINGS SUPPLY VOLTAGE, +Vs to Vs 00V TEMPEATUE, pin solder, 0s 200C BOOST VOLTAGE, ±Vs ±20V TEMPEATUE, junction 2 75 C OUTPUT CUENT, within SOA 25A TEMPEATUE ANGE, storage 40 to 05 C POWE DISSIPATION, internal, DC 25W OPEATING TEMPEATUE, case 40 to 05 C INPUT VOLTAGE, differential ± 20V INPUT VOLTAGE, common mode ±V B PAAMETE TEST CONDITIONS MIN TYP MAX UNITS INPUT OFFSET VOLTAGE 3 mv OFFSET VOLTAGE vs. temperature Full temperature range μv/ O C OFFSET VOLTAGE vs. supply 20 μv/v BIAS CUENT, initial 3 00 pa BIAS CUENT vs. supply 0. pa/v OFFSET CUENT, initial 50 pa INPUT ESISTANCE, DC 00 G Ω INPUT CAPACITANCE 4 pf COMMON MODE VOLTAGE ANGE +V B 5 V COMMON MODE VOLTAGE ANGE V B +7 V COMMON MODE EJECTION, DC db NOISE 00kHz bandwidth, kω S 0 μv MS GAIN OPEN LOOP L = 0kΩ, C C =00pF 08 db GAIN BANDWIDTH MHz C C =00pF 2 MHz PHASE MAGIN Full temperature range degree OUTPUT VOLTAGE SWING I O = 0A ±Vs 8 +Vs 6.6 V VOLTAGE SWING I O = 0A Vs+7 Vs+6 V VOLTAGE SWING +V B =+Vs+0V, I O = 0A +Vs 2 +Vs.2 VOLTAGE SWING -V B =-Vs-0V, I O = -0A -Vs 2.8 +Vs+2.2 CUENT, continuous, DC 0 A SLEW ATE, A V = 0 C C = 00pF 0 5 V/μS SETTLING TIME, to 0.% 2V Step, C C = 00pF 2.5 μs ESISTANCE No load, DC 4 Ω POWE SUPPLY VOLTAGE ± 5 ± 40 ± 50 V CUENT, quiescent, boost supply 22 ma CUENT, total 26 ma THEMAL ESISTANCE, AC, junction to air 5 Full temperature range, f 60Hz 0.9 O C/W ESISTANCE, DC junction to air, outputs Full temperature range.2 O C/W TEMPEATUE ANGE, heat sink O C NOTES:. Unless otherwise noted: T C = 25 O C, compensation Cc = 470pF, DC input specifications are ± value given, power supply voltage is typical rating. 2. Derate internal power dissipation to achieve high MTBF. 3. Doubles for every 0 O C of case temperature increase. 4. +Vs and Vs denote the positive and negative supply voltages to the output stage. +V B and V B denote the positive and negative supply voltages to the input stages. 5. ating applies if the output current alternates between both output transistors at a rate faster than 60Hz. 7. Power supply voltages +V B and V B must not be less than +Vs and Vs respectively. Total voltage +V B to V B 20V maximum. 8. The is constructed with MOSFET transistors and ESD handling procedures must be observed. 3

4 OPEATING CONSIDEATIONS SAFETY FIST The operating voltages of the are potentially deadly. When developing an application circuit it is wise to begin with power supply voltages as low as possible while checking for circuit functionality. Increase supply voltages slowly as confidence in the application circuit increases. Always use a hands off method whereby test equipment probes are attached only when power is off. CUENT LIMIT The current limiting function of the is a versatile circuit that can be used to implement a four-wire current limit configuration. The four-wire current limit configuration insures that parasitic resistance in the output line, p, does not affect the programmed current limit setting. See Figure below. The sense voltage for current limit is 0.7V. Thus: IL 0.7V = Where I L is the value of the limited current and S is the value of the current limit sense resistor. In addition, the sense voltage has a temperature coefficient approximately equal to 2.2mV/ o C. IN IN F S 24 +ILIM 23 -ILIM Figure OUT 5-7 MOUNTING THE AMPLIFIE In most applications the amplifier must be attached to a heat sink. Spread a thin and even coat of heat sink grease across the back of the and also the heat sink where the amplifier is to be mounted. Push the amplifier into the heat sink grease on the heat sink while slightly twisting the amplifier back and forth a few times to bed the amplifier into the heat sink grease. On the final twist align the mounting holes of the amplifier with the mounting holes in the heat sink and finish the mounting using 4-40 hex male-female spacers. Mount the amplifier to the mother board with 4-40 X /4 screws. P S L PHASE COMPENSATION The must be phase compensated. The compensation capacitor, C C, is connected between pins 4 and 6. The compensation capacitor must be an NPO type capacitor rated for the full supply voltage (00V). On page 2, under Amplifier Pinout and Connections, you will find a table that gives recommended compensation capacitance value for various circuit gains and the resulting slew rate for each capacitor value. Consult also the small signal response and phase response plots for the selected compensation value in the Typical Performance Graphs section. A compensation capacitor less than 00pF is not recommended. USING THE IQ PIN FUNCTION When pin 25 (IQ) is tied to pin 6 (Cc) the class AB bias of the output stage becomes C bias. The quiescent current of the typically drops by 0mA. In some applications the reduced quiescent current is important. However, note that applying this option will raise the output impedance of the amplifier which may change the stability of the circuit and will also increase crossover distortion. BOOST OPEATION The small signal stages of the are connected to the ±V B power supply pins. When the ±V B voltages are greater than the ±Vs power supply pins the small signal stages of the amplifier are biased so that the output transistors can be driven very close to the ±Vs rails. Close swings to the supply rails increase the efficiency of the amplifier and make better use the supply voltages. This technique is often used to operate the amplifier with only a single high current power supply, thus reducing the system size and cost. 4

5 TYPICAL PEFOMANCE GAPHS TOTAL POWE DISSIPATION, P D (W) OFFSET VOLTAGE,Vos (mv) OUTPUT SWING FOM +Vs O -Vs, V POWE DEATING CASE TEMPEATUE, T C ( O C) OFFSET VOLTAGE DIFT CASE TEMP, O C OUTPUT SWING FOM SUPPLY AILS TJ=25 O C +OUTPUT, +VB=+VS -OUTPUT -VB=-VS -OUTPUT, -VB=-VS-0V +OUTPUT, +VB=+VS+0V OUTPUT AMPS, A NOMALIZED QUIESCENT CUENT, I Q (%) NOMALIZED QUIESCENT CUENT, IQ(%) DISTOTION, % QUIESCENT CUENT VS SUPPLY VOLTAGE TOTAL SUPPLY VOLTAGE, (V) QUIESCENT CUENT VS TEMPEATUE CASE TEMPEATUE, O C HAMONIC DISTOTION Av = -0 Cc = 00pF 8Ω LOAD ±Vs = ±38V k k 30k FEQUENCY, F(Hz) 5W 50W 5

6 TYPICAL PEFOMANCE GAPHS 20 SMALL SIGNAL ESPONSE -90 SMALL SIGNAL PHASE ESPONSE OPEN LOOP GAIN, A(dB) OUTPUT VOLTAGE SWING, V(p-p) Ω LOAD I O =500mA DC Cc=00pF Cc=470pF Cc=220pF Cc=47pF k k k M 3M FEQUENCY, F(Hz) POWE ESPONSE CC=470pF k k k M FEQUENCY, F(Hz) CC =220pF CC =00pF CC =47pF PHASE, Θ( O ) Cc=470pF Cc=220pF Cc=00pF Cc=47pF k k M 3M FEQUENCY, F(Hz) 0kHz square into 8Ω load, G= 0,C C =00pF, Vs=±50V khz sine clipped by current limit into 00Ω load 30kHz sine into 8Ω load, G= 0,C C =00pF, Vs=±50V 6

7 SAFE OPEATING AEA 30 SAFE OPEATING AEA ms OUTPUT CUENT, Io (A) 0 0. PULSE 3% DUTY CYCLE 25 O C 85 O C 25 O C 0mS 0 00 SUPPLY TO OUTPUT DIFFEENTIAL,Vs-Vo (V) SAFE OPEATING AEA 7

8 DIMENSIONAL INFOMATION