UC3175B Full-Bridge Power Amplifier FEATURES • • • • • DESCRIPTION Precision Current Control This full-bridge power amplifier is rated for continuous output current of 0.8 Amperes and is intended for use in demanding servo applications such as head ±800mA Load Current positioning for high-density disk drives. The device includes a precision current sense amplifier that provides accurate control of load current. Current is 1.25V Total VSAT at 800mA sensed with a single resistor in series with the load. The power amplifier has a Controlled Velocity Head Parking very low output saturation voltage and will operate down to 4V supply levels. Power output stage protection includes current limiting and thermal shutdown. Precision Dual Supply Monitor with Indicator Auxiliary functions on this device include a dual-input under-voltage compara- • Limit Input to Force Output Extremes • Inhibit Input and UVLO • 4V to 15V operation tor, which can monitor two independent supply voltages and force a built-in head park function when either is below minimum. When activated by either the UV comparator, or a command at the separate PARK input, the park circuitry will override the amplifier inputs to convert the power outputs to a programmable constant voltage source which will hold regulation as the supply voltage falls to below 3.0 Volts. Added features include a POWER OK flag output, a LIMIT input to force the drive output to its maximum level in either polarity, and a over-riding INHIBIT input to disable all amplifiers and reduce quiescent supply current. This device is packaged in a power PLCC surface mount configuration which maintains a standard 28-pin outline, but with 7 pins along one edge allocated to ground for optimum thermal transfer. And is also available in a 24-pin surface mount SOIC package. BLOCK DIAGRAM Note: Pin numbers refer to PLCC package. 10/94 UDG-92054-1 UC3175B ABSOLUTE MAXIMUM RATINGS Input Supply Voltage, (+VIN,+VC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20V UV Comparator, and Digital Inputs Maximum forced voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 10V Maximum forced current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±10mA C/S Inputs Maximum forced voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 20V A and B Amplifier Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +VIN Open Collector Output Voltages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20V A and B Output Currents (continuous) Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Internally Limited Sink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0A Parking Drive Output Current Continuous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150mA Pulsed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1A Output Diode Current (pulsed) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1A Power OK Output Current(continuous) . . . . . . . . . . . . . . . . . . . . . . . . . 30mA Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . . -55°C to +150°C Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -65°C to +150°C Note 1: Unless otherwise indicated, voltages are referenced to ground and currents are positive into, negative out of, the specified terminals. "Pulsed" is defined as a less than 10% duty cycle pulse with a maximum duration of 500µs. Note 2: See Unitrode Integrated Circuits databook for information regarding thermal specifications and limitations of packages. Thermal Data QP Package: Thermal Resistance Junction to Leads, θJL . . . . . . . . . . . . . . . . . . . . . . . 15°C/W Thermal Resistance Junction to Ambient, θJA . . . . . . . . . . . . . . . . . . . . . . . 40°C/W CONNECTION DIAGRAMS SOIC-24 (Top View) DW Package PLCC-28 (Top View) QP Package PACKAGE PIN FUNCTION FUNCTION PIN +VIN 1 INH 2 UV2 3 UV1 4 Limit 5 Park Volts 6 C/S7 A+/REF Input 8 A- In 9 A Output 10 A Cur Sen 11 Gnd (Heat Dissipation Pins) 12-18 B Cur Sen 19 B Output 20 21 +VC Supply B- In 22 B+ In 23 C/S+ 24 Pwr OK 25 Park 26 Park Drive 27 C/S Out 28 ELECTRICAL CHARACTERISTICS: Unless otherwise stated specifications apply for 0°C ≤ TA ≤ 70°C, +VIN = 12V, +VC = +VIN, A+/REF Input = 6V. TA=TJ. PARAMETER TEST CONDITIONS MIN TYP MAX 42 UNITS INPUT SUPPLY +VIN Supply Current All Amplifier Outputs = 6V 35 +VC Supply Current IOUT = 0A 1 +VIN UVLO Threshold Low to High 2.8 UVLO Threshold Hysteresis 200 2 mA mA 3.0 V mV UC3175B ELECTRICAL CHARACTERISTICS (cont.) Unless otherwise stated specifications apply for 0°C ≤ TA ≤ 70°C, +VIN = 12V, +VC = +VIN, A+/REF INPUT = 6V. TA=TJ. PARAMETER UNDER VOLTAGE (UV) COMPARATOR TEST CONDITIONS Input Bias Current UV Thresholds Low to High, Other Input = 5V UV Threshold Hysteresis MIN TYP -1.5 -0.5 1.48 1.50 15 25 MAX UNITS µA 1.52 V 40 mV Pwr OK VSAT IOUT = 5mA 0.45 V Pwr OK Leakage VOUT = 20V 5 µA Input Offset Voltage VCM = 6V, A Amplifier B Amplifier 8 12 mV mV Input Offset Drift Note 1, A Amplifier Only 25 µV/°C Input Bias Current VCM = 6V, except A+/REF Input Input Offset Current VCM = 6V, B Amplifier Only 200 nA 105 µA/V POWER AMPLIFIERS A and B -500 -150 nA Input Bias Current at A+/Ref Input (A+/Ref–C/S+)/12k, TJ = 25°C 60 84 CMRR 1V ≤ VCM ≤ 10V 70 90 dB PSRR +VIN = 4V to 15V, VCM = 1.5V 70 90 dB Large Signal Voltage Gain VOUT = 1V, Sinking 500mA to VOUT = 11V, 3.0 15.0 Sourcing 500mA Slew Rate Unity Gain Bandwidth 1 to 13V, 13 to 1V, TJ = 25°C V/mV 2.1 V/µs Note 1, A Amplifier 2 MHz Note 1, B Amplifier 1 MHz High-Side Current Limit Output Saturation Voltage 1 1.0 A High-Side, ISOURCE = 250mA 0.8 0.7 V High-Side, ISOURCE = 800mA 0.85 V Low-Side, ISINK = 250mA 0.3 0.4 V V Low-Side, ISINK = 800mA Total, IOUT = 250mA 1.0 1.2 V Total, IOUT = 800mA 1.25 1.6 V High Side Diode VF ID = 800mA, Inhibit Activated 1.0 V Low Side Diode VF ID = 800mA, Inhibit Activated 1.0 V CURRENT SENSE AMPLIFIER Input Offset Voltage VCM = 6V Input Offset Change with Common Mode 0V ≤ VCM ≤ 12V Input 1500 µV/V 8 µV/°C 2.05 V Low-Side, ISINK = 1.5mA 0.3 0.5 V High-Side, ISOURCE = 1.5mA 0.4 0.7 V 2.6 3.0 V 1.1 1.7 V Note 1 -1.0V ≤ VDIFF ≤ +1.0V, VCM = 6V Maximum A+/Ref Input mV 2.00 Input Offset Drift Voltage Gain Output Saturation Voltage 2.0 1.95 Volts Below +VIN, C/S+ & C/S- = BOUTPUT Max @ 10mA Output Current, +VIN = 4.5V, C/S VIO ≤ 5mV PARKING FUNCTION Park Input Threshold 0.7 Park Input Current Park Input = 1.7V 60 100 µA Park Drive Saturation Voltage, PDVSAT ISINK = 100mA 0.3 0.5 V Parking Drive Leakage VOUT = 20V 100 µA Amplifier A Aux Input Bias Current -500 3 -150 nA UC3175B ELECTRICAL CHARACTERISTICS (cont.) Unless otherwise stated specifications apply for 0°C ≤ TA ≤ 70°C, +VIN = 12V, +VC = +VIN, A+/REF Input = 6V. TA=TJ. PARAMETER TEST CONDITIONS MIN TYP MAX UNITS 0.65 0.8 V 1.50 1.53 V 1.7 1.9 V 0.8 2.2 2.3 V V 1.8 V PARKING FUNCTIONS (cont.) Amplifier A Saturation Voltage, AHVSAT ISOURCE = 50mA, +VIN = 3V Regulating Voltage at Park Volts Minimum Parking Supply Voltage 1.47 AHVSAT + PDVSAT ≤ 1.3V @ 50mA AUXILIARY FUNCTIONS Limit Input Low Voltage Limit Input High Voltage A Output Forced Low A Output Forced High Limit Inactive 1.2 Limit Open Circuit Voltage Limit Input Resistance 0.7 1.45 1.2V ≤ Limit Input ≤ 1.8V Inhibit Input Threshold Inhibit Input = 1.7V Supply Current when Inhibited The sum of +VIN and +VC currents Thermal Shutdown Temperature 1.55 10 0.7 Inhibit Input Current 1.50 V kΩ 1.1 1.7 V 400 700 µA 2 6 mA 165 °C Note 1: This specification not tested in production. UC3175B Series Current Sensing UDG-92058 GO = IL Rfb = VS Rfa • 2 • RS 4 UC3175B Parking Function UDG-92059 1.5V • R1 + R2 R2 − (IL • RP) RP is optional for current limiting. Inhibit and Park Inputs are active high. Pwr OK is low on power failure. Notes: Parking voltage = UNITRODE INTEGRATED CIRCUITS 7 CONTINENTAL BLVD. • MERRIMACK, NH 03054 TEL. (603) 424-2410 • FAX (603) 424-3460 5 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 acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. 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