UCC39151 15V Programmable Hot Swap Power Manager FEATURES DESCRIPTION • Integrated 0.15Ω Power MOSFET The UCC39151 Programmable Hot Swap Power Manager provides complete power management, hot swap capability, and circuit breaker functions. The only external component required to operate the device, other than power supply bypassing, is the fault timing capacitor, CT. All control and housekeeping functions are integrated, and externally programmable. These include the fault current level, maximum output sourcing current, maximum fault time, and startup delay. In the event of a constant fault, the Internal fixed 2% duty cycle ratio limits average output power. • 7V to 15V Operation • Digital Programmable Current Limit from 0A to 3A • Programmable ON Time • Programmable Start Delay • Fixed 2% Duty Cycle • Thermal Shutdown • Fault Output Indicator • Maximum Output Current can be set to 1A above the Programmed Fault Level or to a full 4A • Power SOIC and TSSOP, Low Thermal Resistance Packaging The internal 4 bit DAC allows programming of the fault level current from 0A to 3A with 0.25A resolution. The IMAX control pin sets the maximum sourcing current to 1A above the trip level or to a full 4A of output current for fast output capacitor charging. When the output current is below the fault level, the output MOSFET is switched ON with a nominal ON resistance of 0.15Ω. When the output current exceeds the fault level, but is less than the maximum sourcing level, the output remains switched ON, but the fault timer starts, charging CT. Once CT charges to a preset threshold, the switch is turned OFF, and remains OFF for 50 times the programmed fault time. When the output current reaches the maximum sourcing level, the MOSFET transitions from a switch to a constant current source. BLOCK DIAGRAM Note: Pin numbers refer to DIL-16 and SOIC-16 packages. 02/99 (continued) UDG-94136-3 UCC39151 ABSOLUTE MAXIMUM RATINGS DESCRIPTION (cont.) VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +15.5 Volts VOUT VIN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.3V FAULT Sink Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA FAULT Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 to 8V Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . Self Limiting TTL Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 to VIN Storage Temperature . . . . . . . . . . . . . . . . . . . 65 C to +150 C Junction Temperature . . . . . . . . . . . . . . . . . . . 55 C to +150 C Lead Temperature (Soldering, 10 sec.) . . . . . . . . . . . . . +300 C The UCC39151 can be put into sleep mode, drawing only 20mA of supply current. Other features include an open drain Fault Output Indicator, Thermal Shutdown, Undervoltage Lockout, 7V to 15V operation, and low thermal resistance SOIC and TSSOP Power Packages. Currents are positive into, negative out of the specified terminal. Consult Packaging Section of Databook for thermal limitations and considerations of packages. CONNECTION DIAGRAMS DIL-16, SOIC-16 (Top View) N, DP Package SHTDWN 1 PWP-24 (Top View) TSSOP Package 16 FAULT VIN 2 15 VOUT VIN 3 14 VOUT GND* 4 13 GND* EGND* 5 12 GND* B3 6 11 CT B2 7 10 IMAX B1 8 9 SHTDWN 1 24 FAULT VIN 2 23 VOUT B0 *Pin 5 serves as lowest impedance to the electrical ground; Pins 4, 12, and 13 serve as heat sink/ground. These pins should be connected to large etch areas to help dissipate heat. For N Package, pins 4, 12, and 13 are N/C. VIN 3 22 VOUT N/C 4 21 N/C GND* 5 20 GND* GND* 6 19 GND* GND* 7 18 GND* GND* 8 17 GND* EGND* 9 16 N/C B3 10 15 CT B2 11 14 IMAX B1 12 13 B0 *Pin 9 serves as lowest impedance to the electrical ground; other GND pins serve as heat sink/ground. These pins should be connected to large etch areas to help dissipate heat. ELECTRICAL CHARACTERISTICS Unless otherwise stated, these specifications apply for TA = 0°C to 70°C for the UCC39151, VIN = 12V, IMAX = 0.4V, SHTDWN = 2.4V, TA = TJ. PARAMETER TEST CONDITIONS MIN TYP MAX UNITS Supply Section Voltage Input Range 7.0 Supply Current Sleep Mode Current SHTDWN = 0.2V, No load Output Leakage SHTDWN = 0.2V 15.0 V 1.0 2.0 mA 100 150 µA 20 mA Output Section Voltage Drop IOUT = 1A (10V to 12V) 0.15 0.3 V IOUT = 2A (10V to 12V) 0.3 0.6 V IOUT = 3A (10V to 12V) 0.45 0.9 V IOUT = 1A, VIN = 7V and 15V 0.2 0.4 V IOUT = 2A, VIN = 7V and 15V 0.4 0.8 V IOUT = 3A, VIN = 7V, 12V Max. 0.6 1.2 V 2 UCC39151 ELECTRICAL CHARACTERISTICS Unless otherwise stated, these specifications apply for TA = 0°C to 70°C for the UCC39151, VIN = 12V, IMAX = 0.4V, SHTDWN = 2.4V, TA = TJ. PARAMETER TEST CONDITIONS MIN TYP MAX UNITS Output Section (continued) Initial Startup Time (Note 2) 100 µs Short Circuit Response (Note 2) 100 ns DAC Section Trip Current Code = 0000-0011 (Device Off) Code = 0100 0.07 0.25 0.45 A Code = 0101 0.32 Code = 0110 0.50 0.50 0.7 A 0.75 0.98 A Code = 0111 0.75 1.00 1.3 A Code = 1000 1.0 1.25 1.6 A Code = 1001 1.25 1.50 1.85 A Code = 1010 1.5 1.75 2.15 A Code = 1011 1.70 2.00 2.4 A Code = 1100 1.90 2.25 2.7 A Code = 1101 2.1 2.50 2.95 A Code = 1110 2.30 2.75 3.25 A Code = 1111 2.50 3.0 3.5 A Max Output Current Over Trip (Current Source Mode) Code = 0100 to 1111, IMAX = 0V 0.35 1.0 1.65 A Max Output Current (Current Source Mode) Code = 0100 to 1111, IMAX = 2.4V 3.0 4.0 5.2 A Fault Output Section CT Charge Current VCT = 1.0V 83 –62 47 µA CT Discharge Current VCT = 1.0V 0.8 1.2 1.8 µA Output Duty Cycle VOUT = 0V 1.0 1.9 3.3 % CT Fault Threshold 1.2 1.5 1.7 V CT Reset Threshold 0.4 0.5 0.6 V 1.1 1.5 1.9 V Shutdown Section Shutdown Threshold Shutdown Hysteresis 150 Input Current 100 mV 500 nA 250 µA 0.8 V 0.8 V Open Drain Output Section High Level Output Current FAULT = 5V Low Level Output Voltage IOUT = 5mA 0.2 TTL Input DC Characteristics Section TTL Input Voltage High 2.0 V TTL Input Voltage Low TTL Input High Current VIH = 2.4V TTL Input Low Current VIL = 0.4V 3 Note 1: All voltages are with respect to Ground. Current is positive into and negative out of the specified terminal. Note 2: Guaranteed by design. Not 100% tested in production. 3 10 µA 1 µA UCC39151 PIN DESCRIPTIONS IMAX: When this pin is set to a logic low, the maximum sourcing current will always be 1A above the programmed fault level. When set to a logic high, the maximum sourcing current will be a constant 4A for applications which require fast charging of load capacitance. B0, B1, B2, B3: These pins provide digital input to the DAC, which sets the fault current threshold. They can be used to provide a digital soft-start and adaptive current limiting. CT: A capacitor connected to ground sets the maximum fault time. The maximum fault time must be more than the time required to charge the external capacitance in one cycle. The maximum fault time is defined as: SHTDWN: When this pin is brought to a logic low, the IC is put into a sleep mode drawing typically less than 100µA of ICC (with VOUT unloaded). The input threshold is hysteretic, allowing the user to program a startup delay with an external RC circuit. TFAULT = 16 .1 • 10 3 • CT . Once the fault time is reached the output will shutdown for a time given by: VIN: Input voltage to the UCC39151. The recommended voltage range is 7V to 15V. Both VIN pins should be connected together and connected to power source. TSD = 833 • 10 3 • CT , this equates to a 1.9% duty cycle. VOUT: Output voltage from the UCC39151. Both VOUT pins should be connected together and connected to the load. When switched: FAULT: Open drain output, which pulls low upon any fault or interrupt condition, Fault, or Thermal Shutdown. VOUT ≈ VIN − (0 .15 Ω • IOUT ) VOUT must not exceed VIN by more than 0.3V. APPLICATIONS INFORMATION HEATSINK GROUND PINS VIN +5V 2 VIN 3 VIN 4 12 13 5 GND GND GND GND VOUT 14 CIN RL 15 R1 COUT UCC39151 RSD LED 16 FAULT SHTDWN VIN 1 S6 CSD 11 CT CT B0 B1 B2 B3 IMAX 9 8 7 6 10 VIN S1 S2 S3 S4 S5 DIP SWITCH UDG-98176 Figure 1. Evaluation circuit. 4 UCC39151 APPLICATION INFORMATION (cont.) UDG-94138 Estimating Maximum Load Capacitance For hot swap applications, the rate at which the total output capacitance can be charged depends on the maximum output current available and the nature of the load. For a constant-current, current-limited application, the output will come up if the load asks for less than the maximum available short-circuit current. Where VOUT is the output voltage. For a resistive load of value RI, the value of COUT(max) can be estimated from: To guarantee recovery of a duty-cycle from a shortcircuited load condition, there is a maximum total output capacitance which can be charged for a given unit ON time (Fault time). The design value of ON or Fault time can be adjusted by changing the timing capacitor CT. COUT (max) For worst-case constant-current load of value just less than the trip limit; COUT(max) can be estimated from: COUT (max) ≈ (IMAX 16 .1 • 10 3 • CT ≈ 1 RL • n VOUT 1 − I MAX • R L Long CT times must consider the maximum temperature. Thermal shutdown protection may be the limiting Fault time. 16 .1 • 10 3 • CT − ILOAD ) • VOUT Figure 2. Load current, timing capacitor voltage, and output voltage of the UCC39151 under fault conditions. SAFETY RECOMMENDATIONS Although the UCC39151 is designed to provide system protection for all fault conditions, all integrated circuits can ultimately fail short. For this reason, if the UCC39151 is intended for use in safety critical applications where UL or some other safety rating is required, a redundant safety device such as a fuse should be placed in series with the device. The UCC39151 will prevent the fuse from blowing for virtually all fault conditions, increasing system reliability and reducing maintenance cost, in addition to providing the hot swap benefits of the device. UNITRODE CORPORATION 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. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. 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