TCL1587-1.5CAB

7A / 5A / 4.6A / 3A, FAST RESPONSE, LOW DROPOUT POSITIVE LINEAR VOLTAGE REGULATORS PRELIMINARY INFORMATION TCL1584 TCL1584 TCL1585 TCL1585 TCL1587 TCL1587 7A / 5A / 4.6A / 3A, FAST RESPONSE, LOW DROPOUT POSITIVE LINEAR VOLTAGE REGULATORS FEATURES s s s s s s s s Fixed and Adjustable Voltages ........ 1.5V and 3.3V Optimized for Low Voltage Applications Output Current Capability ..........7A / 5A / 4.6A / 3A Guaranteed Dropout Voltage up to Full Rated Output Integrated Thermal and Short-Circuit Protection Compact 3-Pin Surface-Mount and Thru-Hole Standard Power Packages VREF Accuracy ................................................. 2.0% Load Regulation ............................................. 0.05% The TCL1584/1585/1587 are low dropout, positive linear voltage regulators. They have a maximum current output specification of 7A, 5A, 4.6A and 3A respectively. All three devices are supplied in fixed and adjustable output voltage versions. Good transient load response combined with low dropout voltage makes these devices ideal for the latest low voltage microprocessor power supplies. Additionally, shortcircuit, thermal and safe operating area (SOA) protection is provided internally to ensure reliable operation. The TCL1587, TCL1585 and TCL1584 are available in a 3-pin TO-220 tabbed power package and in a 3-pin surface mount DDPAK-3 package. APPLICATIONS s s s s s PentiumTM*, PentiumProTM* CPU Power Supplies PowerPCTM* CPU Power Supplies PentiumProTM* System GTL+ Bus Terminators Low-Voltage, High Speed Microprocessors Post-Regulator for Switch-Mode Power Supplies ORDERING INFORMATION Part Number TCL1584-3.3CAB TCL1584-3.3CEB TCL1584-ADJCAB TCL1584-ADJCEB TCL1585-1.5CAB TCL1585-1.5CEB TCL1585-3.3CAB TCL1585-3.3CEB TCL1585-ADJCAB TCL1585-ADJCEB Package TO-220-3 DDPAK-3 TO-220-3 DDPAK-3 TO-220-3 DDPAK-3 TO-220-3 DDPAK-3 TO-220-3 DDPAK-3 TO-220-3 DDPAK-3 TO-220-3 DDPAK-3 TO-220-3 DDPAK-3 Temp. Range 0°C to + 70°C 0°C to + 70°C 0°C to + 70°C 0°C to + 70°C 0°C to + 70°C 0°C to + 70°C 0°C to + 70°C 0°C to + 70°C 0°C to + 70°C 0°C to + 70°C 0°C to + 70°C 0°C to + 70°C 0°C to + 70°C 0°C to + 70°C 0°C to + 70°C 0°C to + 70°C GENERAL DESCRIPTION PIN CONFIGURATIONS TO-220-3 DDPAK-3 1 2 3 1 2 3 TCL1584CAB TCL1585CAB TCL1587CAB ADJ/GND ADJ/GND VOUT VOUT VIN VIN TCL1584CEB TCL1585CEB TCL1587CEB NOTE: For TO-220 ΘJA = 53°C/W. For DDPAK-3 ΘJA = 76°C/W. ΘJA for both packages are specified without external heat sinks. See Applications Section for details. TCL1587-1.5CAB TCL1587-1.5CEB TCL1587-3.3CAB TCL1587-3.3CEB TCL1587-ADJCAB TCL1587-ADJCEB TYPICAL OPERATING CIRCUIT Fixed Output Voltage Version VIN = 5V C1 = 10µF VIN VOUT TCL158x-3.3 GND VOUT = 3.3V C2* (Tantalum) VIN = 5V C1 = 10µF Adjustable Output Voltage Version VIN TCL158x ADJ VOUT R1 VOUT = (1+ R1/R2)VREF C2* (Tantalum) R2 *NOTE: C2 is required to ensure output stability. Minimum 22µF (TCL1584) or 10µF (TCL1585/7), low ESR tantalum type. Larger values may be required for high output current transient regulation. See Applications section. TCL1584/1585/1587-04 6/6/97 TCL1584/1585/1587-04 6/6/97 *All Trademarks and Trade Names are the property of their respective owners. 1 TelCom Semiconductor reserves the right to make changes in the circuitry and specifications of its devices. PRELIMINARY INFORMATION TCL1584 TCL1585 TCL1587 ABSOLUTE MAXIMUM RATINGS* Input Voltage (VIN to GND) ...........................................7V Operating Junction Temperature Range Control Circuitry ................................... 0°C to +125°C Output Transistor ................................. 0°C to +150°C Power Dissipation ..................... See Applications Section Storage Temperature (unbiased) .......... – 65°C to +150°C Lead Temperature (Soldering, 10 sec) ................. +300°C 7A / 5A / 4.6A / 3A, FAST RESPONSE, LOW DROPOUT POSITIVE LINEAR VOLTAGE REGULATORS *This is a stress rating only, and functional operation of the device at these or any other conditions beyond those indicated in the operation section of the specifications is not implied. Exposure to absolute maximum ratings conditions for extended periods of time may affect device reliability. ELECTRICAL CHARACTERISTICS: TA = Operating Temperature Range, 4.75V ≤ VIN ≤ 5.25V, unless otherwise specified. Parameter Device Reference TCL1584 Voltage TCL1585 Test Conditions Min 1.225 Typ 1.25 Max 1.275 Unit V 1.5V ≤ (VIN – VOUT) ≤ 3V, 10mA ≤ IOUT ≤ 7A 1.5V ≤ (VIN – VOUT) ≤ 5.75V, 10mA ≤ IOUT ≤ 4.6A, TJ ≥ 25°C 1.5V ≤ (VIN – VOUT) ≤ 5.75V, 10mA ≤ IOUT ≤ 4A, TJ < 25°C TCL1587 1.5V ≤ (VIN – VOUT) ≤ 5.75V, 10mA ≤ IOUT ≤ 3A Output TCL1587-1.5 4.75V ≤ VIN ≤ 7V, 0mA ≤ IOUT ≤ 3A Voltage TCL1584-3.3 4.75V ≤ VIN ≤ 6.3V, 0mA ≤ IOUT ≤ 7A TCL1585-3.3 4.75V ≤ VIN ≤ 7V, 0mA ≤ IOUT ≤ 4.6A, TJ ≥ 25°C 4.75V ≤ VIN ≤ 7V, 0mA ≤ IOUT ≤ 4A, TJ < 25°C TCL1587-3.3 4.75V ≤ VIN ≤ 7V, 0mA ≤ IOUT ≤ 3A Line TCL1584/5/7 2.75V ≤ VIN ≤ 7V, IOUT = 10mA Regulation TCL1587-1.5 4.75V ≤ VIN ≤ 7V, IOUT = 0mA (Notes 1, 2) TCL1584/5/7-3.3 4.75V ≤ VIN ≤ 7V, IOUT = 0mA Load TCL1584/5/7 (VIN – VOUT) = 3V, TJ = 25°C, 10mA ≤ IOUT ≤ IFULL LOAD Regulation TCL1587-1.5 VIN = 5V, TJ = 25°C, 0mA ≤ IOUT ≤ IFULL LOAD (Notes 1, TCL1584/5/7-3.3 VIN = 5V, TJ = 25°C, 0mA ≤ IOUT ≤ IFULL LOAD 2, 3) Over Operating Temperature Range Dropout TCL1585/7 ∆VREF = 1%, IOUT = 3A Voltage TCL1587-1.5 ∆VOUT = 1%, IOUT = 3A TCL1585/7-3.3 ∆VOUT = 1%, IOUT = 3A TCL1585 ∆VREF = 1%, IOUT = 4.6A, TJ ≥ 25°C ∆VREF = 1%, IOUT = 4A, TJ < 25°C TCL1585-3.3 ∆VOUT = 1%, IOUT = 4.6A, TJ ≥ 25°C ∆VOUT = 1%, IOUT = 4A, TJ < 25°C TCL1584 ∆VREF = 1%, IOUT = 6A TCL1584-3.3 ∆VOUT = 1%, IOUT = 6A: TJ ≥ 25°C TJ < 25°C TCL1584 ∆VREF = 1%, IOUT = 7A TCL1584-3.3 ∆VOUT = 1%, IOUT = 7A Current TCL1584 (VIN – VOUT) = 3V 7.10 Limit TCL1584-3.3 (VIN – VOUT) = 3V (Note 3) TCL1585 (VIN – VOUT) = 5.5V: TJ < 25°C TCL1585-3.3 (VIN – VOUT) = 5.5V: TJ ≥ 25°C TCL1587 (VIN – VOUT) = 5.5V TCL1587-1.5 (VIN – VOUT) = 5.5V TCL1587-3.3 (VIN – VOUT) = 5.5V Temperature TBD TBD Coefficient ADJ Pin TCL1584/5/7 Current TCL1584/1585/1587-04 6/6/97 3.235 3.30 3.365 V — 0.005 0.2 % — 0.05 0.3 % — — 0.05 1.15 0.5 1.30 V — 1.20 1.40 V — — — 8.25 4.10 4.60 3.10 1.20 1.30 1.25 — 5.25 5.25 3.75 1.30 1.35 1.40 A — — V V | A A — 55 120 µA 2 7A / 5A / 4.6A / 3A, FAST RESPONSE, LOW DROPOUT POSITIVE LINEAR VOLTAGE REGULATORS PRELIMINARY INFORMATION TCL1584 TCL1585 TCL1587 ELECTRICAL CHARACTERISTICS: (Cont.) TA = Operating Temperature Range, 4.75V ≤ VIN ≤ 5.25V, unless otherwise specified. Parameter Device ADJ Pin Current Change (Note 3) Minimum Load Current Quiescent Current Ripple Rejection TCL1584 TCL1585/7 Test Conditions 1.5V ≤ (VIN – VOUT) ≤ 3V, 10mA ≤ IOUT ≤ IFULL LOAD 1.5V ≤ (VIN – VOUT) ≤ 5.75V, 10mA ≤ IOUT ≤ IFULL LOAD Min — Typ 0.2 Max 5 Unit µA TCL1584/5/7 1.5V ≤ (VIN –VOUT) ≤ 5.75V — 2 10 mA VIN = 5V VIN = 5V f = 120Hz, COUT = 25µF Tant. (VIN – VOUT) = 2.5V, IOUT = 7A f = 120Hz, COUT = 25µF Tant., VIN = 5.8V, IOUT = 7A f = 120Hz, COUT = 25µF Tant., (VIN – VOUT) = 3V, IOUT = 4.6A, TJ ≥ 25°C f = 120Hz, COUT = 25µF Tant., (VIN – VOUT) = 3V, IOUT = 4A, TJ ≤ 25°C TCL1585-3.3 f = 120Hz, COUT = 25µF Tant.,VIN = 6.3V, IOUT = 4.6A, TJ ≥ 25°C f = 120Hz, COUT = 25µF Tant.,VIN = 6.3V, IOUT = 4.6A, TJ ≤ 25°C TCL1587 f = 120Hz, COUT = 25µF Tant., (VIN – VOUT) = 3V, IOUT = 3A TCL1587-1.5 f = 120Hz, COUT = 25µF Tant., VIN = 5.0V, IOUT = 3A TCL1587-3.3 f = 120Hz, COUT = 25µF Tant., VIN = 6.3V, IOUT = 3A Thermal TCL1584/5/7 TA = 25°C, 30msec Pulse Regulation TCL1587-1.5 TA = 25°C, 30msec Pulse TCL1584/5/7-3.3 TA = 25°C, 30msec Pulse Temperature VIN = 5V, IOUT = 0.5A Stability Long Term TA = 125°C, 1000Hrs. Stability RMS TA = 25°C, 10Hz ≤ f ≤ 10kHz Output Noise (% of VOUT) Thermal TCL1584 “A” pkg. (TO-220): Control Circuitry/Power Transistor Resistance TCL1585 “A” pkg. (TO-220): Control Circuitry/Power Transistor (Junction to TCL1585 “E” pkg. (TO-263): Control Circuitry/Power Transistor Case, ΘJA) TCL1587 “A” pkg. (TO-220): Control Circuitry/Power Transistor TCL1587 “E” pkg. (TO-263): Control Circuitry/Power Transistor TCL1587-1.5 TCL1584/5/7-3.3 TCL1584 TCL1584-3.3 TCL1585 — 60 8 72 13 — mA dB — 0.004 0.02 %/W — — — 0.5 0.03 0.003 — 1.0 — % % % — — — — — — — — — — 0.65/2.7 0.7/3.0 0.7/3.0 0.7/3.0 0.7/3.0 °C/W °C/W °C/W °C/W °C/W NOTES: 1. See thermal regulation specifications for changes in output voltage due to heating effects. Load and line regulation are measured at a constant junction temperature by low duty cycle pulse testing. 2. Load and line regulation are guaranteed up to the maximum power dissipation (25W for the TCL1584 in “A” pkg., 26.5W for the TCL1585 in “A” pkg., 18W for the TCL1587 in “A” pkg.). Power dissipation is determined by input/output voltage differential and output current. Guaranteed maximum output current/power will not be available over full input/output voltage range. 3. IFULL LOAD is defined as the maximum value of output load current as a function of input-to-output voltage. IFULL LOAD is a nominal 7A for TCL1584, decreasing to approximately 3A as VIN – VOUT increases from 3V to 7V. For all other fixed voltage TCL1585’s, IFULL LOAD is 4A. For the TCL1587, IFULL LOAD is 3A. The TCL1585 and 1587 have constant current limit with respect to VIN and VOUT. TCL1584/1585/1587-04 6/6/97 3 PRELIMINARY INFORMATION TCL1584 TCL1585 TCL1587 7A / 5A / 4.6A / 3A, FAST RESPONSE, LOW DROPOUT POSITIVE LINEAR VOLTAGE REGULATORS Typical Dropout Voltage vs. Output Current 1.5 INPUT/OUTPUT DIFFERENTIAL (V) 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 0 OUTPUT CURRENT (A) IFULL LOAD SIMPLIFIED SCHEMATIC VIN + TCL1584/5/7 – VOUT THERMAL LIMIT ADJ GND FOR FIXED VOLTAGE DEVICE TCL1584/1585/1587-04 6/6/97 4 7A / 5A / 4.6A / 3A, FAST RESPONSE, LOW DROPOUT POSITIVE LINEAR VOLTAGE REGULATORS PRELIMINARY INFORMATION TCL1584 TCL1585 TCL1587 age response to step load current change is illustrated in Figure 1. The capacitor’s ESR and ESL cause immediate step changes in the output voltage. These are calculated as follows: ∆VESR = ∆I x ESR DVESL = DI/Dt x ESL To reduce the initial voltage droop, one should select low ESR and ESL capacitors. It should also be noted that the ESR effect is multiplied by absolute change in load current while the ESL effect is multiplied by the rate of change in load current. After the initial voltage drop, the capacitor value dominates the rate of change in voltage. This rate is calculated as follows: ∆V = ∆t x ∆I/C APPLICATIONS General The TCL158x family of devices combine high current output (up to 7A) with low dropout voltage and built-in fault protection in a traditional three-terminal LDO format. All three device types are available in fixed output voltage and adjustable output versions. Fault protection includes shortcircuit current limit, over-temperature limit, and safe-operating-area (SOA) governing. These devices are pin-compatible upgrades for the 1083/1084/1085 family of LDO’s. However, the TCL158x family delivers lower dropout voltage, faster load transient response and improved internal frequency compensation. Maximum supply voltage rating is 7.0V. Modern processors cycle load current from near zero to several amps in a time period measured in tens of nanoseconds. Load step response requirements are worsened by tighter output voltage tolerances. The TCL1584/85/87 family of regulators meets these stringent requirements without an obnoxious amount of output capacitance, saving both board space and cost. ESR EFFECTS ESL EFFECTS SLOPE, V = ∆I t C POINT AT WHICH REGULATOR TAKES CONTROL CAPACITANCE EFFECTS Stability and Transient Response Like most low dropout voltage regulators, the TCL158x devices require the use of output capacitors to maintain stability. Normally a 22µF solid tantalum or a 100µF aluminum electrolytic unit will ensure stability over all operating conditions. Keep in mind that commercially available capacitors can have significant non-ideal effects such as capacitance value tolerance, temperature coefficient, ESR, ESL. The TCL158x devices are optimized for use with low ESR (100µF) be used. The value of the output capacitor can be increased without limit and will only improve transient regulation. In a typical high-performance microprocessor application, the sudden transients can be so fast that the output decoupling network must handle the sudden current demand until the internal voltage regulator is able to respond. In this case the non-ideal effects of the output capacitor are critical in determining the regulator’s response. Output voltTCL1584/1585/1587-04 6/6/97 Figure 1. Transient Load Voltage Response Typically high quality ceramic and tantalum capacitors must be used in combination to minimize ESR and maximize C. This decoupling network must also be placed close to the microprocessor to reduce ESL (parasitic board trace inductance). If possible, the capacitors should be placed inside the microprocessor socket cavity. Of course, robust power and ground planes will also improve performance by reducing parasitic voltage drops. The TCL1584 has an adaptive current limiting scheme where to ensure SOA for the output transistor, the current limit is reduced for increasing input to output differential. This means that the TCL1584 exhibits a negative resistance characteristic under certain conditions. This is a common technique in LDO design to ensure SOA - especially LDO’s with high maximum input voltage ratings. This negative resistance can interact with the external capacitance and inductance and cause oscillations during current limit. This effect is highly dependent on system parameters and is difficult to predict. However this oscillation, if it occurs, will not damage the regulator and can be ignored if the system 5 PRELIMINARY INFORMATION TCL1584 TCL1585 TCL1587 parameters will allow it. Typically, increasing the output capacitance helps reduce the oscillation. NOTE: The TCL1585 and TCL1584 have fixed current limit over the entire voltage range and are not susceptible to this phenomenon. 7A / 5A / 4.6A / 3A, FAST RESPONSE, LOW DROPOUT POSITIVE LINEAR VOLTAGE REGULATORS Overload Recovery The built-in Short Circuit and Safe-Operating-Area (SOA) protection function of the TCL158x family can cause secondary effects which must be considered for robust system design. The behavior of the regulator under heavy loads (short circuit) at start-up is such that the output voltage will remain low while sourcing maximum current until the load is removed or reduced. Normally, the output voltage will rise as the load is reduced and trace a line I-V relationship according to the SOA limit. If the load line intersects this output curve at two points the output voltage may not recover from the heavy load/short-circuit condition. This condition is illustrated in Figure 3. The current limit constraint does not allow any load point above it and the load line is defined absolutely by the I-V characteristics of the load (a resistor, in this case). Under these conditions it may be necessary to cycle the power supply off and then on again. This phenomenon is common for LDO’s with fold-back current limiting schemes. NOTE: Overload recovery is always guaranteed on the TCL1585 and TCL1587 because of the constant current limit characteristic. Protection Diodes The TCL158x family of devices do not normally require any external current limiting circuitry such as protection diodes, frequently used with older LDO regulators. A diode is internally present between the output and input which is capable of handling short-duration surge currents of up to 100A. This capability typically ensures safe operation except for the case where output capacitance is exceedingly large (>1000µF) and the input is suddenly shorted to ground. This situation can produce excessive reverse current in the device - enough to cause damage. An external high current diode should be used as shown in Figure 2. The ADJ pin does not normally need protection diodes either. It can handle ±7V without any performance degradation or device damage. Current at this pin is internally limited by a series resistor so the bypass capacitors do not present any danger. Of course, exceeding 7V differential between any two pins will cause catastrophic junction breakdowns and possible damage to the device. Ripple Rejection A typical ripple rejection curve for the fixed output voltage devices is shown in Figure 3. It is possible to obtain improved performance in ripple rejection by using the adjustable output TCL158x with a bypass capacitor (CADJ) shown in Figure 2. This capacitor should be chosen to have a value such that its impedance at the ripple frequency is less than R1 (see Figure 2.). Usually this is on the order of 100Ω. Example: If R1 = 100Ω and fRIPPLE = 120Hz, the bypass capacitor should be chosen to be 22µF or greater. If these conditions are met the ripple rejection will be improved by a factor of VOUT/1.25 when compared to the performance of the fixed output devices. D1 1N4002 (OPTIONAL) VIN IN TCL1584-3.3 OUT GND VOUT + C1 10µF + C2 22µF D1 1N4002 (OPTIONAL) Current Limit Curve VIN C1 + 10µF IN TCL1584 ADJ OUT R1 VOUT + C2 22µF IOUT Load Line Unrecoverable I-V Point Start Up Point + CADJ R2 Figure 2. Protection Diodes and CADJ VIN – VOUT (Constant VIN) Figure 3. Overload Recovery TCL1584/1585/1587-04 6/6/97 6 7A / 5A / 4.6A / 3A, FAST RESPONSE, LOW DROPOUT POSITIVE LINEAR VOLTAGE REGULATORS PRELIMINARY INFORMATION TCL1584 TCL1585 TCL1587 RP PARASITIC LINE RESISTANCE VIN IN TCL1584-3.3 OUT GND RL Output Voltage The output voltage for the fixed output versions of the TCL158x is set internally and cannot be adjusted. For the adjustable output versions, the output voltage is set by two external resistors: R1 and R2 (see Figure 3). A 1.25V reference voltage is maintained between the OUTPUT pin and the ADJ pin. NOTE: the ADJ pin typically will source 55µA. R1 should be chosen to conduct at least the specified minimum load current of 10mA (i.e. at most 125Ω). Now R2 will determine the total output voltage according to the equation below: VOUT = VREF(1+ R2/R1) + R2(IADJ) The contribution due to the IADJ term is relatively small as IADJ is only 55µA compared to 10mA for the total current in the adjust circuit. Figure 5. Connection for Best Load Regulation In both cases, because the effect of parasitic trace resistance (RP) cannot be completely eliminated, it is important to keep the positive output lead as short as possible. Otherwise, at high output currents, the load regulation will degrade appreciably. Example: RP = 5mΩ IOUT = 3A VDROP = (0.005) x (3) = 15mV VIN C1 + 10µF IN TCL1584 ADJ IADJ 55µA OUT VREF R1 VOUT C2 22µF VOUT = VREF 1+ R2 R1 ( ) + IADJ (R2) R2 VIN IN TCL1584 ADJ OUT RP PARASITIC LINE RESISTANCE Figure 4. Adjustable Voltage Regulator Load Regulation Because the TCL158x family are three terminal devices, it is not possible to perform true Kelvin load voltage sensing. Therefore load regulation is limited somewhat by parasitic trace resistance. The load regulation specifications are measured directly at the TCL158x package. To minimize degradation in load regulation performance the following guidelines should be used. For fixed voltage devices, the GND pin should be connected directly to the negative side of the load instead of to a common ground bus. This provides Kelvin sensing at the negative side while the positive side is still limited by RP (See Figure 5). For adjustable output devices, the bottom of R2 connects to the negative side of the load. For the positive side, best regulation is obtained when the top of R1 is connected directly to the TCL158x and not to the load (See Figure 6). If R1 connects to the load the effective resistance between the output and the load is: RP x (1 + R2/R1) TCL1584/1585/1587-04 6/6/97 R1* RL R2* *CONNECT R1 TO CASE CONNECT R2 TO LOAD Figure 6. Connection for Best Load Regulation Thermal Considerations The TCL158x family includes built-in thermal overload protection. However, maximum operating junction temperature must not be exceeded for any condition. Since these devices are capable of dissipating up to 25W or more under some conditions, careful thermal design is required for reliable, continuous operation. In most cases, external heat sinking will be required. 7 PRELIMINARY INFORMATION TCL1584 TCL1585 TCL1587 When generating the overall thermal design, it is important to consider all sources of thermal resistance between the silicon die and ambient - junction-to-case (ΘJC), case-toheat sink (ΘCH), heat sink-to-ambient (ΘHA). NOTE: there are two separate ΘJC specifications for the power transistor and the control circuitry. Both junction temperatures must be calculated and kept under each respective maximum limit to ensure proper operation. This ΘJC is for the physical path between the die and the bottom metal portion of the case (both TO-220 and DDPAK-3. Heat flow will be greatest through this path. It is important that good thermal coupling is made between the case and heat sink. If electrical isolation from the heat sink is not required, it is recommended that thermally conductive compound be used. Otherwise, use a thermally conductive dielectric spacer. The following is a thermal design example: Using a TCL1585-3.3 in a TO-220 package: Assumptions: TA = +70°C VIN = 5.25V (5V + 5%) VOUT = 3.30V IOUT = 4.6A ΘHA = 3.5°C/W (heat sink-to-ambient) ΘCH = 1.5°C/W (case-to-heat sink) ΘJC = 3°C/W (power transistor) ΘJC = 0.7°C/W (control circuitry) Power dissipation: PD = (VIN – VOUT)(IOUT) = (5.25 – 3.3)(4.6) = 8.97W Junction Temperatures: TJ = TA + PD(ΘHA + ΘCH + ΘJC) Control Circuitry: TJ = 70 + 8.97(3.5 + 1.5 + 0.7) = 121.1°C Power Transistor: TJ = 70 + 8.97(3.5 + 1.5 + 3) = 141.8°C These values for TJ fall within the maximum allowed junction temperature for each die section indicating adequate heat sinking with some margin. 7A / 5A / 4.6A / 3A, FAST RESPONSE, LOW DROPOUT POSITIVE LINEAR VOLTAGE REGULATORS NOTE: Without heat sinking, the thermal resistance for the TO-220 and DDPAK-3 packages are 53°C/W and 76°C/W respectively. TCL1584/1585/1587-04 6/6/97 8 7A / 5A / 4.6A / 3A, FAST RESPONSE, LOW DROPOUT POSITIVE LINEAR VOLTAGE REGULATORS PRELIMINARY INFORMATION TCL1584 TCL1585 TCL1587 TYPICAL APPLICATIONS Typical Intel™* 486Dx4 Microprocessor Application PLACE AT MICROPROCESSOR SOCKET VCC PINS 3.30V 3A C2 22µF 10V C3 TO C6 47µF 10V C7 TO C15 0.1µF C16 TO C24 0.01µF VIN ≥ 4.75V C1 10µF 10V VIN VOUT TCL1587-3.3 GND ESR OF THE 47µF IS < 0.1Ω Intel™* 90MHz Pentium™* Power Supply THERMALLOY 7020B-MT PLACE IN MICROPROCESSOR SOCKET CAVITY 3.38V 4.6A R1 110Ω 0.1% R2 187Ω 0.1% C5 TO C10 100µF 10V AVX TPS 6 EACH C11 TO C20 1µF 16V AVX Y5V 0805 10 EACH 4.75V TO 5.25V C1 TO C3 220µF 10V AVX TPS 3 EACH VIN TCL1585 ADJ VOUT C4 330µF 16V AVX X7R 0805 AVX Corp. (803) 448-9411 Sanyo Video Components (USA) Corp. (619) 661-6322 Thermalloy Inc. (214) 243-4321 DO NOT SUBSTITUTE COMPONENTS Transient Response for 3.8A Load Current Step* VOUT 50mV/DIV IOUT 2A/DIV 100µsec/DIV *TRANSIENT RESPONSE MEASURED WITH AN INTEL POWER VALIDATOR™. VOUT IS MEASURED AT THE POWER VALIDATOR. All Trademarks and Trade Names are the property of their respective owners. TCL1584/1585/1587-04 6/6/97 9 PRELIMINARY INFORMATION TCL1584 TCL1585 TCL1587 TYPICAL APPLICATIONS (Cont.) 7A / 5A / 4.6A / 3A, FAST RESPONSE, LOW DROPOUT POSITIVE LINEAR VOLTAGE REGULATORS Typical Intel™* Pentium™* Pro GTL+ Bus Terminator Application Using TCL1587-1.5 VOUT = 1.5V @ 3A VIN = 5V or 3.3V C1 = 10µF VIN VOUT TCL1587-1.5 GND C2 = 10µF (Tantalum) RTERM C3 =1µF x 5 = 100Ω x 71 (Ceramic) Lines RREF GTL+ Bus (ZO) VREF = 1.0V VOUT = 1.5V @ 3A VIN = 5V or 3.3V C1 = 10µF VIN VOUT TCL1587-1.5 GND C2 = 10µF (Tantalum) C3 = 1µF x 5 (Ceramic) RTERM = 100Ω x 71 Lines 2RREF NOTES: 1. It is recommended that the GTL+ bus be terminated at each end by a separate regulator to avoid power distribution losses. 2. The GTL+ bus transmission line symbol will consist of all the components (chip set IC's) on the GTL+ bus. 3. RREF and 2RREF should be chosen such that VREF loading does not appreciably degrade VREF regulation. Values