RC1585M

www.fairchildsemi.com RC1585 5A Adjustable/Fixed Low Dropout Linear Regulator Features Description • Fast transient response • Low dropout voltage at up to 5A • Load regulation: 0.05% typical • Trimmed current limit • On-chip thermal limiting • Standard TO-220 and TO-263 packages The RC1585 and RC1585-1.5 are low dropout three-terminal regulators with 5A output current capability. These devices have been optimized for low voltage applications including VTT bus termination, where transient response and minimum input voltage are critical. The RC1585 is ideal for low voltage microprocessor applications requiring a regulated output from 1.5V to 3.6V with an input supply of 5V or less. The RC1585-1.5 offers fixed 1.5V with 5A current capabilities for GTL+ bus VTT termination. Applications Current limit is trimmed to ensure specified output current and controlled short-circuit current. On-chip thermal limiting provides protection against any combination of overload and ambient temperature that would create excessive junction temperatures. • Pentium® Pro and Pentium II GTL+ bus supply • Low voltage logic supply • Battery-powered circuitry • Post regulator for switching supply The RC1585 series regulators are available in the industry-standard TO-220 and TO-263 power packages. Typical Applications VIN = 3.3V 10µF + RC1585 VOUT VIN ADJ 1.5V at 5A + 22µF 124Ω 24.9Ω VIN = 3.3V 10µF + RC1585-1.5 VOUT VIN GND Pentium is a registered trademark of Intel Corporation 1.0.2 1.5V at 5A + 22µF Rev. RC1585 PRODUCT SPECIFICATION Pin Assignments RC1585M-1.5 RC1585M FRONT VIEW FRONT 1 2 3 1 GND OUT IN ADJ 2 OUT RC1585T RC1585T-1.5 FRONT VIEW FRONT VIEW 1 3 2 1 3 2 IN ADJ OUT 3-Lead Plastic TO-263 ΘJA=30°C/W* IN GND OUT IN 3-Lead Plastic TO-220 ΘJA=50°C/W *With package soldered to 0.5 square inch copper area over backside ground plane or internal power plane. ΘJA can vary from 20°C/W to >40°C/W with other mounting techniques. Absolute Maximum Ratings Parameter VIN Operating Junction Temperature Range Control Section Power Transistor Storage Temperature Range Lead Temperature (Soldering, 10 sec.) 2 3 Min. Max. 7 Unit V 0 0 -65 125 150 150 300 °C °C °C °C RC1585 PRODUCT SPECIFICATION Electrical Characteristics Preconditioning: 100% Thermal Limit Functional Test. TJ=25°C unless otherwise specified. The • denotes specifications which apply over the specified operating temperature range. Parameter Reference Voltage3 Output Voltage4 Line Regulation1,2 Load Regulation1,2,3 Dropout Voltage Current Limit Adjust Pin Current3 Adjust Pin Current Change3 Minimum Load Current Quiescent Current Ripple Rejection Thermal Regulation Temperature Stability Long-Term Stability RMS Output Noise (% of VOUT) Thermal Resistance, Junction to Case Thermal Shutdown Conditions 1.5V≤ (VIN-VOUT) ≤ 5.75V, 10mA ≤ IOUT ≤ 5A 3V≤VIN ≤7V 10mA ≤ IOUT ≤ 5A (VOUT + 1.5V) ≤ VIN ≤ 7V, IOUT = 10mA (VIN - VOUT) = 3V, 10mA ≤ IOUT ≤ 5A ∆VREF = 1%, IOUT = 5A (VIN - VOUT) = 2V 1.5V ≤ (VIN - VOUT) ≤ 5.75V, 10mA ≤ IOUT ≤ 5A 1.5V ≤ (VIN - VOUT) ≤ 5.75V VIN = 5V f = 120Hz, COUT = 22µF Tantalum, (VIN - VOUT) = 3V, IOUT = 5A TA = 25°C, 30ms pulse Units V 1.5 Max. 1.275 (+2%) 1.53 • 0.005 0.2 % • 0.05 0.5 % • • • • 1.150 5.5 35 0.2 1.300 V A µA µA 4 72 13 0.004 0.5 0.03 0.003 0.02 • • • • 5.1 Typ. 1.250 120 5 10 60 • TA = 125°C, 1000 hrs. TA = 25°C, 10Hz ≤ f ≤ 10kHz Min. 1.225 (-2%) 1.47 Control Section Power Transistor 1.0 0.7 3.0 150 V mA mA dB %/W % % % °C/W °C/W °C Notes: 1. 2. 3. 4. 3 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. Line and load regulation are guaranteed up to the maximum power dissipation (18W). Power dissipation is determined by input/output differential and the output current. Guaranteed maximum output power will not be available over the full input/output voltage range. RC1585 only. RC1585-1.5 only. RC1585 PRODUCT SPECIFICATION 1.5 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 OUTPUT VOLTAGE DEVIATION (%) DROPOUT VOLTAGE (V) Typical Performance Characteristics T=0°C T=25°C T=125°C 0 1 2 3 4 5 OUTPUT CURRENT (A) OUTPUT VOLTAGE (V) REFERENCE VOLTAGE 3 2 1 0 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (°C) Figure 5. Minimum Load Current vs. Temperature 0 -0.05 -0.10 -0.15 -0.20 -75 –50 –25 0 25 50 75 100 125 150 175 OUT 1 OUT 1 OUT 1 OUT TEMPERATURE (°C) Figure 4. Output Voltage vs. Temperature 100 Note: 90 1. RC1585 only 80 70 60 50 40 30 20 10 0 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (°C) Figure 6. Adjust Pin Current vs. Temperature Typical Performance Characteristics (continued) 8 4 7 1 OUT ADJUST PIN CURRENT (µA) MINIMUM LOAD CURRENT (mA) 4 0.05 3.70 V SET WITH 1% RESISTORS V = 3.6V 3.65 3.60 3.55 V = 3.45V 3.50 3.45 V = 3.38V 3.40 V = 3.3V 3.35 3.30 Note: 1. RC1585 Only 3.25 3.20 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (°C) Figure 3. Reference Voltage vs. Temperature 5 ∆I=5A TEMPERATURE (°C) Figure 2. Load Regulation vs. Temperature Figure 1. Dropout Voltage vs. Output current 1.250 1.245 1.240 1.235 1.230 1.225 1.220 1.215 1.210 1.205 1.200 -75 -50 -25 0 25 50 75 100 125 150 175 0.10 RC1585 PRODUCT SPECIFICATION RIPPLE REJECTIONS (dB) SHORT-CIRCUIT CURRENT (A) 90 80 70 60 50 40 30 20 10 0 -75 -50 -25 0 25 50 75 100 125 150 175 TEMPERATURE (°C) Figure 7. Short-Circuit Current vs. Temperature (VIN – VOUT) ≤ 3V 0.5V ≤ VRIPPLE ≤ 2V IOUT = 5A 10 POWER (W) 100K Figure 8. Ripple Rejection vs. Frequency 20 15 10 5 0 50 60 70 80 90 100 110 120 130 140 150 CASE TEMPERATURE Figure 9. Maximum Power Dissipation 5 100 1K 10K FREQUENCY (Hz) RC1585 PRODUCT SPECIFICATION Applications Information General The RC1585 and RC1585-1.5 are three-terminal regulators optimized for GTL+ VTT termination and logic applications. These devices are short-circuit protected, safe area protected, and offer thermal shutdown to turn off the regulator when the junction temperature exceeds about 150°C. The RC1585 series provides low dropout voltage and fast transient response. Frequency compensation uses capacitors with low ESR while still maintaining stability. This is critical in addressing the needs of low voltage high speed microprocessor buses like GTL+. VIN The adjust pin can be driven on a transient basis ±7V with respect to the output, without any device degradation. As with any IC regulator, exceeding the maximum input-to-output voltage differential causes the internal transistors to break down and none of the protection circuitry is then functional. D1 1N4002 (OPTIONAL) IN C1 + 10µF Stability The RC1585 series requires an output capacitor as a part of the frequency compensation. It is recommended to use a 22µF solid tantalum or a 100 µF aluminum electrolytic on the output to ensure stability. The frequency compensation of these devices optimizes the frequency response with low ESR capacitors. In general, it is suggested to use capacitors with an ESR of