RC1587T

www.fairchildsemi.com RC1587 3A Adjustable/Fixed Low Dropout Linear Regulator Description Features • Fast transient response • Low dropout voltage at up to 3A • Load regulation: 0.05% typical • Trimmed current limit • On-chip thermal limiting • Standard TO-220, TO-263, TO-263 center cut, and TO-252 packages The RC1587, RC1587-1.5, and RC1587-3.3 are low dropout three-terminal regulators with 3A 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 RC1587 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 RC1587-1.5 offers fixed 1.5V with 3A current capability for GTL+ bus VTT termination. The RC1587-3.3 offers fixed 3.3V current capability for logic IC operation. Applications • Pentium® Class GTL+ bus supply • Low voltage logic supply • Post regulator for switching supply 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. The RC1587, RC1587-1.5, and RC1587-3.3 are available in the industry-standard TO-220, TO-263, TO-263 center cut, and TO-252 (DPAK) power packages. Typical Applications VIN VIN = 3.3V 10µF + RC1587 VOUT ADJ 1.5V at 3A + R1 124Ω 22µF R2 24.9Ω VOUT = VREF (1 + R2/R1) + IADJ * R2 RC1587-1.5 VOUT VIN VIN = 3.3V + GND 1.5V at 3A + 10µF 22µF RC1587-3.3 VIN VIN = 5V + 10µF VOUT GND 3.3V at 3A + 22µF 65-1587-16 Pentium is a registered trademark of Intel Corporation. REV. 1.5.4 3/25/02 RC1587 PRODUCT SPECIFICATION Pin Assignments RC1587M-1.5, 3.3 RC1587M FRONT VIEW FRONT VIEW RC1587T RC1587T-1.5, -3.3V FRONT VIEW FRONT VIEW 1 1 2 3 1 GND OUT IN 2 2 1 3 2 3 3 ADJ OUT IN ADJ OUT IN 3-Lead Plastic TO-263 θJC = 3°C/W* GND OUT IN 3-Lead Plastic TO-220 θJC = 3°C/W RC1587MC-1.5, 3.3 RC1587MC RC1587D-1.5, 3.3 RC1587D FRONT VIEW FRONT VIEW FRONT VIEW FRONT VIEW Tab is Out. Tab is Out. 1 2 3 1 2 1 IN ADJ 3 1 IN ADJ 2 3 3 GND GND 2 IN IN 3-Lead Plastic TO-252 θJC = 3°C/W* 3-Lead Plastic TO-263 Center Cut θJC = 3°C/W* *With package soldered to 0.5 square inch copper area over backside ground plane or internal power plane, θJA can vary from 30°CW to more than 40°C/W. Other mounting techniques can provide a thermal resistance lower than 30°C/W. Absolute Maximum Ratings Parameter Min. Max. 7 V 0 125 °C -65 150 °C 300 °C VIN Operating Junction Temperature Range Storage Temperature Range Lead Temperature (Soldering, 10 sec.) 2 Unit REV. 1.5.4 3/25/02 PRODUCT SPECIFICATION RC1587 Electrical Characteristics Tj = 25°C unless otherwise specified. The • denotes specifications which apply over the specified operating temperature range. Parameter Conditions 3 Min. Typ. Max Units Reference Voltage 1.5V ≤ (VIN – VOUT) ≤ 5.75V, 10mA ≤ IOUT ≤ 3A • 1.225 (-2%) 1.250 1.275 (+2%) V Output Voltage4 3.3V ≤ VIN ≤ 7V 10mA ≤ IOUT ≤ 3A • 1.47 1.5 1.53 V Output Voltage5 5.1V ≤ VIN ≤ 7V 10mA ≤ IOUT ≤ 3A • 3.234 3.3 3.366 V Line Regulation1, 2 (VOUT + 1.5V) ≤ VIN ≤ 7V, IOUT = 10mA • 0.005 0.2 % Load Regulation1, 2 (VIN – VOUT) = 3V 10mA ≤ IOUT ≤ 3A • 0.05 0.5 % Dropout Voltage ∆VREF = 1%, IOUT = 3A • 1.150 1.300 Current Limit (VIN – VOUT) = 2V • Adjust Pin Current3 3.1 4 V A • 35 120 µA 1.5V ≤ (VIN – VOUT) ≤ 5.75V, 10mA ≤ IOUT ≤ 3A • 0.2 5 µA Minimum Load Current 1.5V ≤ (VIN – VOUT) ≤ 5.75V • Quiescent Current VIN = 5V • 4 13 Ripple Rejection f = 120Hz, COUT = 22µF Tantalum, (VIN – VOUT) = 3V, IOUT = 3A Thermal Regulation TA = 25°C, 30ms pulse Adjust Pin Current Change3 60 mA 72 0.004 • Temperature Stability 10 mA dB 0.02 0.5 %/W % Long-Term Stability TA = 125°C, 1000 hrs. 0.03 RMS Output Noise (% of VOUT) TA = 25°C, 10Hz ≤ f ≤ 10kHz 0.003 % Thermal Resistance, Junction to Case TO-220 3 °C/W 3 °C/W 150 °C Thermal Shutdown TO-263, TO-252 1.0 % 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. Line and load regulation are guaranteed up to the maximum power dissipation (18W). Power dissipation is determined by input/output differential and the output currrent. Guaranteed maximum output power will not be available over the full input/ output voltage range. 3. RC1587 only. 4. RC1587-1.5 only. 5. RC1587-3.3 only. REV. 1.5.4 3/25/02 3 RC1587 PRODUCT SPECIFICATION Typical Performance Characteristics 0.10 1.2 1.1 1.0 T=0°C 0.9 T=125°C T=25°C 0.8 0.7 0.6 0.5 0 0.5 1 1.5 2 2.5 ∆I = 3A 0.05 0 -0.05 -0.10 65-1587-04 1.3 65-1587-03 DROPOUT VOLTAGE (V) 1.4 OUTPUT VOLTAGE DEVIATION (%) 1.5 -0.15 -0.20 -75 -50 -25 3.0 0 25 50 75 100 125 150 175 JUNCTION TEMPERATURE (°C) OUTPUT CURRENT (A) Figure 1. Dropout Voltage vs. Output Current Figure 2. Load Regulation vs. Temperature 1.275 3.70 1.270 1.255 1.250 1.245 1.240 1.235 1.230 1.225 -75 -50 -25 3.55 3.50 3.45 3.40 0 3.30 3.20 -75 -50 -25 0 25 50 75 100 125 150 175 JUNCTION TEMPERATURE (°C) JUNCTION TEMPERATURE (°C) Figure 4. Output Voltage vs. Temperature 5 100 Note: 1. RC1587 Only 3 2 1 0 -75 -50 -25 0 25 50 75 100 125 150 175 JUNCTION TEMPERATURE (°C) Figure 5. Minimum Load Current vs. Temperature 80 70 60 50 40 30 20 65-1587-08 4 ADJUST PIN CURRENT (µA) 90 65-1587-07 MINIMUM LOAD CURRENT (mA) Note: 1. RC1587 Only 2. RC1587, -3.3 3.25 25 50 75 100 125 150 175 Figure 3. Reference Voltage vs. Temperature 4 VOUT = 3.3V2 3.35 65-1587-06 1.260 VOUT SET WITH 1% RESISTORS VOUT = 3.6V1 3.60 REFERENCE VOLTAGE (V) 1.265 65-1585-05 REFERENCE VOLTAGE (V) 3.65 10 0 -75 -50 -25 0 25 50 75 100 125 150 175 JUNCTION TEMPERATURE (°C) Figure 6. Adjust Pin Current vs. Temperature REV. 1.5.4 3/25/02 PRODUCT SPECIFICATION RC1587 Typical Performance Characteristics (continued) 90 5.0 4.0 3.5 3.0 -75 -50 -25 0 25 50 75 100 125 150 175 70 60 50 40 30 20 10 (VIN – VOUT) ≤ 3V 0.5V ≤ VRIPPLE ≤ 2V IOUT = 3A 0 10 JUNCTION TEMPERATURE (°C) 100 1K 65-1587-10 RIPPLE REJECTIONS (dB) 4.5 65-1587-09 SHORT-CIRCUIT CURRENT (A) 80 10K 100K FREQUENCY (Hz) Figure 7. Short-Circuit Current vs. Temperature Figure 8. Ripple Rejection vs. Frequency 15 10 65-1587-11 POWER (W) 20 5 0 50 60 70 80 90 100 110 120 130 140 150 CASE TEMPERATURE (°C) Figure 9. Maximum Power Dissipation REV. 1.5.4 3/25/02 5 RC1587 PRODUCT SPECIFICATION Applications Information General The RC1587, RC1587-1.5, and RC1587-3.3 are three-terminal regulators optimized for GTL+ VTT termination applications. These devices are short-circuit protected, and offer thermal shutdown to turn off the regulator when the junction temperature exceeds about 150°C. The RC1587 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+. D1 1N4002 (OPTIONAL) RC1587 VIN IN + C1 10µF OUT ADJ + R1 VOUT C2 22µF + CADJ R2 Stability The RC1587 series require an output capacitor as a part of the frequency compensation. It is recommended to use a 22µF solid tantalum or a 100µF 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