FAN1589_03

www.fairchildsemi.com FAN1589 2.7A, 1.2V Low Dropout Linear Regulator for VRM8.5 Features • • • • • • Fast transient response Low dropout voltage at up to 2.7A Load regulation: 0.05% typical Trimmed current limit On-chip thermal limiting Standard TO-220, TO-263, TO-263 center cut and TO-252 (DPAK) packages Description The FAN1589 is a low dropout three-terminal regulator with 2.7A output current capability. This device has been optimized for VTT bus termination, where transient response and minimum input voltage are critical. The FAN1589 offers fixed 1.2V with 2.7A current capability for a GTL+ bus VTT termination. 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 FAN1589 is available in the industry-standard TO-220, TO-263, TO-263 center cut and TO-252 (DPAK) power packages. Applications • A GTL+ bus supply for VRM 8.5 • Low voltage logic supply • Post regulator for switching supply Typical Application FAN1589 VOUT VIN + GND + VIN = 3.3V 10µF 1.2V at 2.7A 22µF REV. 1.0.5 11/10/03 FAN1589 PRODUCT SPECIFICATION Pin Assignments FAN1589T FRONT VIEW FAN1589M FRONT VIEW Tab is OUT Tab is OUT 1 2 3 1 2 3 GND OUT IN 3-Lead Plastic TO-263 θJC = 3°C/W* GND OUT IN 3-Lead Plastic TO-220 θJC = 3°C/W FAN1589MC FRONT VIEW FAN1589D Tab is OUT 1 2 3 123 FRONT VIEW Tab is OUT GND IN GND OUT 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°C/W to more than 40°C/W. Other mounting techniques can provide a thermal resistance lower than 30°C/W. Absolute Maximum Ratings Parameter VIN Operating Junction Temperature Range Storage Temperature Range Lead Temperature (Soldering, 10 sec.) 0 -65 Min. Max. 7 125 150 300 Unit V °C °C °C 2 REV. 1.0.5 11/10/03 PRODUCT SPECIFICATION FAN1589 Electrical Characteristics Tj = 25°C unless otherwise specified. The • denotes specifications which apply over the specified operating temperature range. Parameter Output Voltage Line Regulation1, 2 Load Regulation1, 2 Dropout Voltage Current Limit 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 TA = 125°C, 1000 hrs. TA = 25°C, 10Hz ≤ f ≤ 10kHz TO-220 TO-263, TO-252 Conditions 3.3V ≤ VIN ≤ 7V 10mA ≤ IOUT ≤ 2.7A (VOUT + 1.5V) ≤ VIN ≤ 7V, IOUT = 10mA (VIN – VOUT) = 3V 10mA ≤ IOUT ≤ 2.7A ∆VREF = 1%, IOUT = 2.7A (VIN – VOUT) = 2V 1.5V ≤ (VIN – VOUT) ≤ 5.75V VIN = 5V f = 120Hz, COUT = 22µF Tantalum, (VIN – VOUT) = 3V, IOUT = 2.7A TA = 25°C, 30ms pulse • • • • • • • • 60 3.1 10 4 72 0.004 0.5 0.03 0.003 3 3 150 1.0 0.02 13 Min. 1.176 Typ. 1.200 0.005 0.15 1.150 4 Max 1.224 0.2 1.5 1.300 Units V % % V A mA mA dB %/W % % % °C/W °C/W °C 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. REV. 1.0.5 11/10/03 3 FAN1589 PRODUCT SPECIFICATION Typical Performance Characteristics 1.5 0.10 OUTPUT VOLTAGE DEVIATION (%) ∆I = 2.7A 1.4 DROPOUT VOLTAGE (V) 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 0 0.5 1 1.5 2 2.5 3.0 OUTPUT CURRENT (A) T=0°C T=25°C T=125°C 0.05 0 -0.05 -0.10 -0.15 -0.20 -75 -50 -25 0 25 50 75 100 125 150 175 JUNCTION TEMPERATURE (°C) Figure 1. Dropout Voltage vs. Output Current Figure 2. Load Regulation vs. Temperature 1.30 VOUT SET WITH 1% RESISTORS MINIMUM LOAD CURRENT (mA) REFERENCE VOLTAGE (V) 1.20 5 4 1.10 3 1.00 2 0.90 1 0.80 -75 -50 -25 0 25 50 75 100 125 150 175 0 -75 -50 -25 0 25 50 75 100 125 150 175 JUNCTION TEMPERATURE (°C) JUNCTION TEMPERATURE (°C) Figure 3. Output Voltage vs. Temperature Figure 4. Minimum Load Current vs. Temperature 5.0 SHORT-CIRCUIT CURRENT (A) 90 80 RIPPLE REJECTIONS (dB) 4.5 70 60 50 40 30 20 10 (VIN – VOUT) ≤ 3V 0.5V ≤ VRIPPLE ≤ 2V IOUT = 2.7A 100 1K FREQUENCY (Hz) 10K 100K 4.0 3.5 3.0 -75 -50 -25 0 25 50 75 100 125 150 175 0 10 JUNCTION TEMPERATURE (°C) Figure 5. Short-Circuit Current vs. Temperature Figure 6. Ripple Rejection vs. Frequency 4 REV. 1.0.5 11/10/03 PRODUCT SPECIFICATION FAN1589 Typical Performance Characteristics (continued) 20 15 10 OUTPUT CAPACITANCE ESR, (Ω) 2.5 POWER (W) 2 1.5 Area of Instability 1 5 0 50 60 70 80 90 100 110 120 130 140 150 CASE TEMPERATURE (°C) 0.5 Stable Area 0 0 1000 2000 2700 LOAD CURRENT (mA) Figure 7. Maximum Power Dissipation Figure 9. Stability Region REV. 1.0.5 11/10/03 5 FAN1589 PRODUCT SPECIFICATION Applications Information General The FAN1589 is a three-terminal regulator optimized for a GTL+ VTT termination applications. It is short-circuit protected, and offers thermal shutdown to turn off the regulator when the junction temperature exceeds about 150°C. The FAN1589 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 a GTL+. Load Regulation It is not possible to provide true remote load sensing because the FAN1589 is a three-terminal device. Load regulation is limited by the resistance of the wire connecting the regulators to the load. Load regulation per the data sheet specification is measured at the bottom of the package. For fixed voltage devices, negative side sensing is a true Kelvin connection with the ground pin of the device returned to the negative side of the load. This is illustrated in Figure 10. RP PARASITIC LINE RESISTANCE FAN1589 Stability The FAN1589 requires 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