FAN1951

www.fairchildsemi.com FAN1950/FAN1951 1.5A Low-Voltage Low-Dropout Regulator Features • 1.5A minimum guaranteed output current • 500mV maximum dropout at 1.5A Ideal for 2.5V to 1.8V or 1.65V conversion Ideal for 3.0V to 2.5V conversion • Current Limiting and Thermal shutdown • External Shut-down control (FAN1951 only) • Error flag output (FAN1951 only) • Fast transient response • Low ground current General Description The FAN1950 and FAN1951 are 1.5A low-dropout linear regulators that provide a low voltage, high current output with a minimum of external components. Both of these devices use a PNP output pass element achieving a maximum 500mV dropout at 1.5A load current. In addition these devices offer overcurrent limit and thermal shutdown features to ensure full protection. The FAN1951 offers a logic level enable pin and an error flag output to indicate undervoltage and over-current conditions. 1.8V and 2.5V fixed output versions are available. 3.3V, 1.65V and 1.5V options are available upon request. Applications • General purpose conversion for low-voltage CPUs, DSP and FPGAs • SMPS post regulator • Cable/Satellite set-top boxes • PCI Graphics adapter cards Typical Application FAN1950-2.5V 3.0V IN OUT GND 2.5V 10µF 100KΩ Error Output On/Off FLAG EN GND FAN1951-1.8V 2.5V IN OUT 1.8V 10µF REV. 0.1.6 8/30/04 FAN1950/FAN1951 Pin Assignments FAN1950Dx FRONT VIEW FAN1951Dx FRONT VIEW 1 2 3 1 2 3 4 5 GND (TAB) GND (TAB) OUT EN OUT IN IN 3-Lead Plastic TO-252 (DPAK) 5-Lead Plastic TO-252 (DPAK) Pin Descriptions Pin Number FAN1950 NA 1 2 3 NA FAN1951 1 2 3 4 5 Pin Name EN IN GND OUT FLAG Pin Function Description Enable (Input) – TTL/CMOS compatible input. Logic HIGH enables the output Input Supply Voltage Ground. This pin and TAB are ground. Output Voltage Error Flag (Output). Open-collector output. Active-low indicates an output fault condition. 2 FLAG REV. 0.1.6 8/30/04 FAN1950/FAN1951 Absolute Maximum Ratings Absolute maximum ratings are the values beyond which the device may be damaged or have its useful life impaired. Functional operation under these conditions is not implied. Parameter Supply Voltage: IN Enable Voltage: EN FLAG voltage: FLAG Junction Temperature (TJ) Storage Temperature Lead Soldering Temperature, 10 seconds Power Dissipation (PD) Min. -0.2 -0.2 -0.2 –55 –65 Typ. Max. 15 15 15 150 150 300 Internally Limited Units V V V °C °C °C W Recommended Operating Conditions Parameter Supply Voltage Package Thermal Resistance (θJC) Junction Operating Temperature TO-252 -40 Conditions Min. 2.25 3 125 Typ. Max. 14 Units V °C/W °C Electrical Specifications (VIN = VOUT + 1V, VEN = 2.5V, Tj = +25°C unless specified otherwise) The • denotes specifications which apply over the full operating temperature range. Parameter Output Voltage (VOUT) Tolerance Conditions 10mA ≤ IOUT ≤ 1.0A, 10mA ≤ IOUT ≤ 1.5A, VOUT + 1V ≤ VIN ≤ 8V IOUT = 10mA, VOUT + 1V ≤ VIN ≤ 14V VIN = VOUT + 1V, 10mA ≤ IOUT ≤ 1.5A IOUT = 1.5A, ∆VOUT = -1% • Ground Current Minimum Load Current Current Limit EN Input Voltage (FAN1951 only) EN Input Current (FAN1951 only) FLAG Threshold Voltage (FAN1951 only) FLAG Output Leakage (FAN1951 only) Current4 IOUT = 750mA IOUT = 1.5A VOUT + 1V ≤ VIN ≤ 8V VOUT = 0V, VIN = VOUT + 1V VIH (On) VIL (Off) IIH, VEN = 2.25V IIL, VEN = 0.8V Low threshold, % VOUT High threshold, % VOUT Hysteresis VFLAG = 14V IOL = 250µA • • • • • • • • • 93 99.2 1 2 400 2.25 0.8 30 4 10 20 5 2.5 • • Min. -2 -2.5 .06 0.2 350 500 20 10 mA mA mA A V V µA µA % % % µA mV Typ. Max. 2 2.5 0.5 1 Units % Line Regulation1,2 Load Regulation1,2 Dropout Voltage3 % % mV FLAG Output-Low Voltage (FAN1951 only) REV. 0.1.6 8/30/04 3 FAN1950/FAN1951 Parameter Thermal Shutdown Temperature Thermal Shutdown Hysteresis Shutdown output current Conditions Min. Typ. 150 10 Max. Units °C °C VEN ≤ 0.8V, VIN ≤ 8V, VOUT = 0V • 20 µA 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. 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. 3. Dropout voltage = VIN – VOUT when VOUT decreases to 98% of its nominal output voltage with VIN = VOUT + 1V. For output voltages below 2.25V, dropout voltage is the input-to-output voltage differential with the minimum input voltage being 2.25V. Minimum input operating voltage is 2.25V. 4. Flag output cannot be pulled to a voltage higher than VIN. 4 REV. 0.1.6 8/30/04 FAN1950/FAN1951 Typical Performance Characteristics Dropout Voltage vs. Output Current 0.6 0.5 Dropout (V) 0.4 -40°C +125°C 0.6 0.5 Dropout (V) +75°C Dropout Voltage vs. Temperature IL = 1.5A 0.4 IL = 1A 0.3 0.2 0.1 0 0.5 0.7 0.9 1.1 +25°C -10°C 0.3 0.2 0.1 1.3 1.5 0 -50 Load Current (A) 50 100 Tj Vout = 2.5V, 1.8V, Iout = 1A, 1.5A 0 150 Ground Current vs. Load Current Vin = Vout + 1V, 25°C 25.00 20.00 15.00 I gnd (mA) 10.00 5.00 0.00 0 500 1000 1500 2000 Load Current (mA) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0 Ground Current vs. Supply Voltage Vin = Vout + 1V, 25°C Ground Current (mA) (V) Ground Current (mA) 5 10 Vin (V) Iout = 10mA 15 20 REV. 0.1.6 8/30/04 5 FAN1950/FAN1951 Typical Performance Characteristics (continued) Ground Current vs. Temperature Vin = 3V 30.00 Ground Current (mA) 25.00 IGND_ @ 1.5A 20.00 15.00 10.00 5.00 IGND_@10mA IGND @ 750mA 0.00 -50 0 50 Temperature (C) 100 150 FAN1950D18 Short-Circuit Recovery Response FAN1950D18 Short-Circuit Transient Response Vin = 3V, Vout = 1.8V Ch.1 – Vout (1V/div) Ch.2 – Load Current (2A/div) Vin = 3V, Vout = 1.8V Ch.1 – Vout (1V/div) Ch.2 – Load Current (2A/div) FAN1950D25 Short-Circuit Recovery Response FAN1950D25 Short-Circuit Transient Response Vin = 3V, Vout = 2.5V Ch.1 – Vout (1V/div) Ch.2 – Load Current (2A/div) Vin = 3V, Vout = 2.5V Ch.1 – Vout (1V/div) Ch.2 – Load Current (2A/div) 6 REV. 0.1.6 8/30/04 FAN1950/FAN1951 Typical Performance Characteristics (continued) Load Transient Response Vin=2.5V, Vout=1.8V, Cin=10µF Ceramic Load Transient Response Vin=2.5V, Vout=1.8V, Cin=10µF Ceramic Cout = 10µF Tantalum (ESR~700mΩ) Ch1 – Vout (AC, 0.5V/div) Ch2 – Load Current (1A/div.) Cout = 10µF Ceramic Ch1 – Vout (AC, 0.5V/div.) Ch2 – Load Current (1A/div.) Vout vs. Temperature 1.834 1.824 1.814 Vout (V) 1.804 1.794 1.784 1.774 1.764 -100 -50 0 50 100 Junction Temperature (°C) Iout = 10 mA; Vout = 1.8V 150 2.450 -50 -25 Vout (V) 2.525 2.500 2.475 2.550 Vout vs. Temperature (°C) (10 mA Load) 0 25 50 75 100 125 Junction Temperature (°C) Iout = 10 mA; Vout = 2.5V 150 FAN1950D18 Ripple Rejection (PSRR) FAN1950D25 Ripple Rejection (PSRR) Vin = 5V Vin = 3V Vin = 3V and 5V Vout = 1.8V Iload = 1A Cin = Cout = 10µF/ 6.3V Tantalum PSRR – 10dB/div Vin = 5V Vout = 2.5V Iload = 1A Cin = Cout = 10µF/ 6.3V Tantalum PSRR – 10dB/div REV. 0.1.6 8/30/04 7 FAN1950/FAN1951 Input and Output Capacitor Requirements A 4.7µF or greater Input Capacitor (Ceramic or Tantalum), installed closely between VIN and GND leads of the part, is required for stability, better transient response, noise and ripple rejection. A higher value of electrolytic input capacitor can be recommended if the bulk capacitor of the power supply is located more than 3– 4 inches from the device or a large and fast-risetime load is a requirement. FAN1950 and FAN1951, as most of LDO regulators, require an Output Capacitor. The recommended value of this capacitor is 10µF. The larger capacitor will additionally improve the Transient Response, Ripple Rejection and output noise. The low-ESR Tantalum capacitors are the best for this application: they provide stable work and good transient response over the temperature range. Using the Ceramic capacitors as the Output capacitor can provoke instability (oscillation in the Output Voltage). Aluminum electrolytic capacitors also can be used if their ESR is below 3Ω. 8 REV. 0.1.6 8/30/04 FAN1950/FAN1951 Mechanical Dimensions 5-Lead TO-252 DPAK Package A 6.80 6.35 5.64 5.04 6.00 MIN 1.27 0.50 6.56 MIN 6.30 5.90 1.02 0.60 6.25 3.00 MIN C 1 (0.44) 0.57±0.07 0.25 M A M C 1.27 LAND PATTERN RECOMMENDATION 5.08 B 2.40 2.18 (5.09) 0.60 0.40 2 3 4 5 1.27 0.69±0.15 1 1.27 1.00 3.81 (4.05) 10.42 9.20 SEE DETAIL A 3 5 4 2 1 0.10 B GAGE PLANE 0.60 0.40 0.51 (1.54) NOTES: UNLESS OTHERWISE SPECIFIED A) ALL DIMENSIONS ARE IN MILLIMETERS. B) THIS PACKAGE CONFORMS TO JEDEC, TO-252, ISSUE C, VARIATION AA, DATED NOV. 1999. 0.13 MAX SEATING PLANE 10° 0° 1.78 1.40 (2.90) DETAIL A (ROTATED 90°) SCALE: 2X REV. 0.1.6 8/30/04 9 FAN1950/FAN1951 Mechanical Dimensions 3-Lead TO-252 DPAK Package 6.73 6.35 5.46 5.21 A 6.00 MIN L3 4 6.50 MIN D 1.02 0.64 C 1 2 3 1 1.14 0.76 2.29 4.57 3 6.25 3.00 MIN (0.59) 0.89 0.64 0.25 M A M C 1.40 MIN 4.60 2.30 LAND PATTERN RECOMMENDATION B 2.39 2.18 SEE NOTE D E1 4 0.58 0.46 D1 10.41 9.40 SEE DETAIL A 2 3 1 0.10 B GAGE PLANE 0.61 0.46 10° 0° 0.51 NOTES: UNLESS OTHERWISE SPECIFIED A) B) (1.54) C) D) ALL DIMENSIONS ARE IN MILLIMETERS. THIS PACKAGE CONFORMS TO JEDEC, TO-252, ISSUE C. VARIATION AA & AB, DATED NOV. 1999. DIMENSIONING AND TOLERANCING PER ASME Y14.5–1994. HEAT SINK TOP EDGE COULD BE IN CHAMFERED CORNERS OR EDGE PROTRUSION. DIMENSIONS L3, D, E1 & D1 TABLE: OPTION AA OPTION AB L3 0.89 – 1.27 1.52 – 2.03 D 5.97 – 6.22 5.33 – 5.59 E1 4.32 MIN 3.81 MIN D1 5.21 MIN 4.57 MIN 1.78 1.40 (2.90) 0.127 MAX SEATING PLANE E) DETAIL A (ROTATED –90°) SCALE 12X 10 REV. 0.1.6 8/30/04 FAN1950/FAN1951 Ordering Information Part Number FAN1951D18X FAN1951D25X FAN1950D25X Output Voltage 1.8V 2.5V 2.5V Package 5 Lead TO-252 DPAK in Tape and Reel 5 Lead TO-252 DPAK in Tape and Reel 3 Lead TO-252 DPAK in Tape and Reel Note: Please contact sales for other voltage and package options. DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. 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