www.fairchildsemi.com FAN1950/FAN1951 1.5A Low-Voltage Low-Dropout Regulator Features General Description • 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 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 FAN1951-1.8V 2.5V 10µF 2.5V IN OUT 100KΩ Error Output On/Off 1.8V 10µF FLAG EN GND REV. 0.1.6 8/30/04 FAN1950/FAN1951 Pin Assignments 1 3-Lead Plastic TO-252 (DPAK) 2 3 4 5 OUT 3 FLAG 2 IN IN 1 GND (TAB) FRONT VIEW EN FRONT VIEW OUT FAN1951Dx GND (TAB) FAN1950Dx 5-Lead Plastic TO-252 (DPAK) Pin Descriptions Pin Number 2 FAN1950 FAN1951 Pin Name Pin Function Description NA 1 EN Enable (Input) – TTL/CMOS compatible input. Logic HIGH enables the output 1 2 IN Input Supply Voltage 2 3 GND Ground. This pin and TAB are ground. 3 4 OUT Output Voltage NA 5 FLAG Error Flag (Output). Open-collector output. Active-low indicates an output fault condition. 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 Min. Supply Voltage: IN Typ. Max. Units -0.2 15 V Enable Voltage: EN -0.2 15 V FLAG voltage: FLAG -0.2 15 V Junction Temperature (TJ) –55 150 °C Storage Temperature –65 150 °C 300 °C Internally Limited W Lead Soldering Temperature, 10 seconds Power Dissipation (PD) Recommended Operating Conditions Parameter Conditions Supply Voltage Min. Typ. 2.25 Package Thermal Resistance (θJC) TO-252 Junction Operating Temperature Max. Units 14 V °C/W 3 -40 °C 125 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 Conditions Output Voltage (VOUT) Tolerance 10mA ≤ IOUT ≤ 1.0A, 10mA ≤ IOUT ≤ 1.5A, VOUT + 1V ≤ VIN ≤ 8V Min. • • Typ. -2 -2.5 Max. Units 2 2.5 % Line Regulation1,2 IOUT = 10mA, VOUT + 1V ≤ VIN ≤ 14V .06 0.5 % Load Regulation1,2 VIN = VOUT + 1V, 10mA ≤ IOUT ≤ 1.5A 0.2 1 % Dropout Voltage3 IOUT = 1.5A, ∆VOUT = -1% 350 • mV 500 Ground Current IOUT = 750mA IOUT = 1.5A • 10 20 20 mA mA Minimum Load Current VOUT + 1V ≤ VIN ≤ 8V • 5 10 mA Current Limit VOUT = 0V, VIN = VOUT + 1V • 2.5 EN Input Voltage (FAN1951 only) VIH (On) VIL (Off) • • EN Input Current (FAN1951 only) IIH, VEN = 2.25V IIL, VEN = 0.8V • • FLAG Threshold Voltage (FAN1951 only) Low threshold, % VOUT High threshold, % VOUT Hysteresis FLAG Output Leakage (FAN1951 only) Current4 FLAG Output-Low Voltage (FAN1951 only) REV. 0.1.6 8/30/04 A 2.25 0.8 V V 30 4 µA µA 99.2 % % % 93 1 VFLAG = 14V • 2 µA IOL = 250µA • 400 mV 3 FAN1950/FAN1951 Parameter Conditions Min. Thermal Shutdown Temperature Max. 150 Thermal Shutdown Hysteresis Shutdown output current Typ. °C 10 VEN ≤ 0.8V, VIN ≤ 8V, VOUT = 0V • Units °C 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 IL = 1.5A 0.5 +125°C +75°C 0.4 Dropout (V) 0.5 Dropout (V) Dropout Voltage vs. Temperature 0.6 0.6 -40°C 0.3 -10°C 0.2 0.4 IL = 1A 0.3 0.2 +25°C 0.1 0.1 0 0.5 0.7 0.9 1.1 1.3 0 -50 1.5 Load Current (A) Ground Current vs. Load Current Vin = Vout + 1V, 25°C Ground Current (mA) (V) Ground Current (mA) 25.00 20.00 15.00 I gnd (mA) 10.00 5.00 0.00 0 500 1000 1500 Load Current (mA) REV. 0.1.6 8/30/04 2000 0 50 100 Tj Vout = 2.5V, 1.8V, Iout = 1A, 1.5A 150 Ground Current vs. Supply Voltage Vin = Vout + 1V, 25°C 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0 5 10 Vin (V) Iout = 10mA 15 20 5 FAN1950/FAN1951 Typical Performance Characteristics (continued) Ground Current vs. Temperature Vin = 3V Ground Current (mA) 30.00 25.00 IGND_ @ 1.5A 20.00 15.00 IGND @ 750mA 10.00 5.00 IGND_@10mA 0.00 -50 0 50 100 150 Temperature (C) 6 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) 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 Vout vs. Temperature (°C) 2.550 1.834 (10 mA Load) 1.824 2.525 Vout (V) Vout (V) 1.814 1.804 1.794 1.784 2.500 2.475 1.774 1.764 -100 -50 0 50 100 Junction Temperature (°C) Iout = 10 mA; Vout = 1.8V FAN1950D18 Ripple Rejection (PSRR) 150 2.450 -50 -25 0 25 50 75 100 125 Junction Temperature (°C) Iout = 10 mA; Vout = 2.5V 150 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 REV. 0.1.6 8/30/04 Vin = 5V Vout = 2.5V Iload = 1A Cin = Cout = 10µF/ 6.3V Tantalum PSRR – 10dB/div 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. 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. FAN1950 and FAN1951, as most of LDO regulators, require an Output Capacitor. The recommended value of this capacitor is 10µF. The larger capacitor will 8 REV. 0.1.6 8/30/04 FAN1950/FAN1951 Mechanical Dimensions 5-Lead TO-252 DPAK Package 6.00 MIN A 6.80 6.35 5.64 5.04 1.27 0.50 6.56 MIN 6.30 5.90 6.25 1.02 0.60 3.00 MIN C 1 3 2 1 5 4 1.27 (0.44) 0.57±0.07 1.27 1.00 3.81 0.69±0.15 1.27 0.25 M A M C LAND PATTERN RECOMMENDATION 5.08 B 2.40 2.18 0.60 0.40 (5.09) (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 10° 0° 1.78 1.40 A) ALL DIMENSIONS ARE IN MILLIMETERS. B) THIS PACKAGE CONFORMS TO JEDEC, TO-252, ISSUE C, VARIATION AA, DATED NOV. 1999. 0.13 MAX (2.90) SEATING PLANE DETAIL A (ROTATED 90°) SCALE: 2X REV. 0.1.6 8/30/04 9 FAN1950/FAN1951 Mechanical Dimensions 3-Lead TO-252 DPAK Package A 6.73 6.35 5.46 5.21 6.00 MIN L3 4 6.50 MIN D 6.25 1.02 0.64 C 1 3.00 MIN 2 3 1 1.14 0.76 (0.59) 0.89 0.64 2.30 1.40 MIN 4.60 2.29 4.57 0.25 M A M C 3 LAND PATTERN RECOMMENDATION B 2.39 2.18 SEE NOTE D E1 0.58 0.46 4 D1 10.41 9.40 SEE DETAIL A 2 3 1 0.10 B 0.61 0.46 (1.54) 10° 0° 1.78 1.40 0.127 MAX (2.90) SEATING PLANE DETAIL A (ROTATED –90°) SCALE 12X 10 NOTES: UNLESS OTHERWISE SPECIFIED 0.51 GAGE PLANE A) B) ALL DIMENSIONS ARE IN MILLIMETERS. THIS PACKAGE CONFORMS TO JEDEC, TO-252, ISSUE C. VARIATION AA & AB, DATED NOV. 1999. C) DIMENSIONING AND TOLERANCING PER ASME Y14.5–1994. D) HEAT SINK TOP EDGE COULD BE IN CHAMFERED CORNERS OR EDGE PROTRUSION. E) 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 REV. 0.1.6 8/30/04 FAN1950/FAN1951 Ordering Information Part Number Output Voltage Package FAN1951D18X 1.8V 5 Lead TO-252 DPAK in Tape and Reel FAN1951D25X 2.5V 5 Lead TO-252 DPAK in Tape and Reel FAN1950D25X 2.5V 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. LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. 2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. www.fairchildsemi.com 8/30/04 0.0m 005 Stock#DS30001950 2003 Fairchild Semiconductor Corporation