FAN1538PBX

www.fairchildsemi.com FAN1538 Dual Channel 1A Low Dropout Linear Regulator with UVLO and Soft-start Features • • • • • • Two independent outputs Load regulation: 0.05% typical Under-voltage lockout and softstart Over Temperature protection T0-252 DPAK, 5-lead SPAK packages Fixed 3.3V and adjustable or fixed 2.5V output General Description The FAN1538 provides two output voltages: a fixed 3.3V ouput and either a fixed 2.5V or adjustable output with 1A output current capability. Refer to Ordering Information for details. Current limit protects against short circuit currents and on chip over temperature circuitry limits the maximum die temperature. Under voltage lockout and softstart circuitry protects against unregulated output voltages when the input voltage is below specification. Applications • • • • Hard Disk Drives, CD-Roms Set-top Boxes ADSL line cards Motherboards with multiple supplies Block Diagram FAN1538A V1 VIN = 5V 22µF + VIN NC GND V2 + 22µF 22 + 22µF 2.5V at 1.0A 3.3V at 1.0A FAN1538B V1 VIN = 5V 22 µF GND FB V2 R1 250 22µF R2 1250 1.5V at 1.0A 22µF 3.3V at 1.0A V2 = VREF (1 + R1/R2) REV. 1.0.2 12/17/03 FAN1538 PRODUCT SPECIFICATION Pin Assignments FAN1538PA FRONT VIEW FAN1538PB FRONT VIEW FAN1538DA FRONT VIEW FAN1538DB FRONT VIEW 1 123 45 123 45 2 3 4 5 1 2 3 4 5 V1 V1 V1 FB GND GND NC GND GND V2 V2 V2 V2 NC VIN VIN VIN VIN 5-Lead SPAK ΘJC=2°C/W 5-Lead SPAK ΘJC=2°C/W 5-Lead Plastic TO-252 DPAK ΘJC=3°C/W Tab is GND Pin Descriptions Pin Name VIN NC/FB V1 V2 GND SPAK DPAK 1 2 4/5 5/4 3 Pin Function Input supply voltage For V2 fixed, no connect. For V2 adjustable, feedback voltage. Output #1 Output #2 Ground Absolute Maximum Ratings Parameter VIN Storage Temperature Range Lead Soldering Temperature, 10 seconds Min. -65 Max. 10 150 300 Units V °C °C Recommended Operating Conditions Parameter VIN Ambient Operating Temperature (TA) Conditions Vin to GND Min. 4.75 0 Typ. 5 Max. 5.25 125 Units V °C 2 FB V1 REV. 1.0.2 12/17/03 PRODUCT SPECIFICATION FAN1538 Electrical Specifications (Operating Conditions: VIN = 5V, TJ=25°C unless otherwise specified) The • denotes specifications which apply over the full operating temperature range. Parameter V1 Output Voltage V2 Output Voltage (FAN1538A) V2 Minimum Output Voltage (FAN1538B) Reference Voltage (FAN1538B) (FB) FB Pin Bias Current Line Regulation (Both Outputs) Load Regulation (Both Outputs) Current Limit (Both Outputs) Minimum Load Current (Both Outputs) Quiescent Current Ripple Rejection (Both Outputs) VIN Rising threshold VIN Falling threshold V1 & V2 delay start time V1 softstart slew rate V2 softstart slew rate V1 & V2 Thermal Shutdown Shut down Temperature Thermal hysteresis 165 40 °C °C R1 = 1250 & R2 = 250 ohms VIN < 3.4 • VIN > UVLO Rising Threshold 4.50V ≤ VIN ≤ 7V Iout = 10mA VIN=5.0V 10mA ≤ Iout ≤ 1A VIN = 5V 4.50V ≤ VIN ≤ 7V VIN = 5V F = 60Hz, Cout = 22µF VIN = 5V, Iout =100mA • • • • 60 Conditions 10mA ≤ Iout ≤ 1A 4.50V ≤ VIN ≤ 7V 10mA ≤ Iout ≤ 1A 4.50V ≤ VIN ≤ 7V 10mA ≤ Iout ≤ 1A 4.50V ≤ VIN ≤ 7V 10mA