CS5231-3

CS5231-3 CS5231-3 500mA, 3.3V Linear Regulator with Auxiliary Control Description The CS5231-3 combines a threeterminal linear regulator with circuitry to control an external PFET transistor with the intent of managing two input supplies. A 5V supply powers the regulator while an auxiliary 3.3V supply is controlled by the IC. The design has been optimized to provide a “glitch-free” transition between the two supplies. The CS5231-3 linear regulator provides a fixed 3.3V output @ 500mA with an overall accuracy of ± 2%. The NPN-PNP composite pass transistor provides a low dropout voltage and requires less supply current than PNP designs. Full protection including current limit and thermal shutdown is provided. Also designed for low reverse current, the IC prevents excessive current from flowing from the output to ground if the regulator input voltage is lower than the output voltage. The CS5231-3 also controls an auxiliary supply that can provide power to the regulator output when input voltage for the regulator is not available. The AuxDrv auxiliary output is normally pulled up to the regulator input voltage and drives low whenever the input voltage drops below 4.4V (nominal). It is typically used to control a PFET switch that connects a 3.3V auxiliary supply to the regulator output. The CS5231-3 is available in a 5-lead D2PAK (TO-263) package. Applications include Network Interface Cards (NICs), modem cards and power supplies with multiple input sources. Features Linear Regulator s 3.3V ± 2% Output Voltage s 3mA Quiescent Current @ 500mA s Fast Transient Response s Current Limit s Thermal Shutdown with Hysteresis s 450µA Reverse Output Current s Fast Transient Response System Power Management s Auxiliary Supply Control Package Options 5 Lead D2PAK VOUT Block Diagram VIN 10kΩ 50kΩ Internal Bias Current Limit − AuxDrv VIN UV Comparator Bandgap Reference Gnd Thermal Shutdown + Error Amp Shutdown − + 1 1. No Connect 2. VIN 3. Gnd 4. VOUT 5. AuxDrv Tab = Gnd VREF Consult factory for other package options. Cherry Semiconductor Corporation 2000 South County Trail, East Greenwich, RI 02818 Tel: (401)885-3600 Fax: (401)885-5786 Email: info@cherry-semi.com Web Site: www.cherry-semi.com Rev. 3/31/99 1 A ® Company CS5231-3 Absolute Maximum Ratings Maximum Operating Junction Temperature ..........................................................................................................................150°C Storage Temperature Range .....................................................................................................................................-65°C to +150°C Lead Temperature Soldering Reflow (SMD styles only) ...........................................................................................60 sec. max above 183°C, 230°C peak ESD Damage Threshold (Human Body Model)....................................................................................................................2kV PIN SYMBOL PIN NAME VMAX 14V 6V 14V N/A VMIN -0.3V -0.3V -0.3V N/A ISOURCE 100mA Internally Limited 10mA N/A ISINK Internally Limited 100mA 50mA N/A VIN VOUT AuxDrv Gnd IC Power Input Output Voltage Auxiliary Drive Output IC Ground Electrical Characteristics: 0°C < TA < 70°C, 0°C < TJ < 125°C, 4.75V ≤ VCC < 6V, COUT ≥ 10µF with ESR < 1Ω, IOUT = 10mA, unless otherwise specified. TEST CONDITIONS PARAMETER MIN TYP MAX UNIT s Linear Regulator Output Voltage Line Regulation Load Regulation Ground Current Reverse Current Current Limit Thermal Shutdown Thermal Shutdown Hysteresis s Auxiliary Drive Upper VIN Threshold Lower VIN Threshold VIN Threshold Hysteresis Output Low Voltage Output Low Peak Voltage AuxDrv Current Limit Response Time Pull-Up/Down Resistance 10mA < IOUT < 500mA IOUT = 10mA, VIN = 4.75V to 6V VIN = 5V, IOUT = 10mA to 500mA IOUT = 10mA IOUT = 500mA VIN = 0V, VOUT = 3.3V 0V < VOUT < 3.2V Note 1 Note 1 3.234 -2% 3.300 1 5 2 3 0.45 0.85 180 25 3.366 +2% 5 15 3 6 1 1.2 210 V mV mV mA mA mA A °C °C 0.55 150 Increase VIN until regulator turns on and AuxDrv drives high Decrease VIN until regulator turns off and AuxDrv drives low IAuxDrv = 100µA, 1V < VIN < 4.5V Increase VIN from 0V to 1V. Record peak AuxDrv output voltage VAuxDrv = 1V, VIN = 4.0V Step VIN from 5V to 4V, measure time for VAuxDrv to drive low. Note 1 VIN = 0V and VIN > 4.7V 4.35 4.25 75 4.5 4.4 100 0.1 0.65 4.65 4.55 125 0.4 0.9 25 10 25 V V mV V V mA µs kΩ 0.5 6 1 5 10 Note 1: Guaranteed by design, not 100% production tested. Thermal shutdown is 100% functionally tested at wafer probe. 2 CS5231-3 Package Pin Description PACKAGE PIN # PIN SYMBOL FUNCTION 5Lead D2 1 2 3 4 5 PAK N/C VIN Gnd VOUT AuxDrv No connection. Input voltage. Ground and IC substrate connection (case). Regulated output voltage. Output used to control an auxiliary supply voltage. This lead is driven low if VIN is less than 4.5V, and is otherwise pulled up to VIN through an internal 10kΩ resistor. Typical Performance Characteristics 3.302 IOUT = 10mA 80 4.75V