19-2426; Rev 0; 4/02 Regulated 5V USB Charge Pump with Programmable Current Limit Features ♦ Regulated 5V Output Up to 125mA ♦ Indefinite Short-Circuit Protection ♦ Adjustable Output Current Limit ♦ No Inductors Required ♦ 0.1µA Shutdown Current ♦ Thermal Shutdown ♦ Fault Output Indicates Overcurrent or Output Voltage Out of Regulation ♦ 2.95V to 5.5V Input Voltage Range ♦ 10-Pin µMAX Package Applications Ordering Information Flash Memory Supplies PART USB Host Devices TEMP RANGE MAX5008CUB 0°C to +70°C PIN-PACKAGE 10 µMAX Battery-Powered Systems Pin Configuration appears at end of data sheet. 3.3V to 5V Local Conversion Typical Operating Circuit CX 0.68µF VIN 2.95V TO 5.5V 4.7µF 8 5 7 9 CXN CXP IN 2 SHDN 100kΩ 200Ω* VOUT 5V OUT 47nF* MAX5008 3 RCS FAULT RCS 0.4Ω COUT 4.7µF 1 200Ω* CEXT GND PGND 4 6 10 IOUT CEXT 6.8µF *USE IF PRECISION CURRENT LIMIT IS REQUIRED. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX5008 General Description The MAX5008 charge-pump regulator generates a regulated 5V output up to 125mA with a 2.95V to 5.5V input voltage range. The device includes resistor-programmable overcurrent limit. The MAX5008 requires a minimum number of external components for normal operation. The high 1MHz switching frequency allows the use of small surface-mount ceramic capacitors. The fault-protection circuitry limits the output current when it exceeds the limit set by an external resistor. The output current can range from 1mA to 150mA to accommodate circuit requirements. A FAULT output indicates when the device is in current limit or the output is out of regulation. A low-power shutdown mode reduces supply current to less than 1µA and places the output in a high-impedance state. The MAX5008 is offered in a space-saving 10-pin µMAX package that is only 1.1mm high. MAX5008 Regulated 5V USB Charge Pump with Programmable Current Limit ABSOLUTE MAXIMUM RATINGS IN, SHDN, RCS, FAULT, OUT to GND .....................-0.3V to +6V PGND to GND.....................................................................±0.3V CXN to GND ................................................-0.3V to (VIN + 0.3V) CXP to GND ............................................-0.3V to (VCEXT + 0.3V) CEXT to GND ..........................................-0.3V to (VCEXT + 0.3V) Short-Circuit Duration to GND .......................................Indefinite Continuous Power Dissipation (TA = +70°C) 10-Pin µMAX.................................................................444mW Operating Temperature Range...............................0°C to +70°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VIN = SHDN = 3V, CIN = 4.7µF, CX = 0.68µF, CEXT = 6.8µF, COUT = 4.7µF, RCS = 0.4Ω, TA = 0°C to +70°C, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX IOUT = 125mA 2.95 4.25 IOUT = 70mA 2.95 5.50 Input Undervoltage Lockout Threshold Rising edge 2.0 Input Undervoltage Lockout Hysteresis Falling edge Input Voltage Range (Note 1) VIN Output Voltage (Note 2) VOUT Output Voltage Ripple VRIP VOUT Fault Threshold VTH Maximum Output Current IOUT No-Load Input Current IQ SHDN Logic High VINH,SHDN SHDN Logic Low VINL,SHDN Shutdown Supply Current IQSHDN Current-Sense Trip Level VCS FAULT Leakage Current 2.35 2.6 100 4.75 5.0 5.30 0mA ≤ IOUT ≤ 100mA, 2.95V ≤ VIN ≤ 4.25V 4.75 5.0 5.25 100 4.22 VOUT = 5V ±4% 100 140 0.6 6 1 6 2.4 V mA V 0.4 55 V mA IOUT = 0, VIN = 3.3V VCS = IOUT x RCS (Note 3) V mV 4.50 IOUT = 0, VIN = 4.25V SHDN = low V mV 0 ≤ IOUT < 30mA, 2.95V < VIN < 5.5V 0mA ≤ IOUT ≤ 125mA UNITS V 0.1 10 µA 60 73 mV 1 µA VFAULT = 5V, OUT in regulation FAULT Logic Low IOUT > ILIMIT, or VOUT < VTH, IFAULT = 1mA FAULT Assertion Delay (Note 4) IOUT > ILIMIT 2 ms VOUT < VTH 30 µs FAULT Deassertion Delay (Note 5) tFD tFDD IOUT < ILIMIT and VOUT > 4.5V Switching Frequency Startup Time 2 0.4 16 0.5 tSTART VOUT > VTH, RLOAD = 46Ω, from rising edge of SHDN 1 200 _______________________________________________________________________________________ V ms 1.5 MHz µs Regulated 5V USB Charge Pump with Programmable Current Limit (VIN = SHDN = 3V, CIN = 4.7µF, CX = 0.68µF, CEXT = 6.8µF, COUT = 4.7µF, RCS = 0.4Ω, TA = 0°C to +70°C, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Thermal Shutdown Junction Temperature 150 °C Thermal Shutdown Hysteresis 30 °C When the input exceeds 4.25V, the power dissipation on the chip exceeds the maximum rating if the output current is 125mA. The MIN/MAX limits are 100% production tested at +25°C and +70°C, and guaranteed by design at 0°C. IOUT is output current flowing from CEXT. The delay from the fault event to the assertion of FAULT. Fault delays are specified with either a current fault or a voltage fault, but not both simultaneously. Note 5: The delay from the removal of the fault event to the deassertion of FAULT. Note 1: Note 2: Note 3: Note 4: Typical Operating Characteristics (VIN = 3V, CIN = 4.7µF, CX = 0.47µF, COUT = 4.7µF, CEXT = 4.7µF, RCS = 0.4Ω, TA = +25°C, unless otherwise noted.) 1.0 0.5 VIN = 5.0V 5.1 4.9 VIN = 2.9V VIN = 3.3V 4.7 0 3.0 3.5 4.0 4.5 SUPPLY VOLTAGE (V) 5.0 5.5 ILOAD = 100mA 5 4 3 2 1 4.5 2.5 6 OUTPUT VOLTAGE (V) 5.3 1.5 OUTPUT VOLTAGE vs. SUPPLY VOLTAGE MAX5008 toc02 MAX5008 toc01 5.5 OUTPUT VOLTAGE (V) SUPPLY CURRENT (mA) 2.0 OUTPUT VOLTAGE vs. LOAD CURRENT MAX5008 toc03 NO-LOAD SUPPLY CURRENT vs. SUPPLY VOLTAGE 0 1 10 100 LOAD CURRENT (mA) 1000 0 1 2 3 4 5 6 SUPPLY VOLTAGE (V) _______________________________________________________________________________________ 3 MAX5008 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (continued) (VIN = 3V, CIN = 4.7µF, CX = 0.47µF, COUT = 4.7µF, CEXT = 4.7µF, RCS = 0.4Ω, TA = +25°C, unless otherwise noted.) EFFICIENCY vs. LOAD CURRENT VIN = 2.95V 90 OUTPUT WAVEFORM SHUTDOWN TIMING MAX5008 toc05 MAX5008 toc06 MAX5008 toc04 100 80 EFFICIENCY (%) MAX5008 Regulated 5V USB Charge Pump with Programmable Current Limit RL = 46Ω 5V VOUT 70 60 VIN = 3.3V 10mV/div 50 40 0 5V 30 SHDN 0 20 10 0 1 10 100 200ns/div 1000 1ms/div LOAD CURRENT (mA) LINE-TRANSIENT RESPONSE LOAD-TRANSIENT RESPONSE MAX5008 toc07 MAX5008 toc08 ILOAD = 100mA A 100mA 3.6V 3.1V A 10mA B 40µs/div A: INPUT VOLTAGE: 500mV/div B: OUTPUT VOLTAGE: AC-COUPLED, 100mV/div 4 B 40µs/div A: LOAD CURRENT B: OUTPUT VOLTAGE: AC-COUPLED, 100mV/div _______________________________________________________________________________________ Regulated 5V USB Charge Pump with Programmable Current Limit PIN NAME 1 RCS 2 OUT 3 FAULT 4 GND 5 SHDN 6 PGND 7 CXN 8 IN FUNCTION External Current-Sense Resistor. Connect a resistor from RCS to OUT to set the overcurrent threshold. ILIMIT = 60mV / RCS. Fixed 5V Output. Bypass OUT to GND with a 4.7µF capacitor. Output Fault Indicator. FAULT is asserted when either IOUT > ILIMIT or VOUT < VTH. FAULT is an open-drain output that is high during normal operation or during shutdown. Ground Pin. Connect GND to PGND. Shutdown Input. When SHDN = low, the device turns off. Drive SHDN high or connect to IN for normal operation. Power Ground Pin. Connect PGND to GND. Negative Terminal of the Charge-Pump Capacitor. Connect a 0.68µF capacitor from CXN to CXP. Input Supply, 2.95V to 5.5V. Bypass IN to GND with a 4.7µF ceramic capacitor. 9 CXP Positive Terminal of the Charge-Pump Capacitor. Connect a 0.68µF capacitor from CXP to CXN. 10 CEXT Charge-Pump Output. Bypass CEXT to PGND with a 6.8µF capacitor. Detailed Description The MAX5008 charge pump provides a regulated 5V output from a 2.95V to 5.5V input. The device delivers a maximum of 125mA load current. Designed specifically for compact applications, a complete regulator circuit requires a minimum number of external components. Adjustable Current Limit The MAX5008 has an adjustable overcurrent protection. An external current-sense resistor is connected from RCS to OUT to set the current limit. The current limit is defined by: ILIMIT = VCS / RCS where VCS is the current-sense trip level, typically 60mV. For example, ILIMIT = 150mA when RCS = 0.40Ω. When the output current limit is exceeded, the output voltage falls and the device maintains the average output current at ILIMIT. Upon removal of the overcurrent condition, the part resumes normal operation. FAULT Indication When IOUT > ILIMIT or VOUT < VTH, FAULT asserts. FAULT is an open-drain output that needs to be connected through a 100kΩ (typ) pullup resistor to a logic supply voltage. Thermal Shutdown The MAX5008 has internal thermal shutdown circuitry, which shuts down the device when the die temperature exceeds +150°C. The thermal shutdown circuitry has 30°C hysteresis. Shutdown Mode Driving SHDN low places the device in shutdown mode, which disables the oscillator, the control logic, and the reference. The output goes into high-impedance state and drops to ground if loaded. Placing the device in shutdown mode reduces the supply current to less than 0.1µA. In normal operation, SHDN is driven high or connected to IN. Applications Information Capacitor Selection The MAX5008 requires four external capacitors. Their values depend on the required output current. Table 1 shows the capacitor values recommended for different load currents. Input Voltage Range The MAX5008 maintains a regulated 5V output with input voltages from 2.95V to 5.5V. If the input voltage exceeds 4.25V, limit the output current to 75mA or less. This keeps the MAX5008 within its maximum power dissipation limits. Table 1. Recommended Capacitor Values IOUT CIN (µF) CX (µF) CEXT (µF) COUT (µF) 50mA 3.3 0.33 3.3 3.3 125 mA 4.7 0.68 6.8 4.7 Layout Considerations All capacitors should be located as close to the IC as practical. Connect GND and PGND through a short, _______________________________________________________________________________________ 5 MAX5008 Pin Description Regulated 5V USB Charge Pump with Programmable Current Limit MAX5008 Functional Diagram Pin Configuration TOP VIEW CEXT IN RCS CXN OUT SWITCHES CXP CONTROL RCS 1 OUT 2 FAULT 3 GND SHDN 10 CEXT 9 CXP 8 IN 4 7 CXN 5 6 PGND MAX5008 µMAX MAX5008 PGND FAULT SHDN GND low-impedance trace, and connect the ground for CIN, CEXT, and COUT directly to PGND in a star configuration. Connect RCS to CEXT through a short and low impedance trace. 6 Chip Information TRANSISTOR COUNT: 2632 PROCESS: BiCMOS _______________________________________________________________________________________ Regulated 5V USB Charge Pump with Programmable Current Limit 10LUMAX.EPS Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 7 © 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX5008 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.)