19-4357; Rev 0; 10/08 Adjustable Overvoltage Protector with High Accuracy Features ♦ Input Voltage Protection Up to +28V The MAX14527/MAX14528 overvoltage protection devices feature a low 100mΩ (typ) RON internal FET and protect low-voltage systems against voltage faults up to +28V. When the input voltage exceeds the overvoltage threshold, the internal FET is turned off to prevent damage to the protected components. The overvoltage protection threshold can be adjusted with optional external resistors to any voltage between 4V and 8V. With the OVLO input set below the external OVLO select voltage, the MAX14527/MAX14528 automatically choose the internal ±2.5% accurate trip thresholds. The internal overvoltage thresholds (OVLO) are preset to 5.75V typical (MAX14527) or 6.76V typical (MAX14528). The MAX14527/MAX14528 are also protected against overcurrent events with an internal thermal shutdown. ♦ Preset Internal ±2.5% Accurate OVLO Thresholds 5.75V (MAX14527) 6.76V (MAX14528) ♦ Adjustable Overvoltage Protection Trip Level ♦ Integrated 100mΩ (typ) n-Channel MOSFET Switch ♦ Soft-Start to Minimize In-Rush Current ♦ Automatic Overvoltage Protection Trip-Level Selection ♦ Internal 15ms Startup Delay ♦ Thermal Shutdown Protection ♦ 8-Pin TDFN (2mm x 2mm) Package The MAX14527/MAX14528 are offered in a small, 8-pin TDFN-EP package and operate over the -40°C to +85°C extended temperature range. ♦ -40°C to +85°C Operating Temperature Range Ordering Information Applications Cell Phones PART Media Players PDAs and Palmtop Devices PIN-PACKAGE TOP MARK OVLO (V) MAX14527ETA+T 8 TDFN-EP* ACR 5.75 MAX14528ETA+T 8 TDFN-EP* ACS 6.76 Note: Devices are specified over the -40°C to +85°C temperature range. +Denotes a lead-free/RoHS-compliant package. T = Tape and reel. *EP = Exposed pad. Pin Configuration appears at end of data sheet. Typical Application Circuit VBUS USB CONNECTOR 1µF IN OUT IN OUT CHARGER INPUT PMIC MAX14527 MAX14528 R1 OVLO * GND R2 *R1 AND R2 ARE REQUIRED ONLY FOR ADJUSTABLE OVLO; OTHERWISE, CONNECT OVLO TO GND. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. 1 MAX14527/MAX14528 General Description MAX14527/MAX14528 Adjustable Overvoltage Protector with High Accuracy ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND.) IN ............................................................................-0.3V to +30V OUT .............................................................-0.3V to (VIN + 0.3V) OVLO........................................................................-0.3V to +6V Continuous IN Current .............................................................1A Peak IN Current (Note 1)..........................................................5A Continuous OVLO Current ...................................................50µA Continuous Power Dissipation (TA = +70°C) 8-Pin TDFN (derate 11.9mW/°C above +70°C) ...........954mW Package Junction-to-Ambient Thermal Resistance (θJA) (Note 2) .....................................................................83.9°C/W Package Junction-to-Case Thermal Resistance (θJC) (Note 2) ........................................................................37°C/W Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering) .........................................+300°C Note 1: Limited by thermal shutdown. Note 2: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial. 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 = +2.2V to +28V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VIN = +5.0V and TA = +25°C.) (Note 3) PARAMETER SYMBOL Input Voltage Range Input Supply Current VIN IIN CONDITIONS VIN_OVLO VIN falling V µA 5.9 5.75 6.765 MAX14527 MAX14528 5.54 6.5 1.2 VOVLO_SELECT 7 5.84 6.95 1 ICLAMP = 10µA VOVLO_THRESH = 1.245V V % 1.245 1.29 V 4 0.15 0.33 8 0.5 V V 100 200 mΩ 3 4.56 5.5 V 1000 +100 µF nA RON COUT IOVLO 28 160 5.6 VIN_OVLO_HYS OUT Capacitor OVLO Input Leakage Current 80 6.55 VOVLO_THRESH OVLO Clamp UNITS MAX14528 OVLO Set Threshold Switch On-Resistance MAX MAX14527 IN Overvoltage Lockout Hysteresis Adjustable OVLO Threshold Range External OVLO Select Threshold TYP 2.2 VIN < OVLO VIN rising IN Overvoltage Trip Level MIN -100 Thermal Shutdown 150 °C Thermal Shutdown Hysteresis 20 °C 15 ms TIMING CHARACTERISTICS (Figure 1) Debounce Time Switch Turn-On Time Switch Turn-Off Time tINDBC tON tOFF Time from 2.2V < VIN < VIN_OVLO to VOUT = 10% of VIN 2.2V < VIN < VIN_OVLO, RLOAD = 100Ω, CLOAD = 100µF; VOUT from 10% to 90% of VIN 2.2V < VIN < VIN_OVLO, RLOAD = 100Ω, CLOAD = 1mF; VOUT from 10% to 90% of VIN VIN > VOVLO_THRESH to VOUT = 80% of VIN_OVLO; RLOAD = 1kΩ, VIN rising at 2V/100ns 0.7 ms 1.4 1.3 3.5 µs Note 3: All specifications are 100% production tested at TA = +25°C, unless otherwise noted. Specifications are over -40°C to +85°C and are guaranteed by design. 2 _______________________________________________________________________________________ Adjustable Overvoltage Protector with High Accuracy OVLO 2.2V IN tON VIN_OVLO tON 80% VIN_OVLO 90% 90% 10% OUT 10% tOFF tINDBC tINDBC NOTE: WAVEFORMS ARE NOT TO SCALE. Figure 1. Timing Characteristics _______________________________________________________________________________________ 3 MAX14527/MAX14528 Timing Diagram Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) IN SUPPLY CURRENT vs. IN VOLTAGE TA = +85°C TA = +25°C 30 20 1.1 1.0 0.9 0.7 TA = -40°C 10 0.6 0 0.5 0 7 14 IN VOLTAGE (V) 21 28 1.04 1.03 1.02 1.01 1.00 0.99 0.98 0.97 0.96 0.95 -15 10 35 60 NORMALIZED EXTERNAL OVLO SELECT THRESHOLD MAX14527/8 toc04 1.05 85 1.03 1.02 1.01 1.00 0.99 0.98 0.97 0.96 0.95 -40 NORMALIZED EXTERNAL OVLO SET THRESHOLD vs. TEMPERATURE -40 VIN = 5.0V 0.8 -15 10 35 60 -40 85 35 60 NORMALIZED EXTERNAL OVLO SELECT THRESHOLD vs. TEMPERATURE NORMALIZED DEBOUNCE TIME vs. TEMPERATURE 1.5 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 1.05 85 1.04 1.03 1.02 1.01 1.00 0.99 0.98 0.97 0.96 0.6 0.95 0.5 -40 -15 10 35 60 -40 85 -15 POWER-UP RESPONSE 10 35 TEMPERATURE (°C) TEMPERATURE (°C) OVERVOLTAGE FAULT RESPONSE MAX14527/8 toc07 MAX14527/8 toc08 VIN 5V/div VIN 5V/div VOUT 5V/div VOUT 5V/div IOUT 100mA/div 10ms/div 10 TEMPERATURE (°C) TEMPERATURE (°C) 4 -15 TEMPERATURE (°C) MAX14527/8 toc05 40 VIN = 3.6V 1.04 MAX14527/8 toc06 NORMALIZED RON 60 1.2 MAX14527/8 toc03 1.3 1.05 NORMALIZED OVLO THRESHOLD 1.4 NORMALIZED DEBOUNCE TIME 70 MAX14527/8 toc02 1.5 MAX14527/8 toc01 IN SUPPLY CURRENT (µA) 80 50 NORMALIZED OVLO THRESHOLD vs. TEMPERATURE NORMALIZED R0N vs. TEMPERATURE 90 NORMALIZED EXTERNAL OVLO SET THRESHOLD MAX14527/MAX14528 Adjustable Overvoltage Protector with High Accuracy IOUT 50mA/div 1μs/div _______________________________________________________________________________________ 60 85 Adjustable Overvoltage Protector with High Accuracy PIN NAME FUNCTION 1, 2 IN Voltage Input. Bypass IN with a 1µF ceramic capacitor as close as possible to the device to obtain ±15kV Human Body Model (HBM) ESD protection. Connect all the IN pins together for proper operation. IN is protected to ±2kV HBM when IN is not bypassed with a capacitor to GND. 3 OVLO External OVLO Adjustment. Connect OVLO to GND when using the internal threshold. Connect a resistordivider to OVLO to set a different OVLO threshold; this external resistor-divider is completely independent from the internal threshold. 4, 5 I.C. 6 GND Internally Connected. Do not connect. Leave I.C. unconnected. Ground 7, 8 OUT Output Voltage. Output of internal switch. Connect all the OUT outputs together for proper operation. — EP Exposed Pad. Connect exposed pad to ground. For enhanced thermal dissipation, connect EP to a copper area as large as possible. Do not use EP as a sole ground connection. Functional Diagram IN OUT IN OUT CHARGE PUMP TEMPERATURE FAULTS VBG REFERENCE LOGIC CONTROL + - OVLO SEL GND Detailed Description The MAX14527/MAX14528 overvoltage protection devices feature a low RON internal FET and protect lowvoltage systems against voltage faults up to +28V. If the input voltage exceeds the overvoltage threshold, the internal FET is turned off to prevent damage to the protected components. The 15ms debounce time prevents false turn-on of the internal FET during startup. MAX14527 MAX14528 Device Operation The MAX14527/MAX14528 have timing logic that controls the turn-on of the internal FET. If V IN < VOVLO_THRESH, the internal charge pump is enabled. The charge-pump startup, after a 15ms debounce delay, turns on the internal FET (see the Functional Diagram ). At any time, if V IN rises above V OVLO_ THRESH, OUT is disconnected from IN. _______________________________________________________________________________________ 5 MAX14527/MAX14528 Pin Description MAX14527/MAX14528 Adjustable Overvoltage Protector with High Accuracy Internal Switch The MAX14527/MAX14528 incorporate an internal FET with a 100mΩ (typ) RON. The FET is internally driven by a charge pump that generates a necessary gate voltage above IN. The internal FET is capable of passing more than 5A inrush current. Overvoltage Lockout (OVLO) The MAX14527 has a 5.75V (typ) overvoltage threshold (OVLO).The MAX14528 has a 6.76V (typ) OVLO threshold. Thermal-Shutdown Protection ESD Test Conditions ESD performance depends on a number of conditions. The MAX14527/MAX14528 are specified for ±15kV (HBM) typical ESD resistance on IN when IN is bypassed to ground with a 1µF ceramic capacitor. HBM ESD Protection Figure 2a shows the Human Body Model, and Figure 2b shows the current waveform it generates when discharged into a low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of interest, which is then discharged into the device through a 1.5kΩ resistor. The MAX14527/MAX14528 feature thermal shutdown circuitry. The internal FET turns off when the junction temperature exceeds +150°C (typ). The device exits thermal shutdown after the junction temperature cools by 20°C (typ). RC 1MΩ CHARGE-CURRENTLIMIT RESISTOR Applications Information IN Bypass Capacitor For most applications, bypass IN to GND with a 1µF ceramic capacitor as close as possible to the device to enable ±15kV (HBM) ESD protection on IN. If ±15kV (HBM) ESD is not required, there is no capacitor required at IN. If the power source has significant inductance due to long lead length, take care to prevent overshoots due to the LC tank circuit and provide protection if necessary to prevent exceeding the +30V absolute maximum rating on IN. HIGHVOLTAGE DC SOURCE Cs 100pF RD 1.5kΩ DISCHARGE RESISTANCE DEVICE UNDER TEST STORAGE CAPACITOR Figure 2a. Human Body ESD Test Model OUT Output Capacitor The slow turn-on time provides a soft-start function that allows the MAX14527/MAX14528 to charge an output capacitor up to 1000µF. IP 100% 90% IR PEAK-TO-PEAK RINGING (NOT DRAWN TO SCALE) AMPERES External OVLO Adjustment Functionality If OVLO is connected to ground, the internal OVLO comparator uses the internally set OVLO value. If an external resistor-divider is connected to OVLO and V OVLO exceeds the OVLO select voltage, VOVLO_ SELECT, the internal OVLO comparator reads the IN fraction fixed by the external resistor divider. R1 = 1MΩ is a good starting value for minimum current consumption. Since VIN_OVLO, VOVLO_THRESH, and R1 are known, R2 can be calculated from the following formula: 36.8% 10% 0 0 tRL TIME tDL CURRENT WAVEFORM Figure 2b. Human Body Current Waveform ⎡ R ⎤ VIN_OVLO = VOVLO_THRESH × ⎢1 + 1 ⎥ R 2⎦ ⎣ This external resistor-divider is completely independent from the internal resistor-divider. 6 _______________________________________________________________________________________ Adjustable Overvoltage Protector with High Accuracy Chip Information PROCESS: BiCMOS TOP VIEW IN 1 IN 2 OVLO 3 I.C. 4 MAX14527 MAX14528 *EP 8 OUT 7 OUT 6 GND 5 I.C. TDFN 2mm x 2mm *CONNECT EXPOSED PAD TO GND. Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 8 TDFN-EP T822+2 21-0168 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 © 2008 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc. MAX14527/MAX14528 Pin Configuration