19-1059; Rev 0; 11/07 Overvoltage-Protection Controller with USB ESD Protection The MAX4987AE/MAX4987BE are overvoltage protection devices with built-in ESD protection for USB data lines. These devices feature a low 100mΩ (typ) RON internal nFET switch and protect low-voltage systems against voltage faults up to +28V. When the input voltage exceeds the overvoltage threshold or decreases below the undervoltage threshold, the internal nFET switch is turned off to prevent damage to the protected components. All switches feature a minimum 1.5A current-limit protection. During a short-circuit occurrence, the switch operates in an autoretry mode where the internal nFET switch is turned on to check if the fault has been removed. The autoretry interval is 30ms, and if the fault is removed, the nFET switch remains on. The MAX4987AE/MAX4987BE feature low-capacitance (3pF) ESD protection for USB data lines that allow transmission of high-speed USB 2.0 signals. The overvoltage threshold (OVLO) is preset to 6.15V. The undervoltage thresholds (UVLO) are preset to 2.55V (MAX4987AE) or 4.2V (MAX4987BE). When the input voltage drops below the undervoltage (UVLO) threshold, the devices enter a low-current standby mode. All devices are offered in a small 2mm x 3mm, 8-pin TDFN package and operate over the -40°C to +85°C extended temperature range. Features o o o o Input Voltage Protection Up to +28V Integrated Low RON (100mΩ) nFET Switch Internal Overcurrent Protection 1.5A (min) Overcurrent Protection (Autoretry) o Enable Input o Internal 30ms Startup Delay o Low-Capacitance USB High-Speed Data Line ESD Protection (3pF) ±15kV Human Body Model ±15kV IEC61000-4-2 Air Gap ±6kV IEC61000-4-2 Contact o Thermal-Shutdown Protection o 2mm x 3mm, 8-Pin TDFN Package Pin Configuration TOP VIEW OUT ACOK 8 Applications 7 EN VCC 6 5 MAX4987AE/ MAX4987BE Cell Phones Media Players *EP Typical Operating Circuit appears at end of data sheet. *CONNECT EXPOSED PAD TO GND. 1 2 3 4 IN CD+ GND CD- TDFN-EP 2mm x 3mm Ordering Information/Selector Guide PINPACKAGE PART TOP MARK PACKAGE CODE UVLO (V) OVLO (V) OVERCURRENT MODE MAX4987AEETA+ 8 TDFN-EP** AAI T823-1 2.55 6.15 Autoretry MAX4987BEETA+* 8 TDFN-EP** AAJ T823-1 4.2 6.15 Autoretry Note: All devices are specified over the -40°C to +85°C operating temperature range. +Denotes a lead-free package. *Future product—contact factory for availability. **EP = Exposed paddle. ________________________________________________________________ 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 MAX4987AE/MAX4987BE General Description MAX4987AE/MAX4987BE Overvoltage-Protection Controller with USB ESD Protection ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND.) IN ............................................................................-0.3V to +30V OUT.............................................................-0.3V to +(IN + 0.3V) VCC, EN, ACOK, CD+, CD- ......................................-0.3V to +6V Continuous Power Dissipation (TA = +70°C) for multilayer board: 8-Pin TDFN (derate 16.7mW/°C above +70°C) .........1333mW Package Junction-to-Ambient Thermal Resistance (θJA) (Note 1) ................................................................60.0°C/W Package Junction-to-Case Thermal Resistance (θJC) (Note 1) ................................................................10.8°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: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a 4-layer board. For detailed information on package thermal considerations, go 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 = +5V and TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNIT ANALOG SWITCH Input-Voltage Range VIN VCC Input Voltage VCC Input Supply Current IIN UVLO Supply Current IUVLO 2.2 60 150 EN = 5V, VIN > VUVLO 50 100 VIN < VUVLO 40 MAX4987AE MAX4987BE 3.8 2.35 2.55 2.75 MAX4987BE 3.85 4.2 4.45 (VIN rising) 5.55 6.15 (VIN falling) 5.5 IN Undervoltage Lockout Hysteresis 1 VOVLO IN Overvoltage Lockout Hysteresis RON Overcurrent Protection Threshold ILIM Maximum Output Capacitance CD+ and CD- Leakage Current CD+ and CD- Capacitance VIN = 5V, IOUT = 500mA 100 1.5 VIN = 5V, no overcurrent shutdown ILKG_CD VCC = 5.5V, VCD_ = 0V, 3.3V CCD f = 1MHz, VCD_ = 0.5P-P VOL ISINK = 1mA µA V % 200 4.2 1000 -300 V % 6.45 1 Switch On-Resistance µA 2.3 MAX4987AE VUVLO (VIN rising) Overvoltage Trip Level V V EN = 0V, VIN > VUVLO (VIN falling) IN Undervoltage Lockout 28 5.5 mΩ A µF +300 3 nA pF DIGITAL SIGNALS ACOK Output Low Voltage ACOK High-Leakage Current VIH EN Input-Voltage Low VIL EN Input-Leakage Current 2 VACOK = 5.5V, flag deasserted EN Input-Voltage High ILEAK 0.4 V 1 µA 0.4 V +1 µA 1.4 VEN = 5.5V -1 _______________________________________________________________________________________ V Overvoltage-Protection Controller with USB ESD Protection (VIN = +2.2V to +28V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VIN = +5V and TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNIT TIMING CHARACTERISTICS (Note 2) Debounce Time tINDBC Time from VUVLO < VIN < VOVLO to charge-pump enable 30 ms ACOK Assertion Time tACOK VUVLO < VIN < VOVLO, to ACOK low 30 ms 3 ms Switch Turn-On Time tON VUVLO < VIN < VOVLO, RLOAD = 100Ω, from 10% to 90% of VOUT Switch Turn-Off Time tOFF VIN < VUVLO or VIN > VOVLO to internal switch off, RLOAD = 100Ω Current-Limit Turn-Off Time Autoretry Time 10 µs tBLANK Overcurrent fault to internal switch off 10 µs tRETRY From overcurrent fault to internal switch turn-on 30 ms THERMAL PROTECTION Thermal Shutdown TSHDN Thermal-Shutdown Hysteresis 150 °C 40 °C ESD PROTECTION Human Body Model ±15 CD+ and CD- IEC61000-4-2 Air Gap ±15 IEC61000-4-2 Contact ±6 All Other Pins Human Body Model ±2 kV kV Note 2: All timing is specified using 20% and 80% levels, unless otherwise noted. Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) SWITCH ON-RESISTANCE vs. TEMPERATURE 160 140 RON (mΩ) 50 180 40 30 120 100 80 60 20 40 10 20 0 0 2 6 10 14 18 IN VOLTAGE (V) 22 26 1.010 MAX4987AE/BE toc03 60 MAX4987AE/BE toc02 MAX4987AE 70 IN SUPPLY CURRENT (μA) 200 MAX4987AE/BE toc01 80 NORMALIZED UVLO THRESHOLD vs. TEMPERATURE 1.008 NORMALIZED UVLO THRESHOLD (V) IN SUPPLY CURRENT vs. IN VOLTAGE 1.006 1.004 1.002 1.000 0.998 0.996 0.994 0.992 0.990 -40 -15 10 35 TEMPERATURE (°C) 60 85 -40 -15 10 35 60 85 TEMPERATURE (°C) _______________________________________________________________________________________ 3 MAX4987AE/MAX4987BE ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) NORMALIZED OVLO THRESHOLD vs. TEMPERATURE 1.12 1.002 1.000 0.998 0.996 1.08 1.04 1.00 0.96 0.92 0.994 0.88 0.992 0.84 0.990 4.0 -15 10 35 60 85 3.0 2.0 1.0 0 0.80 -40 MAX4987AE/BE toc06 1.004 1.16 TURN ON TIME (ms) 1.006 5.0 MAX4987AE/BE toc05 1.20 CURRENT LIMIT (%) NORMALIZED OVLO THRESHOLD (V) 1.008 TURN-ON TIME vs. TEMPERATURE NORMALIZED CURRENT LIMIT vs. TEMPERATURE MAX4987AE/BE toc04 1.010 -40 -15 10 35 60 TEMPERATURE (°C) TEMPERATURE (°C) DEBOUNCE TIME vs. TEMPERATURE POWER-UP RESPONSE -40 85 -15 10 35 MAX4987AE/BE toc07 45.0 35.0 MAX4987AE/BE toc09 VACOK 5V/div 30.0 IOUT 1A/div 25.0 8V 5V 8V 5V VIN 5V/div VOUT 5V/div 0 VACOK 5V/div 0 IOUT 1A/div 0 20.0 -15 10 35 60 10ms/div 85 2μs/div TEMPERATURE (°C) UNDERVOLTAGE FAULT RESPONSE SHORT-CIRCUIT FAULT RESPONSE MAX4987AE/BE toc10 MAX4987AE/BE toc11 5 VIN 2V/div 2 VOUT 2V/div 0 CIN = 100μF VIN 5V/div VOUT 5V/div 0 0 VACOK 5V/div 0 IOUT 1A/div 0 4μs/div 4 85 OVERVOLTAGE FAULT RESPONSE VIN 5V/div VOUT 5V/div 40.0 -40 60 TEMPERATURE (°C) MAX4987AE/BE toc08 50.0 DEBOUNCE TIME (ms) MAX4987AE/MAX4987BE Overvoltage-Protection Controller with USB ESD Protection VACOK 5V/div 0 IOUT 1A/div 0 10μs/div _______________________________________________________________________________________ Overvoltage-Protection Controller with USB ESD Protection PIN NAME 1 IN 2 CD+ USB Data Line 3 GND Ground 4 CD- USB Data Line 5 VCC Positive Supply-Voltage Input. VCC is required only when USB signals are present. 6 EN 7 ACOK 8 OUT EP EP FUNCTION Voltage Input. Bypass IN with a 1µF ceramic capacitor as close to the device as possible to obtain ±15kV HBM ESD protection. No capacitor required to obtain ±2kV HBM ESD protection. Enable Active-Low Input. Drive EN low to enable the switch. Drive EN high to disable the switch. Open-Drain Adapter-Voltage Indicator Output. ACOK is driven low after the VIN voltage is stable between UVLO and OVLO for 30ms (typ). Connect a pullup resistor from ACOK to the logic I/O voltage of the host system. Output Voltage. Output of internal switch. Exposed Pad. Connect exposed pad to ground. Do not use EP as a sole ground connection. Functional Diagram IN OUT OVERCURRENT FAULT CHARGE PUMP ACOK + VBG REFERENCE CONTROL LOGIC OV - EN + - EN UV VCC CD+ MAX4987AE/ MAX4987BE CD- GND _______________________________________________________________________________________ 5 MAX4987AE/MAX4987BE Pin Description MAX4987AE/MAX4987BE Overvoltage-Protection Controller with USB ESD Protection OVLO UVLO tOFF IN tOFF tON 90% VOUT 10% VOUT OUT tINDBC tINDBC tINDBC ACOK Figure 1. MAX4987AE/MAX4987BE Timing Diagram Detailed Description Internal nFET Switch The MAX4987AE/MAX4987BE are overvoltage protection devices with integrated ESD protection for USB data lines. These devices feature a low RON internal FET and protect low-voltage systems against voltage faults up to +28V. If the input voltage exceeds the overvoltage threshold, the internal nFET switch is turned off to prevent damage to the protected components. The 30ms debounce time prevents false turn-on of the internal nFET switch during startup. An open-drain activelow logic output is available to signal that a successful power-up has occurred. The MAX4987AE/MAX4987BE incorporate an internal nFET switch with a 100mΩ (typ) on-resistance. The nFET switch is internally driven by a charge pump that generates a voltage above the input voltage. The MAX4987AE/MAX4987BE is equipped with a 1.5A (min) current-limit protection that turns off the nFET switch within 5µs (typ) during an overcurrent fault condition. Device Operation The MAX4987AE/MAX4987BE have an internal oscillator and charge pump that control the turn-on of the internal nFET switch. The internal oscillator controls the timers that enable the turn-on of the charge pump and controls the state of the open-drain ACOK output. If VIN < V UVLO or if V IN > V OVLO , the internal oscillator remains off, thus disabling the charge pump. If VUVLO < VIN < VOVLO, the internal charge pump is enabled. The charge-pump startup, after a 30ms internal delay, turns on the internal nFET switch and asserts ACOK (see Figure 1). At any time, if VIN drops below VUVLO or rises above VOVLO, ACOK is pulled high and the charge pump is disabled. 6 Autoretry The MAX4987AE/MAX4987BE have an overcurrent autoretry function that turns on the nFET switch again after a 30ms (typ) retry time (see Figure 2). If the faulty load condition is still present after the blanking time, the switch turns off again and the cycle is repeated. The fast turn-off time and 30ms retry time result in a very low duty cycle in order to keep power consumption low. If the faulty load condition is not present, the switch remains on. Undervoltage Lockout (UVLO) The MAX4987AE has a 2.55V undervoltage-lockout threshold (UVLO), while the MAX4987BE has a 4.15V UVLO threshold. When VIN is less than VUVLO, ACOK is high impedance. _______________________________________________________________________________________ Overvoltage-Protection Controller with USB ESD Protection MAX4987AE/MAX4987BE Overvoltage Lockout (OVLO) The MAX4987AE/MAX4987BE have a 6.15V (typ) overvoltage threshold (OVLO). When VIN is greater than VOVLO, ACOK is high impedance. tOFF nFET SWITCH ON nFET SWITCH ON ACOK ACOK is an active-low open-drain output that asserts low when VUVLO < VIN < VOVLO following the 30ms (typ) debounce period. Connect a pullup resistor from ACOK to the logic I/O voltage of the host system. During a short-circuit fault, ACOK may deassert due to VIN not being in the valid operating voltage range. Thermal-Shutdown Protection The MAX4987AE/MAX4987BE feature thermal-shutdown circuitry. The internal nFET switch turns off when the junction temperature exceeds TSHDN and immediately goes into a fault mode. The device exits thermal shutdown after the junction temperature cools by +40°C (typ). tRETRY CURRENT THROUGH nFET SWITCH SWITCH OFF ILIM Figure 2. Autoretry Timing Diagram Applications Information IN Bypass Capacitor For most applications, bypass IN to GND with a 1µF ceramic capacitor as close to the device as possible to enable ±15kV HBM ESD protection on IN. If ±15kV HBM ESD protection 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 absolute maximum rating on IN. RC 1MΩ CHARGE CURRENTLIMIT RESISTOR HIGHVOLTAGE DC SOURCE Cs 100pF RD 1.5kΩ DISCHARGE RESISTANCE DEVICE UNDER TEST STORAGE CAPACITOR ESD Test Conditions ESD performance depends on a number of conditions. The MAX4987AE/MAX4987BE are specified for ±15kV HBM ESD protection on the CD+, CD-, and IN pins when IN is bypassed to ground with a 1µF ceramic capacitor. The CD+ and CD- inputs are also protected against ±15kV airgap and ±6kV contact IEC61000-4-2 ESD events. Figure 3. Human Body ESD Test Model IP 100% 90% Ir PEAK-TO-PEAK RINGING (NOT DRAWN TO SCALE) Human Body Model Figure 3 shows the Human Body Model, and Figure 4 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, that is then discharged into the device through a 1.5kΩ resistor. IEC 61000-4-2 The IEC 61000-4-2 standard covers ESD testing and performance of finished equipment. It does not specifically refer to integrated circuits. The MAX4987AE/ MAX4987BE AMPERES 36.8% 10% 0 0 tRL TIME tDL CURRENT WAVEFORM Figure 4. Human Body Current Waveform _______________________________________________________________________________________ 7 MAX4987AE/MAX4987BE Overvoltage-Protection Controller with USB ESD Protection are specified for ±15kV Air-Gap Discharge and ±6kV Contact Discharge IEC 61000-4-2 on the CD+ and CDpins. The major difference between tests done using the Human Body Model and IEC 61000-4-2 is a higher peak current in IEC 61000-4-2, due to lower series resistance. Hence, the ESD withstand voltage measured to IEC 61000-4-2 generally is lower than that measured using the Human Body Model. Figure 5 shows the IEC 610004-2 model. The Contact Discharge method connects the probe to the device before the probe is charged. The Air-Gap Discharge test involves approaching the device with a charged probe. RD 330Ω RC 50MΩ TO 100MΩ DISCHARGE RESISTANCE CHARGE-CURRENTLIMIT RESISTOR HIGHVOLTAGE DC SOURCE Cs 150pF DEVICE UNDER TEST STORAGE CAPACITOR Figure 5. IEC 61000-4-2 ESD Test Model Typical Operating Circuit IN OUT BATTERY CHARGER PHONE LOAD VIO OVERCURRENT FAULT CHARGE PUMP ACOK + VBG REFERENCE CONTROL LOGIC OV - EN + - UV VCC USB CONNECTOR VCC VCC VBUS D+ D+ D- D- CD+ CD- USB TRANSCEIVER MAX4987AE/ MAX4987BE GND Chip Information PROCESS: BiCMOS 8 _______________________________________________________________________________________ Overvoltage-Protection Controller with USB ESD Protection 8L, TDFN.EPS PACKAGE OUTLINE 8L TDFN, EXPOSED PAD, 2x3x0.8mm 21-0174 B 1 2 _______________________________________________________________________________________ 9 MAX4987AE/MAX4987BE 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.) MAX4987AE/MAX4987BE Overvoltage-Protection Controller with USB ESD Protection Package Information (continued) (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.) DIMENSIONS SYMBOL A E D A1 L k A2 MIN. 0.70 NOM. 0.75 MAX. 0.80 2.95 3.00 3.05 1.95 0.00 2.00 0.02 2.05 0.05 0.30 0.40 0.20 MIN. 0.20 REF. 0.50 N e b 0.18 8 0.50 BSC 0.25 EXPOSED PAD PACKAGE E2 D2 PKG. CODE MIN. NOM. MAX. MIN. NOM. MAX. T823-1 1.60 1.75 1.90 1.50 1.63 1.75 0.30 PACKAGE OUTLINE 8L TDFN, EXPOSED PAD, 2x3x0.8mm 21-0174 B 2 2 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. 10 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2007 Maxim Integrated Products SPRINGER is a registered trademark of Maxim Integrated Products, Inc.