19-3263; Rev 1; 7/04 Positive High-Voltage, Hot-Swap Controllers Features The MAX5933A–MAX5933F/MAX5947A/B/C fully integrated hot-swap controllers for +9V to +80V positive supply rails (MAX5947A/B/C), allow for the safe insertion and removal of circuit cards into live backplanes without causing glitches on the backplane power-supply rail. The MAX5947B is pin- and function-compatible with the LT1641-2. The other devices offer added features such as a choice of active-high or active-low power-good outputs (PWRGD/PWRGD), latched/autoretry fault management, and autoretry duty-cycle options of 3.75% or 0.94% (see the Selector Guide). The MAX5933A–MAX5933F are available with a default undervoltage lockout threshold of +31V and operate over a supply voltage range of +33V to +80V. The MAX5947A/B/C are available with a default undervoltage of +8.3V. All devices feature a programmable analog foldback current limit. If the device remains in current limit for more than a programmable time, the external n-channel MOSFET is either latched off (MAX5933A/ MAX5933C/MAX5947A) or is set to automatically restart after a timeout delay (MAX5933B/MAX5933D/MAX5933E/ MAX5933F/MAX5947B/MAX5947C). The MAX5933_ and MAX5947_ operate in the extended temperature range of -40°C to +85°C. These devices are available in an 8-pin SO package. ♦ Pin- and Function-Compatible with the LT1641-2 (MAX5947B) ♦ Provides Safe Hot Swap for +9V to +80V PowerSupply Range (MAX5947A/B/C) ♦ Safe Board Insertion and Removal from Live Backplanes ♦ Latched/Autoretry Management ♦ Active-Low or Active-High Power-Good Output ♦ Programmable Foldback Current Limiting ♦ High-Side Drive for an External N-Channel MOSFET ♦ Built-In Thermal Shutdown ♦ Undervoltage Lockout (UVLO) ♦ Overvoltage Protection ♦ User-Programmable Supply Voltage Power-Up Rate Ordering Information PART Applications TEMP RANGE PIN-PACKAGE MAX5933_ESA* -40°C to +85°C 8 SO MAX5947_ESA* -40°C to +85°C 8 SO *Insert the desired suffix from the Selector Guide into the blank to complete the part number. Hot Board Insertion Electronic Circuit Breakers Industrial High-Side Switch/Circuit Breakers Network Routers and Switches Typical Application Circuit and Pin Configuration appear at end of data sheet. 24V/48V Industrial/Alarm Systems Selector Guide PART LATCHED FAULT PROTECTION AUTORETRY FAULT PROTECTION PWRGD OUTPUT LOGIC MAX5933A MAX5933B Yes — — Yes MAX5933C MAX5933D Yes — — Yes MAX5933E — SUPPLY VOLTAGE RANGE (V) DUTY CYCLE (%) DEFAULT UVLO (V) High — 31 33 to 80 High 3.75 31 33 to 80 Low — 31 33 to 80 Low 3.75 31 33 to 80 Yes High 0.94 31 33 to 80 33 to 80 MAX5933F — Yes Low 0.94 31 MAX5947A Yes — Low — 8.3 9 to 80 MAX5947B — Yes High 3.75 8.3 9 to 80 MAX5947C — Yes Low 3.75 8.3 9 to 80 ________________________________________________________________ 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 MAX5933A–MAX5933F/MAX5947A/B/C General Description MAX5933A–MAX5933F/MAX5947A/B/C Positive High-Voltage, Hot-Swap Controllers ABSOLUTE MAXIMUM RATINGS (Voltages Referenced to GND) VCC .........................................................................-0.3V to +85V SENSE, FB, ON ..........................................-0.3V to (VCC + 0.3V) TIMER, PWRGD, PWRGD.......................................-0.3V to +85V GATE ......................................................................-0.3V to +95V Maximum GATE Current ....................................-50mA, +150mA Maximum Current into Any Other Pin................................±50mA Continuous Power Dissipation (TA = +70°C) 8-Pin SO (derate 5.9mW/°C above +70°C)..................470mW Operating Temperature Range ...........................-40°C to +85°C Maximum Junction Temperature .....................................+150°C Storage Temperature Range .............................-60°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C ESD Rating (Human Body Model)......................................2000V 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 (VCC = +24V (MAX5947A/B/C), VCC = +48V (MAX5933A–MAX5933F), GND = 0V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Supply Voltage Range Supply Current SYMBOL VCC ICC CONDITIONS MIN TYP MAX MAX5947A/B/C 9 80 MAX5933A–MAX5933F 33 80 UNITS V VON = 3V, VCC = 80V VCC low-to-high transition 1.4 3.5 MAX5947A/B/C 7.5 8.3 8.8 MAX5933A–MAX5933F 29.5 31 32.5 mA VCC Undervoltage Lockout VLKO VCC Undervoltage Lockout Hysteresis VLKOHYST FB High-Voltage Threshold VFBH FB low-to-high transition 1.280 1.313 1.345 V FB Low-Voltage Threshold VFBL FB high-to-low transition 1.221 1.233 1.245 V FB Hysteresis FB Input Bias Current FB Threshold Line Regulation SENSE Trip Voltage (VCC - VSENSE) V MAX5947A/B/C 0.4 MAX5933A–MAX5933F VFBHYST 80 IINFB VFB = 0V ∆VFB VCC(MIN) ≤ VCC ≤ 80V, ON = 0V, TA = 0°C to +70°C VSENSETRIP V 2 -1 mV +1 µA 0.05 mV/V VFB = 0V, TA = 0°C to +70°C 8 12 17 VFB = 1V, TA = 0°C to +70°C 39 47 55 mV GATE Pullup Current IGATEUP Charge pump on, VGATE = 7V -5 -10 -20 µA GATE Pulldown Current IGATEDN Any fault condition, VGATE = 2V 35 70 100 mA MAX5933A–MAX5933F 10 13.6 18 VCC = 10.8V to 20V, MAX5947A/B/C 4.5 6.2 18.0 VCC = 20V to 80V, MAX5947A/B/C 10 13.2 18 -24 -80 -120 MAX5933A–MAX5933D, MAX5947A/B/C 1.5 3 4.5 MAX5933E/MAX5933F 0.37 0.75 1.12 External N-Channel Gate Drive ∆VGATE VGATE - VCC TIMER Pullup Current ITIMERUP VTIMER = 0V TIMER Pulldown Current ITIMERON VTIMER = 1V V µA µA ON Logic-High Threshold VONH ON low-to-high transition 1.280 1.313 1.345 V ON Logic-Low Threshold VONL ON high-to-low transition 1.221 1.233 1.245 V 2 _______________________________________________________________________________________ Positive High-Voltage, Hot-Swap Controllers (VCC = +24V (MAX5947A/B/C), VCC = +48V (MAX5933A–MAX5933F), GND = 0V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER ON Hysteresis SYMBOL CONDITIONS MIN VONHYST ON Input Bias Current IINON TYP MAX UNITS 80 +1 µA PWRGD Leakage Current IOH VPWRGD = 80V 10 µA PWRGD Leakage Current IOL VPWRGD = 80V 10 µA IO = 2mA 0.4 IO = 4mA 2.5 PWRGD/PWRGD Output Low Voltage SENSE Input Bias Current ISENSE Thermal Shutdown VON = 0V VSENSE = 0V to VCC -1 mV -1 Temperature rising Thermal Shutdown Hysteresis +3 V µA +150 °C 20 °C ON Low-to-GATE Low Propagation Delay tPHLON CGATE = 0, Figures 1, 2 6 µs ON High-to-GATE High Propagation Delay tPLHON CGATE = 0, Figures 1, 2 1.7 µs FB Low-to-PWRGD Low Propagation Delay tPHLFB Figures 1, 3 3.2 µs FB High-to-PWRGD High Propagation Delay tPLHFB Figures 1, 3 1.5 µs (VCC - VSENSE) High-to-GATE Low Propagation Delay tPHLSENSE TA = +25°C, CGATE = 0, Figures 1, 4 0.5 2 µs Note 1: All currents into the device are positive and all currents out of the device are negative. All voltages are referenced to ground, unless otherwise noted. _______________________________________________________________________________________ 3 MAX5933A–MAX5933F/MAX5947A/B/C ELECTRICAL CHARACTERISTICS (continued) MAX5933A–MAX5933F/MAX5947A/B/C Positive High-Voltage, Hot-Swap Controllers Test Circuit and Timing Diagrams ON VCC 24V FB SENSE 1.313V 1.233V FB MAX5933_ MAX5947_ tPLHFB tPHLFB V+ = 5V PWRGD PWRGD GATE 5kΩ 1V 1V 10nF GND TIMER Figure 3. FB to PWRGD Timing Figure 1. Test Circuit 1.313V 1.233V VCC - SENSE ON tPLHON 47mV tPHLON tPHLSENSE GATE GATE 5V Figure 2. ON to GATE Timing 4 1V VCC Figure 4. SENSE to GATE Timing _______________________________________________________________________________________ Positive High-Voltage, Hot-Swap Controllers 1.245 2.0 TA = +85°C ICC (mA) TA = +25°C 1.5 1.2 0.9 2.5 FB LOW-VOLTAGE THRESHOLD (V) 2.1 1.250 MAX5933 toc02 2.4 VCC = 48V (MAX5933_/MAX5947_) 1.5 1.0 TA = -40°C 0.6 VCC = 24V (MAX5947_) 0.5 0.3 1.235 1.230 1.225 1.220 1.215 1.210 1.205 0 0 40 48 56 64 72 1.200 -40 80 -15 10 35 85 60 -40 10 35 60 TEMPERATURE (°C) TEMPERATURE (°C) FB HIGH-VOLTAGE THRESHOLD vs. TEMPERATURE FB HYSTERESIS vs. TEMPERATURE IGATE PULLUP CURRENT vs. TEMPERATURE 0.11 1.330 1.325 0.10 FB HYSTERESIS (V) 1.320 1.315 1.310 1.305 1.300 -5 -6 IGATE PULLUP CURRENT (µA) MAX5933 toc04 1.335 0.09 0.08 0.07 0.06 1.295 1.290 0.05 0.04 1.280 -15 10 35 60 -15 10 35 85 60 -10 -11 -15 60 85 12 11 10 9 8 VCC = 10.8V (MAX5947_) MAX5933 toc08 13 35 16 14 GATE DRIVE (VGATE - VCC) (V) VCC = 48V (MAX5933_/MAX5947_) 10 TEMPERATURE (°C) MAX5947_ GATE DRIVE vs. VCC MAX5933 toc07 15 GATE DRIVE (VGATE - VCC) (V) -9 -40 GATE DRIVE vs. TEMPERATURE 7 -8 TEMPERATURE (°C) TEMPERATURE (°C) 14 -7 -13 -40 85 85 -12 1.285 -40 -15 VCC (V) MAX5933 toc05 33 FB HIGH-VOLTAGE THRESHOLD (V) 1.240 MAX5933 toc06 ICC (mA) 3.0 MAX5933 toc01 2.7 1.8 FB LOW-VOLTAGE THRESHOLD vs. TEMPERATURE ICC vs. TEMPERATURE MAX5933 toc03 ICC vs. VCC 12 10 8 6 4 2 6 5 -40 -15 10 35 TEMPERATURE (°C) 60 85 0 0 10 20 30 40 50 60 70 80 VCC (V) _______________________________________________________________________________________ 5 MAX5933A–MAX5933F/MAX5947A/B/C Typical Operating Characteristics (VCC = +48V, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VCC = +48V, TA = +25°C, unless otherwise noted.) -75 -80 -85 -75 -76 TA = 0°C -77 TA = -40°C -75 -76 -15 10 35 -79 30 40 50 60 70 VCC (V) ON HIGH-VOLTAGE THRESHOLD vs. TEMPERATURE ON LOW-VOLTAGE THRESHOLD vs. TEMPERATURE 1.303 1.293 1.283 1.255 1.245 1.235 1.225 -15 10 35 85 60 TEMPERATURE (°C) -15 10 35 -15 35 60 8 6 TA = -40°C 2 50 MAX5933 toc16 MAX5933 toc15 10 TA = +25°C 10 TEMPERATURE (°C) SENSE REGULATION VOLTAGE (mV) PWRGD VOUT LOW (V) 12 TA = +85°C -40 SENSE REGULATION VOLTAGE vs. VFB 14 4 45 40 35 30 25 20 15 10 5 0 0 10 30 50 ILOAD (mA) 70 70 80 0.077 85 60 PWRGD VOUT LOW vs. ILOAD 16 60 0.079 TEMPERATURE (°C) 18 50 0.073 -40 20 40 0.075 1.215 1.205 -40 30 0.081 ON HYSTERESIS (V) 1.313 20 0.083 MAX5933 toc13 ON LOW-VOLTAGE THRESHOLD (V) 1.323 10 ON HYSTERESIS vs. TEMPERATURE 1.265 MAX5933 toc12 1.333 0 80 VCC (V) TEMPERATURE (°C) 1.343 TA = -40°C -78 85 60 TA = 0°C -77 -79 -40 TA = +85°C TA = +25°C -78 -90 6 -74 MAX5933 toc11 TA = +85°C TA = +25°C MAX5933 toc14 -70 -74 -73 TIMER PULLUP CURRENT (µA) TIMER PULLUP CURRENT (µA) -65 MAX5933 toc10 -73 MAX5933 toc09 -60 TIMER PULLUP CURRENT (µA) MAX5947_ TIMER PULLUP CURRENT vs. VCC MAX5933_ TIMER PULLUP CURRENT vs. VCC TIMER PULLUP CURRENT vs. TEMPERATURE ON HIGH-VOLTAGE THRESHOLD (V) MAX5933A–MAX5933F/MAX5947A/B/C Positive High-Voltage, Hot-Swap Controllers 90 0 0.2 0.4 0.6 0.8 VFB (V) _______________________________________________________________________________________ 1.0 85 Positive High-Voltage, Hot-Swap Controllers PIN NAME FUNCTION 1 ON ON/OFF Control Input. ON is used to implement the undervoltage lockout threshold and resets the part after a fault condition for the latched-off version (MAX5933A/MAX5933C/MAX5947A, see the Detailed Description section). 2 FB Power-Good Comparator Input. Connect a resistive divider from output to FB to GND to monitor the output voltage (see the Power-Good Detection section). FB is also used as a feedback for the current-limit foldback function. 3 PWRGD/ PWRGD Open-Drain Power-Good Output. PWRGD is high (PWRGD is low) when VFB is higher than VFBH. PWRGD is low (PWRGD is high) when VFB is lower than VFBL. 4 GND Ground 5 TIMER Timing Input. Connect a capacitor from TIMER to GND to program the maximum time the part is allowed to remain in current limit (see the TIMER section). 6 GATE Gate-Drive Output. The high-side gate drive for the external N-channel MOSFET (see the GATE Voltage section). 7 SENSE Current-Sense Input. Connect a sense resistor from VCC to SENSE and the drain of the external n-channel MOSFET. 8 VCC Power-Supply Input. Bypass VCC to GND with a 0.1µF capacitor. Input voltage range is from +9V to +80V for the MAX5947A/B/C. Input voltage range is from +33V to +80V for the MAX5933A–MAX5933F. _______________________________________________________________________________________ 7 MAX5933A–MAX5933F/MAX5947A/B/C Pin Description Positive High-Voltage, Hot-Swap Controllers MAX5933A–MAX5933F/MAX5947A/B/C Functional Diagram FB VCC SENSE MAX5933_ MAX5947_ VP GEN CHARGE PUMP AND GATE DRIVER REF GEN 0.5V PWRGD (PWRGD) OPEN DRAIN GATE 12mV TO 47mV 1.233V ON VCC UNDERVOLTAGE LOCKOUT VUVLO LOGIC VP 0.5V 80µA 1.233V TIMER 3µA *0.75µA ( ) FOR THE MAX5933C/D/F AND THE MAX5947A/C. *FOR THE MAX5933E/MAX5933F. 8 GND _______________________________________________________________________________________ Positive High-Voltage, Hot-Swap Controllers The MAX5933_ and MAX5947_ monitor the input voltage, the output voltage, the output current, and the die temperature. These devices feature power-good outputs (PWRGD/PWRGD) to indicate the status of the output voltage by monitoring the voltage at FB (see the PowerGood Detection section). The MAX5933_ and MAX5947_ are fully integrated hotswap controllers for positive supply rails. The devices allow for the safe insertion and removal of circuit cards into live backplanes without causing glitches on the backplane power-supply rail. During startup, the MAX5933_ and MAX5947_ act as current regulators using an external sense resistor and a MOSFET to limit the amount of current drawn by the load. The MAX5933_ operate from a +33V to +80V supply voltage range and have a default undervoltage lockout (UVLO) set to +31V. The MAX5947_ operate from a +9V to +80V supply voltage range and have a default UVLO set to +8.3V. The UVLO threshold is adjustable using a resistive divider connected from VCC to ON to GND (see Figure 5). RSENSE 0.025Ω VIN 24V As shown in Figure 5, a sense resistor is connected between V CC and SENSE to regulate the voltage across the sense resistor (VIN - VSENSE) to 47mV when the voltage at FB ≥ 0.5V. The current-limit threshold (VSENSETRIP) decreases linearly from 47mV to 12mV as FB decreases from 0.5V to 0V. An undervoltage fault is detected when ON goes below the threshold (VONL = 1.233V) and the voltage at GATE goes low as a result to turn off the MOSFET. ON must pass the V ONH = 1.313V threshold to turn on the MOSFET again. Q1 IRF530 CL R1 49.9kΩ 1% R5 10Ω 5% 0.1µF 8 VCC 1 7 SENSE R6 1kΩ 5% TIMER R7 24kΩ 5% C1 10nF GATE 2 R4 3.57kΩ 1% MAX5933A 5 R3 59kΩ 1% 6 FB ON R2 3.4kΩ 1% C2 0.68µF D1 CMPZ5248B PWRGD 3 PWRGD GND 4 GND Figure 5. Application Circuit _______________________________________________________________________________________ 9 MAX5933A–MAX5933F/MAX5947A/B/C Detailed Description MAX5933A–MAX5933F/MAX5947A/B/C Positive High-Voltage, Hot-Swap Controllers Applications Information Hot-Circuit Insertion When circuit boards are inserted into a live backplane, the supply bypass capacitors on the boards draw high peak currents from the backplane power bus as they charge up. The transient currents can permanently damage the connector pins and glitch the system supply, causing other boards in the system to reset. Power-Up Sequence The power supply on a board is controlled by placing an external n-channel MOSFET (Q1) in the power path (Figure 5). Resistor RSENSE provides current detection and capacitor C1 provides control of the GATE slew rate. Resistor R6 provides current control-loop compensation, while R5 prevents high-frequency oscillations in Q1. Resistors R1 and R2 provide undervoltage sensing. After the power pins first make contact, transistor Q1 is turned off. When the voltage at ON exceeds the turn-on threshold voltage, the voltage on V CC exceeds the undervoltage lockout threshold, and when the voltage on TIMER is less than 1.233V, transistor Q1 turns on (Figure 6). The voltage at GATE rises with a slope equal to 10µA/C1 and the supply inrush current is set at: IINRUSH = CL x 10µA/C1 When the voltage across the current-sense resistor RSENSE reaches VSENSETRIP, the inrush current is limited by the internal current-limit circuitry that adjusts the voltage on GATE to maintain a constant voltage across the sense resistor. Once the voltage at the output has reached its final value, as sensed by resistors R3 and R4, PWRGD goes high or PWRGD goes low. POWER-UP WAVEFORMS Short-Circuit Protection The MAX5933_/MAX5947_ feature a programmable foldback current limit with an electronic circuit breaker that protects against short circuits or excessive supply currents. The current limit is set by placing a sense resistor between VCC (pin 8) and SENSE (pin 7). To prevent excessive power dissipation in the pass transistor and to prevent voltage spikes on the input supply during short-circuit conditions at the output, the current folds back as a function of the output voltage that is sensed at FB (Figure 7). When the voltage at FB is 0V, the current-limit circuit drives GATE to force a constant 12mV drop across the sense resistor. As the output voltage at FB increases, the voltage across the sense resistor increases until FB reaches 0.5V. At this point, the voltage across the sense resistor is held constant at 47mV. The maximum current limit is calculated as: ILIMIT = 47mV / RSENSE For a 0.025Ω sense resistor, the current limit is set at 1.88A and folds back to 480mA when the output is shorted to ground. The MAX5933_/MAX5947_ also feature a variable overcurrent response time. The time required to regulate Q1’s drain current depends on: 1) Q1’s input capacitance 2) GATE capacitor C1 and compensation resistor R6 3) The internal delay from SENSE to GATE Figure 8 shows the delay from a voltage step at SENSE until GATE voltage starts falling, as a function of overdrive. VCC - VSENSE GATE 50V/div 47mV ISENSE 2A/div OUTPUT 50V/div 12mV PWRGD 50V/div 0V 0.5V VFB 20ms/div Figure 6. Power-Up Waveforms 10 Figure 7. Current-Limit Sense Voltage vs. Feedback Voltage ______________________________________________________________________________________ Positive High-Voltage, Hot-Swap Controllers SHORT-CIRCUIT WAVEFORMS OUTPUT 50V/div PROPAGATION DELAY (µs) 12 10 ISENSE 1A/div 8 GATE 50V/div 6 4 TIMER 1V/div 2 0 0 100 200 300 10ms/div VCC - VSENSE (mV) Figure 8. Response Time to Overcurrent Figure 9. Short-Circuit Waveforms TIMER TIMER provides a method for programming the maximum time the device is allowed to operate in current limit. When the current-limit circuitry is not active, TIMER is pulled to GND by a 3µA current source. After the current-limit circuit becomes active, an 80µA pullup current source is connected to TIMER, and the voltage rises with a slope equal to 77µA/CTIMER, as long as the current-limit circuit remains active. Once the desired maximum current-limit time is chosen, the capacitor value is: C(nF) = 65 x t(ms) or TLIMIT = (CTIMER/80µA) x 1.233V When the current-limit circuit turns off, TIMER is discharged to GND by the 3µA current source. Whenever TIMER reaches 1.233V, the internal fault latch is set. GATE is immediately pulled to GND and TIMER is pulled back to GND by the 3µA current source. When TIMER falls below 0.5V, ON is pulsed low to reset the internal fault latch. The waveform in Figure 9 shows how the output latches off following a short circuit. The drop across the sense resistor is held at 12mV as the timer ramps up. Since the output did not rise, FB remains below 0.5V and the circuit latches off. For Figure 9, CT = 100nF. Undervoltage and Overvoltage Detection ON can be used to detect an undervoltage condition at the power-supply input. ON is internally connected to an analog comparator with 80mV of hysteresis. If ON falls below its threshold voltage (1.233V), GATE is pulled low and is held low until ON is high again. Figure 10 shows an overvoltage detection circuit. When the input voltage exceeds the Zener diode’s breakdown voltage, D1 turns on and starts to pull TIMER high. After TIMER is pulled higher than 1.233V, the fault latch is set and GATE is pulled to GND immediately, turning off transistor Q1 (see Figure 11). Operation is restored either by interrupting power or by pulsing ON low. Power-Good Detection The MAX5933_/MAX5947_ include a comparator for monitoring the output voltage. The noninverting input (FB) is compared against an internal 1.233V precision reference and exhibits 80mV hysteresis. The comparator’s output (PWRGD) is open drain and capable of operating from a pullup as high as 80V. The PWRGD is similar to PWRGD with an opposite polarity (active low) output. The PWRGD (PWRGD) can be used to directly enable/disable a power module with an active-high enable input. Figure 12 shows how to use PWRGD to control an active-low enable-input power module. Signal inversion is accomplished by transistor Q2 and R7. Supply Transient Protection The MAX5933_/MAX5947_ are 100% tested and guaranteed to be safe from damage with supply voltages up to 80V. However, spikes above 85V may damage the device. During a short-circuit condition, the large change in currents flowing through the power-supply traces can cause inductive voltage spikes which could exceed 85V. To minimize the spikes, the power-trace parasitic inductance should be minimized by using wider traces or heavier trace plating and a 0.1µF bypass capacitor placed between VCC and GND. A transient voltage suppressor (TVS) at the input can also prevent damage from voltage surges. ______________________________________________________________________________________ 11 MAX5933A–MAX5933F/MAX5947A/B/C RESPONSE TIME TO OVERCURRENT 14 MAX5933A–MAX5933F/MAX5947A/B/C Positive High-Voltage, Hot-Swap Controllers RSENSE 0.025Ω Q1 IRF530 VIN CL SHORT PIN R1 49.9kΩ 1% D1 30V 1N5256B D2 CMPZ5248B R5 10Ω 5% R6 1kΩ 5% 0.1µF 8 VCC 1 7 SENSE C1 10nF GATE 2 R4 3.57kΩ 1% MAX5933B MAX5947B R2 3.4kΩ 1% 5 TIMER C2 0.68µF R7 24kΩ 5% 6 FB ON R3 59kΩ 1% PWRGD 3 PWRGD GND 4 GND Figure 10. Overvoltage Detection GATE Voltage OVERVOLTAGE WAVEFORMS IN 50V/div ISENSE 5A/div GATE 50V/div TIMER 10V/div OUTPUT 50V/div 10µs/div Figure 11. Overvoltage Waveforms 12 A curve of Gate Drive vs. VCC is shown in Figure 13. GATE is clamped to a maximum voltage of 18V above the input voltage. At a minimum input-supply voltage of 33V, the minimum gate drive voltage is 10V. When the input supply voltage is higher than 20V, the gate-drive voltage is at least 10V and a standard n-channel MOSFET can be used. Using the MAX5947 in applications over a 9V to 20V range, a logic-level N-FET must be used with a proper protection Zener diode between its gate and source (see D1 in Figure 5). Thermal Shutdown If the MAX5933_/MAX5947_ die temperature reaches +150°C, an overtemperature fault is generated. As a result, GATE goes low and turns the external MOSFET off. The MAX5933_/MAX5947_ die temperature must cool down below +130°C before the overtemperature fault condition is removed. ______________________________________________________________________________________ Positive High-Voltage, Hot-Swap Controllers Q1 IRF530 VIN SHORT PIN R1 294kΩ 1% 0.1µF 8 7 SENSE VCC 1 D1 CMPZ5248B R5 10Ω 5% R6 1kΩ 5% C1 10nF GATE 5 TIMER VIN+ VOUT+ VOUT ON/OFF VIN- VOUT- R4 4.22kΩ 1% PWRGD C2 0.68µF CL 220µF 2 MAX5933A R2 10.2kΩ 1% R7 47kΩ 5% 6 FB ON R3 143kΩ 1% 3 GND 4 GND Figure 12. Active-Low Enable Module Layout Considerations GATE DRIVE vs. VCC 16 GATE DRIVE (VGATE - VCC) (V) 14 12 10 8 6 4 2 0 0 20 40 VCC (V) 60 80 To achieve accurate current sensing, a Kelvin connection is recommended. The minimum trace width for 1oz copper foil is 0.02in per amplifier to ensure the trace stays at a reasonable temperature. However, 0.03in. per amplifier or wider is recommended. Note that 1oz copper exhibits a sheet resistance of approximately 530µΩ/square. Small resistances add up quickly in high-current applications. To improve noise immunity, connect the resistor-divider to ON close to the device, and keep traces to V CC and GND short. A 0.1µF capacitor from ON to GND also helps reject induced noise. Figure 14 shows a layout that addresses these issues. It is recommended that 2oz copper is used, particularly as the external MOSFET must be thermally coupled to the MAX5933_/MAX5947_ to ensure proper thermal-shutdown operation. Figure 13. Gate Drive vs. Supply Voltage ______________________________________________________________________________________ 13 MAX5933A–MAX5933F/MAX5947A/B/C RSENSE 0.01Ω MAX5933A–MAX5933F/MAX5947A/B/C Positive High-Voltage, Hot-Swap Controllers Chip Information TRANSISTOR COUNT: 1573 PROCESS: BiCMOS Pin Configuration MAX5933_ MAX5947_ TOP VIEW IRF530 ON 1 FB 2 PWRGD (PWRGD) 3 MAX5933_ MAX5947_ GND 4 8 VCC 7 SENSE 6 GATE 5 TIMER SO ( ) ONLY FOR THE MAX5933C/D/F/MAX5947A/MAX5947C. Figure 14. Recommended Layout for R1, R2, and RSENSE Typical Application Circuit RSENSE 0.01Ω Q1 IRF530 VIN CL *SMBJ51A R1 49.9kΩ 1% R5 10Ω 5% 0.1µF 8 VCC 1 7 SENSE R6 1kΩ 5% TIMER R7 24kΩ 5% C1 10nF GATE 2 R4 3.57kΩ 1% MAX5933A 5 R3 59kΩ 1% 6 FB ON R2 3.4kΩ 1% C2 0.68µF D1 CMPZ5248B PWRGD 3 GND 4 GND *DIODES, INC. 14 ______________________________________________________________________________________ PWRGD Positive High-Voltage, Hot-Swap Controllers N E H INCHES MILLIMETERS MAX MIN 0.069 0.053 0.010 0.004 0.014 0.019 0.007 0.010 0.050 BSC 0.150 0.157 0.228 0.244 0.016 0.050 MAX MIN 1.35 1.75 0.10 0.25 0.35 0.49 0.19 0.25 1.27 BSC 3.80 4.00 5.80 6.20 0.40 SOICN .EPS DIM A A1 B C e E H L 1.27 VARIATIONS: 1 INCHES TOP VIEW DIM D D D MIN 0.189 0.337 0.386 MAX 0.197 0.344 0.394 MILLIMETERS MIN 4.80 8.55 9.80 MAX 5.00 8.75 10.00 N MS012 8 AA 14 AB 16 AC D A B e C 0∞-8∞ A1 L FRONT VIEW SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, .150" SOIC APPROVAL DOCUMENT CONTROL NO. 21-0041 REV. B 1 1 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 ____________________ 15 © 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX5933A–MAX5933F/MAX5947A/B/C 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.)