a 48 V Hot Swap Controller ADM1070 FEATURES FUNCTIONAL BLOCK DIAGRAM Allows Safe Board Insertion and Removal from a Live 0V 48 V Backplane Typically Operates from 36 V to 80 V V DD 16k C R V LOAD OUT DROP Tolerates Transients up to 200 V (Limited by External V IN Components) Accurate Programmable Linear Current Limit for In-Rush Control and Short Circuit Protection V V AND CC CC R1 REFERENCE Programmable Timeout in Current Limit V GENERATOR 12V REF Limited Consecutive Retry: Auto-Restart after Current Limit Timeout Shutdown after Seven Consecutive Auto Restarts UV/OV OVER-UNDER Provides Immunity from Step Induced Current Spikes EN VOLTAGE DETECTION V IN CIRCUIT Default Timing Provided with no TIMER Capacitor 45 A Single Pin Undervoltage/Overvoltage Detection 100mV Programmable Operating Voltage Window R2 FAULT TIMER AND Q1 CONTROL Programmable Undervoltage/Overvoltage Time Filter GATE Small 6-Lead SOT-23 Package TIMER OSCILLATOR SENSE R APPLICATIONS SENSE ()* Central Office Switching ADM1070 V EE 48 V Distributed Power Systems 48V Negative Power Supply Control V EE *OPTIONAL TIMER CAPACITOR Hot Board Insertion Electronic Circuit Breaker High Availability Servers Programmable Current Limiting Circuit 48 V Power Supply Modules GENERAL DESCRIPTION The ADM1070 also features single-pin undervoltage and over- The ADM1070 is a negative voltage hot swap controller that voltage detection. The FET is turned off if a nontransient allows a board to be safely inserted and removed from a live voltage less than the undervoltage threshold, typically 36 V, or 48 V backplane. The part achieves this by providing robust greater than the overvoltage threshold, typically 77 V, is detected current limiting, protection against transient and nontransient on the UV/OV Pin. The operating voltage window of the short circuits and overvoltage and undervoltage conditions. The ADM1070 is programmable and is determined by the ratio R1/R2. ADM1070 typically operates from a negative voltage of up to Time filtering on the undervoltage and overvoltage detection 80 V and can tolerate transient voltages of up to 200 V. and current limiting is programmable via the TIMER Pin. An In-rush current is limited to a programmable value by control- external capacitor connected between the TIMER Pin and V EE ling the gate drive of an external N-channel FET. The current determines the undervoltage/overvoltage time filter and the limit can be controlled by the choice of the sense resistor, timeout in current limit. If the pin is tied to V , the time filter EE R . Added control of the in-rush current is provided by an values and the current limit timeout revert to default figures. SENSE on-chip timer that uses pulsewidth modulation to allow the The ADM1070 is fabricated using BiCMOS technology for mini- maximum current to flow for only 3% of the time. An autorestart mal power consumption. The part is available in a small occurs after a current limit timeout. After seven successive 6-Lead SOT-23 package. autorestarts, the fault will be latched and the part goes into shutdown with the result that the external FET is disabled until the power is reset. REV. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. use, nor for any infringements of patents or other rights of third parties that Tel: 781/329-4700 www.analog.com may result from its use. No license is granted by implication or otherwise Fax: 781/326-8703 Analog Devices, Inc., 2002 under any patent or patent rights of Analog Devices.(V = 0 V, V = 48 V, R = 16 k , T = 40 C to +85 C, unless other- DD EE DROP A ADM1070SPECIFICATIONS wise noted.) Parameter Min Typ Max Unit Test Conditions BOARD SUPPLY (not connected directly to device) Maximum Voltage Range 200 48 20 V Limited by Voltage Capability of External Components* Typical Operating Voltage Range 77 48 36 V R = 16 k , R1/R2 = 40* DROP VIN PINSHUNT REGULATOR Operating Supply Voltage Range, V 11.5 12.3 13 V I = 1.5 mA to 4.25 mA SS SS Quiescent Supply Current, I 0.4 0.85 1.3 mA V = 11.5 V SS SS Maximum Shunt Supply Voltage, V 12.5 14 V I = 20 mA SS SS Undervoltage Lockout, V 7 8.5 10.5 V LKO UV/OV PINUNDERVOLTAGE AND OVERVOLTAGE DETECTION Undervoltage Falling Threshold, V 0.81 0.86 0.91 V UVF Undervoltage Rising Threshold, V 0.86 0.91 0.96 V UVR 45 mV Undervoltage Hysteresis, V UVH Overvoltage Falling Threshold, V 1.85 1.93 2.01 V OVF Overvoltage Rising Threshold, V 1.89 1.97 2.05 V OVR 45 mV Overvoltage Hysteresis V OVH Power-On Reset Delay, t 1.10 1.70 2.30 ms TIMER Pin Tied to V POR EE (V < UV/OV < V ) UVR OVF = 470 pF 0.90 1.21 1.51 ms C TIMER (V < UV/OV < V ) UVR OVF Voltage Fault Filter Time (UV/OV Out of Window), t 1.10 1.70 2.30 ms TIMER Pin Tied to V Voltage FLT EE (V < UV/OV < V ) UVR OVF 0.90 1.21 1.51 ms C = 470 pF TIMER < UV/OV < V )* (V UVR OVF Input Current, I 1.0 A VMON GATE PINFET DRIVER Maximum Gate Voltage, V 11 12 13 V I = 1 A GMAX GATE Minimum Gate Voltage, V 050mVI = 1 A GMIN GATE Pull-Up Current, I 20 40 55 AV = 0 V to 9 V, V = 0 GUP GATE SENSE Pull-Down Current, I 10 30 mA V = V GDP GATE SS Hold-off Impedance, R 10 k V < 2 V, V > 11 V GOFF GATE SS 30 k V < 2 V, V > 2 V GATE SS SENSE PINCURRENT SENSE Analog Current Limit Voltage (Rising),V 90 100 110 mV I = 0 A to 15 A LIM GATE Circuit Breaker Limit Voltage (Rising) 75 88 100 mV Circuit Breaker Limit Voltage (Rising) 12 mV (With Respect to V ), V LIM LIMITON Circuit Breaker Limit Voltage (Falling) 60 79 95 mV Circuit Breaker Limit Voltage (Falling) 21 mV (With Respect to V ), V LIM LIMITOFF Fast Current Limit Voltage 107 126 145 mV Fast Current Limit Voltage 26 mV (With Respect to V ) LIM Control Loop Transconductance, 1.5 2.75 4 A/mV I < 30 A, T = 25C GATE A /dV ) (dI GATE SENSE Maximum Current Limit On Time, t 10 14 18 ms TIMER Pin Tied to V LIMITON EE (V < UV/OV < V ) UVR OVF = 470 pF 7.4 9.9 12.4 ms C TIMER (V < UV/OV < V )* UVR OVF Current Limit PWM Off Time 320 450 580 ms TIMER Pin Tied to V EE (V < UV/OV < V )* UVR OVF 240 320 400 ms C = 470 pF TIMER (V < UV/OV < V )* UVR OVF Current Limit PWM Duty Cycle 3 % (Typical Only) Number of Consecutive PWM Retry Cycles 7 (Typical Only) 2 REV. 0