DEMO MANUAL DC1625A LTC4227-1/LTC4227-2/ LTC4227-3/LTC4227-4 Dual Ideal Diode and Single Hot Swap Controller Description Demonstration circuit 1625A is intended to demonstrate jumpers for enabling the second ideal diode (D2ON SEL) performance of the LTC4227-1/LTC4227-2/LTC4227-3/ and Hot Swap controller (HS ON), two LEDs to indicate LTC4227-4 dual ideal diode and Hot Swap controller. Each power good (PWRGD) and fault (FAULT) conditions, seven rail has an individual ideal diode. Ideal diode outputs are banana jacks for connecting power supplies and load, many connected to the load through a single Hot Swap circuit. turrets and pads for observing circuit signals. Table 1. DC1625A Assembly Options The DC1625 allows verifying the LTC4227 Hot Swap and OVERCURRENT START-UP ideal diode functionality during individual supply ramp-up VERSION PART FAULT DELAY and ramp-down transients, during power supply switch- DC1625A-A LTC4227-1 LATCHOFF 100ms over, steady state, and overcurrent fault conditions. DC1625A-B LTC4227-2 RETRY 100ms Each DC1625A rail circuit is assembled to operate over DC1625A-C LTC4227-3 LATCHOFF 1.6ms the full operating voltage range of the LTC4227: 2.9V to DC1625A-D LTC4227-4 RETRY 1.6ms 18V, with a 7.6A maximum current load. Design files for this circuit board are available at The boards main components include the LTC4227 con- DEMO MANUAL DC1625A FMA UMMAs Yr (T = 25C) A SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Hot Swap Control V Circuit Breaker Trip Sense Voltage 47.5 50 52.5 mV SENSE(CB) + (V - V ) SENSE SENSE V Active Current Limit Sense Voltage 60 65 70 mV SENSE(ACL) + (V - V ) SENSE SENSE V External N-Channel Gate Drive (V - V ) IN < 7V, I = 0, 1A 4.8 7 14 V HGATE HGATE OUT IN = 7V to 18V, I = 0, 1A 10 12 14 V I External N-Channel Gate Pull-Up Current Gate Drive On, HGATE = 0V 7 10 13 A GATE(UP) I External N-Channel Gate Pull-Down Current Gate Drive Off, OUT = 12V, HGATE = OUT + 5V 150 300 500 A HGATE(DN) I External N-Channel Gate Fast Pull-Down Fast Turn-Off, OUT = 12V, HGATE = OUT + 5V 100 200 300 mA HGATE(FPD) Current Input/Output Pin + + + V SENSE Undervoltage Lockout SENSE Rising 1.75 1.9 2.05 V SENSE (UVL) V ON Pin Threshold Voltage ON Rising 1.21 1.235 1.26 V ON(TH) V ON Pin Fault Reset Threshold Voltage ON Falling 0.55 0.6 0.65 V ON(RESET) V D2ON Pin Threshold Voltage D2ON Rising 1.21 1.235 1.26 V D2ON(TH) V TMR Pin Threshold Voltage TMR Rising 1.198 1.235 1.272 V TMR(TH) TMR Falling 0.15 0.2 0.25 V I TMR Pull-Up Current TMR = 1V, In Fault Mode 75 100 125 A TMR(UP) I TMR Pull-Down Current TMR = 2V, No Faults 1.4 2 2.6 A TMR(DN) I TMR Current Ratio I / I 1.4 2 2.7 % TMR(RATIO) TMR(DN) TMR(UP) Ao ting p The LTC4227 is intended to build a combination of two The Hot Swap fast acting current limit and internal timed diode-OR circuits (for two rails) and a common single circuit breaker protect circuit components when a short- Hot Swap path for inrush current limiting and overcurrent circuit fault occurs. protection. The Hot Swap function on the LTC4227 controller has The LTC4227 regulates the forward voltage drop across independent on/off control. the MOSFETs to ensure smooth current transfer from one Each ideal diode MOSFET is activated from individual supply to other without oscillation. A fast turn-on reduces charge pump sources and the second ideal diode path the load voltage droop during supply switchover. If the has additional on/off control. input supply fails or is shorted, a fast turn-off minimizes The LTC4227-1 and LTC4227-3 feature a latchoff circuit reverse current transients. breaker, while the LTC4227-2 and the LTC4227-4 provide automatic retry after a fault. dc1625afa 2 rinciples per nce or per