DEMO MANUAL DC1886B LTC4232 and LTC4232-1: 5A Integrated Hot Swap Controller DESCRIPTION Demonstration circuit 1886B features the LTC4232 and The LTC4232 debounce time is 100ms, while the LTC4232-1 the LTC4232-1 5A integrated Hot Swap controllers. The is 16ms. Both are available in a 16-lead 5mm 3mm DFN LTC4232 is ideally suited for demanding power distribution package. The LTC4232 is showcased on demonstration control in 2.9V to 15V applications for hot board inser- circuit 1886B-A. The LTC4232-1 is installed on DC1886B-B. tion protection, high side power switching, and electronic Both demo boards are configured for 12V application. By circuit breaker functions. The LTC4232 provides a rich set changing a few passive components, 2.9V to 15V applica- of features to support Hot Swap applications including: tions can be easily evaluated. 2% accurate undervoltage and overvoltage comparators The LTC4232 has limited output voltage slew rate with a typical value of 300V/s, while the LTC4232-1 does not Thermal protection have a special circuit to limit this parameter. The natural Adjustable inrush current control (maximum) gate voltage slew rate (S ) of the LTC4232-1 N is defined by the internal MOSFET C (reverse transfer RSS Adjustable, 10% accurate current limit with program- capacitance) value and gate driver current capability. It is mable cutout time 48000V/s as a typical value. Foldback current limiting Design files for this circuit board are available at Programmable output voltage ramp rate DEMO MANUAL DC1886B JUMPERS AND LEDS Two demo board jumpers, JP1 and JP2, allow selection When selecting AUTORETRY option for the circuit with a of controller operation: predominantly resistive load, particularly for LTC4232-1, pay special attention to the power MOSFET thermal con- JP1 TIMER DURATION: Set to FIXED 2ms position for dition. The initial low current limit (due to the foldback the internal 2ms timer period (FIXED 2ms not recom- characteristic) can power the load only during a very short mended for LTC4232-1 during auto-retry) or ADJUST- time, and the MOSFET will experience the maximum cur- ABLE determined by TIMER capacitor C1 (12ms for rent limit for almost all of the remaining power up period. LTC4232 and 1.2ms for LTC4232-1). (Default position: This may exceed the MOSFET SOA, if allowed to autoretry. ADJUSTABLE) Four LEDs indicate the state of the hot swap circuit. Red JP2 AUTORETRY: Set to ON for auto-retry or OFF for LEDs, D3 and D5, provide fault status and low output latchoff on overcurrent fault. (Default position: OFF) voltage (it is a NOT power good signal). Two green LEDs, D2 and D4, signal the presence of valid input and output voltages. Figure 1. Proper Measurement Equipment Setup dc1886bfa 2