DC1052A-A Analog Devices

DEMO MANUAL DC1052A LTC4218 Hot Swap Controller Description Demonstration circuit DC1052A includes two separate voltage, and it may be converted into a voltage signal with circuits for performance evaluation of the LTC 4218 Hot an appropriate resistor. Swap controller. The standard version of the control- The current limit may be reduced by placing an external ler (LTC4218) is intended to operate with 2.9V to 26.5V resistor between GND and the ISET pin. rails, while the LTC4218-12 has internal adjustment for The LTC4218 protects the load from overvoltage and 12V applications. undervoltage conditions. One circuit of DC1052A located on the upper board area The DC1052A schematic allows the LTC4218 to operate in is assembled with the LTC4218 configured for operation turn-on and turn-off modes as well as in the steady-state with a 24V rail. The circuit on the lower board area includes mode with different loads, and in the fault state. the LTC4218-12. Circuit breaker thresholds in both cases are adjusted to 7.5A. Design files for this circuit board are available at DEMO MANUAL DC1052A o p The LTC4218 is suited for low voltage power control in Adjustable inrush current control applications for hot board insertion or removal with elec- Load current monitoring tronic circuit breaker function, foldback current limit and Adjustable current limit timer before power is turned load current monitoring. The LTC4218 has a rich set of off features to support Hot Swap applications, including: Power good and fault signaling 2% accurate undervoltage and overvoltage protection Adjustable 5% accurate current limit Quick s p D Demonstration circuit 1052A is easy to set up to evaluate For the 12V circuit: the performance of the LTC4218 and LTC4218-12. Refer 6. Place jumpers in the following positions: to Figure 1 for the proper measurement equipment setup JP3 FAULT Signal and follow the procedure below. JP4 AUX UV ON For the 24V circuit: 7. With power off, connect the 12V power supply terminals 1. Place jumpers in the following positions: to the 12V (E9) and GND (E12) turrets. IN JP1 FAULT Signal 8. Turn on the 12V supply and verify the output voltage JP2 AUX UV ON at the V (E10) and GND (E11) turrets. Green LEDs OUT 2. With power off, connect the 24V power supply terminals 12V (D9) and V (D11) should light up. IN OUT to the 24V (E1) and GND (E4) turrets. IN 9. Check the current limit by providing an electronic or 3. Turn on the 24V supply and verify the output voltage resistive load. It should be in the range of 7.05A to between the V (E2) and GND (E3) turrets. Green 7.95A. During this measurement verify the current OUT LEDs 24VIN (D2) and V (D4) should light up. monitor performance. The monitor signal related to OUT the current limit level should be 2.0V 0.17V. The 4. Check the current limit by providing an electronic or monitor signal has a 3.75A/V scale. resistive load. It should be in the range of 7.05A to 7.95A. During this measurement, verify the current 10. Check the output voltage slew rate with an oscilloscope monitor performance. The monitor signal related to without a load connected. It should be in the range of the current limit level should be 2.0V 0.17V. The 1680V/s to 2300V/s. monitor signal has a 3.75A/V scale. 11. Use an 1800F capacitive load to confirm that during 5. Use an oscilloscope to check the output voltage slew power-up the timer period expires and a current limit rate without a load connected. It should be in the range fault is indicated by the FAULT red LED (D12) accom- of 1680V/s to 2300V/s. Use an 1800F capacitive load panied by the PG red LED (D13) to indicate that the to confirm that during power-up, the timer period output voltage is lower than the power good level. expires and a current limit fault is indicated by the FAULT red LED (D5). The PG red LED (D6) indicates that the output voltage is lower than the power good level. dc1052af 2 ure roce tart rinciples perating