DEMO MANUAL DC1505A LTC4360 Overvoltage Protection Controller DESCRIPTION Demonstration circuit DC1505A features the LTC®4360 an overvoltage protection controller that safeguards 2.5V to 5.5V systems from input supply overvoltage. The LTC4360 is designed for portable devices with multiple power supply options including wall adapters, car battery adapters and USB ports. provides power good monitoring for VIN. The LTC4360-1 features a soft shutdown controlled by the ON pin. The LTC4360-2 has a GATEP pin that drives an optional external P-channel MOSFET for negative voltage protection. Following an overvoltage condition, the LTC4360 automatically restarts with a start-up delay. The LTC4360 controls an external N-channel MOSFET in series with the input power supply. During overvoltage transients, the LTC4360 turns off the MOSFET within 1µs, isolating downstream components from the input supply. Inductive cable transients are absorbed by the MOSFET and load capacitance. In most applications, the LTC4360 provides protection from transients up to 80V without requiring transient voltage suppressors or other external components. DC1505A demonstrates three protection schemes selected with a jumper: (A) overvoltage protection, (B) overvoltage and negative voltage protection, and (C) overvoltage, negative voltage, and reverse current protection. Each option has an output LED and can be applied to a USB protected output. Protection (A) features the LTC4360-1 with ON control. Protection (B) and (C) feature the LTC4360-2 and a P-channel MOSFET driven by GATEP. The LTC4360 has a delayed start-up and adjustable dV/dt ramp-up for inrush current limiting. A PWRGD pin Design files for this circuit board are available at http://www.linear.com/demo L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. 1505a FO1 Figure 1. Demonstration Circuit 1505A dc1505af 1 DEMO MANUAL DC1505A PERFORMANCE SUMMARY Table 1. Typical DC1505A Performance Summary (TA = 25°C) PARAMETER CONDITION VALUE Input Voltage Protection (A) OV Protection (B) OV/NV Protection (C) OV/NV/RC 0V to 30V –30V to 30V –30V to 30V Output Voltage Input Range for Gate Turn-On 2.1V to 5.8V Device Used and Difference Protection (A) OV Protection (B) OV/NV Protection (C) OV/NV/RC LTC4360-1, ON Control LTC4360-2, GATEP LTC4360-2, GATEP QUICK START PROCEDURE Demonstration circuit description 1505A is easy to set up to evaluate the performance of the LTC4360. Refer to Figure 2 and Figure 3 for proper measurement equipment setup and follow the procedure below. c.For overvoltage, negative voltage, and reverse current protection select (C) OV/NV/RC, connect to OUT(C). Figure 2c. 1. Connect a power supply across VIN and GND. 4. For USB protection, connect a USB cable from J2 to the USB device (Figure 3). Select the protection type at JP1 and match JP3 to JP1. Connect a second USB cable from a computer to J1. 2. Select protection type at JP1 and connect a voltmeter across the corresponding output and GND: a.For overvoltage protection select (A) OV and connect to OUT(A). Figure 2a. 3. Select ENABLE at JP2 for protection (A) to enable. b.For overvoltage and negative voltage protection select (B) OV/NV and connect to OUT(B). Figure 2b. dc1505af 2 DEMO MANUAL DC1505A QUICK START PROCEDURE SELECT PROTECTION (A) OVERVOLTAGE PROTECTED OUT PWRGD + – V VIN SELECT ENABLE 1505a FO2a Figure 2a. DC1505A Protection (A) Setup for Overvoltage dc1505af 3 DEMO MANUAL DC1505A QUICK START PROCEDURE SELECT PROTECTION (B) + – VIN OVERVOLTAGE, NEGATIVE VOLTAGE PROTECTED OUT PWRGD V 1505a FO2b Figure 2b. DC1505A Protection (B) Setup for Overvoltage, and Negative Voltage SELECT PROTECTION (C) + – VIN OVERVOLTAGE, NEGATIVE VOLTAGE, REVERSE CURRENT PROTECTED OUT PWRGD V 1505a FO2c Figure 2c. DC1505A Protection (C) Setup for Overvoltage, Negative Voltage, and Reverse Current 4 dc1505af DEMO MANUAL DC1505A QUICK START PROCEDURE HOT PLUG USB CABLE USB CABLE PC USB DEVICE SELECT PROTECTION SELECT USB PROTECTION (JP3 MUST MATCH JP1) PROTECTION (A) SELECT ENABLE 1505a FO3 Figure 3. DC1505A USB Protection Setup dc1505af 5 DEMO MANUAL DC1505A QUICK START PROCEDURE OPERATION The DC1505A is used to evaluate the LTC4360 in three protection configurations selected at JP1. The device in need of protection is connected to one of the three OUT test points or to the USB output connector J2. An input supply is connected at VIN or a USB source is connected at J1. ON Control protect the output against an inadvertent negative voltage connection at the input. The amber VIN LED indicates if the input supply is on while a green OUT(B) LED indicates the gate is on and the input is passed over to the output. A red –VIN LED indicates if a negative input voltage is present. Protection (C) OV/NV/RC The first selection at JP1 is protection (A) OV which protects against overvoltage. The LTC4360 turns on a single N-channel MOSFET when the input voltage is below the overvoltage threshold. An amber input LED indicates if the input supply is on while a green OUT(A) LED indicates the gate is on and the input is passed over to the output. The third selection at JP1 is protection (C) OV/OC/NV/RC which protects against overvoltage, overcurrent, negative voltage and reverse current. The LTC4360 turns on back-to-back N-channel MOSFETs when the input voltage is below the overvoltage threshold. The back-to-back N-channel MOSFETs blocks reverse current feeding in to the input. A P-channel MOSFET is driven by the GATEP pin of the LTC4360-2 to protect the output against an inadvertent negative voltage connection at the input. The amber VIN LED indicates if the input supply is on while a green OUT(C) LED indicates the gate is on and the input is passed over to the output. The red –VIN LED indicates if a negative input voltage is present. Protection (B) OV/NV USB Protection The second selection at JP1 is protection (B) OV/NV which protects against overvoltage and negative voltage. The LTC4360 turns on an N-channel MOSFET when the input voltage is below the overvoltage threshold. A P-channel MOSFET is driven by the GATEP pin of the LTC4360-2 to DC1505A also provides connection for USB protection. First connect a USB device with a USB cable at J2. Select the protection type at JP1 and match this with JP3. Select ENABLE at JP2. The USB source can then be connected at J1. The ON pin for protection (A) with the LTC4360-1 is controlled at JP2. Select ENABLE to enable the selected protection, or DISABLE to enter a low current sleep mode. Protection (A) OV dc1505af 6 Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. A B C D GND D+ D- VCC GND D+ D- VCC 5 4 4 5 3 GND GND GATE GND PWRGD OUT GND PWRGD OUT REV ECO 2 DILIAN R. APPROVED DATE 1 www.linear.com 1 TECHNOLOGY DESCRIPTION REVISION HISTORY APPROVALS 2 GND GND GATEP IN GND OUT PWRGD GND GATE GND GATEP IN ON IN GATE 3 A B C D DEMO MANUAL DC1505A SCHEMATIC DIAGRAM dc1505af 7 DEMO MANUAL DC1505A DEMONSTRATION BOARD IMPORTANT NOTICE Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions: This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations. If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE. 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