DEMO MANUAL DC1840A DC1682A and DC1680A LTC4270/LTC4271 12-Port PSE with Digital Isolation Description Demonstration kit DC1840A is a 12-port Type 2 power sourcing equipment (PSE) composed of a DC1682A daughter card and DC1680A mother board. The kit is used for evaluation of the LTC4270B and LTC4271 PSE chipset. Up to 12 powered devices (PDs) can be connected and powered from this system using a single power supply. A DC590 is connected to the DC1680A for I2C interfacing with QuikEval™.
DEMO MANUAL DC1840A Quick Start Procedure Demonstration kit DC1840A includes the DC1682A daughter card and DC1680A mother board. The kit is set up for evaluating the LTC4270/LTC4271. Follow the procedure below and refer to Figures 1 through 4 for proper equipment setup. 1. On the DC1682A set AUTO jumper JP1 to HI (Figure 1) to enable AUTO pin mode. 2. On the DC1682A set MID jumper JP2 to LO (Figure 1) to disable midspan mode. 3.
DEMO MANUAL DC1840A quick start procedure Figure 3. DC1680A Basic Setup Figure 4.
DEMO MANUAL DC1840A Demonstration Circuit 1682A Operation 12-Port PSE Daughter Card with Digital Isolation Demonstration circuit 1682A (Figure 5) features the LTC4270/LTC4271 chipset on a compact daughter card with digital isolation. The LTC4270/LTC4271 chipset is a 12-port power sourcing equipment (PSE) controller designed for use in IEEE 802.3at Type 1 and Type 2 (high power) compliant Power over Ethernet (PoE) systems.
DEMO MANUAL DC1840A Demonstration Circuit 1682A Operation Board Layout Isolation and Power Supplies Proper board layout is crucial for proper LTC4270/LTC4271 chipset operation, robustness, and accuracy. When laying out, pay attention to parts placement, Kelvin sensing, power paths, and copper fill. It is imperative to follow the LTC4270/LTC4271 Layout Guide document when laying out the board.
DEMO MANUAL DC1840A Demonstration Circuit 1682A Operation I2C Communication and Addressing The LTC4271 internal registers are accessed via I2C to read and/or write configuration, status, and interrupt registers. The I2C lines SDAOUT, SDAIN and SCL connect to the 34-pin connector (Figure 7). Subsequently, the I2C bus is accessed on the DC1680A. The LTC4270/LTC4271 chipset has an address of (A610A3A2A1A0b), where A6, A3, A2, A1, and A0 are the logic state of the AD6, AD3, AD2, AD1, and AD0 pins respectively.
DEMO MANUAL DC1840A Demonstration Circuit 1682A Operation AUTO and MID Jumpers S1B Diodes Port Protection The AUTO and MID pins of the LTC4271 are set by jumpers JP1 and JP2 respectively on the DC1682A (Figure 10). Setting JP1 to HI enables the AUTO pin mode in the LTC4270/LTC4271 chipset. J2 provides test points for access to AUTO and MID.
DEMO MANUAL DC1840A Demonstration Circuit 1680A Operation Demonstration circuit 1680A is a 12-Port, IEEE802.3at Type 1 and Type 2 PoE PSE mother board. This board accepts various PSE daughter cards featuring Linear Technology PSE controllers. The DC1680A is capable of powering up to 12 PDs. DC1680A USER FEATURES Daughter Card Insertion Precautions The DC1680A has an onboard VDD33 digital supply generated from the VEE supply. VDD33 is tied to AGND, and DGND is a negative voltage referenced to AGND.
DEMO MANUAL DC1840A Demonstration Circuit 1680A Operation MSD and RESET Pushbuttons Pushbutton switch SW1, when pressed, pulls the RESET pin of the daughter card logic low. The PSE controller is then held inactive with all ports off and all internal registers reset to their power-up states. When SW1 is released, RESET is pulled high, and the PSE begins normal operation. Pushbutton switch SW2 when pressed pulls the maskable shutdown input (MSD) pin of the daughter card logic low.
DEMO MANUAL DC1840A Demonstration Circuit 1680A Operation Interrupt LED DC1680A System Setup A red LED indicates when the INT line is pulled logic low by the daughter card. When the interrupt is cleared (high) via I2C servicing, the LED is turned off. Figure 14 shows a basic DC1680A system setup. The DC1682A daughter card is inserted in the 34-pin connector J1. A power supply is connected to VEE with banana cables. The DC590 connects with 14-pin ribbon cable to the DC1680A and to a PC via USB.
DEMO MANUAL DC1840A Demonstration Circuit 1680A Operation Figure 14.
DEMO MANUAL DC1840A Demonstration Circuit 1682A Layout Top Silkscreen Layer 1: Top Layer Layer 2: VEE Plane 1 dc1840afa 12
DEMO MANUAL DC1840A Demonstration Circuit 1682A Layout Layer 3: VEE Plane 2 Layer 4: Bottom Layer Bottom Silkscreen dc1840afa 13
DEMO MANUAL DC1840A Demonstration Circuit 1680A Layout Top Silkscreen dc1840afa 14
DEMO MANUAL DC1840A Demonstration Circuit 1680A Layout Layer 1: Top Layer dc1840afa 15
DEMO MANUAL DC1840A Demonstration Circuit 1680A Layout Layer 2: AGND, CGND Plane 1 dc1840afa 16
DEMO MANUAL DC1840A Demonstration Circuit 1680A Layout Layer 3: SIG, AGND, CGND Plane 2 dc1840afa 17
DEMO MANUAL DC1840A Demonstration Circuit 1680A Layout Layer 4: SIG, AGND, CGND Plane 3 dc1840afa 18
DEMO MANUAL DC1840A Demonstration Circuit 1680A Layout Layer 5: SIG, CGND, CGND Plane 4 dc1840afa 19
DEMO MANUAL DC1840A Demonstration Circuit 1680A Layout Layer 6: Bottom Layer dc1840afa 20
DEMO MANUAL DC1840A Demonstration Circuit 1680A Layout Bottom Silkscreen dc1840afa 21
DEMO MANUAL DC1840A parts list DC1682A ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 12 C1 TO C12 CAP, X7R, 0.22µF, 100V, 10% 0805 AVX, 08051C224KAT2A 2 1 C19 CAP, X7R, 1µF, 100V, 10% 1206 AVX, 12061C105KAT2A 3 3 C20, C22, C23 CAP, X7R, 1µF, 16V, 10% 0603 AVX, 0603YC105KAT2A 4 3 C21, C25, C26 CAP, X7R, 0.
DEMO MANUAL DC1840A parts list DC1680A ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 2 J7, J8 JACK BANANA KEYSTONE, 575-4 2 1 C1 CAP, ALUM, 47µF, 100V H13 size PANASONIC, EEEFK2A470AQ 3 3 C2, C13, C14 CAP, X7R, 0.1µF 25V, 10% 0603 AVX, 06033C104KAT2A 4 3 C3, C11, C12 CAP, X7R, 1µF 16V, 10% 0603 TDK, C1608X7R1C105K 5 1 C4 CAP, X7R, 0.
DEMO MANUAL DC1840A Parts List DC1680A ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER 35 2 R18, R19 RES, CHIP, 0, 1/16W, 0603 VISHAY, CRCW06030000Z0EA 36 2 R20, R21 RES, CHIP, 1k, 1/8W, 5%, 0805 AAC, CR10-102JM 37 0 R22, R23 (OPT) RES, 0805 38 2 SW1, SW2 SWITCH, PUSH BOTTOM PANASONIC, EVQPE104K (IN STOCK 500 PCS) 39 1 SW3 SWITCH, 219-3MST CTS ELECTRIC COMPONENTS, 219-3MST 40 10 E18 TO E27 TESTPOINT, TURRET, 0.
A C19 1uF 100V 1206 VEE R27 OPT C25 0.
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.
DEMO MANUAL DC1840A 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.