DEMO MANUAL DC2087A LTM4676EY 26A Step-Down Module Regulator with PMBus Power System Management DESCRIPTION Demonstration circuit 2087A is a single-output, high ef- board. LTpowerPlay allows the user to reconfigure the part ficiency, high density, Module regulator with 4.5V to 16V on the fly and store the configuration in EEPROM, view input range. It can supply 26A maximum load current. The telemetry of voltage, current, temperature and fault status. demo board has a LTM 4676 Module regulator, which is GUI Download a dual 13A or single 26A step-down regulator with PMBus power system management. Please see LTM4676 data The software can be downloaded from: sheet for more detailed information. DEMO MANUAL DC2087A PERFORMANCE SUMMARY Specifications are at T = 25C A PARAMETER CONDITION VALUE Input Voltage Range 4.5V to 16V Output Voltage, V V = 4.5 to 16V, I = 0A to 26A 0.5V to 4V, Default: 1V OUT IN OUT Maximum Output Current, I V = 4.5 to 16V, V = 0.5V to 4V 26A OUT IN OUT Typical Efficiency V = 12V, V = 1.2V, I = 26A 83.2% IN OUT OUT Default Switching Frequency 350kHz QUICK START PROCEDURE Table 1. LTM4676 Demo Cards for Up to 100A Point-of-Load Regulation NUMBER OF LTM4676 MODULE MAXIMUM OUTPUT CURRENT NUMBER OF OUPUT VOLTAGES REGULATORS ON THE BOARD DEMO BOARD NUMBER 13A, 13A 2 1 DC1811A 26A 1 1 DC2087A 50A 1 2 DC1989A-A 75A 1 3 DC1989A-B 100A 1 4 DC1989A-C 100A 1 1(+3 LTM4620A) DC2106A-A 130A 1 DC2106A-B 1(+3 LTM4630) Demonstration circuit 2087A is easy to set up to evaluate Note: When measuring the output or input voltage ripple, the performance of the LTM4676EY. Refer to Figure 2 for do not use the long ground lead on the oscilloscope probe. the proper measurement equipment setup and follow the See Figure 3 for the proper scope probe technique. Short, procedure below. stiff leads need to be soldered to the (+) and () terminals of an output capacitor. The probes ground ring needs to 1. With power off, connect the input power supply to VIN touch the () lead and the probe tip needs to touch the (4.5V16V) and GND (input return). (+) lead. 2. Connect the 1.0V output load between VOUT and GND (Initial load: no load). Connecting a PC to DC2087A 3. Connect the DVMs to the input and outputs. Set default You can use a PC to reconfigure the power management jumper position: JP1: ON. features of the LTM4676 such as: nominal V , margin OUT set points, OV/UV limits, temperature fault limits, sequenc- 4. Turn on the input power supply and check for the proper ing parameters, the fault log, fault responses, GPIOs and output voltages. V should be 1.0V 1 %. OUT other functionality. The DC1613A dongle may be plugged 5. Once the proper output voltages are established, ad- when V is present. IN just the loads within the operating range and observe the output voltage regulation, ripple voltage and other parameters. 6. Connect the dongle and control the output voltages from the GUI. See LTpowerPlay GUI for the LTM4676 Quick Start Guide for details. dc2087af 2