User’s Guide Full-Featured –48-V Hot Swap Power Manager (TPS2392 and TPS2393) User’s Guide
EVM IMPORTANT NOTICE Texas Instruments (TI) provides the enclosed product(s) under the following conditions: This evaluation kit being sold by TI is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not considered by TI to be fit for commercial use.
DYNAMIC WARNINGS AND RESTRICTIONS It is important to operate this EVM within the maximum input voltage ranges specified in Table 2. Exceeding the specified input range may cause unexpected operation and/or irreversible damage to the EVM. If there are questions concerning the input range, please contact a TI field representative prior to connecting the input power. Applying loads outside of the specified output range may result in unintended operation and/or possible permanent damage to the EVM.
SLUU155 – March 2003 Full-Featured –48-V Hot Swap Power Manager (TPS2392 and TPS2393) Andy Ripanti Power Interface Products ABSTRACT The TPS2392 and TPS2393 integrated circuits are hot swap power managers optimized for use in nominal –48-V systems. They operate over a supply voltage range of –20 V to –80 V, and are rated to withstand spikes to –100 V.
SLUU155 – March 2003 1 Introduction This User’s Guide describes the use and features of the full-featured –48-V hot swap evaluation module (EVM). This EVM can be used to learn about the TPS2392 and TPS2393 hot swap power manager (HSPM) integrated circuits from Texas Instruments. The TPS2392 and TPS2393 are negative voltage hot swap controllers intended for use in systems needing to hot swap telecom distribution-level voltages.
SLUU155 – March 2003 2 The Full-Featured –48-V Hot Swap Controller EVM Kit The full-featured –48-V hot swap controller EVM kit is a two-board platform that enables designers to rapidly learn about the TPS2392 and TPS2393 operation, and evaluate their performance during hot swap events.
SLUU155 – March 2003 Figure 1. Evaluation Module Main Board Top Assembly 2.1.2 EVM Schematic Diagram and List of Materials The EVM main board schematic diagram is shown in Figure 2. The EVM main board list of materials is provided in Table 1.
+ + SLUU155 – March 2003 Figure 2.
SLUU155 – March 2003 Table 1. Evaluation Module List of Materials REF DES QUANTITY DESCRIPTION MANUFACTURER PART NUMBER –002 –001 U1 1 – IC, full-featured –48 V hot swap controller, w/retry Texas Instruments TPS2393PW U1 – 1 IC, full-featured –48 V hot swap controller, latching Texas Instruments TPS2392PW U2 1 1 IC, linear, optocoupler, 30 V, h(FE) = 0.2 min. Fairchild 4N25.
SLUU155 – March 2003 2.2 2.2.1 The Full-Featured –48-V Hot Swap EVM Jumper Card Description The EVM jumper card is used to apply the –48-V supply voltage, present at the input banana jacks, to the supply input of the main board’s plug-in side. Inserting and removing the jumper card into and out of the main board P1 connector simulates hot swap events. There are no components mounted on the jumper card; it simply makes the point-to-point connections to apply input power to the plug-in electronics.
SLUU155 – March 2003 2.2.2 Jumper Card Schematic Diagram The EVM jumper card schematic diagram is shown in Figure 4. Figure 4. EVM Jumper Card Schematic There are no components installed on the jumper card, and consequently no list of materials required.
SLUU155 – March 2003 2.3 Full-Featured –48-V Hot Swap EVM Operating Specifications The full-featured –48-V hot swap EVM is intended to allow some degree of user reconfiguration. This allows designers to set up the circuit to better represent the characteristics of their target application. Potential modifications include changing the inrush limiting, the fault timing, and load characteristics.
SLUU155 – March 2003 3.2 Verifying the EVM Operation The following procedure steps may be used to verify functional operation of the EVM after receipt. 3.2.1 Equipment Setup On the EVM board, place the ENABLE switch S1 in the OFF position. Set the DIP switches 1 through 4 of switch SW1 to the ON position. Turn on power supply number 1 and adjust the output for about 48 V. Verify the supply current limit is set to allow at least 3 amps. Turn on power supply number 2 and adjust its output to 5 V.
SLUU155 – March 2003 3.2.2 Functional Test Turn on both power supplies. Insert the jumper card into the P1 connector, observing the proper insertion keying. On the EVM main board, verify the red LED (D1) is OFF. Verify the voltage readings indicated in Table 4 are obtained at the corresponding test points. Table 4. Test Point Voltages (Outputs OFF) TEST POINT REFERENCE VOLTAGE READING TP1 TP8/TP15 Approx. 2.13 V TP14 TP8/TP15 Approx. 0.94 V TP20 TP22/J4 0 ± 200 mV J6 TP22/J4 4.70 V min.
SLUU155 – March 2003 4 Using the EVM Kit to Evaluate the TPS2392 and TPS2393 Procedures similar to the steps of Section 3.2.2 for functional test of the EVM can also be used to continue evaluation of the TPS2392 and TPS2393 hot swap controller devices. Additional details about the EVM features are provided in this section. 4.1 Supply Connections and Test Points Supply connections to the EVM should be made as shown in Figure 5.
SLUU155 – March 2003 4.2 Load Capacitors Capacitor patterns C8 and C9 are available on the EVM for installation of components to represent the module input bulk capacitance; i.e., the load capacitance seen by the hot swap interface circuit. As supplied from the factory, the EVM contains a 100-µF aluminum electrolytic installed at C8. Further customization to approximate the user’s application can be done using either C8 or C9.
SLUU155 – March 2003 4.4 Changing the Inrush Slew Rate The TPS2392 and TPS2393 also feature slew rate limiting as current is ramped to charge the load capacitance. The slew rate is easily programmed, once the sense resistor is determined, with a small-value capacitor connected between the IRAMP and –VIN pins. The EVM comes equipped with three preset capacitor values, selectable either individually or combined by closing the appropriate DIP switches of SW1.
SLUU155 – March 2003 4.5 Fault Timing With the TPS2392/93 Whenever the hot swap controller is limiting current to the load, an on-chip timer is monitoring this operation against an established time limit. The timeout period is generated by the constant-current charging of a capacitor at the FLTTIME pin. If current regulation ceases prior to expiration of the timer, the capacitor is discharged, and normal steady-state operation of the load either starts or resumes.
SLUU155 – March 2003 Table 8. Nominal UVLO and OVLO settings. PARAMETER DESCRIPTION VALUE (V) VUV_L VUV_H VOV_L UVLO threshold, supply low (VIN < VUV) UVLO threshold, supply high (VIN > VUV) 32.8 OVLO threshold, supply low (VIN < VOV) 72.6 VOV_H OVLO threshold, supply high (VIN > VOV) 70.5 30.8 The thresholds are easily modified by changing the resistor values.
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