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11 page 
Data Sheet ADM1075 Rev. A | Page 11 of 52 PIN CONFIGURATION AND FUNCTION DESCRIPTION 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 VIN UVH UVL VCAP PLIM OV DRAIN GATE SENSE+ SENSE– ADC_AUX SPLYGD VEE ADC_V ISET SS ADR SHDN LATCH TIMER PWRGD SCL SDAI GPO1/ALERT1/CONV RESTART GPO2/ALERT2 SDAO VEE_G TOP VIEW (Not to Scale) ADM1075 Figure 3. TSSOP Pin Configuration NOTES 1. EXPOSED PAD. SOLDER THE EXPOSED PAD TO THE BOARD TO IMPROVE THERMAL DISSIPATION. THE EXPOSED PAD CAN BE CONNECTED TO VEE. 1 OV 2 PLIM 3 VCAP 4 ADC_V 5 ISET 6 SS 7 TIMER 17 PWRGD 18 ADC_AUX 19 SPLYGD 20 VEE 21 SENSE– 16 SCL 15 SDAI TOP VIEW (Not to Scale) ADM1075 Figure 4. LFCSP Pin Configuration Table 5. Pin Function Descriptions Pin No. TSSOP LFCSP Mnemonic Description 1 25 DRAIN Connect to the drain pin of the FET through a resistor. The current in this resistor is used to determine the VDS of the MOSFET. This is used for PWRGD. 2 26 VIN Shunt Regulated Positive Supply to Chip. Connect to the positive supply rail via a shunt resistor. A 1 μF capacitor to VEE is recommended on the VIN pin. 3 27 UVH Undervoltage Rising Input Pin. An external resistor divider is used from the supply to this pin to allow an internal comparator to detect if the supply is under the UVH limit. 4 28 UVL Undervoltage Falling Input Pin. An external resistor divider is used from the supply to this pin to allow an internal comparator to detect if the supply is under the UVL limit. 5 1 OV Overvoltage Input Pin. An external resistor divider is used from the supply to this pin to allow an internal comparator to detect if the supply is above the OV limit. 6 2 PLIM The voltage on this pin is proportional to the VDS voltage of the FET. As the PLIM voltage changes, the current limit automatically adjusts to maintain constant power across the FET. 7 3 VCAP A capacitor with a value of 1 μF or greater should be placed on this pin to maintain good accuracy. This is an internal regulated supply. This pin can be used as a reference to program the ISET pin voltage. 8 4 ADC_V This pin is used to read back the input voltage using the internal ADC. It can be connected to the OV string or a separate divider. 9 5 ISET This pin allows the current limit threshold to be programmed. The default limit is set when this pin is connected directly to VCAP. Alternatively, using a resistor divider from VCAP, the current limit can be adjusted to achieve a user defined sense voltage. An external reference can also be used. 10 6 SS A capacitor is used on this pin to set the inrush current soft start ramp profile. The voltage on the soft start pin controls the current sense voltage limit, allowing control over the inrush current profile. 11 7 TIMER Timer Pin. An external capacitor, CTIMER, sets an initial timing cycle delay and a fault delay. The GATE pin turns off when the voltage on the TIMER pin exceeds the upper threshold. 12 8 LATCH This pin signals the device latching off after an overcurrent fault. This pin is also used to configure the desired retry scheme. See the Hot Swap Fault Retry section for additional details. 13 9 ADR PMBus Address Pin. This pin can be tied low, tied to VCAP, left floating, or tied low through a resistor to set four different PMBus addresses. |
