WWW.Microsemi .COM NX7101 NX7101 NX7101 2A, High Voltage Synchronous Buck Regulator PRODUCTION DATA SHEET D E S C R IP T I ON KE Y FE A T UR ES NX7101 is a 340kHz fixed The controller is equipped with output 2A Synchronous Step-down frequency, current mode, PWM over-voltage protection which protects the Regulator synchronous buck (step-down) DC- IC under a open load condition. Operational Input Supply DC converter, capable of driving a 2A Additional safety features include under Voltage Range: 4.5V-18V load with high efficiency, excellent voltage lock-out (UVLO), programmable Integrated Upper NMOS and line and load regulation. The device soft-start and over-temperature protection Lower NMOS integrates N-channel power MOSFET (OTP) to protect the circuit. 340kHz Switching Frequency switches with low on-resistance. This IC is available in SOIC-8 Input UVLO Current mode control provides fast package. Enable transient response and cycle-by-cycle Programmable External Soft- current limit. Start Cycle-By-Cycle Over-Current Protection Over Voltage Protection Frequency Fold Back Under Short Condition A P P L IC A T I ONS Set-Top Box LCD TVs Notebook/Netbook PoE Powered Devices P R OD UC T HI GHL I GHT 12V IN(2) VIN BST(1) C5 CIN 10nF 2*10uF(25V,X5R) L1 NX7101 10uH 3.3V C4 0.1u OUT SW(3) SS(8) R1 COUT R4 100k 26.1k EN(7) 2*22uF(6.3V,X5R) FB(5) R2 GND(4) COMP(6) 10k R3 10k C3 3.9nF Figure 1 NX7101 typical application P A C KA GE ORD E R INF O Plastic SOIC 8 Pin DM T ( C) A RoHS Compliant / Pb-free NX7101IDM -40 to 85 Note: Available in Tape & Reel. Append the letters TR to the part number. (i.e. NX7101IDM-TR) Page 1 Copyright 2010 Microsemi Rev. 1.7, 2014-06-24 Analog Mixed Signal Group One Enterprise, Aliso Viejo, CA 92656 949-380-6100, fax 949-215-4996 WWW.Microsemi .COM NX7101 NX7101 M S C 7 1 0 1 I D M X X X X NX7101 2A, High Voltage Synchronous Buck Regulator PRODUCTION DATA SHEET A B S OL UTE M A X IM UM R AT I NGS P A C KA GE P I N OUT Supply Input Voltage (VIN) ........................................................................... -0.3V to 20V Switch Voltage (SW) ..................................................................................................... 21V BST 1 8 SS EN .................................................................................................................. -0.3V to VIN VIN BST ................................................................................................... -0.3V to (VSW + 6V) 2 7 EN COMP, FB, SS ................................................................................................. -0.3V to 6V SW 3 6 COMP Maximum Operating Junction Temperature .............................................................. 150C Storage Temperature Range ......................................................................... -65 C to 150C GND 4 5 FB Package Peak Temp. for Solder Reflow (40 seconds maximum exposure) ............... 260C DM PACKAGE (Top View) Note: Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of specified terminal. DM PART MARKING xxxx Denote Date Code and Lot Identification RoHS / Pb-free 100% Matte Tin Pin Finish MSL3 T HE R M AL DA T A Plastic SOIC 8-Pin DM THERMAL RESISTANCE-JUNCTION TO AMBIENT, 105C/W JA Junction Temperature Calculation: T = T + (P x ). J A D JA The numbers are guidelines for the thermal performance of the device/pc-board system. All of the JA above assume no ambient airflow. F UNC T I ONAL PI N DE S C R I PT I ON Pin Name Description Bootstrap pin. A minimum 10nF bootstrap capacitor is connected between the BS pin and SW pin. 1 BST The voltage across the bootstrap capacitor drives the internal high side NMOS. Supply input pin. A capacitor should be connected between the IN pin and GND pin to keep the input 2 VIN voltage constant. 3 SW Power switch output pin. This pin is connected to the inductor and bootstrap capacitor. 4 GND Ground. Feedback pin. This pin is connected to an external resistor divider to program the system output voltage. When the FB pin voltage exceeds 20% of the nominal regulation value of 0.925V, the over 5 FB voltage protection is triggered. When the FB pin voltage is below 0.3V, the oscillator frequency is lowered to realize short circuit protection. Compensation pin. This pin is the output of the transconductance error amplifier and the input to the 6 COMP current comparator. It is used to compensate the control loop. Connect a series RC network from this pin to GND. In some cases, an additional capacitor from this pin to GND pin is required. Control input pin. Forcing this pin above 2V enables the IC. Forcing this pin below 0.75V shuts down 7 EN the IC. When the IC is in shutdown mode, all functions are disabled to decrease the supply current below 1A. Soft-start control input pin. SS controls the soft start period. Connect a capacitor from SS to GND to 8 SS set the soft-start period. A 0.1F capacitor sets the soft-start period to 15ms. To disable the soft-start feature, leave SS unconnected. Page 2 Copyright 2010 Microsemi Rev. 1.7, 2014-06-24 Analog Mixed Signal Group One Enterprise, Aliso Viejo, CA 92656 949-380-6100, fax 949-215-4996