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NX7102
N X7 1 0 2
3A High Voltage Synchronous Buck Converter
PRODUCTION DATA SHEET
D E S C R IP T I ON KE Y FE A T UR ES
NX7102 is a 340kHz fixed The controller is equipped with 3A Synchronous Step-down
frequency, current mode, PWM output over-voltage protection which Regulator
synchronous buck (step-down) DC- protects the IC under an open load Operational Input Supply
DC converter, capable of driving a 3A condition. Additional safety features Voltage Range: 4. 5V-18V
load with high efficiency, excellent include under voltage lock-out Integrated Upper NMOS and
line and load regulation. The device (UVLO), programmable soft-start and Lower NMOS
integrates N-channel power MOSFET over-temperature protection (OTP) to 340kHz Switching Frequency
switches with low on-resistance. protect the circuit. Input UVLO
Current mode control provides fast This IC is available in SOIC-8 with Enable
transient response and cycle-by-cycle exposed pad package. 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
2x10uF(25V,X5R) L1
NX7102
10uH 3.3V
C4 0.1u
OUT
SW(3)
SS(8)
R1
COUT
R4 100k
26.1k
2*22uF(10V,X5R)
EN(7)
FB(5)
R2
GND(4) COMP(6)
PAD
10k
R3
10k
C3
5.6nF
Figure 1 12V Input, 3.3V Output with Ceramic Cap
P A C KA GE ORD E R INF O
Plastic SOIC 8 Pin
DE
T ( C) With Exposed Pad
A
RoHS Compliant / Pb-free
-40 to 85 NX7102IDE
Note: Available in Tape & Reel. Append the letters TR to the part
number. (i.e. NX7102IDE-TR)
Page 1
Copyright 2010
Microsemi
Rev.1.6, 2015-02-20
Analog Mixed Signal Group
One Enterprise, Aliso Viejo, CA, 949-380-6100, Fax: 949-215-4996
WWW.Microsemi .COM
NX7102
M S C
7 1 0 2 I D E
X X X X
N X7 1 0 2
3A High Voltage Synchronous Buck Converter
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) ............................................................................. -1V to (VIN + 1V)
BST 1 8 SS
EN ................................................................................................... -0.3V to (VIN + 0.3V)
BST ................................................................................................... -0.3V to (VSW + 6V) VIN 2 7
EN
COMP, FB, SS ................................................................................................. -0.3V to 6V
SW 3 6
COMP
Maximum Operating Junction Temperature ............................................................... 150 C
Storage Temperature Range .........................................................................-65 C to 150 C
GND 4 5
FB
Package Peak Temp. for Solder Reflow (40 seconds maximum exposure) ................ 260C
DE 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.
DE PART MARKING
xxxx Denote Date Code and Lot Identification
RoHS / Pb-free 100% Matte Tin Pin Finish
T HE R M AL DA T A
Plastic SOIC 8-Pin With Exposed Pad
DE
THERMAL RESISTANCE-JUNCTION TO AMBIENT, 60 C/W
JA
Junction Temperature Calculation: TJ = TA + (PD x 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 VIN pin and GND pin to keep the
2 VIN
input 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
5 FB
over 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
6 COMP the 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 2.7V enables the IC. Forcing this pin below 1.1V shuts
7 EN down 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
8 SS to set the soft-start period. A 0.1F capacitor sets the soft-start period to 9ms. To disable the soft-
start feature, leave SS unconnected.
Page 2
Copyright 2010
Microsemi
Rev.1.6, 2015-02-20
Analog Mixed Signal Group
One Enterprise, Aliso Viejo, CA, 949-380-6100, Fax: 949-215-4996