NCP349
Positive Overvoltage
Protection Controller with
Internal Low RON NMOS FET
The NCP349 is able to disconnect the systems from its output pin when wrong input operating conditions are detected. The system is positive overvoltage protected up to +28 V.
This device uses an internal NMOS and therefore, no external device is necessary, reducing the system cost and the PCB area of the application board.
The NCP349 is able to instantaneously disconnect the output from the input, due to integrated Low RON Power NMOS (65 mW), if the input voltage exceeds the overvoltage threshold (OVLO) or falls below the undervoltage threshold (UVLO).
At powerup (EN pin = low level), the Vout turns on ton time after the Vin exceeds the undervoltage threshold.
The NCP349 provides a negative going flag (FLAG) output, which alerts the system that a fault has occurred.
In addition, the device has ESD−protected input (15 kV Air) when bypassed with a 1.0 mF or larger capacitor.
Features
• Overvoltage Protection up to 28 V • On−Chip Low RDS(on) NMOS Transistor: 65 mW • Internal Charge Pump • Overvoltage Lockout (OVLO) • Undervoltage Lockout (UVLO) • Soft−Start • Alert FLAG Output • Shutdown EN Input • Compliance to IEC61000−4−2 (Level 4)
8.0 kV (Contact) 15 kV (Air)
• ESD Ratings: Machine Model = B
Human Body Model = 2
• DFN6 1.6x2 mm Package • This is a Pb−Free Device
Applications
• Cell Phones • Camera Phones • Digital Still Cameras • Personal Digital Applications • MP3 Players
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6
1 DFN6 MN SUFFIX CASE 506BM
MARKING DIAGRAM
1 XX MG G
XX = Specific Device Code M = Date Code G = Pb−Free Package
PIN CONNECTIONS
IN 1 GND 2 FLAG 3
PAD1 IN
6 EN 5 OUT 4 OUT
(Top View)
ORDERING INFORMATION
See detailed ordering, marking and shipping information in the package dimensions section on page 11 of this data sheet.
© Semiconductor Components Industries, LLC, 2012
September, 2012 − Rev. 3
1
Q Publication Order Number: NCP349/D
NCP349
Wall Adapter − AC/DC − USB
7 1
NCP349 IN OUT IN OUT
5 4
1 mF
6 EN
FLAG 3
ENABLE/
GND
Microprocessor 2
VBat 10 k
CC/CV
Charger or System
mP
0 Figure 1. Typical Application Circuit
BATTERY 0
7 INPUT 1
Gate Driver
4
OUTPUT 5
VREF
Charge Pump
EN Block
UVLO OVLO
Control
Logic and Timer
EN 6
3 FLAG
Figure 2. Functional Block Diagram
2 GND
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NCP349
PIN FUNCTION DESCRIPTION Pin No. Symbol Function
Description
1, 7 IN INPUT Input Voltage Pins. These pins are connected to the Wall Adapoter (AC−DC, Vbus ..). A 1 mF low ESR ceramic capacitor, or larger, must be connected between these pins and GND, as close as possible to the DUT. The two IN pins must be connected together to power supply. (See PCB recommendation for the pin7).
2
GND
POWER Ground
3
FLAG
OUTPUT Fault Indication Pin. This pin allows an external system to detect a fault on the IN pins. The FLAG pin
goes low when input voltage exceeds OVLO threshold or drops below UVLO threshold. Since the
FLAG pin is open drain functionality, an external pull−up resistor to VCC must be added. (Minimum 10 kW).
4, 5
OUT
OUTPUT Output Voltage Pins. These pins follow IN pins when “no fault” is detected. The two OUT pins must
be hardwired together.
6 EN INPUT Enable Pin. The device enters in shutdown mode when this pin is tied to a high level. In this case the output is disconnected from the input. To allow normal functionality, the EN pin shall be connected to GND to a pull down or to a I/O pin. This pin does not have an impact on the fault detection.
MAXIMUM RATINGS
Rating
Symbol
Value
Unit
Minimum Voltage (IN to GND) Minimum Voltage (All others to GND)
Vminin Vmin
−0.3 −0.3
V V
Maximum Voltage (IN to GND) Maximum Voltage (All others to GND)
Vmaxin Vmax
30 7.0
V V
Maximum Current (UVLO