Document
NJW4170
Current Mode Control High Speed Frequency Internal 1A MOSFET Switching Regulator IC for Buck Converter
GENERAL DESCRIPTION
The NJW4170 is a high speed oscillating frequency buck converter with 40V/1A MOSFET. Current mode control and built-in phase compensation circuit minimize external parts and contribute to using a Low ESR Output Capacitor(MLCC) within wide input range from 4.5V to 40V. Therefore, the NJW4170 can realize downsizing of applications.
Also, it has a soft start function, an external clock synchronization function, an over current protection and a thermal shutdown circuit.
Over 2MHz of Switching frequency can avoid interference with the AM radio frequency.
It is suitable for supplying power to a Car Accessory, Audio Automation Equipment, Industrial Instrument and so on.
FEATURES
Oscillating Frequency
2.4MHz typ. (A ver.)
2.1MHz typ. (B ver.)
Minimum ON time
80ns typ.(A ver.)
85ns typ.(B ver.)
Current mode Control
External Clock Synchronization
Wide Operating Voltage Range 4.5V to 40V
Switching Current
1.4A min.
PWM Control
Built-in Compensation Circuit
Correspond to Ceramic Capacitor (MLCC)
Soft Start Function
4ms typ.
UVLO (Under Voltage Lockout)
Over Current Protection (Hiccup type)
Thermal Shutdown Protection
Standby Function
Package Outline
NJW4170U2 : SOT-89-5
NJW4170KV1 : DFN8-V1(ESON8-V1)
■ PACKAGE OUTLINE NJW4170U2 NJW4170KV1
PRODUCT CLASSIFICATION
Part Number
Version
NJW4170U2-A
A
NJW4170KV1-A
A
NJW4170U2-B
B
Oscillating Frequency 2.4MHz typ.
2.4MHz typ.
2.1MHz typ.
Package
SOT-89-5 DFN8-V1 (ESON8-V1) SOT-89-5
Operating Temperature Range
General Spec. -40 C to +125 C General Spec. -40 C to +125 C General Spec. -40 C to +125 C
Ver.2016-01-25
-1-
NJW4170
PIN CONFIGURATION
EN/SYNC 1 GND 2 IN- 3
5 V+ (2) GND 4 SW
NJW4170U2
SW N.C.
V+ N.C.
1 2 3 4
(Top View)
8 IN7 N.C. 6 GND 5 EN/SYNC
8 7 6 5
1 2 3 4
Exposed PAD on backside connect to GND.
(Bottom View)
NJW4170KV1
PIN DESCRIPTIONS
PIN NAME
PIN NUMBER
SOT-89-5
DFN8-V1 (ESON8)
EN/SYNC
1
5
GND
IN-
SW V+ N.C. Exposed PAD
2
3
4 5 – –
6
8
1 3 2, 4, 7 –
FUNCTION
Standby Control pin The EN/SYNC pin internally pulls down with 100k . Normal Operation at the time of High Level. Standby Mode at the time of Low Level or OPEN. Moreover, it operates by inputting clock signal at the oscillatory frequency that synchronized with the input signal. GND pin Output Voltage Detecting pin Connects output voltage through the resistor divider tap to this pin in order to voltage of the IN- pin become 0.8V. Switch Output pin of Power MOSFET Power Supply pin for Power Line Non connection
Connect to GND (Only DFN8-V1 PKG)
-2-
Ver.2016-01-25
NJW4170
BLOCK DIAGRAM
EN/SYNC
High: ON
Low : OFF(Standby)
100k
IN-
UVLO
Enable (Standby)
SYNC
SLOPE COMP.
OSC
Soft Start
Vref 0.8V
ER AMP
V+
CURRENT SENSE
OCP
PWM
SQ R
Buf f er
TSD
SW
GND
Ver.2016-01-25
-3-
NJW4170
ABSOLUTE MAXIMUM RATINGS
(Ta=25°C)
PARAMETER
Supply Voltage V+.