IR3897 Datasheet, PDF (1/45 Pages) International Rectifier – 4A HIGHLY INTEGRATED SUPLRBUCK

4A Highly Integrated SupIRBuck^TM
Single‐Input Vo_- l₁ta_-ge, Synchronous Buck Regulator
PD‐97663
IR3897
FEATURES
 Single 5V to 21V application
 Wide Input Voltage Range from 1.0V to 21V with
external Vcc
 Output Voltage Range: 0.5V to 0.86* Vin
 Enhanced Line/Load Regulation with Feed‐Forward
 Programmable Switching Frequency up to 1.5MHz
 Internal Digital Soft‐Start/Soft‐Stop
 Enable input with Voltage Monitoring Capability
 Thermally Compensated Current Limit with robust
hiccup mode over current protection
 Smart Internal LDO to improve light load and full load
efficiency
 External Synchronization with Smooth Clocking
 Enhanced Pre‐Bias Start‐Up
 Precision Reference Voltage (0.5V+/‐0.5%) with
margining capability
 Vp for Tracking Applications (Source/Sink Capability
+/‐4A)
 Integrated MOSFET drivers and Bootstrap Diode
 Thermal Shut Down
 Programmable Power Good Output with tracking
capability
 Monotonic Start‐Up
 Operating temp: ‐40^oC < Tj < 125^oC
 Small Size: 4mm x 5mm PQFN
 Lead‐free, Halogen‐free and RoHS Compliant
DESCRIPTION
The IR3897 SupIRBuck^TM is an easy‐to‐use, fully
integrated and highly efficient DC/DC regulator.
The onboard PWM controller and MOSFETs make
IR3897 a space‐efficient solution, providing accurate
power delivery.
IR3897 is a versatile regulator which offers
programmability of switching frequency and internal
current limit while operates in wide input and output
voltage range.
The switching frequency is programmable from 300kHz
to 1.5MHz for an optimum solution.
It also features important protection functions, such as
Pre‐Bias startup, thermally compensated current limit,
over voltage protection and thermal shutdown to give
required system level security in the event of fault
conditions.
APPLICATIONS
 Netcom Applications
 Embedded Telecom Systems
 Server Applications
 Storage Applications
 Distributed Point of Load Power Architectures
BASIC APPLICATION
*
*
* optional
Figure 1: IR3897 Basic Application Circuit
1 AUGUST 08, 2012 |DATA SHEET | Rev 3.3
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0.4
12Vin,Internal bias,Frequency 600KHz
0.8 1.2 1.6
2
2.4 2.8 3.2 3.6
4
Load Current (A)
1.2Vout 3.3Vout
Figure 2:IR3897 Efficiency