IR3898 Datasheet, PDF (1/45 Pages) International Rectifier – 6A HIGHLY INTERGRATED SUPLRBUCK

6A Highly Integrated SupIRBuck^TM
Single-Input Vo_- l₁ta_-ge, Synchronous Buck Regulator
PD-97662
IR3898
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
+/-6A)
• 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 IR3898 SupIRBuck^TM is an easy-to-use, fully
integrated and highly efficient DC/DC regulator.
The onboard PWM controller and MOSFETs make
IR3898 a space-efficient solution, providing accurate
power delivery.
IR3898 is a versatile regulator which offers
programmable switching frequency and the fixed
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
6.8V <Vin<21V
Vref S_Ctrl Vin PVin _Boot
Vcc/
LDO_out
SW
Vo
PGood
Vp
PGood _{IR3898 Vsns}
*
Vp
*
Rt/Sync
Fb
Enable
Gnd
Comp
PGnd
* optional
Figure 1: IR3898 Basic Application Circuit
98
96
94
92
90
88
86
84
82
80
12Vin,Internal bias,Frequency 600KHz
78
0.6
1.2
1.8
2.4
3
3.6
4.2
4.8
5.4
6
Load Current (A)
1.2Vout 3.3Vout
Figure 2:IR3898 Efficiency
1 AUGUST 08, 2012 | DATA SHEET | Rev 3.3