ISL95872 Datasheet, PDF (1/17 Pages) Intersil Corporation – Output Voltage Remote Sense

Buck PWM Controller with Internal Compensation and
External Reference Tracking
ISL95872
The ISL95872 is a Single-Phase Synchronous-Buck PWM
controller featuring Intersil’s proprietary R4™ Technology. The
R4™ modulator has integrated compensation, fast transient
performance, accurate switching frequency control, and
excellent light-load efficiency. These technology advances,
together with integrated MOSFET drivers and a schottky
bootstrap diode, allow for a high performance regulator that is
highly compact and needs few external components.
Differential remote sensing of the output voltage is an
additional feature. For maximum efficiency, the converter
automatically enters diode-emulation mode (DEM) during
light-load conditions such as system standby.
The ISL95872 accepts a wide 3.3V to 25V input voltage range,
making it ideal for systems that run on battery or AC-adapter
power sources. It also is a low-cost solution for applications
requiring tracking of an external reference voltage during soft-
start. When the external reference level meets the internal
reference voltage, the ISL95872 switches from the external
reference to the internal reference. The external reference is
only used during soft-start.
Features
• External Reference Tracking
• Intersil’s R4™ Modulator Technology
- Internal Compensation
- Fast, Optimal Transient Response
• Input Voltage Range: 3.3V to 25V
• Output Voltage Range: 0.5V to 3.3V
• Precision Voltage Regulation
- ±0.5% System Accuracy Over -10°C to +100°C
• Output Voltage Remote Sense
• Fixed 300kHz PWM Frequency in Continuous Conduction
- Proprietary Frequency Control Loop
• Automatic Diode Emulation Mode for Highest Efficiency
• Power-Good Monitor for Soft-Start and Fault Detection
Applications
• Compact Buck Regulators Requiring External Tracking
+5V
R_VCC
C_PVCC
C_VCC
RTN1 ^RFB1
External
Reference
Voltage
GPIO
1
GND
2 _RTN
3 _EN
4
REFIN
BOOT ¹²
UGATE ¹¹
PHASE ¹⁰
9
PGOOD
C_BOOT
Q_HS
Q_LS
L_O
C_SEN
R_O
R_OFS
R_FB
FIGURE 1. ISL95872 APPLICATION SCHEMATIC WITH DCR CURRENT SENSE
V_IN
3.3V TO 25V
CIN
V_OUT
0.5V TO 3.3V
CO
RTN1
0
January 26, 2012
1
FN7974.0
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 |Copyright Intersil Americas Inc. 2012. All Rights Reserved
Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.
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