ZSPM4011B Datasheet, PDF (13/23 Pages) List of Unclassifed Manufacturers – High Efficiency 1A Synchronous Buck Converter

ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
3 Description of Circuit
The ZSPM4011B current-mode synchronous step-down power supply product can be used in the commercial,
industrial, and automotive market segments. It includes flexibility for a wide range of output voltages and is
optimized for high efficiency power conversion with low R_DSON integrated synchronous switches. A 1MHz internal
switching frequency facilitates low-cost LC filter combinations. The fixed-output versions also enable a minimum
external component count to provide a complete regulation solution with only 4 external components: an input
bypass capacitor, an inductor, an output capacitor, and the bootstrap capacitor. The regulator automatically
transitions between pulse frequency modulation (PFM) and pulse width modulation (PWM) mode to maximize
efficiency for the load demand.
See section 5.4.3 for details for adjusting V_OUT for the adjustable output version of the ZSPM4011B.
3.1. Block Diagram
Figure 3.1 provides a block diagram of the ZSPM4011B, and Figure 3.2 illustrates its monitor and control logic
functions, which are explained in section 3.2.
Figure 3.1 ZSPM4011B Block Diagram
PG
EN
VCC
Oscillator
Ramp
Generator
Vref
&
Soft Start
MONITOR
&
CONTROL

4.2V
VCC
VCC
Under-Voltage
Protection
Over-Voltage
Protection
FB
Thermal
Protection
Over Current
Protection
VCC
Bootstrap
Voltage
VCC
Gate Drive
Control
Gate
Drive
High-Side Switch
BST
VSW
Error Amp
Compensation
Network
Comparator
Vref
PFM Mode
Comparator
Gate
Drive
Low-Side Switch
PGND
FB
GND
Data Sheet
April 4, 2013
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.00
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the
prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
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