Data Sheet

Data Sheet
Rev. 1.20 / February 2014
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
Power Management
Power and Precision
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
Brief Description
Benefits
The ZSPM4011B is a DC/DC synchronous
switching regulator with fully integrated power
switches, internal compensation, and full fault
protection. The 1MHz switching frequency enables
using small filter components, resulting in reduced
board space and reduced bill-of-materials costs.

The ZSPM4011B utilizes current mode feedback in
normal regulation pulse-width modulation (PWM)
mode. When the regulator is disabled (EN pin is
low), the ZSPM4011B draws less than 10µA quiescent current.










Junction operating temperature -40°C to 125°C
Packaged in a 16pin QFN (3x3mm)

Related ZMDI Products

ZSPM4012B/ZSPM4013B: 2A/3A synchronous
buck converters, available with adjustable output from 0.9 to 5.5V or fixed output voltages at
1.5V, 1.8V, 2.5V, 3.3V, 5.0V
(16-pin 3x3 QFN)
ZSPM1000: >5A single-phase, single-rail, true
digital PWM controller (24-lead 4x4mm QFN)

ZSPM4011B Application Circuits
Adjustable Output
BST
VCC
VCC
CBYPASS
EN
CBST
VSW
EN
ZSPM4011B

Physical Characteristics
PGND


GND

Output voltage options (depends on order code):
 Fixed output voltages: 1.5V, 1.8V, 2.5V,
3.3V, or 5V with +/- 2% output tolerance
 Adjustable output voltage range: 0.9V to
5.5V with +/- 1.5% reference
Wide input voltage range: 4.5V to 24V
1MHz +/- 10% fixed switching frequency
1A continuous output current
High efficiency – up to 95%
Current mode PWM control with pulsefrequency modulation (PFM) mode for
improved light load efficiency
Voltage supervisor for VOUT reported at the PG
pin
Input supply under voltage lockout
Soft start for controlled startup with no
overshoot
Full protection for over-current, overtemperature, and VOUT over-voltage
Less than 10µA in Disabled Mode
Low external component count
Evaluation Kit
Documentation
VOUT
LOUT
RTOP
COUT
RBOT
FB
VOUT
10 kΩ
(optional)
PG
PG
Fixed Output
VCC
BST
VCC
CBYPASS
EN
ZSPM4011B

Available Support
EN
PGND
Features

GND
The ZSPM4011B integrates a wide range of
protection circuitry, including input supply undervoltage lockout, output voltage soft start, current
limit, VOUT over-voltage, and thermal shutdown.
The ZSPM4011B includes supervisory reporting
through the PG (Power Good) open drain output to
interface other components in the system.
Increased battery life
Minimal external component count
(3 capacitors, 1 inductor)
Inherent fault protection and reporting

VSW
CBST
VOUT
LOUT
COUT
FB
VOUT
10kΩ
(optional)
PG
PG
For more information, contact ZMDI via [email protected]
© 2014 Zentrum Mikroelektronik Dresden AG — Rev.1.20 — February 13, 2014. 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.
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
ZSPM4011B Block Diagram
PG
EN
VCC
4.2V
VCC
VCC
MONITOR
&
CONTROL
Oscillator
Typical Applications





Wireless access points, cable
modems
Set-top boxes
DVD, LCD, LED supplies
Portable products, including
GPS, smart phones, tablet
PCs
Printers
VCC
Over-Voltage
Protection
FB
BST
Over Current
Protection
VCC

Gate
Drive
Gate Drive
Control
VSW
High-Side Switch
Comparator
Gate
Drive
Error Amp
Compensation
Network
Bootstrap
Voltage
Thermal
Protection
Ramp
Generator
Vref
&
Soft Start
Under-Voltage
Protection
Vref
PGND
Low-Side Switch
FB
PFM Mode
Comparator
GND
Ordering Information
Ordering Code
Description
ZSPM4011BA1W00
ZSPM4011BA1W15
ZSPM4011BA1W18
ZSPM4011BA1W25
ZSPM4011BA1W33
ZSPM4011BA1W50
ZSPM4011BKIT
1A Synchronous Buck Converter: adjustable output, 0.9V to 5.5V, 16-pin 3x3mm QFN
1A Synchronous Buck Converter: fixed output, 1.5V,16-pin 3x3mm QFN
1A Synchronous Buck Converter: fixed output, 1.8V,16-pin 3x3mm QFN
1A Synchronous Buck Converter: fixed output, 2.5V,16-pin 3x3mm QFN
1A Synchronous Buck Converter: fixed output, 3.3V,16-pin 3x3mm QFN
1A Synchronous Buck Converter: fixed output, 5.0V,16-pin 3x3mm QFN
ZSPM4011BKIT, Evaluation Kit for 1A Synchronous Buck Converter
Sales and Further Information
Package
www.zmdi.com
7” reel with 1000 ICs
7” reel with 1000 ICs
7” reel with 1000 ICs
7” reel with 1000 ICs
7” reel with 1000 ICs
7” reel with 1000 ICs
Kit
[email protected]
Zentrum Mikroelektronik
Dresden AG
Global Headquarters
Grenzstrasse 28
01109 Dresden, Germany
ZMD America, Inc.
1525 McCarthy Blvd., #212
Milpitas, CA 95035-7453
USA
Central Office:
Phone +49.351.8822.306
Fax
+49.351.8822.337
USA Phone 1.855.275.9634
Phone +1.408.883.6310
Fax
+1.408.883.6358
European Technical Support
Phone +49.351.8822.7.772
Fax
+49.351.8822.87.772
DISCLAIMER: This information applies to a product under development. Its characteristics and specifications are subject to change without notice.
Zentrum Mikroelektronik Dresden AG (ZMD AG) assumes no obligation regarding future manufacture unless otherwise agreed to in writing. The
information furnished hereby is believed to be true and accurate. However, under no circumstances shall ZMD AG be liable to any customer,
licensee, or any other third party for any special, indirect, incidental, or consequential damages of any kind or nature whatsoever arising out of or
in any way related to the furnishing, performance, or use of this technical data. ZMD AG hereby expressly disclaims any liability of ZMD AG to any
customer, licensee or any other third party, and any such customer, licensee and any other third party hereby waives any liability of ZMD AG for
any damages in connection with or arising out of the furnishing, performance or use of this technical data, whether based on contract, warranty,
tort (including negligence), strict liability, or otherwise.
European Sales (Stuttgart)
Phone +49.711.674517.55
Fax
+49.711.674517.87955
Zentrum Mikroelektronik
Dresden AG, Japan Office
2nd Floor, Shinbashi Tokyu Bldg.
4-21-3, Shinbashi, Minato-ku
Tokyo, 105-0004
Japan
ZMD FAR EAST, Ltd.
3F, No. 51, Sec. 2,
Keelung Road
11052 Taipei
Taiwan
Phone +81.3.6895.7410
Fax
+81.3.6895.7301
Phone +886.2.2377.8189
Fax
+886.2.2377.8199
Zentrum Mikroelektronik
Dresden AG, Korea Office
U-space 1 Building
11th Floor, Unit JA-1102
670 Sampyeong-dong
Bundang-gu, Seongnam-si
Gyeonggi-do, 463-400
Korea
Phone +82.31.950.7679
Fax
+82.504.841.3026
© 2014 Zentrum Mikroelektronik Dresden AG — Rev.1.20— February 13, 2014
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.
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
Contents
1
2
3
4
5
6
7
8
9
ZSPM4011B Characteristics ............................................................................................................................... 6
1.1. Absolute Maximum Ratings .......................................................................................................................... 6
1.2. Thermal Characteristics ................................................................................................................................ 6
1.3. Recommended Operating Conditions .......................................................................................................... 7
1.4. Electrical Characteristics .............................................................................................................................. 7
1.5. Regulator Characteristics ............................................................................................................................. 8
Typical Performance Characteristics – ZSPM401x Family ............................................................................... 10
Description of Circuit ......................................................................................................................................... 13
3.1. Block Diagram ............................................................................................................................................ 13
3.2. Internal Protection Details .......................................................................................................................... 14
3.2.1. Internal Current Limit ........................................................................................................................... 14
3.2.2. Thermal Shutdown ............................................................................................................................... 14
3.2.3. Voltage Reference Soft-Start ............................................................................................................... 14
3.2.4. VCC Under-Voltage Lockout ................................................................................................................ 14
3.2.5. Output Over-Voltage Protection ........................................................................................................... 15
3.2.6. Output Under-Voltage Monitoring ........................................................................................................ 15
Application Circuits ............................................................................................................................................ 16
4.1. Selection of External Components ............................................................................................................. 16
4.2. Typical Application Circuits ......................................................................................................................... 16
Pin Configuration and Package ......................................................................................................................... 17
5.1. Package Dimensions .................................................................................................................................. 17
5.2. Marking Diagram & Pin-out ........................................................................................................................ 18
5.3. Pin Description for 16 LEAD 3x3 QFN ....................................................................................................... 19
5.4. Detailed Pin Description ............................................................................................................................. 20
5.4.1. Unregulated Input, VCC (Pins # 2, 3) .................................................................................................. 20
5.4.2. Bootstrap Control, BST (Pin #10) ........................................................................................................ 20
5.4.3. Sense Feedback, FB (Pin #5) .............................................................................................................. 20
5.4.4. Switching Output, VSW (Pins #12, 13) ................................................................................................ 20
5.4.5. Ground, GND (Pin #4) ......................................................................................................................... 20
5.4.6. Power Ground, PGND (Pins #14, 15) .................................................................................................. 20
5.4.7. Enable, EN (Pin #9) ............................................................................................................................. 20
5.4.8. PG Output, PG (Pin #8) ....................................................................................................................... 20
Ordering Information ......................................................................................................................................... 21
Related Documents ........................................................................................................................................... 21
Glossary ............................................................................................................................................................ 21
Document Revision History ............................................................................................................................... 22
Data Sheet
February 13, 2014
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
4 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
List of Figures
Figure 2.1
Figure 2.2
Figure 2.3
Figure 2.4
Figure 2.5
Figure 2.6
Figure 2.7
Figure 2.8
Figure 2.9
Figure 2.10
Figure 2.11
Figure 2.12
Figure 2.13
Figure 2.14
Figure 2.15
Figure 2.16
Figure 2.17
Figure 2.18
Figure 3.1
Figure 3.2
Figure 4.1
Figure 4.2
Figure 5.1
Figure 5.2
Startup Response ................................................................................................................................ 10
100mA to 1A Load Step (VCC= 12V, VOUT =1.8V) ........................................................................... 10
100mA to 2A Load (VCC=12V, VOUT = 1.8V) .................................................................................... 10
100mA t0 1A Load Step (VCC=12V, VOUT = 3.3V) ........................................................................... 10
100mA to 2A Load Step (VCC=12V, VOUT = 3.3V) ........................................................................... 10
Line Transient Response (VCC=10V to 15V, VOUT = 3.3V) .............................................................. 10
Load Regulation ................................................................................................................................... 11
Line Regulation (IOUT=1A) .................................................................................................................... 11
Efficiency vs. Output Current ( VOUT = 1.8V) ..................................................................................... 11
Efficiency vs. Output Current ( VOUT = 3.3V) ..................................................................................... 11
Efficiency vs. Output Current (VOUT= 5V) .......................................................................................... 11
Efficiency vs. Input Voltage (VOUT = 3.3V) ......................................................................................... 11
Standby Current vs. Input Voltage ....................................................................................................... 12
Standby Current vs. Temperature ....................................................................................................... 12
Output Voltage vs. Temperature.......................................................................................................... 12
Oscillator Frequency vs. Temperature (Iout=300mA) ......................................................................... 12
Quiescent Current vs. Temperature (No load) .................................................................................... 12
Input Current vs. Temperature (No load, No switching) ..................................................................... 12
ZSPM4011B Block Diagram ................................................................................................................ 13
Monitor and Control Logic Functionality .............................................................................................. 14
Typical Application for Adjustable Output Voltage............................................................................... 16
Typical Application for Fixed Output Voltage ....................................................................................... 16
ZSPM4011B Package Drawing ........................................................................................................... 17
16 Lead 3x3mm QFN (top view) .......................................................................................................... 18
List of Tables
Table 1.1
Table 1.2
Table 1.3
Table 1.4
Table 1.5
Table 5.1
Absolute Maximum Ratings ................................................................................................................... 6
Thermal Characteristics ......................................................................................................................... 6
Recommended Operating Conditions ................................................................................................... 7
Electrical Characteristics ....................................................................................................................... 7
Regulator Characteristics ...................................................................................................................... 8
Pin Description, 16 lead, 3x3mm QFN ................................................................................................ 19
Data Sheet
February 13, 2014
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
5 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
1
ZSPM4011B Characteristics
Important: Stresses beyond those listed under “Absolute Maximum Ratings” (section 1.1) may cause permanent
damage to the device. These are stress ratings only, and functional operation of the device at these or any other
conditions beyond those indicated under “Recommended Operating Conditions” (section 1.3) is not implied.
Exposure to absolute–maximum–rated conditions for extended periods may affect device reliability.
1.1.
Absolute Maximum Ratings
Over operating free–air temperature range unless otherwise noted.
Table 1.1
Absolute Maximum Ratings
Parameter
Value
1)
UNIT
Voltage on VCC pin
-0.3 to 26.4
V
Voltage on BST pin
-0.3 to (VCC+6)
V
Voltage on VSW pin
-1 to 26.4
V
-0.3 to 6
V
+/-2k
V
+/-500
V
260
C
Voltage on EN, PG, FB pins
Electrostatic Discharge – Human Body Model
2)
Electrostatic Discharge – Charge Device Model
2)
Lead Temperature (soldering, 10 seconds)
1)
2)
All voltage values are with respect to network ground terminal.
ESD testing is performed according to the respective JESD22 JEDEC standard.
1.2.
Thermal Characteristics
Table 1.2
Thermal Characteristics
Parameter
Symbol
Value
Unit
JA
34.5
°C/W
Jc
2.5
°C/W
Storage Temperature Range
TSTG
-65 to 150
°C
Maximum Junction Temperature
TJ MAX
150
°C
TJ
-40 to 125
°C
Thermal Resistance Junction to Air
1)
Thermal Resistance Junction to Case
1)
Operating Junction Temperature Range
1)
Assumes 1 in2 area of 2 oz. copper and 25C ambient temperature.
Data Sheet
February 13, 2014
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
6 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
1.3.
Recommended Operating Conditions
Table 1.3
Recommended Operating Conditions
Parameter
Input Operating Voltage
Bootstrap Capacitor
Output Filter Inductor Typical Value
1)
Output Filter Capacitor Typical Value
2)
Output Filter Capacitor ESR
Input Supply Bypass Capacitor Typical Value
1)
2)
3)
1.4.
3)
Symbol
Min
Typ
Max
Unit
VCC
4.5
12
24
V
CBST
17.6
22
26.4
nF
LOUT
3.76
4.7
5.64
µH
COUT
33
44 (2 x 22)
COUT-ESR
2
35
CBYPASS
8
10
µF
100
m
µF
For best performance, an inductor with a saturation current rating higher than the maximum V OUT load requirement plus the inductor
current ripple.
For best performance, a low ESR ceramic capacitor should be used.
For best performance, a low ESR ceramic capacitor should be used. If CBYPASS is not a low ESR ceramic capacitor, a 0.1µF ceramic
capacitor should be added in parallel to CBYPASS.
Electrical Characteristics
Electrical Characteristics, TJ = -40°C to 125°C, VCC = 12V (unless otherwise noted)
Table 1.4
Electrical Characteristics
Parameter
Symbol
Condition
Min
Typ
Max
Unit
24
V
VCC Supply Voltage
Input Supply Voltage
Quiescent Current:
Normal Mode
Quiescent Current:
Normal Mode, Non-switching
Quiescent Current:
Disabled Mode
VCC
ICC-NORM
ICCNOSWITCH
ICC-DISABLE
4.5
VCC = 12V, ILOAD = 0A, EN  2.2
5.2
mA
VCC=12V, ILOAD=0A, EN  2.2
Non-switching
2.3
mA
VCC = 12V, EN = 0V
5
10
µA
4.1
4.3
4.5
V
300
325
350
mV
0.9
1
1.1
MHz
VCC Under Voltage Lockout
Input Supply Under Voltage
Threshold
Input Supply Under Voltage
Threshold Hysteresis
VCC-UV
VCC-
VCC Increasing
UV_HYST
Oscillator
Oscillator Frequency
Data Sheet
February 13, 2014
fOSC
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
7 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
Parameter
Symbol
Condition
Min
Typ
Max
Unit
PG Open Drain Output
PG Release Timer
tPG
High-Level Output Leakage
IOH-PG
VPG = 5V
Low-Level Output Voltage
VOL-PG
IPG = -0.3mA
10
ms
0.5
µA
0.01
V
EN Input Voltage Thresholds
High Level Input Voltage
VIH-EN
Low Level Input Voltage
VIL-EN
Input Hysteresis
2.2
0.8
VHYST-EN
Input Leakage
IIN-EN
V
V
480
mV
VEN=5V
3.5
µA
VEN=0V
-1.5
µA
170
°C
10
°C
Thermal Shutdown
Thermal Shutdown Junction
Temperature
TSD Hysteresis
1.5.
TSD
Note: Guaranteed by design
150
TSDHYST
Regulator Characteristics
Electrical Characteristics, TJ = -40°C to 125°C, VCC = 12V (unless otherwise noted)
Table 1.5
Regulator Characteristics
See important table notes at the end of the table.
Parameter
Symbol
Condition
Min
Typ
Max
Unit
ILOAD =1A
VOUT –
2%
VOUT
VOUT +
2%
V
ILOAD = 0A
VOUT –
1%
VOUT +
1%
VOUT +
3.5%
V
Switch Mode Regulator: L=4.7µH and C=2 x 22µF
Output Voltage Tolerance in
Pulse-Width Modulation
(PWM) Mode
VOUT-
Output Voltage Tolerance in
Pulse-Frequency Modulation
(PFM) Mode
VOUT-
Differential Voltage Between
VOUT and VCC
PWM
PFM
VIN-OUT
High Side Switch On
1)
Resistance
Low Side Switch On
1)
Resistance
Output Current
Data Sheet
February 13, 2014
Steady State.
(Example, VOUT maximum is
3.3V with VCC min of 4.5V)
1.2
V
IVSW = -1A
180
mΩ
IVSW = 1A
120
mΩ
RDSON
IOUT
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
1
A
8 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
Parameter
Symbol
Over Current Detect
IOCD
Feedback Reference
(Adjustable Mode)
FBTH
Soft Start Ramp Time
tSS
PFM Mode FB Comparator
Tolerance
FBTH-TOL
PFM Mode FB Comparator
Threshold
FBTH-PFM
VOUT Under Voltage
Threshold
VOUT-UV
VOUT Under Voltage
Hysteresis
VOUT Over Voltage Threshold
VOUT Over Voltage
Hysteresis
Max Duty Cycle
1)
2)
1) 2)
Condition
HS switch current
Min
Typ
Max
Unit
1.4
1.8
2.4
A
0.886
0.9
0.914
V
4
For the adjustable version, the
ratio of VCC/Vout cannot exceed
16
-1.5
1.5
VOUT +
1%
88%
VOUT
VOUT-
90%
VOUT
%
V
92%
VOUT
1.5%
VOUT
UV_HYST
VOUT-OV
103%
VOUT
VOUT-
1% VOUT
OV_HYST
DUTYMAX
ms
95%
97%
99%
RDSON is characterized at 1A and tested at lower current in production.
Regulator VSW pin is forced off for 240ns every 8 cycles to ensure the BST cap is replenished.
Data Sheet
February 13, 2014
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
9 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
2
Typical Performance Characteristics – ZSPM401x Family
Graphs apply to ZSPM401x ICs. See section 1 for ZSPM4011B characteristics. Unless otherwise noted, TJ = -40°C to 125°C, VCC = 12V.
Figure 2.1 Startup Response
Figure 2.2 100mA to 1A Load Step (VCC= 12V, VOUT =1.8V)
Figure 2.3 100mA to 2A Load (VCC=12V, VOUT = 1.8V)
Figure 2.4 100mA t0 1A Load Step (VCC=12V, VOUT = 3.3V)
Figure 2.5 100mA to 2A Load Step
(VCC=12V, VOUT = 3.3V)
Figure 2.6 Line Transient Response
(VCC=10V to 15V, VOUT = 3.3V)
Data Sheet
February 13, 2014
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
10 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
Figure 2.7 Load Regulation
Figure 2.8 Line Regulation (IOUT=1A)
Figure 2.9 Efficiency vs. Output Current ( VOUT = 1.8V)
Figure 2.10 Efficiency vs. Output Current ( VOUT = 3.3V)
Figure 2.11 Efficiency vs. Output Current (VOUT= 5V)
Figure 2.12 Efficiency vs. Input Voltage (VOUT = 3.3V)
Data Sheet
February 13, 2014
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
11 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
Figure 2.13 Standby Current vs. Input Voltage
Figure 2.14 Standby Current vs. Temperature
Figure 2.15 Output Voltage vs. Temperature
Figure 2.16 Oscillator Frequency vs. Temperature
(Iout=300mA)
Figure 2.17 Quiescent Current vs. Temperature (No load)
Figure 2.18 Input Current vs. Temperature
(No load, No switching)
Data Sheet
February 13, 2014
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
12 of 22
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 RDSON 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 VOUT 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
4.2V
VCC
VCC
MONITOR
&
CONTROL
Oscillator
VCC
Over-Voltage
Protection
Bootstrap
Voltage
BST
Over Current
Protection
VCC

Gate
Drive
Gate Drive
Control
Comparator
Vref
VSW
High-Side Switch
Gate
Drive
Error Amp
Compensation
Network
FB
Thermal
Protection
Ramp
Generator
Vref
&
Soft Start
Under-Voltage
Protection
PGND
Low-Side Switch
FB
PFM Mode
Comparator
GND
Data Sheet
February 13, 2014
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
13 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
Figure 3.2
Monitor and Control Logic Functionality
PG
VOUT-UV
EN
Filter
Filter
ENABLE
REGULATOR
Internal
POR
Filter
VCC-UV
Filter
TSD
3.2.
3.2.1.
Filter
VOUT-OV
Filter
IOCD
OCD_Filter
TRI-STATE
VSW OUTPUT
Internal Protection Details
Internal Current Limit
The current through the high side FET is sensed on a cycle-by-cycle basis, and if the current limit is reached, the
over-current detection (OCD) circuit will abbreviate the cycle. The device also senses the FB pin to identify hard
short conditions and will direct the VSW output to skip 4 cycles if the current limit occurs when FB is low. This
allows current built up in the inductor during the minimum on-time to decay sufficiently. The current limit is always
active when the regulator is enabled. Soft start ensures that current limit does not prevent regulator startup.
An additional feature of the over-current protection circuitry is that under extended over-current conditions, the
device will automatically disable. A simple toggle of the EN enable pin will return the device to normal operation.
3.2.2.
Thermal Shutdown
If the temperature of the die exceeds 170°C (typical), the thermal shutdown (TSD) circuit will set the VSW outputs
to the tri-state level to protect the device from damage. The PG and all other protection circuitry will stay active to
inform the system of the failure mode. If the ZSPM4011B cools to 160°C (typical), it will attempt to start up again,
following the normal soft start sequence. If the device reaches 170°C, the shutdown/restart sequence will repeat.
3.2.3.
Voltage Reference Soft-Start
The voltage reference in this device is ramped at a rate of 4ms to prevent the output from overshoot during
startup. This ramp restarts whenever there is a rising edge sensed on the EN pin. This occurs in both the fixed
and adjustable versions. During the soft start ramp, current limit is still active and still protects the device if the
output is shorted.
3.2.4.
VCC Under-Voltage Lockout
The ZSPM4011B is held in the off state until VCC reaches 4.3V (typical). See section 1.4 for the input hysteresis.
Data Sheet
February 13, 2014
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
14 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
3.2.5.
Output Over-Voltage Protection
If the output of the regulator exceeds 103% of the regulation voltage, the output over-voltage (OUT-OV) protection
circuit will set the VSW outputs to the tri-state level to protect the ZSPM4011B from damage. (See Figure 3.2.)
This check occurs at the start of each switching cycle. If it occurs during the middle of a cycle, the switching for
that cycle will complete and the VSW outputs will tri-state at the start of the next cycle.
3.2.6.
Output Under-Voltage Monitoring
The switched mode output voltage is also monitored by the output under-voltage circuit (OUT-UV) as shown in
Figure 3.2. The PG line remains low until the output voltage reaches the V OUT-UV threshold (see Table 1.5). Once
the internal comparator detects that the output voltage is above the desired threshold, an internal delay timer is
activated and the PG line is de-asserted (to high) once this delay timer expires. In the event that the output
voltage decreases below VOUT-UV, the PG line will be asserted low and remain low until the output rises above
VOUT-UV and the delay timer times out. There is a hysteresis for the V OUT-UV threshold (see Table 1.5.
Data Sheet
February 13, 2014
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
15 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
4
4.1.
Application Circuits
Selection of External Components
The internal compensation is optimized for a 44µF output capacitor (COUT) and a 4.7µH inductor (LOUT). The
minimum allowable value for the output capacitor is 33µF. To keep the output ripple low, a low ESR (less than
35mΩ) ceramic is recommended. The inductor range is 4.7µH +/-20%. For optimal over-current protection, the
inductor should be able to handle up to the regulator current limit without saturation.
Connect the VCC pin to the bypass capacitor CBYPASS to improve performance (see section 5.4.1). See Table 1.3
for the recommended value.
Connect the BST pin to the bootstrap capacitor CBST as described in section 5.4.2. See Table 1.3 for the
recommended value.
For the adjustable version of the ZSPM4011B, an external voltage resistor divider is required (R TOP and RBOT).
See section 5.4.3 for details.
4.2.
Typical Application Circuits
Figure 4.1
Typical Application for Adjustable Output Voltage
Adjustable Output
BST
VCC
ZSPM4011B
EN
GND
EN
Figure 4.2
CBST
VSW
CBYPASS
PGND
VCC
VOUT
LOUT
RTOP
COUT
RBOT
FB
VOUT
10 kΩ
(optional)
PG
PG
Typical Application for Fixed Output Voltage
Fixed Output
BST
VCC
EN
GND
EN
ZSPM4011B
CBYPASS
Data Sheet
February 13, 2014
PGND
VCC
VSW
CBST
VOUT
LOUT
COUT
FB
VOUT
10kΩ
(optional)
PG
PG
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
16 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
5
5.1.
Pin Configuration and Package
Package Dimensions
Figure 5.1
ZSPM4011B Package Drawing
Data Sheet
February 13, 2014
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
17 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
5.2.
Marking Diagram & Pin-out
Figure 5.2
16 Lead 3x3mm QFN (top view)
4011B: Part Name
B: Revision
XXXXX: Lot number (last five digits)
O: Pin 1 mark
VL: Voltage level
 15 1.5V
 18 1.8V
 25 2.5V
 33 3.3V
 50 5.0V
 00 0.9V – 5.5V variable
MY: Date Code
M = Month
 1 January
 2 February
 3 March
 4 April
 5 May
 6 June
 7 July
 8 August
 9 September
 A October
 B November
 C December
Y = Year
 A 2011
 B 2012
 C 2013
 etc.
Data Sheet
February 13, 2014
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
18 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
5.3.
Pin Description for 16 LEAD 3x3 QFN
Table 5.1
Pin Description, 16 lead, 3x3mm QFN
Name
Pin #
VSW
1
Switching Voltage Node
Connected to a 4.7µH (typical) inductor. Also connect to
additional VSW pins 12, 13, and 16.
VCC
2
Input Voltage
Input voltage. Also connect to additional VCC pins 3 and 11.
VCC
3
Input Voltage
Input voltage. Also connect to additional VCC pins 2 and 11.
GND
4
GND
Primary ground for the majority of the device except the low-side
power FET.
FB
5
Feedback Input
Regulator FB voltage. Connects to VOUT for fixed-mode and the
output resistor divider for adjustable mode.
NC
6
No Connect
Not connected.
NC
7
No Connect
Not connected.
PG
8
PG Output
Open-drain output.
EN
9
Enable Input
Above 2.2V the device is enabled. Ground this pin to disable the
ZSPM4011B. Includes internal pull-up.
BST
10
Bootstrap Capacitor
Bootstrap capacitor for the high-side FET gate driver. Connect a
22nF ceramic capacitor from BST pin to VSW pin.
VCC
11
Input Voltage
Input voltage. Also connect to additional VCC pins 2 and 3.
VSW
12
Switching Voltage Node
Connect to additional VSW pins 1, 13, and 16.
VSW
13
Switching Voltage Node
Connect to additional VSW pins 1, 12, and 16.
PGND
14
Power GND
GND supply for internal low-side FET/integrated diode. Also
connect to additional PGND pin 15.
PGND
15
Power GND
GND supply for internal low-side FET/integrated diode. Also
connect to additional PGND pin 14.
VSW
16
Switching Voltage Node
Connect to additional VSW pins 1, 12, and 13.
Data Sheet
February 13, 2014
Function
Description
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
19 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
5.4.
5.4.1.
Detailed Pin Description
Unregulated Input, VCC (Pins # 2, 3)
This terminal is the unregulated input voltage source for the ZSPM4011B. It is recommended that a 10µF bypass
capacitor be placed close to the device for best performance. Since this is the main supply for the ZSPM4011B,
good layout practices must be followed for this connection.
5.4.2.
Bootstrap Control, BST (Pin #10)
This terminal will provide the bootstrap voltage required for the high-side internal NMOS switch of the buck
regulator. An external ceramic capacitor placed between the BST input terminal, and the VSW pin will provide the
necessary voltage for the high-side switch. In normal operation, the capacitor is re-charged on every low side
synchronous switching action. If the switch mode approaches 100% duty cycle for the high side FET, the device
th
will automatically reduce the duty cycle switch to a minimum off time on every 8 cycle to allow this capacitor to
re-charge.
5.4.3.
Sense Feedback, FB (Pin #5)
This is the input terminal for the output voltage feedback. For the fixed-mode versions, this should be connected
directly to VOUT. The connection on the PCB should be kept as short as possible and should be made as close as
possible to the capacitor. The trace should not be shared with any other connection. For adjustable-mode
versions of the ZSPM4011B, this should be connected to the external resistor divider. To choose the resistors,
use the following equation:
VOUT = 0.9 (1 + RTOP/RBOT)
The input to the FB pin is high impedance, and input current should be less than 100nA. As a result, good layout
practices are required for the feedback resistors and feedback traces. When using the adjustable version, the
feedback trace should be kept as short and narrow as possible to reduce stray capacitance and the injection of
noise.
5.4.4.
Switching Output, VSW (Pins #12, 13)
This is the switching node of the regulator. It should be connected directly to the 4.7µH inductor with a wide, short
trace and to one end of the bootstrap capacitor. It switches between VCC and PGND at the switching frequency.
5.4.5.
Ground, GND (Pin #4)
This ground is used for the majority of the device including the analog reference, control loop, and other circuits.
5.4.6.
Power Ground, PGND (Pins #14, 15)
This is a separate ground connection used for the low-side synchronous switch to isolate switching noise from the
rest of the device.
5.4.7.
Enable, EN (Pin #9)
This is the input terminal to activate the regulator. The input threshold is TTL/CMOS compatible. It also has an
internal pull-up to ensure a stable state if the pin is disconnected.
5.4.8.
PG Output, PG (Pin #8)
This is an open drain, active low output. See section 3.2.6 for a description of the function of this pin.
Data Sheet
February 13, 2014
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
20 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
6
Ordering Information
Ordering Code
Description
Package
ZSPM4011BA1W00
1A Synchronous Buck Converter: adjustable output, 0.9V to 5.5V,
16-pin 3x3mm QFN
7” reel with 1000
ICs
ZSPM4011BA1W15
1A Synchronous Buck Converter: fixed output, 1.5V,16-pin 3x3mm QFN
7” reel with 1000
ICs
ZSPM4011BA1W18
1A Synchronous Buck Converter: fixed output, 1.8V,16-pin 3x3mm QFN
7” reel with 1000
ICs
ZSPM4011BA1W25
1A Synchronous Buck Converter: fixed output, 2.5V,16-pin 3x3mm QFN
7” reel with 1000
ICs
ZSPM4011BA1W33
1A Synchronous Buck Converter: fixed output, 3.3V,16-pin 3x3mm QFN
7” reel with 1000
ICs
ZSPM4011BA1W50
1A Synchronous Buck Converter: fixed output, 5.0V,16-pin 3x3mm QFN
7” reel with 1000
ICs
ZSPM4011BKIT
ZSPM4011BKIT, Evaluation Kit for 1A Synchronous Buck Converter
Kit
7
Related Documents
Document
File Name
ZSPM4011B Feature Sheet
ZSPM4011B_Feature_Sheet_rev_X_xy.pdf
ZSPM4011B Evaluation Kit Description
ZSPM4011B_12B_13B_Eval_Kit_Manual__X_xy.pdf
Note: X_xy denotes the current revision of the document. Visit ZMDI’s website www.zmdi.com or contact your nearest sales
office for the latest version of these documents.
8
Glossary
Term
Description
PWM
Pulse width modulation (fixed frequency).
PFM
Pulse frequency modulation (fixed pulse width).
POR
Power-on reset
ESR
Equivalent series resistance.
Data Sheet
© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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.
February 13, 2014
21 of 22
ZSPM4011B
High Efficiency 1A Synchronous Buck Converter
9
Document Revision History
Revision
Date
Description
1.00
April 4, 2013
1.10
June 21, 2013
1.20
February 13, 2014
First release of ZSPM4011BB, based on ZSPM4011B, silicon revision A.
Update to allow for 5.5V output voltage, new transient response graph, addition of
thermal parameter for “Thermal Resistance Junction to Case (Jc)” specification, and
revision of “Thermal Resistance Junction to Ambient (JA)” specification.
Revision of specifications for “Input Supply Under Voltage Threshold Hysteresis” in
Table 1.4.
Sales and Further Information
www.zmdi.com
[email protected]
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Dresden AG
Global Headquarters
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Fax
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USA Phone 1.855.275.9634
Phone +1.408.883.6310
Fax
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Phone +49.351.8822.7.772
Fax
+49.351.8822.87.772
DISCLAIMER: This information applies to a product under development. Its characteristics and specifications are subject to change without notice.
Zentrum Mikroelektronik Dresden AG (ZMD AG) assumes no obligation regarding future manufacture unless otherwise agreed to in writing. The
information furnished hereby is believed to be true and accurate. However, under no circumstances shall ZMD AG be liable to any customer,
licensee, or any other third party for any special, indirect, incidental, or consequential damages of any kind or nature whatsoever arising out of or
in any way related to the furnishing, performance, or use of this technical data. ZMD AG hereby expressly disclaims any liability of ZMD AG to any
customer, licensee or any other third party, and any such customer, licensee and any other third party hereby waives any liability of ZMD AG for
any damages in connection with or arising out of the furnishing, performance or use of this technical data, whether based on contract, warranty,
tort (including negligence), strict liability, or otherwise.
European Sales (Stuttgart)
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Fax
+49.711.674517.87955
Data Sheet
February 13, 2014
Zentrum Mikroelektronik
Dresden AG, Japan Office
2nd Floor, Shinbashi Tokyu Bldg.
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Phone +81.3.6895.7410
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© 2013 Zentrum Mikroelektronik Dresden AG — Rev. 1.20
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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