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.
•
•
Available Support
Physical Characteristics
•
•
Related IDT Products
•
•
•
•
•
•
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© 2016 Integrated Device Technology, Inc.
ZSPM4011B Application Circuits
Adjustable Output
BST
VCC
EN
ZSPM4011B
CBYPASS
EN
CBST
VSW
PGND
VCC
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
VOUT
LOUT
RTOP
COUT
RBOT
FB
VOUT
10 kΩ
(optional)
PG
PG
Fixed Output
VCC
BST
VCC
CBYPASS
EN
ZSPM4011B
•
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)
EN
1
PGND
•
Junction operating temperature -40°C to 125°C
Packaged in a 16pin QFN (3x3mm)
GND
•
Evaluation Kit
Documentation
•
Features
•
Increased battery life
Minimal external component count
(3 capacitors, 1 inductor)
Inherent fault protection and reporting
•
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.
•
Datasheet
VSW
CBST
VOUT
LOUT
COUT
FB
VOUT
10kΩ
(optional)
PG
PG
January 27, 2016
ZSPM4011B
High Efficiency 1A Synchronous
Buck Converter
ZSPM4011B Block Diagram
EN
PG
Datasheet
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
Bootstrap
Voltage
Thermal
Protection
Ramp
Generator
Vref
&
Soft Start
Under-Voltage
Protection
BST
Over Current
Protection
VCC
S
Gate
Drive
Gate Drive
Control
Comparator
Gate
Drive
Error Amp
Compensation
Network
VSW
High-Side Switch
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
Package
Corporate Headquarters
Sales
6024 Silver Creek Valley Road
San Jose, CA 95138
www.IDT.com
1-800-345-7015 or 408-284-8200
Fax: 408-284-2775
www.IDT.com/go/sales
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
Tech Support
www.IDT.com/go/support
DISCLAIMER Integrated Device Technology, Inc. (IDT) reserves the right to modify the products and/or specifications described herein at any time, without notice, at IDT's sole discretion. Performance
specifications and operating parameters of the described products are determined in an independent state and are not guaranteed to perform the same way when installed in customer products. The
information contained herein is provided without representation or warranty of any kind, whether express or implied, including, but not limited to, the suitability of IDT's products for any particular purpose, an
implied warranty of merchantability, or non-infringement of the intellectual property rights of others. This document is presented only as a guide and does not convey any license under intellectual property
rights of IDT or any third parties.
IDT's products are not intended for use in applications involving extreme environmental conditions or in life support systems or similar devices where the failure or malfunction of an IDT product can be
reasonably expected to significantly affect the health or safety of users. Anyone using an IDT product in such a manner does so at their own risk, absent an express, written agreement by IDT.
Integrated Device Technology, IDT and the IDT logo are trademarks or registered trademarks of IDT and its subsidiaries in the United States and other countries. Other trademarks used herein are the
property of IDT or their respective third party owners. For datasheet type definitions and a glossary of common terms, visit www.idt.com/go/glossary. All contents of this document are copyright of Integrated
Device Technology, Inc. All rights reserved.
© 2016 Integrated Device Technology, Inc.
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ZSPM4011B Datasheet
Contents
1
2
3
4
5
6
7
8
9
ZSPM4011B Characteristics ............................................................................................................................... 5
1.1. Absolute Maximum Ratings .......................................................................................................................... 5
1.2. Thermal Characteristics ................................................................................................................................ 5
1.3. Recommended Operating Conditions .......................................................................................................... 6
1.4. Electrical Characteristics .............................................................................................................................. 6
1.5. Regulator Characteristics ............................................................................................................................. 7
Typical Performance Characteristics – ZSPM401x Family ................................................................................. 9
Description of Circuit ......................................................................................................................................... 12
3.1. Block Diagram ............................................................................................................................................ 12
3.2. Internal Protection Details .......................................................................................................................... 13
3.2.1. Internal Current Limit ........................................................................................................................... 13
3.2.2. Thermal Shutdown ............................................................................................................................... 13
3.2.3. Voltage Reference Soft-Start ............................................................................................................... 13
3.2.4. VCC Under-Voltage Lockout................................................................................................................ 13
3.2.5. Output Over-Voltage Protection ........................................................................................................... 14
3.2.6. Output Under-Voltage Monitoring ........................................................................................................ 14
Application Circuits ............................................................................................................................................ 15
4.1. Selection of External Components ............................................................................................................. 15
4.2. Typical Application Circuits ......................................................................................................................... 15
Pin Configuration and Package ......................................................................................................................... 16
5.1. Package Dimensions .................................................................................................................................. 16
5.2. Marking Diagram & Pin-out ........................................................................................................................ 17
5.3. Pin Description for 16 LEAD 3x3 QFN ....................................................................................................... 18
5.4. Detailed Pin Description ............................................................................................................................. 19
5.4.1. Unregulated Input, VCC (Pins # 2, 3) .................................................................................................. 19
5.4.2. Bootstrap Control, BST (Pin #10) ........................................................................................................ 19
5.4.3. Sense Feedback, FB (Pin #5) .............................................................................................................. 19
5.4.4. Switching Output, VSW (Pins #12, 13) ................................................................................................ 19
5.4.5. Ground, GND (Pin #4) ......................................................................................................................... 19
5.4.6. Power Ground, PGND (Pins #14, 15) .................................................................................................. 19
5.4.7. Enable, EN (Pin #9) ............................................................................................................................. 19
5.4.8. PG Output, PG (Pin #8) ....................................................................................................................... 19
Ordering Information ......................................................................................................................................... 20
Related Documents ........................................................................................................................................... 20
Glossary ............................................................................................................................................................ 20
Document Revision History ............................................................................................................................... 21
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ZSPM4011B Datasheet
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 .................................................................................................................................. 9
100mA to 1A Load Step (VCC= 12V, VOUT =1.8V) ............................................................................. 9
100mA to 2A Load (VCC=12V, VOUT = 1.8V) ...................................................................................... 9
100mA t0 1A Load Step (VCC=12V, VOUT = 3.3V) ............................................................................. 9
100mA to 2A Load Step (VCC=12V, VOUT = 3.3V) ............................................................................. 9
Line Transient Response (VCC=10V to 15V, VOUT = 3.3V) ................................................................ 9
Load Regulation ................................................................................................................................... 10
Line Regulation (IOUT=1A) .................................................................................................................... 10
Efficiency vs. Output Current ( VOUT = 1.8V) ..................................................................................... 10
Efficiency vs. Output Current ( VOUT = 3.3V) ..................................................................................... 10
Efficiency vs. Output Current (VOUT= 5V) .......................................................................................... 10
Efficiency vs. Input Voltage (VOUT = 3.3V) ......................................................................................... 10
Standby Current vs. Input Voltage ....................................................................................................... 11
Standby Current vs. Temperature ....................................................................................................... 11
Output Voltage vs. Temperature.......................................................................................................... 11
Oscillator Frequency vs. Temperature (Iout=300mA) ......................................................................... 11
Quiescent Current vs. Temperature (No load) .................................................................................... 11
Input Current vs. Temperature (No load, No switching) ..................................................................... 11
ZSPM4011B Block Diagram ................................................................................................................ 12
Monitor and Control Logic Functionality .............................................................................................. 13
Typical Application for Adjustable Output Voltage............................................................................... 15
Typical Application for Fixed Output Voltage ....................................................................................... 15
ZSPM4011B Package Drawing ........................................................................................................... 16
16 Lead 3x3mm QFN (top view) .......................................................................................................... 17
List of Tables
Table 1.1
Table 1.2
Table 1.3
Table 1.4
Table 1.5
Table 5.1
Absolute Maximum Ratings ................................................................................................................... 5
Thermal Characteristics ......................................................................................................................... 5
Recommended Operating Conditions ................................................................................................... 6
Electrical Characteristics ....................................................................................................................... 6
Regulator Characteristics ...................................................................................................................... 7
Pin Description, 16 lead, 3x3mm QFN ................................................................................................ 18
© 2016 Integrated Device Technology, Inc.
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ZSPM4011B Datasheet
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
θJA
34.5
°C/W
θJc
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 in area of 2 oz. copper and 25°C ambient temperature.
2
© 2016 Integrated Device Technology, Inc.
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ZSPM4011B Datasheet
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
mΩ
µF
For best performance, an inductor with a saturation current rating higher than the maximum VOUT 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 Increasing
VCCUV_HYST
Oscillator
Oscillator Frequency
fOSC
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ZSPM4011B Datasheet
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
Input Leakage
2.2
0.8
VHYST-EN
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
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
Output Current
IOUT
Over Current Detect
IOCD
© 2016 Integrated Device Technology, Inc.
HS switch current
7
1.4
1.8
1
A
2.4
A
January 27, 2016
ZSPM4011B Datasheet
Parameter
Symbol
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
Min
Typ
Max
Unit
0.886
0.9
0.914
V
4
For the adjustable version, the
ratio of VCC/Vout cannot exceed
16
-1.5
ms
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
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.
© 2016 Integrated Device Technology, Inc.
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ZSPM4011B Datasheet
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)
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ZSPM4011B Datasheet
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)
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ZSPM4011B Datasheet
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)
© 2016 Integrated Device Technology, Inc.
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ZSPM4011B Datasheet
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
EN
PG
VCC
4.2V
VCC
VCC
MONITOR
&
CONTROL
Oscillator
VCC
Over-Voltage
Protection
Bootstrap
Voltage
BST
Over Current
Protection
VCC
S
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
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ZSPM4011B Datasheet
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.
© 2016 Integrated Device Technology, Inc.
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ZSPM4011B Datasheet
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 VOUT-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 VOUT-UV threshold (see Table 1.5.
© 2016 Integrated Device Technology, Inc.
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ZSPM4011B Datasheet
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 (RTOP 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
© 2016 Integrated Device Technology, Inc.
PGND
VCC
VSW
CBST
VOUT
LOUT
COUT
FB
VOUT
10kΩ
(optional)
PG
15
PG
January 27, 2016
ZSPM4011B Datasheet
5
5.1.
Pin Configuration and Package
Package Dimensions
Figure 5.1
ZSPM4011B Package Drawing
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ZSPM4011B Datasheet
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.
© 2016 Integrated Device Technology, Inc.
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ZSPM4011B Datasheet
5.3.
Pin Description for 16 LEAD 3x3 QFN
Table 5.1
Pin Description, 16 lead, 3x3mm QFN
Name
Pin #
Function
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.
© 2016 Integrated Device Technology, Inc.
Description
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January 27, 2016
ZSPM4011B Datasheet
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.
© 2016 Integrated Device Technology, Inc.
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ZSPM4011B Datasheet
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
ZSPM4011B Feature Sheet
ZSPM4011B Evaluation Kit Description
Visit IDT’s website www.IDT.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.
© 2016 Integrated Device Technology, Inc.
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ZSPM4011B Datasheet
9
Document Revision History
Revision
Date
Description
1.00
April 4, 2013
1.10
June 21, 2013
1.20
February 13, 2014
Revision of specifications for “Input Supply Under Voltage Threshold Hysteresis” in
Table 1.4.
January 27, 2016
Changed to IDT branding.
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 (θJc)” specification, and
revision of “Thermal Resistance Junction to Ambient (θJA)” specification.
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www.IDT.com/go/support
DISCLAIMER Integrated Device Technology, Inc. (IDT) reserves the right to modify the products and/or specifications described herein at any time, without notice, at IDT's sole discretion. Performance
specifications and operating parameters of the described products are determined in an independent state and are not guaranteed to perform the same way when installed in customer products. The
information contained herein is provided without representation or warranty of any kind, whether express or implied, including, but not limited to, the suitability of IDT's products for any particular purpose, an
implied warranty of merchantability, or non-infringement of the intellectual property rights of others. This document is presented only as a guide and does not convey any license under intellectual property
rights of IDT or any third parties.
IDT's products are not intended for use in applications involving extreme environmental conditions or in life support systems or similar devices where the failure or malfunction of an IDT product can be
reasonably expected to significantly affect the health or safety of users. Anyone using an IDT product in such a manner does so at their own risk, absent an express, written agreement by IDT.
Integrated Device Technology, IDT and the IDT logo are trademarks or registered trademarks of IDT and its subsidiaries in the United States and other countries. Other trademarks used herein are the
property of IDT or their respective third party owners. For datasheet type definitions and a glossary of common terms, visit www.idt.com/go/glossary. All contents of this document are copyright of Integrated
Device Technology, Inc. All rights reserved.
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