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TPS561201, TPS561208
ZHCSG73 – APRIL 2017
采用 6 引脚 SOT-23 封装的 TPS56120x 4.5V 至 17V 输入、1A 同步降压
稳压器
1 特性
•
1
•
•
•
•
•
•
•
•
•
•
•
•
•
3 说明
TPS561201 和 TPS561208 1A 转换器集成了
140mΩ 和 84mΩ FET
D-CAP2™模式控制，用于快速瞬态响应
输入电压范围：4.5V 至 17V
输出电压范围：0.76V 至 7V
脉冲跳跃模式 (TPS561201) 或持续电流模式
(TPS561208)
580kHz 开关频率
低关断电流（小于 10µA）
2% 反馈电压精度 (25°C)
从预偏置输出电压中启动
逐周期过流限制
断续模式过流保护
非锁存欠压保护 (UVP) 和热关断 (TSD) 保护
固定软启动时间：1.0ms
使用 TPS56120x 并借助 WEBENCH® Power
Designer 创建定制设计方案
TPS561201 和 TPS561208 是采用 SOT-23 封装的简
单易用型 1A 同步降压转换器。
此器件被优化为使用尽可能少的外部组件即可运行，并
且可以实现低待机电流。
这些开关模式电源 (SMPS) 器件采用 D-CAP2 模式控
制，从而提供快速瞬态响应，并且在无需外部补偿组件
的情况下支持诸如高分子聚合物等低等效串联电阻
(ESR) 输出电容器以及超低 ESR 陶瓷电容器。
TPS561201 可在脉冲跳跃模式下运行，从而能在轻载
运行期间保持高效率。TPS561201 和 TPS561208 可
提供 6 引脚 1.6 × 2.9 (mm) SOT (DDC) 封装，额定结
温范围为 –40°C 至 125°C。
器件信息(1)
器件型号
TPS561201
TPS561208
2 应用
•
•
•
•
•
封装
SOT (6)
封装尺寸（标称值）
1.60mm x 2.90mm
(1) 要了解所有可用封装，请参见数据表末尾的可订购产品附录。
数字电视电源
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网络家庭终端设备
数字机顶盒 (STB)
安全监控
简化电路原理图
TPS561201 效率
100%
90%
TPS561201
2
VOUT
COUT
3
VIN
GND
VBST
SW
EN
VIN
VFB
80%
6
70%
5
EN
4
VOUT
Efficiency
1
60%
50%
40%
30%
CIN
Vout = 1.05 V
Vout = 1.5 V
Vout = 3.3 V
Vout = 5 V
20%
10%
Copyright © 2017, Texas Instruments Incorporated
0
0.001
0.01
0.1
Output Current (A)
1
D001
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
English Data Sheet: SLVSC95
TPS561201, TPS561208
ZHCSG73 – APRIL 2017
www.ti.com.cn
目录
1
2
3
4
5
6
7
特性 ..........................................................................
应用 ..........................................................................
说明 ..........................................................................
修订历史记录 ...........................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
4
6.1
6.2
6.3
6.4
6.5
6.6
4
4
4
4
5
6
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
Typical Characteristics ..............................................
7.4 Device Functional Modes........................................ 11
8
Application and Implementation ........................ 12
8.1 Application Information............................................ 12
8.2 Typical Application ................................................. 12
9 Power Supply Recommendations...................... 18
10 Layout................................................................... 18
10.1 Layout Guidelines ................................................. 18
10.2 Layout Example .................................................... 18
11 器件和文档支持 ..................................................... 19
11.1
11.2
11.3
11.4
11.5
Detailed Description .............................................. 9
7.1 Overview ................................................................... 9
7.2 Functional Block Diagram ......................................... 9
7.3 Feature Description................................................... 9
相关链接................................................................
社区资源................................................................
商标 .......................................................................
静电放电警告.........................................................
Glossary ................................................................
19
19
19
19
19
12 机械、封装和可订购信息 ....................................... 19
4 修订历史记录
2
日期
修订版本
注释
2017 年 4 月
*
首次发布。
Copyright © 2017, Texas Instruments Incorporated
TPS561201, TPS561208
www.ti.com.cn
ZHCSG73 – APRIL 2017
5 Pin Configuration and Functions
DDC Package
6-Pin SOT
Top View
1
GND
2
SW
3
VIN
TPS561201
VBST
6
EN
5
VFB
4
Pin Functions
PIN
NAME
DESCRIPTION
NO.
GND
1
Ground pin Source terminal of low-side power NFET as well as the ground terminal for controller circuit.
Connect sensitive VFB to this GND at a single point.
SW
2
Switch node connection between high-side NFET and low-side NFET.
VIN
3
Input voltage supply pin. The drain terminal of high-side power NFET.
VFB
4
Converter feedback input. Connect to output voltage with feedback resistor divider.
EN
5
Enable input control. Active high and must be pulled up to enable the device.
VBST
6
Supply input for the high-side NFET gate drive circuit. Connect 0.1-µF capacitor between VBST and SW pins.
Copyright © 2017, Texas Instruments Incorporated
3
TPS561201, TPS561208
ZHCSG73 – APRIL 2017
www.ti.com.cn
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
MIN
MAX
UNIT
VIN, EN
–0.3
19
V
VBST
–0.3
25
V
VBST (10-ns transient)
–0.3
27
V
VBST (vs SW)
–0.3
6.5
V
VFB
–0.3
6.5
V
SW
–2
19
V
–3.5
21
V
Operating junction temperature, TJ
–40
150
°C
Storage temperature, Tstg
–55
150
°C
Input voltage
SW (10 ns transient)
(1)
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
6.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic
discharge
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1)
±3000
Charged-device model (CDM), per JEDEC specification JESD22-C101 (2)
±1500
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
VIN
MIN
MAX
Supply input voltage
VI
Input voltage
TJ
4.5
17
VBST
–0.1
23
VBST (10-ns transient)
–0.1
26
VBST(vs SW)
–0.1
6.0
EN
–0.1
17
VFB
–0.1
5.5
SW
–1.8
17
SW (10 ns transient)
–3.5
20
–40
125
Operating junction temperature
UNIT
V
V
°C
6.4 Thermal Information
THERMAL METRIC
(1)
TPS561201 and
TPS561208
DDC (SOT)
UNIT
6 PINS
RθJA
Junction-to-ambient thermal resistance
90.8
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance
42.3
°C/W
RθJB
Junction-to-board thermal resistance
16.3
°C/W
ψJT
Junction-to-top characterization parameter
2.6
°C/W
ψJB
Junction-to-board characterization parameter
16.3
°C/W
(1)
4
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report, SPRA953.
Copyright © 2017, Texas Instruments Incorporated
TPS561201, TPS561208
www.ti.com.cn
ZHCSG73 – APRIL 2017
6.5 Electrical Characteristics
TJ = –40°C to 125°C, V = 12 V (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
TPS561201
380
520
TPS561208
590
750
1
10
UNIT
SUPPLY CURRENT
IVIN
Operating – non-switching
supply current
VIN current, EN = 5 V, VFB =
0.8 V
IVINSDN
Shutdown supply current
VIN current, EN = 0 V
µA
µA
LOGIC THRESHOLD
VENH
EN high-level input voltage
EN
VENL
EN low-level input voltage
EN
REN
EN pin resistance to GND
VEN = 12 V
1.6
225
V
400
0.8
V
900
kΩ
VFB VOLTAGE AND DISCHARGE RESISTANCE
VFB threshold voltage
VO = 1.05 V, IO = 10 mA, Eco-mode™ operation
VFBTH
VFB threshold voltage
VO = 1.05 V, continuous mode operation
IVFB
VFB input current
VFB = 0.8 V
RDS(on)h
High-side switch resistance
TA = 25°C, VBST – SW = 5.5 V
RDS(on)l
Low-side switch resistance
TA = 25°C
774
749
mV
768
787
mV
0
±0.1
µA
MOSFET
140
mΩ
84
mΩ
CURRENT LIMIT
Iocl
Current limit
DC current, VOUT = 1.05 V, L1 = 2.2 µH
1.2
1.6
2.0
A
THERMAL SHUTDOWN
TSDN
Thermal shutdown threshold (1)
Shutdown temperature
160
Hysteresis
°C
25
ON-TIME TIMER CONTROL
tOFF(MIN)
Minimum off time
VFB = 0.5 V
220
310
ns
Soft-start time
Internal soft-start time
1.0
ms
Switching frequency
VIN = 12 V, VO = 1.05 V, FCCM mode
580
kHz
SOFT START
tss
Frequency
Fsw
OUTPUT UNDERVOLTAGE AND OVERVOLTAGE PROTECTION
VUVP
Output UVP threshold
THICCUP_WAI
Hiccup detect (H > L)
65%
Hiccup wait time
1.8
ms
Hiccup time before restart
15
ms
T
THICCUP_RE
UVLO
Wake up VIN voltage
UVLO
UVLO threshold
Shut down VIN voltage
Hysteresis VIN voltage
(1)
4.0
3.3
3.6
4.3
V
0.4
Not production tested
Copyright © 2017, Texas Instruments Incorporated
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TPS561201, TPS561208
ZHCSG73 – APRIL 2017
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6.6 Typical Characteristics
VIN = 12 V (unless otherwise noted)
0.762
0.45
FB Voltage (V)
Buck Quiescent Current (mA)
0.5
0.4
0.761
0.76
0.35
0.3
-50
-20
10
40
70
TJ - Junction Temperature (qC)
100
0.759
-50
130
-20
D001
Figure 1. TPS561201 Supply Current vs Junction
Temperature
10
40
70
TJ - Junction Temperature (qC)
100
130
D002
Figure 2. VFB Voltage vs Junction Temperature
1.45
1.23
EN Pin UVLO - High (V)
EN Pin UVLO - Low (V)
1.2
1.17
1.14
1.11
1.08
1.42
1.39
1.36
1.33
1.05
1.02
-50
-20
10
40
70
TJ - Junction Temperature (qC)
100
1.3
-50
130
Figure 3. EN Pin UVLO Low Voltage vs Junction
Temperature
100
130
D003
32
70
28
Low Side Rds_on (m:)
High Side Rds_on (m:)
10
40
70
TJ - Junction Temperature (qC)
Figure 4. EN Pin UVLO High Voltage vs Junction
Temperature
80
60
50
40
24
20
16
30
20
-50
-30
-10
10
30
50
70
90
TJ - Junction Temperature (qC)
110
130
D005
Figure 5. High-Side Rds-on vs Junction Temperature
6
-20
D004
12
-50
-30
-10
10
30
50
70
90
TJ - Junction Temperature (qC)
110
130
D006
Figure 6. Low-Side Rds-on vs Junction Temperature
Copyright © 2017, Texas Instruments Incorporated
TPS561201, TPS561208
www.ti.com.cn
ZHCSG73 – APRIL 2017
Typical Characteristics (continued)
620
600
600
500
Switching Frequency (KHz)
Switching Frequency (KHz)
VIN = 12 V (unless otherwise noted)
580
560
540
Vout = 1.05 V
Vout = 3.3 V
Vout = 5 V
520
6
8
10
12
Input Voltage (V)
14
16
300
200
100
0
0.001
500
4
400
18
D007
Iout = 10 mA
90%
80%
80%
70%
70%
60%
60%
Efficiency
Efficiency
100%
90%
50%
40%
30%
50%
40%
30%
Vin = 5 V
Vin = 9 V
Vin = 12 V
Vin = 15 V
20%
10%
0.01
0.1
Output Current (A)
Vin = 5 V
Vin = 9 V
Vin = 12 V
Vin = 15 V
20%
10%
0
0.001
1
D010
Figure 9. TPS561201 VOUT = 1.05 V Efficiency, L = 2.2 µH
100%
90%
90%
80%
80%
70%
70%
60%
60%
50%
40%
30%
0.01
0.1
Output Current (A)
1
D011
Figure 10. TPS561201 VOUT = 1.5 V Efficiency, L = 2.2 µH
100%
Efficiency
Efficiency
D009
Figure 8. TPS561201 Switching Frequency vs Output
Current
100%
50%
40%
30%
Vin = 5 V
Vin = 9 V
Vin = 12 V
Vin = 15 V
20%
10%
0
0.001
1
VIN = 12 V
Figure 7. TPS561208 Switching Frequency vs Input Voltage
0
0.001
0.01
0.1
Output Current (A)
0.01
0.1
Output Current (A)
20%
1
D012
Figure 11. TPS561201 VOUT = 3.3 V Efficiency, L = 3.3 µH
Copyright © 2017, Texas Instruments Incorporated
Vin = 9 V
Vin = 12 V
Vin = 15 V
10%
0
0.001
0.01
0.1
Output Current (A)
1
D013
Figure 12. TPS561201 VOUT = 5 V Efficiency, L = 4.7 µH
7
TPS561201, TPS561208
ZHCSG73 – APRIL 2017
www.ti.com.cn
Typical Characteristics (continued)
VIN = 12 V (unless otherwise noted)
100%
1
90%
80%
0.8
Efficiency
Efficiency
70%
0.6
0.4
60%
50%
40%
30%
Vin = 5 V
Vin = 9 V
Vin = 12 V
Vin = 15 V
0.2
0
0.001
0.01
0.1
Output Current (A)
10%
0
0.001
1
D014
90%
90%
80%
80%
70%
70%
60%
60%
50%
40%
30%
1
D015
50%
40%
30%
Vin = 5 V
Vin = 9 V
Vin = 12 V
Vin = 15 V
20%
10%
0.01
0.1
Output Current (A)
20%
Vin = 9 V
Vin = 12 V
Vin = 15 V
10%
1
D016
Figure 15. TPS561208 VOUT = 3.3 V Efficiency, L = 3.3 µH
8
0.01
0.1
Output Current (A)
Figure 14. TPS561208 VOUT = 1.5 V Efficiency, L = 2.2 µH
100%
Efficiency
Efficiency
Figure 13. TPS561208 VOUT = 1.05 V Efficiency, L = 2.2 µH
100%
0
0.001
Vin = 5 V
Vin = 9 V
Vin = 12 V
Vin = 15 V
20%
0
0.001
0.01
0.1
Output Current (A)
1
D017
Figure 16. TPS561208 VOUT = 5 V Efficiency, L = 4.7 µH
Copyright © 2017, Texas Instruments Incorporated
TPS561201, TPS561208
www.ti.com.cn
ZHCSG73 – APRIL 2017
7 Detailed Description
7.1 Overview
The TPS561201 and TPS561208 are 1-A synchronous step-down converters. The proprietary D-CAP2 mode
control supports low ESR output capacitors such as specialty polymer capacitors and multi-layer ceramic
capacitors without complex external compensation circuits. The fast transient response of D-CAP2 mode control
can reduce the output capacitance required to meet a specific level of performance.
7.2 Functional Block Diagram
EN 5
VUVP
VOVP
VFB
+
UVP
Hiccup
Ref
Soft Start
SS
6
VBST
2
SW
1
GND
UVLO
4
Voltage
Reference
VIN
VREG5
Regulator
+
OVP
3
PWM
+
+
HS
Control Logic
Ton
One-Shot
XCON
VREG5
TSD
OCL
threshold
LS
OCL
+
+
ZC
Copyright © 2017, Texas Instruments Incorporated
7.3 Feature Description
7.3.1 Adaptive On-Time Control and PWM Operation
The main control loop of the TPS561201 is adaptive on-time pulse width modulation (PWM) controller that
supports a proprietary D-CAP2 mode control. The D-CAP2 mode control combines adaptive on-time control with
an internal compensation circuit for pseudo-fixed frequency and low external component count configuration with
both low ESR and ceramic output capacitors. It is stable even with virtually no ripple at the output.
At the beginning of each cycle, the high-side MOSFET is turned on. This MOSFET is turned off after internal one
shot timer expires. This one shot duration is set proportional to the converter input voltage, VIN, and inversely
proportional to the output voltage, VO, to maintain a pseudo-fixed frequency over the input voltage range, hence
it is called adaptive on-time control. The one-shot timer is reset and the high-side MOSFET is turned on again
when the feedback voltage falls below the reference voltage. An internal ramp is added to reference voltage to
simulate output ripple, eliminating the need for ESR induced output ripple from D-CAP2 mode control.
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Feature Description (continued)
7.3.2 Pulse Skip Control (TPS561201)
The TPS561201 and TPS561208 are designed with Advanced Eco-mode to maintain high light load efficiency.
As the output current decreases from heavy load condition, the inductor current is also reduced and eventually
comes to point that its rippled valley touches zero level, which is the boundary between continuous conduction
and discontinuous conduction modes. The rectifying MOSFET is turned off when the zero inductor current is
detected. As the load current further decreases the converter runs into discontinuous conduction mode. The ontime is kept almost the same as it was in the continuous conduction mode so that it takes longer time to
discharge the output capacitor with smaller load current to the level of the reference voltage. This makes the
switching frequency lower, proportional to the load current, and keeps the light load efficiency high. The transition
point to the light load operation IOUT(LL) current can be calculated in Equation 1.
(V - VOUT ) ´ VOUT
1
IOUT(LL) =
´ IN
2 ´ L ´ fSW
VIN
(1)
7.3.3 Soft Start and Pre-Biased Soft Start
The TPS561201 and TPS561208 have an internal 1.0-ms soft-start. When the EN pin becomes high, the internal
soft-start function begins ramping up the reference voltage to the PWM comparator. If the output capacitor is prebiased at startup, the devices initiate switching and start ramping up only after the internal reference voltage
becomes greater than the feedback voltage VFB. This scheme ensures that the converters ramp up smoothly
into regulation point.
7.3.4
Current Protection
The output over-current limit (OCL) is implemented using a cycle-by-cycle valley detect control circuit. The switch
current is monitored during the OFF state by measuring the low-side FET drain to source voltage. This voltage is
proportional to the switch current. To improve accuracy, the voltage sensing is temperature compensated.
During the on time of the high-side FET switch, the switch current increases at a linear rate determined by Vin,
Vout, the on-time and the output inductor value. During the on time of the low-side FET switch, this current
decreases linearly. The average value of the switch current is the load current Iout. If the monitored current is
above the OCL level, the converter maintains low-side FET on and delays the creation of a new set pulse, even
the voltage feedback loop requires one, until the current level becomes OCL level or lower. In subsequent
switching cycles, the on-time is set to a fixed value and the current is monitored in the same manner.
There are some important considerations for this type of over-current protection. The load current is higher than
the overcurrent threshold by one half of the peak-to-peak inductor ripple current. Also, when the current is being
limited, the output voltage tends to fall as the demanded load current may be higher than the current available
from the converter. This may cause the output voltage to fall. When the VFB voltage falls below the UVP
threshold voltage, the UVP comparator detects it. And then, the device will shut down after the UVP delay time
(typically 24 µs) and restart after the hiccup time (typically 15 ms).
When the over current condition is removed, the output voltage returns to the regulated value.
7.3.5 Undervoltage Lockout (UVLO) Protection
UVLO protection monitors the internal regulator voltage. When the voltage is lower than UVLO threshold voltage,
the device is shut off. This protection is non-latching.
7.3.6 Thermal Shutdown
The device monitors the temperature of itself. If the temperature exceeds the threshold value (typically 160°C),
the device is shut off. This is a non-latch protection.
10
Copyright © 2017, Texas Instruments Incorporated
TPS561201, TPS561208
www.ti.com.cn
ZHCSG73 – APRIL 2017
7.4 Device Functional Modes
7.4.1 Normal Operation
When the input voltage is above the UVLO threshold and the EN voltage is above the enable threshold, the
TPS561208 can operate in their normal switching modes. Normal continuous conduction mode (CCM) occurs
when the minimum switch current is above 0 A. In CCM, the TPS561208 operates at a quasi-fixed frequency of
580 kHz.
7.4.2 Eco-mode Operation
When the TPS561201 and TPS561208 are in the normal CCM operating mode and the switch current falls to 0
A, the TPS561201 begins operating in pulse skipping Eco-mode. Each switching cycle is followed by a period of
energy saving sleep time. The sleep time ends when the VFB voltage falls below the Eco-mode threshold
voltage. As the output current decreases, the perceived time between switching pulses increases.
7.4.3 Standby Operation
When the TPS561201 and TPS561208 are operating in either normal CCM or Eco-mode, they may be placed in
standby by asserting the EN pin low.
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TPS561201, TPS561208
ZHCSG73 – APRIL 2017
www.ti.com.cn
8 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
8.1 Application Information
The devices are typical step-down DC-DC converters. It typically uses to convert a higher dc voltage to a lower
dc voltage with a maximum available output current of 1 A. The following design procedure can be used to select
component values for the TPS561201 and TPS561208. Alternately, the WEBENCH® software may be used to
generate a complete design. The WEBENCH software uses an iterative design procedure and accesses a
comprehensive database of components when generating a design. This section presents a simplified discussion
of the design process.
8.2 Typical Application
The application schematic in Figure 17 was developed to meet the previous requirements. This circuit is
available as the evaluation module (EVM). The sections provide the design procedure.
Figure 17 shows the TPS561201 and TPS561208 4.5-V to 17-V Input, 1.05-V output converter schematics.
C7 0.1 uF
6
1
GND
VOUT = 1.05 V / 1 A L1
2
VOUT
VBST
R3 10.0 k
5
SW
EN
VIN
VFB
EN
2.2 uH
C9
3
C8
4
VOUT
R1 3.09 k
22 uF 22 uF
R2
10 k
1
C1
C2
C3
C4
Not Installed 1
10 uF 10 uF 0.1 uF
VIN
VIN = 4.5 to 17 V
1
Figure 17. TPS561201 and TPS561208 1.05-V/1-A Reference Design
8.2.1 Design Requirements
Table 1 shows the design parameters.
Table 1. Design Parameters
PARAMETER
Input voltage range
Output voltage
Transient response, 1-A load step
12
EXAMPLE VALUE
4.5 to 17 V
1.05 V
ΔVout = ±5%
Input ripple voltage
400 mV
Output ripple voltage
30 mV
Output current rating
1A
Operating frequency
580 kHz
Copyright © 2017, Texas Instruments Incorporated
TPS561201, TPS561208
www.ti.com.cn
ZHCSG73 – APRIL 2017
8.2.2 Detailed Design Procedure
8.2.2.1 Custom Design With WEBENCH® Tools
Click here to create a custom design using the TPS56120x device with the WEBENCH® Power Designer.
1. Start by entering the input voltage (VIN), output voltage (VOUT), and output current (IOUT) requirements.
2. Optimize the design for key parameters such as efficiency, footprint, and cost using the optimizer dial.
3. Compare the generated design with other possible solutions from Texas Instruments.
The WEBENCH Power Designer provides a customized schematic along with a list of materials with real-time
pricing and component availability.
In most cases, these actions are available:
• Run electrical simulations to see important waveforms and circuit performance
• Run thermal simulations to understand board thermal performance
• Export customized schematic and layout into popular CAD formats
• Print PDF reports for the design, and share the design with colleagues
Get more information about WEBENCH tools at www.ti.com/WEBENCH.
8.2.2.2 Output Voltage Resistors Selection
The output voltage is set with a resistor divider from the output node to the VFB pin. TI recommends to use 1%
tolerance or better divider resistors. Start by using Equation 2 to calculate VOUT.
To improve efficiency at very light loads consider using larger value resistors, too high of resistance will be more
susceptible to noise and voltage errors from the VFB input current will be more noticeable.
R1 ö
æ
VOUT = 0.768 ´ ç 1 +
÷
R2
è
ø
(2)
8.2.2.3 Output Filter Selection
The LC filter used as the output filter has double pole at:
1
FP =
2p LOUT ´ COUT
(3)
At low frequencies, the overall loop gain is set by the output set-point resistor divider network and the internal
gain of the device. The low frequency phase is 180 degrees. At the output filter pole frequency, the gain rolls off
at a –40 dB per decade rate and the phase drops rapidly. D-CAP2 introduces a high frequency zero that reduces
the gain roll off to –20 dB per decade and increases the phase to 90 degrees one decade above the zero
frequency. The inductor and capacitor for the output filter must be selected so that the double pole of Equation 3
is located below the high frequency zero but close enough that the phase boost provided be the high frequency
zero provides adequate phase margin for a stable circuit. To meet this requirement use the values recommended
in Table 2.
Table 2. Recommended Component Values
L1 (µH)
OUTPUT VOLTAGE
(V)
R1
(kΩ)
R2
(kΩ)
MIN
TYP
MAX
C8 + C9
(µF)
1
3.09
10.0
2.2
2.2
4.7
20 to 68
1.05
3.74
10.0
2.2
2.2
4.7
20 to 68
1.2
5.76
10.0
2.2
2.2
4.7
20 to 68
1.5
9.53
10.0
2.2
2.2
4.7
20 to 68
1.8
13.7
10.0
2.2
2.2
4.7
20 to 68
2.5
22.6
10.0
3.3
3.3
4.7
20 to 68
3.3
33.2
10.0
3.3
3.3
4.7
20 to 68
5
54.9
10.0
3.3
4.7
4.7
20 to 68
6.5
75
10.0
3.3
4.7
4.7
20 to 68
Copyright © 2017, Texas Instruments Incorporated
13
TPS561201, TPS561208
ZHCSG73 – APRIL 2017
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The inductor peak-to-peak ripple current, peak current and RMS current are calculated using Equation 4,
Equation 5, and Equation 6. The inductor saturation current rating must be greater than the calculated peak
current and the RMS or heating current rating must be greater than the calculated RMS current.
Use 580 kHz for fSW. Make sure the chosen inductor is rated for the peak current of Equation 5 and the RMS
current of Equation 6.
VIN(MAX) - VOUT
VOUT
IlP -P =
´
VIN(MAX)
LO ´ fSW
(4)
IlPEAK = IO +
IlP -P
2
ILO(RMS) = IO2 +
(5)
1
IlP -P2
12
(6)
For this design example, the calculated peak current is 1.69 A and the calculated RMS current is 1.11 A. The
inductor used is a WE 744311330 with a peak current rating of 11 A and an RMS current rating of 6.5 A.
The capacitor value and ESR determines the amount of output voltage ripple. The TPS561201 and TPS561208
are intended for use with ceramic or other low-ESR capacitors. Recommended values range from 20 µF to 68
µF. Use Equation 7 to determine the required RMS current rating for the output capacitor.
V
´ (VIN - VOUT )
ICO(RMS) = OUT
12 ´ VIN ´ LO ´ fSW
(7)
For this design two TDK C3216X5R0J226M 22-µF output capacitors are used. The typical ESR is 2 mΩ each.
The calculated RMS current is 0.286 A.
8.2.2.4 Input Capacitor Selection
The TPS561201 and TPS561208 require an input decoupling capacitor and a bulk capacitor is needed
depending on the application. TI recommends a ceramic capacitor over 10 µF for the decoupling capacitor. An
additional 0.1-µF capacitor (C3) from pin 3 to ground is optional to provide additional high frequency filtering. The
capacitor voltage rating needs to be greater than the maximum input voltage.
8.2.2.5
Bootstrap Capacitor Selection
A 0.1-µF ceramic capacitor must be connected between the VBST to SW pin for proper operation. TI
recommends to use a ceramic capacitor.
14
Copyright © 2017, Texas Instruments Incorporated
TPS561201, TPS561208
www.ti.com.cn
ZHCSG73 – APRIL 2017
8.2.3 Application Curves
3.00%
3.00%
TPS561201
TPS561208
2.00%
Output Voltage (V)
Output Voltage (V)
2.00%
TPS561201
TPS561208
1.00%
0.00
-1.00%
1.00%
0.00
-1.00%
-2.00%
-2.00%
-3.00%
-3.00%
0
0.2
0.4
0.6
Output Current (A)
0.8
0
1
Figure 18. Load Regulation VIN = 5 V
0.4
0.6
Output Current (A)
0.8
1
D019
D018
Figure 19. Load Regulation VIN = 12 V
100%
1.07
TPS561201
TPS561208
1.065
90%
80%
70%
1.06
Efficiency
Output Voltage (V)
0.2
D018
1.055
1.05
60%
50%
40%
30%
Vin = 5 V
Vin = 9 V
Vin = 12 V
Vin = 15 V
20%
1.045
10%
1.04
4
6
8
10
12
Input Voltage (V)
14
16
18
0
0.001
0.01
0.1
Output Current (A)
D020
1
D021
TPS56201 IOUT= 0.5 A
TPS56208 IOUT= 10 mA
Figure 20. Line Regulation
Figure 21. TPS561201 VOUT=1.05 V, Efficiency L = 2.2 µH
50 mV/div
100 mV/div
5 V/div
5 V/div
1 A/div
500 mA/div
1 us/div
Figure 22. TPS561201 Input Voltage Ripple
Copyright © 2017, Texas Instruments Incorporated
4 us/div
Figure 23. TPS561201 Output Voltage Ripple, IOUT = 10 mA
15
TPS561201, TPS561208
ZHCSG73 – APRIL 2017
www.ti.com.cn
20 mV/div
20 mV/div
5 V/div
5 V/div
500 mA/div
500 mA/div
1 us/div
1 us/div
Figure 24. TPS561201 Output Voltage Ripple, IOUT = 0.25 A
Figure 25. TPS561201 Output Voltage Ripple, IOUT = 1 A
50 mV/div
20 mV/div
500 mA/div
5 V/div
100 us/div
1 us/div
Figure 26. TPS561208 Output Voltage Ripple, IOUT = 0 A
50 mV/div
Figure 27. TPS561201 Transient Response, 0.1 to 1 A
50 mV/div
500 mA/div
500 mA/div
100 us/div
Figure 28. TPS561201 Transient Response, 0.5 to 1.5 A
16
100 us/div
Figure 29. TPS561208 Transient Response 0.1 to 1 A
Copyright © 2017, Texas Instruments Incorporated
TPS561201, TPS561208
www.ti.com.cn
ZHCSG73 – APRIL 2017
5 V/div
5 V/div
5 V/div
5 V/div
500 mV/div
500 mV/div
1 ms/div
2 ms/div
Figure 30. TPS561201 Start-Up Relative to VI
Figure 31. TPS561201 Start-Up Relative to EN
5 V/div
5 V/div
5 V/div
5 V/div
500 mV/div
500 mV/div
10 ms/div
Figure 32. TPS561201 Shutdown Relative to VI
Copyright © 2017, Texas Instruments Incorporated
100 us/div
Figure 33. TPS561201 Shutdown Relative to EN
17
TPS561201, TPS561208
ZHCSG73 – APRIL 2017
www.ti.com.cn
9 Power Supply Recommendations
The TPS561201 and TPS561208 are designed to operate from input supply voltage in the range of 4.5 V to 17
V. Buck converters require the input voltage to be higher than the output voltage for proper operation. The
maximum recommended operating duty cycle is 75%. Using that criteria, the minimum recommended input
voltage is VO / 0.75.
10 Layout
10.1 Layout Guidelines
1. VIN and GND traces should be as wide as possible to reduce trace impedance. The wide areas are also of
advantage from the view point of heat dissipation.
2. The input capacitor and output capacitor should be placed as close to the device as possible to minimize
trace impedance.
3. Provide sufficient vias for the input capacitor and output capacitor.
4. Keep the SW trace as physically short and wide as practical to minimize radiated emissions.
5. Do not allow switching current to flow under the device.
6. A separate VOUT path should be connected to the upper feedback resistor.
7. Make a Kelvin connection to the GND pin for the feedback path.
8. Voltage feedback loop should be placed away from the high-voltage switching trace, and preferably has
ground shield.
9. The trace of the VFB node should be as small as possible to avoid noise coupling.
10. The GND trace between the output capacitor and the GND pin should be as wide as possible to minimize
its trace impedance.
10.2 Layout Example
VOUT
GND
OUTPUT
CAPACITOR
Additional
Vias to the
GND plane
Vias to the
internal SW
node copper
BOOST
CAPACITOR
OUTPUT
INDUCTOR
Vias to the
internal SW
node copper
VIN
GND
VBST
SW
EN
VIN
TO ENABLE
CONTROL
FEEDBACK
RESISTORS
VFB
INPUT BYPAS
CAPACITOR
SW node copper
pour area on internal
or bottom layer
Figure 34. TPS561201 and TPS561208 Layout
18
版权 © 2017, Texas Instruments Incorporated
TPS561201, TPS561208
www.ti.com.cn
ZHCSG73 – APRIL 2017
11 器件和文档支持
11.1 相关链接
下面的表格列出了快速访问链接。范围包括技术文档、支持与社区资源、工具和软件，并且可通过快速访问立刻订
购。
表 3. 相关链接
器件
产品文件夹
立即订购
技术文档
工具与软件
支持与社区
TPS561201
请单击此处
请单击此处
请单击此处
请单击此处
请单击此处
TPS561208
请单击此处
请单击此处
请单击此处
请单击此处
请单击此处
11.2 社区资源
The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of
Use.
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help
solve problems with fellow engineers.
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and
contact information for technical support.
11.3 商标
D-CAP2, Eco-mode, E2E are trademarks of Texas Instruments.
WEBENCH is a registered trademark of Texas Instruments.
蓝光 is a trademark of Blu-ray Disc Association.
All other trademarks are the property of their respective owners.
11.4 静电放电警告
这些装置包含有限的内置 ESD 保护。 存储或装卸时，应将导线一起截短或将装置放置于导电泡棉中，以防止 MOS 门极遭受静电损
伤。
11.5 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
12 机械、封装和可订购信息
以下页中包括机械封装和可订购信息。这些信息是针对指定器件可提供的最新数据。这些数据会在无通知且不对本
文档进行修订的情况下发生改变。欲获得该数据表的浏览器版本，请查阅左侧的导航栏。
版权 © 2017, Texas Instruments Incorporated
19
PACKAGE OPTION ADDENDUM
www.ti.com
14-Feb-2018
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
Lead/Ball Finish
MSL Peak Temp
(2)
(6)
(3)
Op Temp (°C)
Device Marking
(4/5)
TPS561201DDCR
ACTIVE
SOT-23-THIN
DDC
6
3000
Green (RoHS
& no Sb/Br)
CU SN
Level-1-260C-UNLIM
-40 to 125
1201
TPS561201DDCT
ACTIVE
SOT-23-THIN
DDC
6
250
Green (RoHS
& no Sb/Br)
CU SN
Level-1-260C-UNLIM
-40 to 125
1201
TPS561208DDCR
ACTIVE
SOT-23-THIN
DDC
6
3000
Green (RoHS
& no Sb/Br)
CU SN
Level-1-260C-UNLIM
-40 to 85
1208
TPS561208DDCT
ACTIVE
SOT-23-THIN
DDC
6
250
Green (RoHS
& no Sb/Br)
CU SN
Level-1-260C-UNLIM
-40 to 85
1208
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
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