LMR14050 SIMPLE SWITCHER® 40V 5A、2.2MHz 降压转换器，具有 40μA IQ
- ZHCSDH4A February 2015 – March 2015 LMR14050
  
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LMR14050 SIMPLE SWITCHER® 40V 5A、2.2MHz 降压转换器，具有 40μA IQ

本资源的原文使用英文撰写。为方便起见，TI 提供了译文；由于翻译过程中可能使用了自动化工具，TI 不保证译文的准确性。为确认准确性，请务必访问 ti.com 参考最新的英文版本（控制文档）。

1 特性

输入电压范围：4V 至 40V
5A 持续输出电流
40µA 超低工作静态电流
90mΩ 高侧金属氧化物半导体场效应晶体 (MOSFET)
最短导通时间：75ns
电流模式控制
可调节开关频率范围：200kHz 至 2.5MHz
与外部时钟频率同步
内部补偿方便使用
支持高占空比运行
精密使能引脚
关断电流：1µA
外部软启动
热保护、过压保护和短路保护
8 引脚 HSOIC PowerPAD™ 封装

2 应用范围

汽车电池稳压
工业用电源
电信和数据通信系统
电池供电系统

3 说明

LMR14050 器件是一款具有集成型高侧 MOSFET 的 40V、5A 降压稳压器。该器件具有 4V 至 40V 的宽输入电压范围，适用于从工业到汽车各类应用中非稳压电源的电源调节。该稳压器在休眠模式下的静态电流为 40µA，非常适合电池供电类系统。并且在关断模式下具有 1μA 的超低电流，可进一步延长电池使用寿命。该稳压器的可调开关频率范围较宽，这使得效率或外部元件尺寸能够得到优化。内部环路补偿意味着用户不用承担设计环路补偿组件的枯燥工作。并且还能够以最大限度减少器件的外部元件数。精密使能输入简化了稳压器控制和系统电源排序。此外，该器件还内置多种保护特性：逐周期电流限制保护、应对功耗过大的热感测和热关断保护、以及输出过压保护。

器件信息⁽¹⁾

器件型号	封装	封装尺寸（标称值）
LMR14050SDDA	HSOIC-8	4.89mm x 3.90mm

要了解所有可用封装，请见数据表末尾的可订购产品附录。

4 简化电路原理图

效率与输出电流间的关系

5 修订历史记录

Changes from * Revision (February 2015) to A Revision

Changed “产品预览”至“量产数据”。 Go

6 Pin Configuration and Functions

HSOIC

8-Pin

Top View

Pin Functions

PIN		TYPE ⁽¹⁾	DESCRIPTION
NAME	NO.	TYPE ⁽¹⁾	DESCRIPTION
BOOT	1	O	Bootstrap capacitor connection for high-side MOSFET driver. Connect a high quality 0.1 μF capacitor from BOOT to SW.
VIN	2	I	Connect to power supply and bypass capacitors C_IN. Path from VIN pin to high frequency bypass C_IN and GND must be as short as possible.
EN	3	I	Enable pin, with internal pull-up current source. Pull below 1.2 V to disable. Float or connect to VIN to enable. Adjust the input under voltage lockout with two resistors. See the Enable and Adjusting Under voltage lockout section.
RT/SYNC	4	I	Resistor Timing or External Clock input. An internal amplifier holds this pin at a fixed voltage when using an external resistor to ground to set the switching frequency. If the pin is pulled above the PLL upper threshold, a mode change occurs and the pin becomes a synchronization input. The internal amplifier is disabled and the pin is a high impedance clock input to the internal PLL. If clocking edges stop, the internal amplifier is re-enabled and the operating mode returns to frequency programming by resistor.
FB	5	I	Feedback input pin, connect to the feedback divider to set V_OUT. Do not short this pin to ground during operation.
SS	6	O	Soft-start control pin. Connect to a capacitor to set soft-start time.
GND	7	G	System ground pin.
SW	8	O	Switching output of the regulator. Internally connected to high-side power MOSFET. Connect to power inductor.
Thermal Pad	9	G	Major heat dissipation path of the die. Must be connected to ground plane on PCB.

(1) I = Input, O = Output, G = Ground

7 Specifications

7.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted) ⁽¹⁾

		MIN	MAX	UNIT
Input Voltages	VIN, EN to GND	-0.3	44	V
	BOOT to GND	-0.3	49
	SS to GND	-0.3	5
	FB to GND	-0.3	7
	RT/SYNC to GND	-0.3	3.6
Output Voltages	BOOT to SW		6.5	V
Output Voltages	SW to GND	-3	44	V
T_J	Junction temperature	-40	150	°C
T_stg	Storage temperature	-65	150	°C

(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.

7.2 ESD Ratings

PARAMETER	DEFINITION		VALUE	UNIT
V_(ESD)	Electrostatic discharge	Human body model (HBM)⁽¹⁾	2	kV
V_(ESD)	Electrostatic discharge	Charged device model (CDM)⁽²⁾	0.5	kV

(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.

(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

7.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)

		MIN	MAX	UNIT
Buck Regulator	VIN	4	40	V
	VOUT	0.8	28
	BOOT		45
	SW	-1	40
	FB	0	5
Control	EN	0	40	V
	RT/SYNC	0	3.3
	SS	0	3
Frequency	Switching frequency range at RT mode	200	2500	kHz
Frequency	Switching frequency range at SYNC mode	250	2300	kHz
Temperature	Operating junction temperature, T_J	-40	125	°C

7.4 Thermal Information

THERMAL METRIC⁽¹⁾		DDA	UNIT
THERMAL METRIC⁽¹⁾		8 PINS	UNIT
R_θJA	Junction-to-ambient thermal resistance	42.5	°C/W
ψ_JT	Junction-to-top characterization parameter	9.9
ψ_JB	Junction-to-board characterization parameter	25.4
R_θJC(top)	Junction-to-case (top) thermal resistance	56.1
R_θJC(bot)	Junction-to-case (bottom) thermal resistance	3.8
R_θJB	Junction-to-board thermal resistance	25.5

(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.

7.5 Electrical Characteristics

Limits apply over the recommended operating junction temperature (T_J) range of -40°C to +125°C, unless otherwise stated. Minimum and Maximum limits are specified through test, design or statistical correlation. Typical values represent the most likely parametric norm at T_J = 25°C, and are provided for reference purposes only. Unless otherwise specified, the following conditions apply: V_IN = 4.0 V to 40 V

PARAMETER		TEST CONDITION	MIN	TYP	MAX	UNIT
POWER SUPPLY (VIN PIN)
V_IN	Operation input voltage		4		40	V
UVLO	Under voltage lockout thresholds	Rising threshold	3.5	3.7	3.9	V
UVLO	Under voltage lockout thresholds	Hysteresis		285		mV
I_SHDN	Shutdown supply current	V_EN = 0 V, T_A = 25°C, 4.0 V ≤ V_IN ≤ 40 V		1.0	3.0	μA
I_Q	Operating quiescent current (non- switching)	V_FB = 1.0 V, T_A = 25°C		40		μA
ENABLE (EN PIN)
V_{EN_TH}	EN Threshold Voltage		1.05	1.20	1.38	V
I_{EN_PIN}	EN PIN current	Enable threshold +50 mV		-4.6		μA
I_{EN_PIN}	EN PIN current	Enable threshold -50 mV		-1.0		μA
I_{EN_HYS}	EN hysteresis current			-3.6		μA
EXTERNAL SOFT-START
I_SS	SS pin current	T_A = 25°C		3		μA
VOLTAGE REFERENCE (FB PIN)
V_FB	Feedback voltage	T_J = 25°C	0.744	0.750	0.756	V
V_FB	Feedback voltage	T_J = -40°C to 125°C	0.735	0.750	0.765	V
HIGH-SIDE MOSFET
R_{DS_ON}	On-resistance	V_IN = 12 V, BOOT to SW = 5.8 V		90	180	mΩ
High-side MOSFET CURRENT LIMIT
I_LIMT	Current limit	V_IN = 12 V, T_A = 25°C, Open Loop	6.2	7.9	9.7	A
THERMAL PERFORMANCE
T_SHDN	Thermal shutdown threshold			170		°C
T_HYS	Hysteresis			12		°C

7.6 Switching Characteristics

over operating free-air temperature range (unless otherwise noted)

PARAMETER		TEST CONDITION	MIN	TYP	MAX	UNIT
f_SW	Switching frequency	R_T = 49.9 kΩ, 1% accuracy	400	500	600	kHz
V_{SYNC_HI}	SYNC clock high level threshold		1.7			V
V_{SYNC_LO}	SYNC clock low level threshold				0.5	V
T_{SYNC_MIN}	Minimum SYNC input pulse width	Measured at 500 kHz, V_{SYNC_HI} > 3 V, V_{SYNC_LO} < 0.3 V		30		ns
T_{LOCK_IN}	PLL lock in time	Measured at 500 kHz		100		µs
T_{ON_MIN}	Minimum controllable on time	V_IN = 12 V, BOOT to SW = 5.8 V, I_Load = 1 A		75		ns
D_MAX	Maximum duty cycle	f_SW = 200 kHz		97		%

7.7 Typical Characteristics

Unless otherwise specified the following conditions apply: V_IN = 12 V, f_SW = 300 kHz, L = 6.5 µH, C_OUT = 47 µF x 4, T_A = 25°C

V_OUT= 5 V

f_SW = 500 kHz

Figure 1. Efficiency vs. Load Current

V_OUT= 3.3 V

f_SW = 1 MHz

Figure 3. Efficiency vs. Load Current

V_OUT = 5 V

f_SW = 500 kHz

Figure 5. Load Regulation

V_OUT = 5 V

f_SW = 500 kHz

Figure 7. Dropout Curve

V_OUT = 5 V

f_SW = 2.2 MHz

Figure 9. Dropout Curve

Figure 11. Shut-down Current and Quiescent Current

V_OUT= 5 V

f_SW = 1 MHz

Figure 2. Efficiency vs. Load Current

V_OUT= 3.3 V

f_SW = 2.2 MHz

Figure 4. Efficiency vs. Load Current

V_OUT = 5 V

f_SW = 500 kHz

Figure 6. Frequency vs V_FB

V_OUT = 5V

f_SW = 1 MHz

Figure 8. Dropout Curve

V_OUT = 3.3 V

f_SW = 2.2 MHz

Figure 10. Dropout Curve

I_OUT = 0 A

Figure 12. UVLO Threshold