LM3262TME/NOPB [TI]
具有旁路模式的 6MHz、800mA 微型、可调节、直流/直流降压转换器 | YFQ | 9 | -30 to 90;型号: | LM3262TME/NOPB |
厂家: | TEXAS INSTRUMENTS |
描述: | 具有旁路模式的 6MHz、800mA 微型、可调节、直流/直流降压转换器 | YFQ | 9 | -30 to 90 转换器 |
文件: | 总32页 (文件大小:2029K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
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LM3262
ZHCSE56O –AUGUST 2012–REVISED DECEMBER 2015
LM3262 适用于 RF 功率放大器的具有自动旁路功能的
6MHz、800mA 微型可调降压 DC-DC 转换器
1 特性
3 说明
1
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•
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由单节锂离子电池供电运行(2.5V 至 5.5V)
LM3262 是一款 DC-DC 转换器,针对由单节锂离子电
池供电的 RF 功率放大器 (PA) 进行了优化。此外,该
器件也可用于其他 应用 ,例如由 USB 供电的便携式
应用。该器件可将介于 2.5V-5.5V 范围内的输入电压
降转换至 0.4V-3.6V 的可调输出电压。输出电压使用
VCON 模拟输入进行设置,可提高 RF 级的 PA 效
率。
6MHz(典型值)脉宽调制 (PWM) 开关频率
可调节输出电压(0.4V 至 3.6V)
800mA 最大负载性能(旁路模式下高达 1A)
高效率(3.8 VIN,3.4 VOUT,500mA 时的典型效率
为 93%)
•
•
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自动 ECO/PWM/BP 模式切换
电流过载和热过载保护
LM3262 具有 5 种工作模式。在脉宽调制 (PWM) 模式
下,该器件以 6MHz(典型值)固定频率运行,因此可
在驱动低到中等负载时最大限度地抑制 RF 干扰。轻负
载时,器件自动进入 ECO 模式并以减少的开关频率运
行。在 ECO 模式下,静态电流被减少并延长了电池使
用寿命。该器件在关断模式下处于关闭状态,电池流耗
降至 0.1µA(典型值)。在低电量状态下,旁路模式可
将压降降至 50mV(典型值)以下。此外,该器件还
具备 休眠模式。
多功能 VCON 引脚
(无需使用独立 BPEN 控制)
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•
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软启动功能
小型片式电感,外壳尺寸为 0805 (2012)
休眠模式下的 IQ 为 25µA(典型值)
2V 步长的上升时间和下降时间为
5µs(典型值)
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9 引脚芯片尺寸球状引脚栅格阵列 (DSBGA) 封装
2 应用
LM3262 采用 9 引脚无引线 DSBGA 封装。高开关频
率 (6MHz) 允许仅使用三个微型表面贴装组件,即一个
电感和两个陶瓷电容。
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高速上行分组接入 (HSUPA),采用长期演进 (LTE)
的手机
•
时分同步码分多址 (TD-SCDMA) 和分时长期演进
(TD-LTE)
器件信息(1)
器件型号
LM3262
封装
封装尺寸(最大值)
•
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手持无线电设备
DSGBA (9)
1.51mm × 1.385mm
RF PC 卡
(1) 要了解所有可用封装,请见数据表末尾的可订购产品附录。
电池供电类 RF 器件
由 USB 供电的便携式 应用
典型应用电路
VIN
2.5 V to 5.5V
VIN
BPEN
VOUT = 2.5 x VCON
0.4 V to 3.6 V
10 mF
0.5 mH
SW
FB
EN
LM3262
VCON
GPO1
4.7 mF
SGND
PGND
DAC
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: SNVS875
LM3262
ZHCSE56O –AUGUST 2012–REVISED DECEMBER 2015
www.ti.com.cn
目录
7.4 Device Functional Modes........................................ 14
Application and Implementation ........................ 16
8.1 Application Information............................................ 16
8.2 Typical Application ................................................. 16
Power Supply Recommendations...................... 19
1
2
3
4
5
6
特性.......................................................................... 1
应用.......................................................................... 1
说明.......................................................................... 1
修订历史记录 ........................................................... 2
Pin Configuration and Functions......................... 3
Specifications......................................................... 4
6.1 Absolute Maximum Ratings ...................................... 4
6.2 ESD Ratings.............................................................. 4
6.3 Recommended Operating Conditions....................... 4
6.4 Thermal Information.................................................. 4
6.5 Electrical Characteristics .......................................... 5
6.6 System Characteristics ............................................ 6
6.7 Timing Requirements................................................ 6
6.8 Typical Characteristics.............................................. 7
Detailed Description ............................................ 11
7.1 Overview ................................................................. 11
7.2 Functional Block Diagram ....................................... 12
7.3 Feature Description................................................. 12
8
9
10 Layout................................................................... 20
10.1 Layout Guidelines ................................................. 20
10.2 Layout Examples................................................... 21
10.3 DSBGA Assembly and Use .................................. 25
11 器件和文档支持 ..................................................... 26
11.1 器件支持................................................................ 26
11.2 文档支持................................................................ 26
11.3 社区资源................................................................ 26
11.4 商标....................................................................... 26
11.5 静电放电警告......................................................... 26
11.6 Glossary................................................................ 26
12 机械、封装和可订购信息....................................... 26
7
4 修订历史记录
注:之前版本的页码可能与当前版本有所不同。
Changes from Revision N (March 2013) to Revision O
Page
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已添加 器件信息和引脚配置和功能部分,ESD 额定值和热性能信息表,特性 描述,器件功能模式,应用和实施,电
源相关建议,布局,器件和文档支持以及机械、封装和可订购信息部分 ................................................................................ 1
2
Copyright © 2012–2015, Texas Instruments Incorporated
LM3262
www.ti.com.cn
ZHCSE56O –AUGUST 2012–REVISED DECEMBER 2015
5 Pin Configuration and Functions
YFQ Package
9-Pin DSBGA
Top View
YFQ Package
9-Pin DSBGA
Bottom View
VCON
PGND
PGND
SGND
VCON
SGND
NC
FB
SW
VIN
NC
FB
EN
SW
VIN
EN
BPEN
BPEN
Pin Functions
PIN
TYPE
DESCRIPTION
NO.
NAME
Voltage control analog input. VCON controls VOUT in PWM and ECO modes. VCON may also
be used to force the device into sleep mode by setting VCON < 80 mV or into bypass condition
by setting VCON > 1.5 V.
A1
VCON
Analog
A2
A3
SGND
PGND
Ground
Ground
Signal ground for analog and control circuitry.
Power ground for the Power MOSFETs and gate drive circuitry
Enable Input. Set this digital input high for normal operation. For shutdown, set low. Do not
leave EN pin floating.
B1
B2
EN
NC
Digital/Input
—
Do not connect to PGND directly — Internally connected to SGND.
Switching node connection to the internal PFET switch and NFET synchronous rectifier.
Connect to an inductor with a saturation current rating that exceeds the maximum switch peak
current limit specification of the LM3262.
B3
C1
SW
Analog
Input
Bypass enable input. Set this digital input high to force bypass operation. For normal operation
with automatic bypass, set low or connect to ground. Do not leave this pin floating.
BPEN
Feedback analog input and bypass FET output. Connect to the output at the output filter
capacitor.
C2
C3
FB
Analog
Input
VIN
Voltage supply input for SMPS converter.
Copyright © 2012–2015, Texas Instruments Incorporated
3
LM3262
ZHCSE56O –AUGUST 2012–REVISED DECEMBER 2015
www.ti.com.cn
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)(2)
MIN
−0.2
MAX
6
UNIT
VIN to SGND
V
V
V
V
PGND to SGND
−0.2
0.2
EN, VCON, BPEN
(SGND − 0.2)
(PGND − 0.2)
(VIN + 0.2)
(VIN + 0.2)
FB, SW
Continuous power dissipation(3)
Junction temperature, TJ-MAX
Maximum lead temperature (soldering, 10 sec)
Storage temperature, Tstg
Internally limited
150
260
150
°C
°C
°C
−65
(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.
(2) All voltages are with respect to the potential at the GND pins.
(3) Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at TJ = 150°C (typical) and
disengages at TJ = 130°C (typical).
6.2 ESD Ratings
VALUE
±2000
±1250
UNIT
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1)
Charged-device model (CDM), per JEDEC specification JESD22-C101(2)
V(ESD)
Electrostatic discharge
V
(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.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)(1)
MIN
MAX
5.5
UNIT
V
Input voltage, VIN
2.5
0
PWM mode
800
1000
125
90
mA
mA
°C
Recommended load current
Junction temperature, TJ
Bypass mode
0
–30
−30
(2)
Ambient temperature, TA
°C
(1) All voltages are with respect to the potential at the GND pins
(2) In applications where high-power dissipation and/or poor package thermal resistance is present, the maximum ambient temperature may
have to be de-rated. Maximum ambient temperature (TA-MAX) is dependent on the maximum operating junction temperature (TJ-MAX-OP
125°C), the maximum power dissipation of the device in the application (PD-MAX), and the junction-to ambient thermal resistance of the
part/package in the application (RθJA), as given by the following equation: TA-MAX = TJ-MAX-OP – (RθJA × PD-MAX).
=
6.4 Thermal Information
LM3262
THERMAL METRIC(1)
YFQ (DSBGA)
9 PINS
UNIT
RθJA
Junction-to-ambient thermal resistance
85
°C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report, SPRA953.
4
Copyright © 2012–2015, Texas Instruments Incorporated
LM3262
www.ti.com.cn
ZHCSE56O –AUGUST 2012–REVISED DECEMBER 2015
6.5 Electrical Characteristics
Unless otherwise noted, all specifications apply to the 典型应用电路 with: VIN = EN = 3.6 V and
BPEN = NC = 0 V. All typical (TYP) limits apply for TA = TJ = 25°C, and all minimum (MIN) and maximum (MAX) apply over
the full operating ambient temperature range (−30°C ≤ TA = TJ ≤ +90°C), unless otherwise specified.(1)(2)(3)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Feedback voltage at minimum
setting
VFB, MIN
PWM mode, VCON = 0.16 V(4)
0.38
0.4
0.42
V
Feedback voltage at maximum
setting
VFB, MAX
ISHDN
PWM mode, VCON = 1.44 V, VIN = 4 V
3.55
3.6
0.1
3.65
1
V
Shutdown supply current
EN = SW = VCON = FB = BPEN = NC =0 V(5)
µA
µA
PWM mode, No switching
VCON = 0.13 V, FB = 1 V(6)
IQ_PWM
PWM mode quiescent current
650
795
EN = VIN, BPEN = NC = 0V, SW = tri state
VCON < 0.8 V, FB = 2.05 V(7)
IQ_SLEEP
Low-power sleep mode
25
µA
ECO mode, No switching
IQ_ECO
ILIM,P
ILIM, BP
ƒOSC
VIH
ECO mode quiescent current
60
1450
400
6
µA
mA
mA
MHz
V
VCON = 0.8 V, FB = 2.05 V(6)
PFET switch peak current limit See(8)
1300
310
5.7
1600
6.3
BPFET switch peak current
limit
VFB = VIN – 1 V
Internal oscillator frequency
EN, BPEN logic high input
threshold
1.2
EN, BPEN logic low input
threshold
VIL
0.4
V
Gain
VCON to VOUT gain
0.16 V ≤ VCON ≤ 1.44 V(9)
2.5
V/V
µA
IVCON
VCON pin leakage current
VCON = 1 V
–1
1
Auto bypass detection
negative threshold
VCON = 1.2 V (VOUT-SET = 3 V)
VBP, NEG
165
200
235
mV
VIN = 3.2 V, RL = 6 Ω (IOUT = 500 mA)(10)
Auto bypass detection positive VCON = 1.2 V (VOUT-SET = 3 V)
threshold
VIN = 3.25 V, RL = 6 Ω (IOUT = 500 mA)(11)
VBP, NEG
IBP, SLEW
215
250
285
mV
mA
BPEN = High, Forced bypass
1600
(1) All voltages are with respect to the potential at the GND pins.
(2) Minimum and maximum limits are specified by design, test, or statistical analysis.
(3) The parameters in the electrical characteristics table are tested under open loop conditions at VIN = 3.6 V unless otherwise specified.
For performance over the input voltage range and closed-loop results, refer to Typical Characteristics.
(4) All 0.4-V VOUT specifications are at steady-state only.
(5) Shutdown current includes leakage current of PFET.
(6) Iq specified here is when the device is not switching. For operating input current at no load, refer to Typical Characteristics.
(7) FB has 200 kΩ to SGND.
(8) Current limit is built-in, fixed, and not adjustable.
(9) Care should be taken to keep the VCON pin voltage less than the VIN pin voltage as this can place the device into a manufacturing test
mode.
(10) Entering bypass mode, VIN is compared to the programmed output voltage (2.5 × VCON). When VIN − (2.5 × VCON) falls below
VBP,NEG longer than TBP,NEG, the bypass FET turns on, and the switching FET turns on.
(11) Bypass mode is exited when VIN − (2.5 × VCON) exceeds VBP,POS longer than TBP,POS, and PWM mode resumes. The hysteresis for
the bypass detection threshold VBP,POS − VBP,NEG is always positive and is approximately 50 mV.
Copyright © 2012–2015, Texas Instruments Incorporated
5
LM3262
ZHCSE56O –AUGUST 2012–REVISED DECEMBER 2015
www.ti.com.cn
6.6 System Characteristics
The following parameters are specified by design and verifications providing the component values in the 典型应用电路 are
used. These parameters are not verified by production testing. Minimum (MIN) and maximum (MAX) values are specified
over the ambient temperature range TA = −30°C ≤ TA ≤ +90°C and over the VIN range = 2.5 V to 5.5 V, unless otherwise
specified; L = 0.5 μH, DCR = 50 mΩ, CIN = 10 μF, 6.3 V, 0402 (1005), COUT = 4.7 μF, 6.3 V, 0402 (1005). For bench
(1)
evaluation, see
.
PARAMETER
Maximum duty cycle
TEST CONDITIONS
MODE = LOW
MIN
TYP
MAX
UNIT
mA
D
100%
2.5 V ≤ VIN ≤ 5.5 V
2.5 × VCON ≤ VIN – 285 mV
800
Maximum output current
capability
IOUT
2.5 V ≤ VIN ≤ 5.5 V
2.5 × VCON ≤ VIN – 165 mV, bypass
mode
1000
–3%
–50
3%
50
VOUT linearity
VCON = 0.16 V to 1.44 V
0 mA ≤ IOUT ≤ 800 mA(2)
mV
VIN = 3.8 V, VOUT = 0.8 V
IOUT = 10 mA, ECO mode
71%
92%
93%
50
VIN = 3.8 V, VOUT = 2.5 V
IOUT = 200 mA, PWM mode
η
Efficiency
VIN = 3.8 V, VOUT = 3.4 V
IOUT = 500 mA, PWM mode
VIN = 3.6 V to 4.2 V, TR = TF = 10 µs,
IOUT = 100 mA, VOUT = 0.8 V
LINE_tr
Line transient response
Load transient response
mVpk
mVpk
VIN = 3.1/3.6/4.5 V, VOUT = 0.8 V
IOUT = 50 mA to 150 mA
TR = TF = 10 µs,
LOAD_tr
50
(1) When the LM3262 device is being evaluated apart from a normal system design or on a PCB other than the TI LM3262 evaluation
module, user should ensure that a 50-µF to 100-μF ceramic input capacitor is added to the PCB to keep input voltage from sagging
during rapid load transitions.
(2) Linearity limits are ±3% or ±50 mV, whichever is larger. VOUT is monotonic in nature with respect to VCON input.
6.7 Timing Requirements
MIN
NOM
MAX
UNIT
VOUT rise time VCON change to 90%; VIN = 3.7 V, VOUT = 1.4 V to 3.4 V
0.1 µs < VCON_TR < 1 µs, RL = 12 Ω
5
µs
TVCON_TR
VOUT fall time VCON change to 10%; VIN = 3.7 V, VOUT = 3.4 V to 1.4 V
5
µs
µs
0.1 µs < VCON_TR < 1 µs, RL = 12 Ω
Turnon time (time for output to reach 95% final value after Enable low-to-
high transition)
EN = low-to-high, VIN = 4.2 V , VOUT = 3.4 V
TON
50
IOUT ≤ 1 mA, COUT = 4.7 µF
TBP, NEG Auto bypass detect negative threshold delay time(1)
TBP, POS Auto bypass detect positive threshold delay time(2)
10
µs
µs
0.1
(1) Entering bypass mode, VIN is compared to the programmed output voltage (2.5 × VCON). When VIN − (2.5 × VCON) falls below VBP,
NEG longer than TBP, NEG, the bypass FET turns on, and the switching FET turns on.
(2) Bypass mode is exited when VIN − (2.5 × VCON) exceeds VBP, POS longer than TBP, POS, and PWM mode resumes. The hysteresis for
the bypass detection threshold VBP, POS − VBP, NEG is always positive and will be approximately 50 mV.
6
Copyright © 2012–2015, Texas Instruments Incorporated
LM3262
www.ti.com.cn
ZHCSE56O –AUGUST 2012–REVISED DECEMBER 2015
6.8 Typical Characteristics
VIN = EN = 3.6 V, L = 0.5 µH, CIN = 10 µF, COUT = 4.7 µF and TA = 25°C, unless otherwise noted.
27
26
25
24
23
22
21
20
VIN = 3.0V
VIN = 3.6V
VIN = 4.2V
-35 -15
5
25
45
65
85 105
AMBIENT TEMPERATURE (°C)
SW = VCON = EN = BPEN = 0V
VCON < 80 mV
EN = VIN
BPEN = 0
Figure 1. Shutdown Current vs Temperature
Figure 2. Sleep Mode Current vs Temperature
900
100
800
700
90
80
70
600
VIN = 25°C
VIN = 3.0V
500
60
VIN = -40°C
VIN = 3.6V
VIN = 95°C
VIN = 4.2V
400
2.5
50
0.5
3.0
3.5
4.0
4.5
5.0
5.5
1.0
1.5
2.0
2.5
3.0
3.5
SUPPLY VOLTAGE (V)
OUTPUT VOLTAGE (V)
No Switching
FB = 1 V
VCON = 0.13 V
Closed Loop
Switching
No load
Figure 3. Quiescent Current vs Supply Voltage
Figure 4. ECO Mode Supply Current vs Output Voltage
2.006
2.004
T
A
= -30°C
T
= +25°C
A
2.002
2.000
1.998
1.996
1.994
T
= +85°C
A
2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
SUPPLY VOLTAGE (V)
VOUT = 2 V
RLOAD = 10 Ω
VOUT = 2 V
IOUT = 200 mA
Figure 6. Output Voltage vs Supply Voltage
Figure 5. Switching Frequency vs Temperature
Copyright © 2012–2015, Texas Instruments Incorporated
7
LM3262
ZHCSE56O –AUGUST 2012–REVISED DECEMBER 2015
www.ti.com.cn
Typical Characteristics (continued)
VIN = EN = 3.6 V, L = 0.5 µH, CIN = 10 µF, COUT = 4.7 µF and TA = 25°C, unless otherwise noted.
VIN = 3.8 V
VOUT = 0.6 V
VIN = 3.8 V
VOUT = 2 V
Figure 7. Output Voltage vs Output Current
Figure 8. Output Voltage vs Output Current
190
190
VIN = 3.0V
VIN = 3.6V
VIN = 4.5V
170
150
130
110
170
150
130
110
90
90
VIN = 3.0V
VIN = 3.6V
VIN = 4.5V
70
70
50
50
0.5
1.0
1.5
2.0
2.5
3.0
0.5
1.0
1.5
2.0
2.5
3.0
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
Figure 9. ECO-PWM Mode Threshold Current
Figure 10. PWM-ECO Mode Threshold Current
vs Output Voltage
vs Output Voltage
3.0
2.5
2.0
1.5
1.0
VIN = 2.5V
VIN = 3.7V
VIN = 5.5V
0.5
0.0
-35 -15
5
25 45 65 85 105
AMBIENT TEMPERATURE (°C)
Figure 11. Closed-Loop Current Limit vs Temperature
Figure 12. EN High Threshold vs Supply Voltage
8
Copyright © 2012–2015, Texas Instruments Incorporated
LM3262
www.ti.com.cn
ZHCSE56O –AUGUST 2012–REVISED DECEMBER 2015
Typical Characteristics (continued)
VIN = EN = 3.6 V, L = 0.5 µH, CIN = 10 µF, COUT = 4.7 µF and TA = 25°C, unless otherwise noted.
VIN = 3.6 V
VOUT = 2 V
IOUT = 200 mA
VOUT = 2 V
IOUT = 50 mA
Figure 13. Output Voltage Ripple in PWM Mode
Figure 14. Output Voltage Ripple in ECO Mode
VIN = 4 V
VOUT = 0.4 V to 3.6 V
RLOAD = 10 Ω
VIN = 3.6 V to 4.2 V
VOUT = 0.6 V
IOUT = 750 mA
Figure 15. VCON Transient Response
Figure 16. Line Transient Response
VIN = 3.6 V
VOUT = 0.5 V
IOUT = 500 mA to 60 mA
VIN = 4.2 V
VOUT = 3.1 V
IOUT = 200 mA to 750 mA
Figure 17. Load Transient Response
Figure 18. Load Transient Response
Copyright © 2012–2015, Texas Instruments Incorporated
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LM3262
ZHCSE56O –AUGUST 2012–REVISED DECEMBER 2015
www.ti.com.cn
Typical Characteristics (continued)
VIN = EN = 3.6 V, L = 0.5 µH, CIN = 10 µF, COUT = 4.7 µF and TA = 25°C, unless otherwise noted.
VIN = 4.2 V
VOUT = 3.4 V
RLOAD = 10 Ω
VIN = 4.2 V
VOUT = 3.4 V
RLOAD = 3.6 kΩ
Figure 20. Shutdown
Figure 19. Start-Up
1000
900
800
700
600
500
400
300
200
100
0
VIN = 3.6V
VIN = 4.2V
VIN = 4.8V
VIN = 5.5V
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40
VCON VOLTAGE (V)
VOUT = 2 V
RLOAD = 10 Ω→ 0 Ω
RLOAD = 10 Ω
Figure 21. Timed Current Limit
Figure 22. Low VCON Voltage vs Output Voltage
10
Copyright © 2012–2015, Texas Instruments Incorporated
LM3262
www.ti.com.cn
ZHCSE56O –AUGUST 2012–REVISED DECEMBER 2015
7 Detailed Description
7.1 Overview
The LM3262 is a simple, step-down DC-DC converter optimized for powering RF power amplifiers (PAs) in
mobile phones, portable communicators, and similar battery powered RF devices. It is designed to allow the RF
PA to operate at maximum efficiency over a wide range of power levels from a single li-ion battery cell. The
device is based on a voltage-mode buck architecture, with synchronous rectification for high efficiency. It is
designed for a maximum load capability of 800 mA in PWM mode. Maximum load range may vary from this
depending on input voltage, output voltage, and the inductor chosen.
There are five modes of operation depending on the current required: pulse width modulation (PWM), ECOnomy
(ECO), bypass (BP), sleep, and shutdown. (See Table 1.) The LM3262 operates in PWM mode at higher load
current conditions. Lighter loads cause the device to automatically switch into ECO mode. Shutdown mode turns
the device off and reduces battery consumption to 0.1 µA (typical).
DC PWM mode output voltage precision is ±2% for 3.6 VOUT. Efficiency is approximately 93% (typical) for a
500-mA load with 3.4-V output, 3.8-V input. The output voltage is dynamically programmable from 0.4 V to 3.6 V
by adjusting the voltage on the control pin (VCON) without the need for external feedback resistors. This ensures
longer battery life by being able to change the PA supply voltage dynamically depending on its transmitting
power.
Additional features include current overload protection and thermal overload shutdown.
The LM3262 is constructed using a chip-scale, 9-pin DSBGA package. This package offers the smallest possible
size for space-critical applications, such as cell phones, where board area is an important design consideration.
Use of a high switching frequency (6 MHz, typical) reduces the size of external components. As shown in the 典
型应用电路, only three external power components are required for implementation. Use of a DSBGA package
requires special design considerations for implementation. (See DSBGA Assembly and Use.) The fine bump-
pitch of the DSBGA package requires careful board design and precision assembly equipment. Use of this
package is best suited for opaque-case applications, where its edges are not subject to high-intensity ambient
red or infrared light. Also, the system controller must set EN low during power-up and other low supply voltage
conditions. (See Shutdown Mode.)
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7.2 Functional Block Diagram
VIN
EN BPEN
VCON
1.5V
ECO COMP
BYPASS
+
2/5
+
-
STANDBY COMP
Ref5
Ref1
OLP
OVER-VOLTAGE
DETECTOR
Ref2
VCON
DELAY
FB
PWM
COMP.
CONTROL LOGIC
DRIVER
ERROR
AMP
FB
SW
RAMP
GENERATOR
NCP
Ref3
OSCILLATOR
Ref4
LIGHT-LOAD
OUTPUT SHORT
PROTECTION
THERMAL
SHUTDOWN
CHECK COMP
SGND
PGND
7.3 Feature Description
7.3.1 Circuit Operation
Referring to the Functional Block Diagram, the LM3262 operates as follows. During the first part of each
switching cycle, the control block in the LM3262 turns on the internal top-side PFET switch. This allows current to
flow from the input through the inductor to the output filter capacitor and load. The inductor limits the current to a
ramp with a slope of around (VIN – VOUT) / L, by storing energy in a magnetic field. During the second part of
each cycle, the controller turns the PFET switch off, blocking current flow from the input, and then turns the
bottom-side NFET synchronous rectifier on. In response, the magnetic field of the inductor collapses, generating
a voltage that forces current from ground through the synchronous rectifier to the output filter capacitor and load.
As the stored energy is transferred back into the circuit and depleted, the inductor current ramps down with a
slope around VOUT / L. The output filter capacitor stores charge when the inductor current is high and releases it
when low, smoothing the voltage across the load.
The output voltage is regulated by modulating the PFET switch on time to control the average current sent to the
load. The effect is identical to sending a duty-cycle modulated rectangular wave formed by the switch and
synchronous rectifier at SW to a low-pass filter formed by the inductor and output filter capacitor. The output
voltage is equal to the average voltage at the SW pin.
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Feature Description (continued)
7.3.2 Internal Synchronous Rectification
While in PWM mode, the LM3262 uses an internal NFET as a synchronous rectifier to reduce rectifier forward
voltage drop and associated power loss. Synchronous rectification provides a significant improvement in
efficiency whenever the output voltage is relatively low compared to the voltage drop across an ordinary rectifier
diode.
With medium and heavy loads, the NFET synchronous rectifier is turned on during the inductor current down
slope in the second part of each cycle. The synchronous rectifier is turned off prior to the next cycle. The NFET
is designed to conduct through its intrinsic body diode during transient intervals before it turns on, eliminating the
need for an external diode.
7.3.3 Current Limiting
The current limit feature allows the LM3262 to protect itself and external components during overload conditions.
In PWM mode, the cycle-by-cycle current limit is a 1450 mA (typical). If an excessive load pulls the output
voltage down to less than 0.3 V (typical), the NFET synchronous rectifier is disabled, and the current limit is
reduced to 530 mA (typical). Moreover, when the output voltage becomes less than 0.15 V (typical), the
switching frequency will decrease to 3 MHz, thereby preventing excess current and thermal stress.
7.3.4 Dynamically Adjustable Output Voltage
The LM3262 features dynamically adjustable output voltage to eliminate the need for external feedback resistors
by controlling this voltage using the analog VCON pin. The input impedance of this pin can be approximated by a
series 50-KΩ resistor and 10-pF capacitor. The output can be set from 0.4 V to 3.6 V by changing the voltage on
the analog VCON pin. This feature is useful in PA applications where peak power is needed only when the
handset is far away from the base station or when data is being transmitted. In other instances the transmitting
power can be reduced. Hence the supply voltage to the PA can be reduced, promoting longer battery life. See
Setting The Output Voltage for further details. The LM3262 moves into pulse-skipping mode when duty cycle is
over approximately 92% or less than approximately 15%, and the output voltage ripple increases slightly.
7.3.5 Thermal Overload Protection
The LM3262 has a thermal overload protection function that operates to protect itself from short-term misuse and
overload conditions. When the junction temperature exceeds around 150°C, the device inhibits operation. Both
the PFET and the NFET are turned off. When the temperature drops below 125°C, normal operation resumes.
Prolonged operation in thermal overload conditions may damage the device and is considered bad practice.
7.3.6 Soft Start
The LM3262 has a soft-start circuit that limits in-rush current during start-up. During start-up, the switch current
limit is increased in steps. Soft start is activated if EN goes from low to high after VIN reaches 2.5 V.
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7.4 Device Functional Modes
7.4.1 PWM Mode Operation
While in PWM mode operation, the converter operates as a voltage-mode controller with input voltage feed
forward. This allows the converter to achieve excellent load and line regulation. The DC gain of the power stage
is proportional to the input voltage. To eliminate this dependence, feed forward inversely proportional to the input
voltage is introduced. While in PWM mode, the output voltage is regulated by switching at a constant frequency,
then modulating the energy per cycle to control power to the load. At the beginning of each clock cycle the PFET
switch is turned on, and the inductor current ramps up until the comparator trips and the control logic turns off the
switch. The current-limit comparator can also turn off the switch if the current limit of the PFET is exceeded — in
this case, the NFET switch is turned on, and the inductor current ramps down. The next cycle is initiated by the
clock turning off the NFET and turning on the PFET.
7.4.2 Bypass Mode Operation
The LM3262 contains an internal BPFET switch for bypassing the PWM DC-DC converter during bypass mode.
In bypass mode, this BPFET is turned on to power the PA directly from the battery for maximum RF output
power. When the device operates in the bypass mode, the output voltage is the input voltage less the voltage
drop across the resistance of the BPFET in parallel with the PFET plus switch inductor. Bypass mode is more
efficient than operating in PWM mode at 100% duty cycle because the combined resistance is significantly less
than the series resistance of the PWM PFET and inductor. This translates into higher voltage available on the
output in bypass mode, for a given battery voltage. The device can be forced into bypass mode by setting the
BPEN pin high or by driving the VCON control pin voltage higher than 1.5 V. This is called forced bypass mode,
and it remains in bypass mode until the BPEN pin goes low or VCON pin drops below 1.5 V. Alternatively, the
device can go into bypass mode automatically. This is called auto-bypass mode or automatic bypass mode. The
bypass switch turns on when the difference between the input voltage and programmed output voltage is less
than 200 mV (typical) for longer than 10 µs (typical). The bypass switch turns off when the input voltage is higher
than the programmed output voltage by 250 mV (typical) for longer than 0.1 µs (typical). This method is very
system resource friendly in that the bypass PFET is turned on automatically when the input voltage gets close to
the output voltage, a typical scenario of a discharging battery. It is also turned off automatically when the input
voltage rises, a typical scenario when connecting a charger. When the device is in SLEEP mode
(VCON < 80 mV), BPEN is don't care.
7.4.3 ECO Mode Operation
At very light loads (50 mA to 100 mA), the LM3262 enters ECO mode operation with reduced switching
frequency and supply current to maintain high efficiency. During ECO mode operation, the LM3262 positions the
output voltage slightly higher (7 mV typical) than the normal output voltage during PWM mode operation, allowing
additional headroom for voltage drop during a load transient from light-to-heavy load.
ECO Mode at Light Load
High ECO Threshold
Load current increases
Target Output Voltage
Low ECO Threshold
PWM Mode at Heavy Load
Figure 23. Operation in ECO Mode and Transfer to PWM Mode
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Device Functional Modes (continued)
7.4.4 Sleep Mode Operation
When VCON is less than 80 mV in 7 µs, the LM3262 goes into sleep mode — the SW pin is in tri-state (floating),
which operates like ECO mode with no switching. The LM3262 device returns to normal operation immediately
when VCON ≥ 130 mV in PWM mode or ECO mode, depending on load detection.
7.4.5 Shutdown Mode
Setting the EN digital pin low (< 0.4 V) places the LM3262 in shutdown mode (0.1 µA typical). During shutdown,
the PFET switch, the NFET synchronous rectifier, reference voltage source, control, and bias circuitry of the
LM3262 are turned off. Setting EN high (> 1.2 V) enables normal operation. EN must be set low to turn off the
LM3262 during power-up and undervoltage conditions when the power supply is less than the 2.5-V minimum
operating voltage. The LM3262 has an undervoltage lockout (UVLO) comparator to turn the power device off in
the case the input voltage or battery voltage is too low. The typical UVLO threshold is approximately 2 V for lock
and 2.1 V for release.
Table 1. Description Of Modes(1)
MODE
Shutdown
Sleep
EN
0
BPEN
VCON
X
IOUT (APPROX.)
FB RES
Open
X
X
0
0
0
1
0
X
1
< 80 mV
X
Open
PWM
1
> 180 mA
Closed
Closed
Closed
Closed
Closed
> 130 mV
< (VIN − 0.2)/2.5
ECO
1
< 140 mA
Auto bypass
1
> (VIN − 0.2)/2.5
> 130 mV
X
X
X
1
Forced bypass
1
> 1.5 V
(1) X = Don't care.
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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 LM3262 DC-DC converter steps down an input voltage from 2.5 V to 5.5 V to a dynamically adjustable
output voltage of 0.4 V to 3.6 V.
8.2 Typical Application
VIN
2.5 V to 5.5V
VIN
BPEN
VOUT = 2.5 x VCON
0.4 V to 3.6 V
10 mF
0.5 mH
SW
FB
EN
LM3262
VCON
GPO1
DAC
4.7 mF
SGND
PGND
Figure 24. LM3262 Typical Application
8.2.1 Design Requirements
For the typical LM3262 buck regulator, use the parameters listed in Table 2.
Table 2. Design Parameters
DESIGN PARAMETER
Input voltage
EXAMPLE VALUE
2.5 V to 5.5 V
0.4 V to 3.6 V
800 mA
Output voltage
Output current
8.2.2 Detailed Design Procedure
8.2.2.1 Inductor Selection
There are two main considerations when choosing an inductor: the inductor must not saturate, and the inductor
current ripple is small enough to achieve the desired output voltage ripple. Different manufacturers follow
different saturation current rating specifications, so attention must be given to details. Saturation current ratings
are typically specified at 25°C so ratings over the ambient temperature of application should be requested from
manufacturer.
The minimum value of inductance to ensure good performance is 0.3 µH at bias current (ILIM (typical)) over the
ambient temperature range. Shielded inductors radiate less noise and are preferred. There are two methods to
choose the inductor saturation current rating.
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8.2.2.1.1 Method 1
The saturation current must be greater than the sum of the maximum load current and the worst-case average-
to-peak inductor current. This is shown in Equation 1 :
ISAT > IOUT_MAX + IRIPPLE
where
«
≈
«
≈
VIN - VOUT
VOUT
VIN
1
f
≈
≈
«
≈
«
IRIPPLE
=
x
x
2 x L
«
where
•
•
•
•
•
•
IRIPPLE: average-to-peak inductor current
IOUT_MAX: maximum load current (800 mA)
VIN: maximum input voltage in application
L: minimum inductor value including worst-case tolerances (30% drop can be considered for Method 1)
F: minimum switching frequency (5.7 MHz)
VOUT: output voltage
(1)
8.2.2.1.2 Method 2
A more conservative and recommended approach is to choose an inductor than can handle the maximum
current limit of 1600 mA.
The resistance of the inductor must be less than 0.1 Ω for good efficiency. Table 3 lists suggested inductors and
suppliers.
Table 3. Suggested Inductors
MODEL
SIZE (W × L × H) (mm)
2 × 1.25 × 1
VENDOR
Murata
LQM21PNR50XGHL11
MIPSZ2012D0R5
LQM21PNR54MG0
LQM2MPNR47NG0
CIG21LR47M
2 × 1.2 × 1
FDK
2 × 1.25 × 0.9
2 × 1.6 × 0.9
2 × 1.25 × 1
Murata
Murata
Samsung
Taiyo Yuden
CKP2012NR47M
2 × 1.25 × 1
8.2.2.2 Capacitor Selection
The LM3262 is designed for use with ceramic capacitors for its input and output filters. Use a 10-µF ceramic
capacitor for input and a sum total of 4.7-µF ceramic capacitance for the output. They should maintain at least
50% capacitance at DC bias and temperature conditions. Ceramic capacitors types such as X5R, X7R, and B
are recommended for both filters. These provide an optimal balance between small size, cost, reliability, and
performance for cell phones and similar applications. Table 4 lists some suggested part numbers and suppliers.
DC-bias characteristics of the capacitors must be considered when selecting the voltage rating and case size of
the capacitor. If it is necessary to choose a 0603 (1608) size capacitor for VIN and 0402 (1005) size capacitor for
VOUT, the operation of the LM3262 must be carefully evaluated on the system board. Use of a 2.2-µF capacitor in
conjunction with multiple 0.47-µF or 1-µF capacitors in parallel may also be considered when connecting to
power amplifier devices that require local decoupling.
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Table 4. Suggested Capacitors And Their Suppliers
CAPACITANCE
2.2 µF
MODEL
SIZE (W × L) (mm)
1 × 0.5
VENDOR
GRM155R60J225M
C1005X5R0J225M
CL05A225MQ5NSNC
C1608JB0J475M
Murata
TDK
2.2 µF
1 × 0.5
2.2 µF
1 × 0.5
Samsung
TDK
4.7 µF
1.6 × 0.8
1 × 0.5
4.7 µF
C1005X5R0J475M
CL05A475MQ5NRNC
C1608X5R0J106M
GRM155r60J106M
CL05A106MQ5NUNC
TDK
4.7 µF
1 × 0.5
Samsung
TDK
10 µF
1.6 × 0.8
1 × 0.5
10 µF
Murata
Samsung
10 µF
1 × 0.5
The input filter capacitor supplies AC current drawn by the PFET switch of the LM3262 in the first part of each
cycle and reduces the voltage ripple imposed on the input power source. The output filter capacitor absorbs the
AC inductor current, helps maintain a steady output voltage during transient load changes and reduces output
voltage ripple. These capacitors must be selected with sufficient capacitance and sufficiently low ESR to perform
these functions. The equivalent series resistance (ESR) of the filter capacitors is generally a major factor in
voltage ripple.
8.2.2.3 Setting The Output Voltage
The LM3262 features a pin-controlled adjustable output voltage to eliminate the need for external feedback
resistors. It can be programmed for an output voltage from 0.4 V to 3.6 V by setting the voltage on the VCON
pin, as in Equation 2:
VOUT = 2.5 × VCON
(2)
When VCON is between 0.16 V and 1.44 V, the output voltage follows proportionally by 2.5 × VCON.
If VCON is less than 0.16 V (VOUT = 0.4 V), the output voltage may not be well regulated. Refer to Figure 22 for
details. This curve exhibits the characteristics of a typical part, and the performance cannot be ensured as there
may be a part-to-part variation for output voltages less than 0.4 V. For VOUT lower than 0.4 V, the converter may
suffer from larger output ripple voltage and higher current limit operation.
8.2.2.4 FB
Typically the FB pin is connected to VOUT for regulating the output voltage maximum of 3.6 V. In any application
case, the voltage on FB pin should not exceed 4.5 V.
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8.2.3 Application Curves
100
95
90
85
80
75
70
65
60
100
95
90
85
80
75
70
VIN = 3.0V
VIN = 3.0V
VIN = 3.8V
VIN = 4.2V
VIN = 3.8V
65
60
VIN = 4.2V
0
100 200 300 400 500 600 700 800
OUTPUT CURRENT (mA)
0
50
100 150 200 250 300
OUTPUT CURRENT (mA)
VOUT = 2.5 V
VOUT = 0.8 V
Figure 26. Efficiency vs Output Current
Figure 25. Efficiency vs Output Current
100
95
90
85
80
75
100
95
90
85
80
75
70
VIN = 3.8V
70
VIN = 3.0V
VIN = 4.2V
VIN = 3.8V
65
60
VIN = 5.0V
65
60
VIN = 4.2V
0
100 200 300 400 500 600 700 800
OUTPUT CURRENT (mA)
0.5
1.0
1.5
2.0
2.5
3.0
3.5
OUTPUT VOLTAGE (V)
VOUT = 3.4 V
RL =10 Ω
Figure 28. Efficiency vs Output Voltage
Figure 27. Efficiency vs Output Current
9 Power Supply Recommendations
The LM3262 device is designed to operate from an input voltage supply range from 2.5 V to 5.5 V. This input
supply should be well-regulated and able to withstand maximum input current and maintain stable voltage
without voltage drop even at load transition condition.
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10 Layout
10.1 Layout Guidelines
PC board layout is critical to successfully designing a DC-DC converter into a product. As much as a 20-dB
improvement in RX noise floor can be achieved by carefully following recommended layout practices. A properly
planned board layout optimizes the performance of a DC-DC converter and minimizes effects on surrounding
circuitry while also addressing manufacturing issues that can have adverse impacts on board quality and final
product yield.
Poor board layout can disrupt the performance of a DC-DC converter and surrounding circuitry by contributing to
EMI, ground bounce, and resistive voltage loss in the traces. Erroneous signals could be sent to the DC-DC
converter device, resulting in poor regulation or instability. Poor layout can also result in re-flow problems leading
to poor solder joints between the DSBGA package and board pads. Poor solder joints can result in erratic or
degraded performance of the converter.
10.1.1 Energy Efficiency
Minimize resistive losses by using wide traces between the power components and doubling up traces on
multiple layers when possible.
10.1.2 EMI
By its very nature, any switching converter generates electrical noise, and the design challenge is to minimize,
contain, or attenuate such switcher-generated noise. A high-frequency switching converter, such as the LM3262,
switches Ampere level currents within nanoseconds, and the traces interconnecting the associated components
can act as radiating antennas. The following guidelines are offered to help to ensure that EMI is maintained
within tolerable levels.
To minimize radiated noise:
•
Place the LM3262 switcher, input capacitor, output filter inductor, and output filter capacitor close together,
making the interconnecting traces as short as possible.
•
Arrange the components so that the switching current loops curl in the same direction. During the first half of
each cycle, current flows from the input filter capacitor, through the internal PFET of the LM3262 and the
inductor, to the output filter capacitor, then back through ground, forming a current loop. In the second half of
each cycle, current is pulled up from ground, through the internal synchronous NFET of the LM3262 by the
inductor, to the output filter capacitor and then back through ground, forming a second current loop. Routing
these loops so the current curls in the same direction prevents magnetic field reversal between the two half-
cycles and reduces radiated noise.
•
Make the current loop area(s) as small as possible.
To minimize ground-plane noise:
•
Reduce the amount of switching current that circulates through the ground plane — connect the ground
bumps of the LM3262 and its input filter capacitor together using generous component-side copper fill as a
pseudo-ground plane. Then connect this copper fill to the system ground-plane (if one is used) with multiple
vias. These multiple vias help to minimize ground bounce at the LM3262 by giving it a low-impedance ground
connection.
To minimize coupling to the voltage feedback trace of the DC-DC converter:
•
Route noise sensitive traces, such as the voltage feedback path, as directly as possible from the switcher FB
pad to the VOUT pad of the output capacitor, but keep it away from noisy traces between the power
components.
To decouple common power supply lines, series impedances may be used to strategically isolate circuits:
•
Take advantage of the inherent inductance of circuit traces to reduce coupling among function blocks, by way
of the power supply traces.
•
•
Use star connection for separately routing VBATT to PVIN and VBATT_PA.
Inserting a single ferrite bead in-line with a power supply trace may offer a favorable tradeoff in terms of
board area by allowing the use of fewer bypass capacitors.
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Layout Guidelines (continued)
10.1.3 Manufacturing Considerations
The LM3262 package employs a 9-pin, 3-mm × 3-mm array of 250 micron solder balls, with a 0.4-mm pad pitch.
The following simple design rules go a long way to ensuring a good layout:
•
•
The pad size must be 0.225 ± 0.02 mm, and the solder mask opening must be 0.325 ± 0.02 mm.
As a thermal relief, connect to each pad with 7-mil wide, 7-mil long traces, incrementally increasing each
trace to its optimal width. Symmetry is important to ensure the solder bumps re-flow evenly (refer to AN-1112
DSBGA Wafer Level Chip Scale Package (SNVA009)).
10.2 Layout Examples
Figure 29. Simplified LM3262 RF Evaluation Board Schematic
1. Bulk Input Capacitor C2 must be placed closer to LM3262 than C1.
2. Add a 1-nF (C1) on input of LM3262 for high frequency filtering.
3. Bulk Output Capacitor C3 must be placed closer to LM3262 than C4.
4. Add a 1-nF (C4) on output of LM3262 for high frequency filtering.
5. Connect both GND terminals of C1 and C4 directly to system GND layer of phone board.
6. Connect bumps SGND (A2), NC (B2), BPEN (C1) directly to System GND.
7. Use 0402 caps for both C2 and C3 due to better high frequency filtering characteristics over 0603 capacitors.
8. TI has seen some improvement in high-frequency filtering for small bypass caps (C1 and C4) when they are
connected to System GND instead of same ground as PGND. These capacitors should be 01005 case size
for minimum footprint and best high frequency characteristics.
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Layout Examples (continued)
Figure 30. LM3262 Recommended Parts Placement (Top View)
10.2.1 Component Placement
•
PVIN
1. Use a star connection from PVIN to LM3262 and PVIN to PA VBATT connection (VCC1). Do not daisy-
chain PVIN connection to LM3262 circuit and then to PA device PVIN connection.
•
TOP LAYER
1. Place a via in LM3262 SGND(A2), BPEN(C1) pads to drop and connect directly to System GND Layer 4.
2. Place two vias at LM3262 SW solder bump to drop VSW trace to Layer 3.
3. Connect C2 and C3 capacitor GND pads to PGND bump on LM3262 using a star connection. Place vias
in C2 and C3 GND pads that connect directly to System GND Layer 4.
4. Add 01005/0201 capacitor footprints (C1, C4) to input/output of LM3262 for improved high frequency
filtering. C1 and C4 GND pads connect directly to System GND Layer 4.
5. Place three vias at L1 inductor pad to bring up VSW trace from Layer 3 to Top Layer.
•
LAYER 2
1. Make FB trace at least 10 mils (0.254 mm) wide.
2. Isolate FB trace away from noisy nodes and connect directly to C3 output capacitor. Place a via in
LM3262 SGND (A2), BPEN (C1) pads to drop and connect directly to System GND Layer 4.
•
•
LAYER 3
1. Make VSW trace at least 15 mils (0.381 mm) wide.
LAYER 4 (System GND)
1. Connect C2 and C3 PGND vias to this layer.
2. Connect C1 and C4 GND vias to this layer.
3. Connect LM3262 SGND (A2), BPEN (C1), and NC (B2) pad vias to this layer.
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Layout Examples (continued)
Figure 31. Board Layer 1 — PVIN and PGND Routing
Figure 32. Board Layer 2 — FB and PVIN Routing
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Layout Examples (continued)
Figure 33. Board Layer 3 — SW, VCON and EN Routing
Figure 34. Board Layer 4 — System GND Plane
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ZHCSE56O –AUGUST 2012–REVISED DECEMBER 2015
10.3 DSBGA Assembly and Use
Use of the DSBGA package requires specialized board layout, precision mounting, and careful re-flow
techniques, as detailed in AN-1112 DSBGA Wafer Level Chip Scale Package (SNVA009). Refer to the section
regarding surface mount technology assembly. For best results in assembly, alignment ordinals on the PC board
must be used to facilitate placement of the device. The pad style used with DSBGA package must be the NSMD
(non-solder mask defined) type. This means that the solder-mask opening is larger than the pad size. This
prevents a lip that otherwise forms if the solder-mask and pad overlap from holding the device off the surface of
the board and interfering with mounting. See SNVA009 for specific instructions on how to do this.
The 9-pin package used for the LM3262 has 250 micron solder balls and requires 0.225-mm pads for mounting
on the circuit board. The trace to each pad must enter the pad with a 90° angle to prevent debris from being
caught in deep corners. Initially, as a thermal relief, the trace to each pad must be a width of 7 mil for a section
approximately 7 mil long. Each trace must neck up or down to its optimal width. The important criterion is
symmetry. This ensures the solder bumps on the LM3262 re-flow evenly, and that the device solders level to the
board. In particular, special attention must be paid to the pads for bumps A3 and C3. Because VIN and PGND
are typically connected to large copper planes, inadequate thermal reliefs can result in late or inadequate re-flow
of these bumps.
The DSBGA package is optimized for the smallest possible size in applications with red or infrared opaque
cases. Because the DSBGA package lacks the plastic encapsulation characteristic of larger devices, it is
vulnerable to light. Backside metallization and/or epoxy coating, along with front-side shading by the printed
circuit board, reduce this sensitivity. However, the package has exposed die edges. In particular, DSBGA
devices are sensitive to light, in the red and infrared range, shining on exposed die edges of the package.
TI recommends using a 10-nF capacitor between VCON and ground for non-standard ESD events or
environments and manufacturing processes to prevent unexpected output voltage drift.
版权 © 2012–2015, Texas Instruments Incorporated
25
LM3262
ZHCSE56O –AUGUST 2012–REVISED DECEMBER 2015
www.ti.com.cn
11 器件和文档支持
11.1 器件支持
11.1.1 Third-Party Products Disclaimer
TI'S PUBLICATION OF INFORMATION REGARDING THIRD-PARTY PRODUCTS OR SERVICES DOES NOT
CONSTITUTE AN ENDORSEMENT REGARDING THE SUITABILITY OF SUCH PRODUCTS OR SERVICES
OR A WARRANTY, REPRESENTATION OR ENDORSEMENT OF SUCH PRODUCTS OR SERVICES, EITHER
ALONE OR IN COMBINATION WITH ANY TI PRODUCT OR SERVICE.
11.2 文档支持
11.2.1 相关文档ꢀ
更多信息,请参见以下文档:
AN-1112《DSBGA 晶圆级芯片规模封装》(文献编号:SNVA009)
11.3 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.
11.4 商标
E2E is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
11.5 静电放电警告
ESD 可能会损坏该集成电路。德州仪器 (TI) 建议通过适当的预防措施处理所有集成电路。如果不遵守正确的处理措施和安装程序 , 可
能会损坏集成电路。
ESD 的损坏小至导致微小的性能降级 , 大至整个器件故障。 精密的集成电路可能更容易受到损坏 , 这是因为非常细微的参数更改都可
能会导致器件与其发布的规格不相符。
11.6 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。
26
版权 © 2012–2015, Texas Instruments Incorporated
PACKAGE OPTION ADDENDUM
www.ti.com
10-Dec-2020
PACKAGING INFORMATION
Orderable Device
Status Package Type Package Pins Package
Eco Plan
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
Samples
Drawing
Qty
(1)
(2)
(3)
(4/5)
(6)
LM3262TME/NOPB
LM3262TMX/NOPB
ACTIVE
ACTIVE
DSBGA
DSBGA
YFQ
YFQ
9
9
250
RoHS & Green
SNAGCU
Level-1-260C-UNLIM
Level-1-260C-UNLIM
-30 to 90
-30 to 90
S6
S6
3000 RoHS & Green
SNAGCU
(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 <=1000ppm threshold. Antimony trioxide based
flame retardants must also meet the <=1000ppm threshold requirement.
(3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
(6)
Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two
lines if the finish value exceeds the maximum column width.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 1
PACKAGE OPTION ADDENDUM
www.ti.com
10-Dec-2020
Addendum-Page 2
PACKAGE MATERIALS INFORMATION
www.ti.com
21-Oct-2021
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
Package Package Pins
Type Drawing
SPQ
Reel
Reel
A0
B0
K0
P1
W
Pin1
Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant
(mm) W1 (mm)
LM3262TME/NOPB
LM3262TMX/NOPB
DSBGA
DSBGA
YFQ
YFQ
9
9
250
178.0
178.0
8.4
8.4
1.57
1.57
1.57
1.57
0.76
0.76
4.0
4.0
8.0
8.0
Q1
Q1
3000
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
21-Oct-2021
*All dimensions are nominal
Device
Package Type Package Drawing Pins
SPQ
Length (mm) Width (mm) Height (mm)
LM3262TME/NOPB
LM3262TMX/NOPB
DSBGA
DSBGA
YFQ
YFQ
9
9
250
208.0
208.0
191.0
191.0
35.0
35.0
3000
Pack Materials-Page 2
MECHANICAL DATA
YFQ0009x
D
0.600±0.075
E
TMD09XXX (Rev A)
D: Max = 1.51 mm, Min = 1.45 mm
E: Max = 1.385 mm, Min =1.325 mm
4215077/A
12/12
A. All linear dimensions are in millimeters. Dimensioning and tolerancing per ASME Y14.5M-1994.
B. This drawing is subject to change without notice.
NOTES:
www.ti.com
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