- 您现在的位置：买卖IC网 > PDF目录69004 > LM3352MTC-3.3/NOPB (NATIONAL SEMICONDUCTOR CORP) SWITCHED CAPACITOR REGULATOR, 1350 kHz SWITCHING FREQ-MAX, PDSO16 PDF资料下载
参数资料
| 型号： | LM3352MTC-3.3/NOPB |
| 厂商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分类： | 稳压器 |
| 英文描述： | SWITCHED CAPACITOR REGULATOR, 1350 kHz SWITCHING FREQ-MAX, PDSO16 |
| 封装： | 1.10 MM HEIGHT, TSSOP-16 |
| 文件页数： | 11/12页 |
| 文件大小： | 545K |
| 代理商： | LM3352MTC-3.3/NOPB |
Applications Information
Operating Principle
The LM3352 is designed to provide a step-up/step-down
voltage regulation in battery powered systems. It combines
switched capacitor circuitry, reference, comparator, and
shutdown logic in a single 16-pin TSSOP package. The
LM3352 can provide a regulated voltage between 1.8V and
4V from an input voltage between 2.5V and 5.5V. It can
supply a load current up to 200 mA.
As shown in Figure 1, the LM3352 employs two feedback
loops to provide regulation in the most efficient manner
possible. The first loop is from V
OUT through the comparator
COMP, the AND gate G
1, the phase generator, and the
switch array. The comparator’s output is high when V
OUT is
less than the reference V
REF. Regulation is provided by
gating the clock to the switch array. In this manner, charge is
transferred to the output only when needed. The second
loop controls the gain configuration of the switch array. This
loop consists of the comparator, the digital control block, the
phase generator, and the switch array. The digital control
block computes the most efficient gain from a set of seven
gains based on inputs from the A/D and the comparator. The
gain signal is sent to the phase generator which then sends
the appropriate timing and configuration signals to the switch
array. This dual loop provides regulation over a wide range of
loads efficiently.
Since efficiency is automatically optimized, the curves for
V
OUT vs. VIN and Efficiency vs. VIN in the Typical Perfor-
mance Characteristics section exhibit small variations. The
reason is that as input voltage or output load changes, the
digital control loops are making decisions on how to optimize
efficiency. As the switch array is reconfigured, small varia-
tions in output voltage and efficiency result. In all cases
where these small variations are observed, the part is oper-
ating correctly; minimizing output voltage changes and opti-
mizing efficiency.
Charge Pump Capacitor Selection
A 0.33 F ceramic capacitor is suggested for C1, C2 and C3.
To ensure proper operation over temperature variations, an
X7R dielectric material is recommended.
Filter Capacitor Selection
a) CAPACITOR TECHNOLOGIES
The three major technologies of capacitors that can be used
as filter capacitors for LM3352 are: i) tantalum, ii) ceramic
and iii) polymer electrolytic technologies.
i) Tantalum
Tantalum capacitors are widely used in switching regulators.
Tantalum capacitors have the highest CV rating of any tech-
nology; as a result, high values of capacitance can be ob-
tained in relatively small package sizes. It is also possible to
obtain high value tantalum capacitors in very low profile
(<1.2 mm) packages. This makes the tantalums attractive
for low-profile, small size applications. Tantalums also pos-
sess very good temperature stability; i.e., the change in the
capacitance value, and impedance over temperature is rela-
tively small. However, the tantalum capacitors have relatively
high ESR values which can lead to higher voltage ripple and
their frequency stability (variation over frequency) is not very
good, especially at high frequencies (>1 MHz).
ii) Ceramic
Ceramic capacitors have the lowest ESR of the three tech-
nologies and their frequency stability is exceptionally good.
These characteristics make the ceramics an attractive
choice for low ripple, high frequency applications. However,
the temperature stability of the ceramics is bad, except for
the X7R and X5R dielectric types. High capacitance values
(>1 F) are achievable from companies such as Taiyo-
10103703
FIGURE 1. Block Diagram
LM3352
www.national.com
8
相关PDF资料 |
PDF描述 |
|---|---|
| LM3352MTC-3.0/NOPB | SWITCHED CAPACITOR REGULATOR, 1350 kHz SWITCHING FREQ-MAX, PDSO16 |
| LM3431SD | SWITCHING CONTROLLER, 1100 kHz SWITCHING FREQ-MAX, QCC28 |
| LM3431SDX | SWITCHING CONTROLLER, 1100 kHz SWITCHING FREQ-MAX, QCC28 |
| LM3543MX-L/NOPB | 3-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO16 |
| LM3543MX-H/NOPB | 3-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO16 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LM3352MTCX-2.5 | 功能描述:IC REG MULTI CONFIG 16-TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:3.3V 输入电压:4.5 V ~ 24 V PWM 型:- 频率 - 开关:- 电流 - 输出:125mA 同步整流器:无 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-6 包装:Digi-Reel® 供应商设备封装:SOT-6 其它名称:MAX1836EUT33#TG16DKR |
| LM3352MTCX-3.0 | 功能描述:IC REG MULTI CONFIG 3V 16-TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:3.3V 输入电压:4.5 V ~ 24 V PWM 型:- 频率 - 开关:- 电流 - 输出:125mA 同步整流器:无 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-6 包装:Digi-Reel® 供应商设备封装:SOT-6 其它名称:MAX1836EUT33#TG16DKR |
| LM3352MTCX-3.3 | 功能描述:IC REG MULTI CONFIG 16-TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:3.3V 输入电压:4.5 V ~ 24 V PWM 型:- 频率 - 开关:- 电流 - 输出:125mA 同步整流器:无 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-6 包装:Digi-Reel® 供应商设备封装:SOT-6 其它名称:MAX1836EUT33#TG16DKR |
| LM3354 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:Regulated 90mA Buck-Boost Switched Capacitor DC/DC Converter |
| LM3354-1.8EVAL | 功能描述:BOARD EVALUATION LM3354-1.8 RoHS:否 类别:编程器，开发系统 >> 评估板 - DC/DC 与 AC/DC（离线）SMPS 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:True Shutdown™ 主要目的:DC/DC，步升 输出及类型:1，非隔离 功率 - 输出:- 输出电压:- 电流 - 输出:1A 输入电压:2.5 V ~ 5.5 V 稳压器拓扑结构:升压 频率 - 开关:3MHz 板类型:完全填充 已供物品:板 已用 IC / 零件:MAX8969 |
发布紧急采购，3分钟左右您将得到回复。